NUTRITIONAL QUALITY AND VALUE ADDITION TO JACK FRUIT SEED FLOUR
Thesis submitted to the University of Agricultural Sciences, Dharwad in partial fulfillment of the requirements for the t he Degree of
MASTER OF HOME SCIENCE
in
FOOD SCIENCE AND NUTRITION
By SAMATA AIRANI
DEPARTMENT OF FOOD SCIENCE AND NUTRITION COLLEGE OF RURAL HOME SCIENCE, DHARWAD UNIVERSITY OF AGRICULTURAL AGRICULTURAL SCIENCES, DHARWAD – 580005
NOVEMBER, 2007
ADVISORY COMMITTEE Dharwad
(RAMA K. NAIK)
NOVERMBER, 2007
MAJOR ADVISOR Approved by:
Chairman : ______________________ _________________ _____ (RAMA K. NAIK)
Members
: 1.____________________ 1.____________ ________ (PUSHPA BHARATI)
2.____________________ (BHARATI .V. CHIMMAD)
3.____________________ (HEMLA NAIK)
ADVISORY COMMITTEE Dharwad
(RAMA K. NAIK)
NOVERMBER, 2007
MAJOR ADVISOR Approved by:
Chairman : ______________________ _________________ _____ (RAMA K. NAIK)
Members
: 1.____________________ 1.____________ ________ (PUSHPA BHARATI)
2.____________________ (BHARATI .V. CHIMMAD)
3.____________________ (HEMLA NAIK)
CONTENTS
Sl. No.
Chapter Particulars CERTIFICATE ACKNOWLEDGEMENT LIST OF TABLES LIST OF FIGURES LIST OF PLATES
1
INTRODUCTION
2
REVIEW OF LITERATURE 2.1 Nutritional composition of seed flour 2.2 Functional properties of seed flour 2.3 Nutritional quality 2.4 Value additions to seed flour
3
MATERIAL AND METHODS 3.1 Preparation of seed material 3.2 Nutrient composition 3.3 Physical and functional qualities of seed flour 3.4 Nutritional quality of the seed flour 3.5 Shelf life of seed flour 3.6 Utilization of seed flour in convenience food 3.7 Statistical analysis
Page No.
Contd….. Sl. No. 4
Chapter Particulars RESULTS 4.1 Physical and functional properties of seed flour 4.2 Nutrient composition of seed flour 4.3 Nutritional quality of jack seed flour 4.4 Storage quality of jack seed flour 4.5 Value added convenience food of j ack seed flour
5
DISCUSSION 5.1 Functional properties of seed flour 5.2 Chemical composition of seed flour 5.3 Shelf life of flour 5.4 Utilization of seed flour in convenience foods
6
SUMMARY
7
REFERENCES APPENDICES
Page No.
LIST OF TABLES Table No.
Title
1
Level of incorporation of flours
2
Functional properties of jack seed flour
3
Viscosity of jack seed flour
4
Proximate composition of jack seed flour (g/100 g)
5
Nutritional quality of seed flour
6
Dough characteristics
7
Physical parameters of biscuits
8
Physical characteristics of jack seed flour incorporated biscuits
9
Colour values of jack seed flour biscuits
10
Consumer acceptability of seed flour based biscuits
11
Computation of composition in different levels of incorporation of jack seed flour with refined wheat flour
Page No.
LIST OF FIGURES Figure No.
Title
1
Colour values of Minolta color meter
2
Yield of jack seed flour
3
Moisture content of stored jack seed flour
4
Sensory scores of jack seed flour based biscuits (initial trials)
5.
Sensory scores of jack seed flour based biscuits
Page No.
LIST OF PLATES
Plate No.
Title
1
Jackfruit seeds
2
Processed jack seed products
3
Jack seed (40%) based biscuits
Page No.
LIST OF APPENDICES
Appendix No.
Title
I
Score card for evaluation of value added products
II
Yield of jack seed flour
III
Moisture content (%) of stored jack seed flour
IV
Sensory scores of jack seed flour based biscuits (initial trial s)
V
Sensory profile of jack seed flour based biscuits
Page No.
1. INTRODUCTION “The jacks…. Are such large and interesting fruits and trees so well behaved that it is difficult to explain the general lack of knowledge concerning them’.
- O.W. Barret (1928) Jackfruit ( Artocarpus heterophyllus Lam.) belongs to the family Moraceae, is a fairly large sized tree and bears the largest fruit among the edible fruits. Jackfruit tree is native to India and popular in several tropical and sub-tropical countries and the fruit is known as the ‘poor man’s fruit’ in eastern and southern parts of India. Jackfruit tree grows well not only under humid and warm climates of hill slopes, but also in arid plains of south India making it as one of the most suitable fruit crops for dryland horticulture. The total area under jack fruit cultivation is around 32,600 ha (Swamy, 2003) and jack tree is largely grown in southern states viz., Kerala, Tamil Nadu, Karnataka and Andhra Pradesh besides, in other states like Assam, Bihar, Orissa, Maharashtra and West Bengal. In Karnataka, jack fruit is grown on an area of 10,004 ha with a production of 2,42,296 tonnes per annum (Anon., 2001). Jack fruit is largely propagated by seed and being a highly heterozygous and cross-pollinated crop, has resulted in immense variation in the population for yield, size, shape and quality of fruit and period of maturity. Cutting a jackfruit may seem quite a challenging task but once cut opened, the rest is easy and enjoyable. Jackfruit appears in the market in spring and continues until summer. The interior of ripe fruit consists of large, pleasant flavoured yellow sweet bulbs (fully developed perianths), massed among narrow ribbons of thin, though undeveloped perianths and a central pithy core constitute 25-30 per cent of the total fruit. Each bulb encloses a smooth, oval, light brown seed (endocarp) covered by a thin white membrane (exocarp). The seed is 2-4 cm long and 1.5 – 2.5 cm thick. There may be 100-120 or upto 500 seeds in a single fruit comprising 5-6 per cent of the total fruit. The pump (bulb) colour ranges from thin white, cream, yellow to bright orange. The size of the fruit lets ranges widely from small to big and thickness of pulp ranges from thin wafery to as thick as 0.5 cm while the sweetness ranges from slightly insipid to very sweet, the texture of the pulp ranges from soft to crispy. The pulp flavour ranges from very mildly scented to strongly scented and the size of the whole fruit ranges from 8 inches to 3 ft, as big as one weighing 20-50 kgs similarly the tree height also ranges from 50 t o 60 ft. The tender jack fruit is a popular vegetable and used in making soup and pickles. Chips and papads are also prepared from ripe and unripe pulp. The juicy pulp of the ripe fruit is eaten fresh or preserved in syrup and has wide potential for preparing jam, jelly due to the presence of pectin and used in the preparation of inumerous value added products. There is good market for these processed products in U.S., U.K. and gulf countries. The rind or skin of the fruit and leaves are excellent cattle feed. The yellow hard wood of the tree is valued timber for making of furniture’s. Jackfruit trees are also grown for shade to betel, pepper and cardamom plantations. The seeds are generally eaten in boiled or roasted form or used in many culinary preparations, as it contains similar compositions as that of grains. As jack fruit is highly seasonal and seeds have shorter shelf life, hence go waste during the seasonal glut. So, the seed flour can be an alternative intermediatory product, which can be stored and utilized, both for value addition and to blend with other grain flours without affecting the functional and sensory profile of the final product. Moreover, the incorporation of seed flour to deep fat fried products has found to reduce the fat absorption to a remarkable extent (Rajarajeshwari and Jamuna, 1999). The ripened fruit is a normally fibrous and composed of sugars like glucose, fructose, xylose, rhamnose, arabinose and galactose. The seeds are also rich source of carbohydrates and proteins and good source of fibre and B-complex vitamins. Chinese consider the j ack fruit pulp and seeds useful in overcoming the effects of alcohol. In India too, the jack seed is an important ingredient in antidote preparation for heavy drinkers. The latex from the bark
contains resin which is used sometimes to plug holes in earthern vats and in other products. The latex from the leaves has got capacity to kill bacteria. Jacalin, the major protein from the jack seeds has proved useful tool for the evaluation of immune status of patients infected with HIV (Morton, 1987). Being a good source of vitamin A, vitamin C and pectin, jackfruit also helps in alleviating the pancreatic ailments and aid in blood purification. With all these medicinal values and efficient ingredients in value added products the utilization of seed flour in convenience food has a long way to utilize the flour with value addition for marketability and to create employment among rural women for economic empowerment. The utilization of jack seed flour in an industrial level is important for product market strategy. Hence, the study was undertaken with jack seed with following specific objectives. 1.
To assess the physical and functional qualities of seed flour.
2.
To determine the nutrient composition of jack seed flour
3.
To evaluate starch and protein digestibilities of seed flour and
4.
To study the shelf-life of seed flour and to utilize the seed flour in convenience food.
2. REVIEW OF LITERATURE A conceptual framework for the study based on the ideas and concepts gathered from review work of existing literature of both theoretical and empirical nature will facilitate planning the study in a comprehensive manner. It also helps to know the previous research work carried out in the area and acts as a t orch for new research. Jackfruit is a tropical fruit appears in the market in spring and continues until summer. Fruits are consumed by all sector of community irrespective of age and gender but, the seeds are used in some local dishes. Though jack seeds are utilized at domestic level, scientific literature related to seed and its utilization is limited. Hence, an attempt is made here to put together some of the closely related findings about the seed in general from other fruit or vegetable sources and has been reviewed in this chapter with special reference to jack seed.
2.1
NUTRIENT COMPOSITION OF SEED AND SEED FLOUR
Literature related to the proximate compositions viz., protein, fat, crude fibre, ash, carbohydrates and mineral contents of the seed and its forms are presented in this section. George and Boskou (1975) analysed the chemical composition of tomato seeds. The seeds contained 24.5 per cent protein, 28.1 per cent fat, 2.9 per cent of total sugars (as glucose), 5.4 and 19.1 percentage of ash and crude fibre, respectively. Higher mineral contents (mg/100 g) for potassium (780), phosphorus (690), magnesium (300), Calcium (160), sodium (110) and ferrous (17) were reported. In the year 1975, Oyenuga and Fetuga evaluated the nutritive value of two local varieties of watermelon seed flour. Bara and Serewe , the two local varieties documented good amount of protein ( 35.70 and 30.60 % ), crude fibre (2.40 and 3.10%), ether extract (54.20 and 56.90 %), total ash (4.20 and 3.40 %) and carbohydrates (3.50 and 6.00 %), respectively. Fleming et al. (1976) determined the composition of sunflower seed flour. The defatted flour contained protein (53.00%), crude fat (1.80%), higher levels of crude fibre (3.60%) and ash (8.20%). Bobbio et al. (1978) reported the proximate composition of jack seeds. Jack seeds contained 61.50 per cent moisture, 12.30 per cent protein, 25.10 per cent carbohydrates and 0.50 per cent crude lipids. Carlson et al. (1981) investigated the nutritional composition of tomato seed. The mean values of moisture (9.60%), crude fat (22.20%), crude fibre (18.30%) and crude protein (33.90%) were documented. A study was conducted by Akobundu et al. (1982) to analyse the chemical compositions of egusi (cucurbitaceae) seed kernels. Study revealed that, hull-free kernels contained protein (28.40%), lipid (52.00%), crude fibre (2.70%), ash (3.68%) and carbohydrate (8.21%). Egusi seed flour had good quantities of minerals (mg/100g) viz., sulphur (580), calcium (354), potassium (1442) and phosphorus (1950). Besides, seed flour also recorded significant amounts of vitamins, especially thiamine (4.16 µg/g) and niacin (35.40 µg/g) Dingra and Kapoor (1984) documented the composition of mango seed kernel. The seed kernels constituted 5 per cent protein (g), 6-7 per cent crude fat (g), tannins (0.19 0.44%), oleic acid (42.00%) and stearic acid (39.00%). Nutritional and fatty acid contents of pumpkin and melon seed flour was documented by Lazos (1986). The data obtained for pumpkin and melon seeds on a dry basis were, crude oil (45.40 and 37.80%), crude protein (32.30 and 25.20g%), crude fibre (12.10 and 15.40g%) and ash (4.65 and 3.85g%), respectively. The major fatty acid of both oils was linoleic acid (18:2), in concentrations of 43.10 and 64.60 per cent, respectively followed by oleic acid (18:1), 37.8 and 20.10 per cent, respectively. Mineral content (mg) indicated rich sources of K (1111.00 and 1288.00%), P (852.00 and 557.00%) and Mg (205.50 and 256.00%), respectively.
Yanez et al. (1986) analysed the chemical composition of amaranth seed flour. The mean values (g) for moisture (9.67%), protein (2.69%), ash (2.80%), fat (7.15%) fibre (3.34%), and carbohydrates (62.30%) were documented. Hemavathy et al. (1987) studied the polar lipids of Alphonso mango kernel. Total lipid (g) in the kernel of alphonso mango extracted, amounted to 11.60 per cent of the dry kernel. Total lipid consisted of 96.10 per cent of neutral and 3.90 per cent of polar lipids which comprised 2.90 per cent glycolipids and 1.00 per cent of phospholipids. A study was conducted by Kumar et al. (1988) on the proximate composition of jackfruit seed flour. The seeds of Kathari and Bharat Baramasi varieties of jackfruit were found good sources of carbohydrates (28.01 and 26.83g %), protein (6.75 and 6.25g %), fat (0.78 and .89g %) and ash (1.27 and 1.16g %), respectively. The calorific value of both Kathari and Bharat Baramasi were found as 146.06 and 140.33 K.Cal/100g, respectively . Kathari variety was observed to be nutritionally excelling, compared to the Bharat Baramasi variety on the basis of most of the constituents analysed. In a review, Singhal and Kulkarni (1988) reported the compositions of amaranthus seed flour. The seeds contained moisture, protein, fat, crude fibre, and ash with the mean values (g), 6.20, 13.20, 6.30, 3.60 and 2.80 percentages, respectively. Giami and Bekebian (1992) investigated the nutritional properties of pumpkin seed flour. The mean values (g %) were 4.20, 28.10, 47.00, 3.10 and 12.90 for moisture, crude protein, ether extract, total ash, crude fibre and carbohydrates, respectively. Iron and total phosphorus contents recorded were 4.50 and 140.00 mg/100g, respectively. Rajarajeshwari and Jamuna (1999) studied the nutritional profile of the jack seed flour. The flour contained the moisture (4.43 %), protein (21.30g %), fat (2.73g %), total ash (2.00g %), crude fibre (5.69g %) and carbohydrates (63.85g %). Vishwanathan et al. (1999) analysed the compositions of Teramnus labialis spreng. seeds flour documented (g) crude protein, crude fat, ash and nitrogen free extracts constituted 22.86, 6.10, 4.62 and 58.15 per cent, respectively. The calorific value of 100grams dry matter of seed material was 379 K.calories. In the year 2001, Nagaraj evaluated the nutritional value of defatted cashew kernel flour. The mean values (%) were 63.50, 20.30 and 12.90 for protein, carbohydrate and sugars, respectively. Tananuwong et al. (2002) reported the chemical compositions of jackfruit seed flour. The major components of the flour were carbohydrates (82.25%), protein (11.17%), lipid (0.99%) and crude fibre (1.67%). The total starch and amylose contents were analysed and the values recorded as 77.76 and 32.05 g/100g, respectively. In the year 2004, Akubor conducted a study to investigate the compositions of melon seeds. The seeds documented 6.00 g per cent moisture, 29.30g per cent protein, 54.90g per cent crude fat and 3.00, 2.80 and 4.00g percentages of ash, crude fibre and carbohydrates, respectively. Further Akubor (2005), evaluated the chemical composition of breadfruit seed flour. The flour documented the proximate compositions (g) such as moisture (8.60%), protein (17.30%), crude fibre (2.50%), ash (2.80%), fat (11.00%) and carbohydrates (62.80%). The calorific value was noted as 419.40 K.calories per 100grams of seed flour. A study by Amoo (2005) was conducted on the proximate compositions (g) of cashew kernel flour. The kernel flour contained 20.90 per cent protein, 42.80 per cent fat, 8.00 per cent moisture, total ash and crude fibre contents were 2.80 and 1.40 per cent, respectively. The carbohydrate content was noted as 24.10 per cent. Aremu et al. (2006) assessed the compositional characteristics of cashew nut flour. The mean values of proximate compositions (g %) were moisture (5.70), ash (4.40), ether extract (36.70), crude protein (25.30), crude fibre (1.20), and carbohydrate (26.80). The calorific value was 2243 KJ/100g and fatty acid content was noted as 29.40 per cent. Abundant minerals (mg/100g) constituted were K, Mg, Na and Ca while least were Cu, Zn, and Fe. Amino acid analysis revealed that cashew nut flour contained nutritionally useful quantities of most of the essential amino acids.
2.2
FUNCTIONAL PROPERTIES OF SEED FLOUR
Functional properties of seed flour viz., water and oil absorption capacities, bulk density, least gelation and emulsification capacities, foam capacity and stability related literature from other fruit or vegetable sources are reviewed in this section. A study was conducted to characterize the viscosity and water absorption properties of sunflower seed flour. The sunflower seed flour had the water absorption in terms of gH 2 0/g between 1.28 to 2.75 depending upon the duration of mixing between 1 to 10min. The viscosity (cps) of the flour was increased exponentially at different concentrations (5-20 w/w) of the flour (Fleming et al., 1976). Bobbio et al. (1978) documented the gel rigidity of jackfruit seed flour using an Exchange Ridgelimeter. The starch (8%) of the seed formed a highly rigid gel that had no particular odor and was extremely firm with practically no sag value. Gel did not develop º synersis during storage at 4 C for 5 days. The starch granules were not susceptible to ° breakdown by thermal or mechanical shear. At 94 C, the viscosity of the flour increased to reach a peak value (450 AU), indicating that jackfruit seed starch would swell readily withstanding severe thermal conditions. Carlson et al. (1981) studied the functional properties of tomato seed flour. At different pH levels viz., 4, 5, 6 and 7 the water absorption capacities (ml /100g) were found 325, 240, 214 and 159, respectively indicating the decrease in water absorption capacity with increase in pH levels. A study was conducted by Akobundu et al . (1982) to assess the functional characteristics of egusi seed flour. The water holding capacity for both hull free and 10 per cent hull containing flours was 0.7 ml/g indicating the level of hull per cent in the flour had no influence on its water holding capacity. The oil absorption capacity for the hull free and 10 per cent hull containing flour were found 2.6 and 2.7 ml/g, respectively. Suspensions of egusi seed flour formed two types of emulsions with in the pH range of 2.5-10.5. Very thin and thick emulsions were formed with 80 and 196 ml of oil, respectively. Increase in the viscosity was observed between the pH 5.0 and 8.0 and it could be related to the degree of soluble protein in the suspensions. Singhal and Kulkarni (1991) evaluated the functional properties of amaranths paniculates seed flour. The bulk density of the seed flour was recorded as 0.75 g/ml, while it was decreased in puffed seed flour (0.48). The puffed seed flour registered the higher water and fat absorption capacities (384 and 189.5 g/100g) compared to unpuffed seed flour (102.50 and 91.00 g/100g), respectively. Further the least gelation concentration in terms of per cent w/v was noted as 10.0in unpuffed flour and was higher in puffed seed flour (12.0). The viscosity of the unpuffed flour at 5.0 and 7.5 per cents were 69.6 and 247.3 cps , respectively and it decreased in puffed amaranths seed flour (45.3 and 144.4 cps, respectively) which could be due to changes in starch caused by dextrinization. Giami and Bekebain (1992) reported the functional characteristics of pumpkin seed flour. The raw fluted seed flour was significantly higher in water absorption capacity (3.40gg 1 -1 ) compared to germinated fluted pumpkin flour (2.50gg )and fermented fluted pumpkin flour -1 -1 (1.20 gg ) . On the other hand, the germinated fluted pumpkin flour (0.43 gg ) registered -1 higher fat absorption capacity compared to raw fluted pumpkin flour (0.37gg ) and fermented -1 fluted pumpkin flour (0.20 gg ). The foam capacity and stability was observed higher in raw fluted flour found as 9.5ml and 7.1ml at 30min, respectively compared to germinated fluted flour (4.3 and 3.2ml) and fermented fluted flour (4.0 and 1.4ml, respectively) indicated that, germination and fermentation did not improve foam capacity and stability of raw fluted pumpkin flour. Further, the bulk density of the raw fluted pumpkin flour was observed higher -1 -1 as 0.20 in terms of gml compared to fermented fluted ( 0.18 gml ) and germinated fluted -1 pumpkin flour (0.11gml ). Badifu and Gabriel (1999) documented the functional properties of defatted flour of melon seed flour. Water holding capacity of the flour recorded as 226.3 per cent. The viscosity of the flour was noted, 150 cps. A study was conducted to characterize the functionality of jack seed flour by Rajarajeshwari and Jamuna (1999). The flour had a very low solubility at acidic pH, which
exhibited a steep rise between pH 4.0 and 8.0 attaining a maximum value of 95 per cent. Bulk density of the flour was documented as 1.39 g/ml. water and fat absorption capacities were found as 210 and 160 ml/100g, respectively. A study by Nagaraj (2001) evaluated the functional properties of defatted cashew kernel flour. Water and oil absorption capacities were recorded as 56.3 and 128.8 per cent, respectively. Foaming and emulsification capacity of the flour were 53.0 and 33.7 per cent, respectively. Foam stability of the flour was achieved between the pH le vels 3.0 and 8.0. Amita and Saroj (2002) studied the functional properties of defatted sapium and cucurbita seed flour. Water absorption capacity of sapium meal (2.80 g/g ) was slightly higher than cucurbita meal (2.16 g/g). Fat absorption capacities of sapium and cucurbita meals were noted as 3.68 and 2.18 g/g, respectively. Protein solubility profile of sapium and cucurbita meals at different pH values indicated that, solubility of sapium meal protein was minimum (0.84%) at pH 4, and it increased slowly with increase in pH showing maximum solubility 8.81 per cent at pH 12. Cucurbita meal proteins indicated very high solubility (17.58 %) at pH 12 and least value was 2.23 per cent at pH 4. In the year 2002, a study was conducted by Tananuwong et al. to analyze the functional properties of jack seed flour. The flour had good capacities of water absorption (205.00%) and oil absorption (93.00%). The pasting properties of 8 per cent jack seed starch were studied along with tapioca and corn starches for comparision. The lower breakdown of viscosity during heating cycle of jack seed starch as compared to that of tapioca and corn starch indicated good stability of the starch paste and bonding forces within the starch granules. Akubor (2005) documented the functional properties of melon seed flour. The bulk -3 density (g/cm ) and least gelation concentration (w/v) of the flour were 0.68 and 8.00, respectively. The water and oil absorption capacites in terms of g/kg were recorded as 1300 and 700, respectively. Emulsification activity (g/kg) was recorded as 620 and emulsification stability of the flour was 710 per cent. The flour had the 15 and 92 per cent of foam capacity and stability, respectively. A systematic study was conducted by Odoemelam (2005) to evaluate the functional properties of jack seed flour. The flour had the 16 per cent (w/v) least gelation concentration. -1 -1 Water and oil absorption capacities were found as 2.30 mlg and 2.8 gg , respectively. Bulk -1 density of the flour recorded as 0.61gml .The foam capacity of the flour was noted as 7.10 -1 -1 gml and found gradually decreased to 2.00 gml after 120min. An emulsification capacity of -1 -1 flour was observed as 6.40 mlg at pH 1 and was gradually decreased to 4.8 mlg flour at pH 4, which is also the pH of minimum nitrogen solubility. Maximum nitrogen solubility of the flour noted 40.6 per cent at pH 10.
2.3
NUTRITIONAL QUALITY Digestibilities of nutritive components reveal the quality of food.
Adeyeye (1997) assessed the in-vitro protein digestibilities of the flours of six colour varieties of African yam bean made from both hulled and dehulled seed flours. Hulled seed flours gave a digestibility increase of 6 per cent compared with raw flours, where as in dehulled samples the digestibility documented an increase of 5 per cent. In the year 2005, Fagbemi et al. evaluated the processing effects on in-vitro protein digestibility of fluted pumpkin seed flour. The boiled samples were most digestible followed b y the fermented samples while the raw and germinated samples were least. The protein digestibility of fluted pumpkin recorded as 72.00 to 86.00 per cent. Khalil (2006), analysed the in-vitro digestibility of melon seed kernels. The kernels had a good digestibility of 90.80 per cent.
2.4
VALUE ADDITION TO SEED FLOUR
Value addition not only enhances proper utilization during glut, it also enhances the shelf life of food materials in processed form. It is important to introduce new products using underutilized food ingredients which are available abundantly.
Carlson et al. (1981) studied the influence of tomato seed addition on the quality of wheat flour breads. The addition of tomato seed to the bread had a positive effect on loaf volume with the high concentration of crude fat present in the tomato seed and improved the overall quality of the bread. Supplementation with tomato seeds at a replacement level slightly above 10 per cent was recommended for nutritional as well as for functional considerations. In the year 1991, Yaseen et al. evaluated the balady bread fortified with tomato seed meal. The addition of whole tomato seed meal to wheat flour resulted increase in the fat content (4.00%) of the bread, while the addition of defatted tomato seed meal lowered the fat content (1.00%). The protein and fibre content of the bread were increased to 14.71 to 16.22 per cent and 4.63 to 5.10 per cent in the replacement of wheat flour with whole tomato and defatted tomato seed meal, respectively. Overall quality of the bread was found decreased with increase in the tomato meal replacement. It was observed that, 10 per cent of replacement with both whole and defatt ed tomato seed meal was successfully accepted. Rajarajeshwari and Jamuna (1999) assessed the use of jackfruit seed in product formulation. On incorporation of jack seed to two deep fat fried products viz., karasev and jamun revealed that, it was important to bring down fat absorption to a remarkable extent. In the savoury product none of the sensory attributes were affected, where as in sweet product the quality of texture and flavour was affected. For the presence of off flavour and after taste, no significant responses were obtained. The responses were significant with higher proportion of jack seed to the products. In the year 2002, Tananuwong et al. evaluated the possibility of substitution of jack seed flour in bread preparation. With increasing level of replacement, the water absorption capacity increased and bread dough peak time and dough stability time were reduced. The specific baking volume of the bread was reduced by 51 per cent at 5 per cent replacement with jack seed flour. Study revealed that, less than 5 per cent of wheat flour can be replaced with jack seed flour in the bread preparation. Naik (2007) incorporated 10 to 50 per cent jack seed flour in 50:50 blend of wheat flour (maida and full wheat flour ) for the preparation of cookies. The product at 20 and 30 per cent incorporation were acceptable with good sensory profile, while 50 per cent incorporation though was acceptable had hard texture. A study by Gaimi and Amasisi (2003) noted the performance of African bread fruit seed flour in bread preparation. There were no significant differences between wheat flour and blends containing 5 to 10 per cent of African bread fruit seed flour in the alveograph values for resistance to extension, extensibility and mechanical work for deformation of doughs. Upto 10 per cent substitution with bread fruit seed flour produced bread with crust colour, crumb colour, crumb texture, loaf height and loaf volume similar to the control. Use of higher levels (15-25%) however, resulted in the reduction of these quality attributes. Thus it can be concluded from the above studies that the replacement of seed flour up to 5 to 30 per cent is possible in various products depending upon the composition of flour and functional quality for better utilization or end use.
3. MATERIAL AND METHODS The present investigation on “Nutritional and functional quality and value addition to jackfruit seed flour” was carried out during the year 2006-2007, with jackfruit seed flour nutrient, physical and functional profile, in–vitro protein and starch digestibility, shelf life status and utilization in convenience food. The material and methods adopted for the study are recorded in this section.
3.1
PREPARATION OF SEED FLOUR
3.1.1 Procurement of seed material The jackfruit seeds were collected from the local market of Dharwad and North Canara districts during the season.
3.1.2 Seed treatment The jackfruit seeds (4 kgs ) were cleaned manually and white arils (seed coat ) were manually peeled off. Seeds were lye peeled, soaking in 3 per cent sodium hydroxide solution for 3-5 minutes to remove the thin brown spermoderm which covers the cotyledons. The spermoderm layer was removed by rubbing the seeds between the hands and washing thoroughly under running water.
3.1.3 Preparation of jackfruit seed flour The lye peeled seeds were sliced into thin chips and dried at 50- 60° C to a constant moisture. The dried chips were powdered in a flour mill, passed through 105 µ mesh sieve and packed in polyethylene pouches and stored in a refrigerator (<10°C) f or further analysis.
3.2
NUTRIENT COMPOSITION OF JACKFRUIT SEED FLOUR
3.2.1 Proximate composition The seed flour was analysed for proximate composition viz., moisture, crude protein, crude fat, crude fibre and total mineral matter and expressed in percentage. All the analysis were done in triplicates on moisture free basis except crude protein content.
3.2.1.1 Moisture Five grams of powdered seed sample was weighed into a previously weighed moisture cup and dried in an oven at 60°C till a constant weight was attained (Anon., 1990 )
Initial weight (g) – Final weight (g) Moisture % = ------------------------------------------× 100 Sample weight (g)
3.2.1.2
Crude protein
The nitrogen content of flour was estimated by Microkjeldahl method in Parnas and Wagner apparatus (Anon.,1990). The crude protein content was calculated by multiplying w ith factor 6.25 and expressed on per cent basis.
Protein % =
(Titre—Blank ) × Normality of HCL × 14.007 × 6.25 ------------------------------ ------------------------------- × 100 Sample weight (g)
Plate 1. Jackfruit seeds
3.2.1.3 Crude fat Moisture free sample was weighed in moisture free thimbles and crude fat was extracted by refluxing in soxhlet apparatus using petroleum ether as solvent. Per cent crude fat was calculated by difference (Anon., 1990).
Crude fat % =
3.2.1.4
Initial weight (g) – Weight after extraction (g) --------------------------------- ------------------------ × 100 Sample weight (g)
Crude fibre
Fat free seed flour sample was hydrolyzed with dilute sulphuric acid (0.255 N) and dilute alkali (0.313 N) to estimate crude fibre by employing the methods of Mayanard (1970). Weight residue with crucible (g) – W eight of ash with crucible Crude fibre %=-------------------------------------------------------------------- ×100 Weight of fat free sample (g)
3.2.1.5
Total mineral matter
Total mineral matter ( ash ) was determined by igniting samples in muffle furnace at 600°c for 3 - 4 hours ( Anon., 1990). The total m ineral matter was expressed as per cent. Weight of crucible with ash (g) Total mineral matter % = -------------------------------------------- × 100 Weight of crucible with sample (g)
3.2.1.6
Carbohydrates
The carbohydrates content was calculated by deducting the sum of the values for moisture, crude protein, crude fat, crude fibre and total mineral matter in 100 ( Raghuramulu et al., 1983 ).
3.2.1.7
Calorific value
The calorific value was computed by summing up the values obtained by multiplying the values of carbohydrate, crude protein and crude fat with the factors 4,4 and 9 respectively and expressed as K calories per 100 grams of seed flour. The calorific value of jack seed flour was also determined by using Bomb Calorimeter (Model Toshiwal digital bomb). The principle of operation is mentioned below A known amount of the sample was burned in a sealed chamber (BOMB). The air was replaced by pure oxygen. Sample was ignited electrically. As the sample was burned, heat was produced. The rise in temperature was measured. Since barring the loss of heat, the amount of heat produced by burning the sample must be equal to the amount of heat absorbed by the calorimeter assembly. A knowledge of the water equivalent of the calorimeter assembly and of the rise in temperature enables to calculate the heat of combustion of the sample. Rest of the calculation was done according to the method referred in t he manual.
3.3. PHYSICAL AND FUNCTIONAL QUALITIES OF SEED FLOUR Physical and functional qualities of jackfruit seed flour were determined and recorded.
3.3.1 Physical characters Physical characters such as number of seeds per fruit and seed flour yield were documented.
3.3.1.1 Hundred grams of jack seeds were weighed and number of seeds were counted and recorded. 3.3.1.2 Flour Yield Hundred grams of jack seed was considered for yield calculation. After the processing steps (3.1.3.), the total flour was weighed and expressed as percentage.
3.3.2 Functional qualities Functional qualities such as water and oil absorption capacities, swelling power, per cent solubility, flour dispersibility and viscosity of the s eed flour were analysed.
3.3.2.1 Water absorption capacity Twenty grams of seed flour was taken and required quantity of water added to get a dough of moderately stiff consistency. The amount of water required was noted and expressed in percent ( Austin and Ram., 1971).
3.3.2.2 Fat absorption capacity One gram of seed flour sample was taken in a centrifuge tube and weight was recorded. Six milliliters of refined oil was added to the flour and centrifuged at 4000rpm for 25min. Free oil was decanted and weight of the centrifuge tube was noted (Sosulki, 1962). Fat absorption capacity of the seed flour was calculated as: Weight of sample Weight of sample after centrifugation – before centrifugation % Fat absorption capacity = ----------------------------------------------------------- × 100 Weight of original sample taken
3.3.2.3 Swelling power and per cent solubility of seed flour Swelling power and per cent solubility of seed flour was determined according to the method of Schoch (1964). About 500 milligrams (W 1) of jack seed flour was taken in a centrifuge tube and weighed the centrifuge tube with sample (W 2) and 20ml (VE) of distilled water was added. Then it was allowed for 30min in a boiling water bath at 100°C. The contents were cooled and centrifuged at 5000rpm for 10min. The supernatant was carefully decanted in a test tube. The water adhering to the sides of centrifuge tube was wiped well and weight of the centrifuge tube was taken with swollen material (W 3). The swelling power of seed flour per gram was calculated by the formula: (W 3 —W2) × 1 Swelling power (g/g) = ------------------W1 Where,
W1 = Weight of seed flour sample W 2 = Weight of the centrifuge tube with seed flour sample W 3 = Weight of the centrifuge tube with swollen material
For per cent solubility of seed flour, t he dried petriplate was weighed (W 4) and 10ml of supernatant (VA) was pipetted into the petriplate. Then it w as dried at 105°C in a hot air oven till constant weight was attained and cooled in a descicator and again weighed the petriplate with dry solids (W5). The per cent solubility of the supernatant was calculated by, (W5 – W 4) 100 % solubility = -------------- × ------VA W1
Where,
W1 = Weight of seed flour sample W 4 = Weight of the petriplate W 5 = Weight of the petriplate with dry solids VE = Volume of water added VA = Volume of supernatant taken
3.3.2.4 Flour dispersibility Dispersibility was measured by placing 10 grams of seed flour sample in 100ml stoppered measuring cylinder. Distilled water added to t he volume of 100ml, stirred vigorously and allowed to settle for three hours. The volume of settled particles was subtracted from 100 and the difference was reported as percentage dispersibility. 3.3.2.5 Viscosity Cold and hot paste viscosities of seed flour was tested at 5 and 10 per cent slurry concentrations (100ml) using Viscometer at 100 rpm with spindle number two. (RTV model, Brooke field viscometer, UAS)
3.4
NUTRITIONAL QUALITY OF THE SEED FLOUR
In-vitro protein and starch digestibility of the seed flour was carried out by enzymatic method described by Moulishwar et al (1993). The procedures followed are given below,
3.4.1 In-vitro protein digestibility Sample containing 100 milligrams of protein was treated with 0.1N HCl containing 19.5 milligrams of pepsin at 37°C for three hours. The contents were neutralized w ith 0.5N sodium hydroxide, then 25ml of phosphate buffer containing 6mg of pancreatin was added and incubated for 24hours at 37°C. The volume was made upto 100ml with distilled water and 50ml of the aliquot was treated with 10per cent trichloroacetic acid and left overnight to precipitate the proteins. The suspensions were centrifuged and residue was analysed for protein by microkjeldahl method . the amount of protein digested was calculated as, Digested protein = Total protein – Undigested protein Thus, obtained values of digested protein were expressed in percentage.
3.4.2 In-vitro starch digestibility Sample of 500mg in 25ml of distilled water was cooked on boiling water bath for 15min. To the cooled sample 0.2N sodium hydroxide was added and volume made upto 100ml. Ten milliliters of this aliquot was taken, and 0.05M phosphate buffer containing 7.5mg of pancreatin and 7.5mg of amyloglucosidase was added and incubated at 37°C. The samples were withdrawn at 30 and 60min. of incubation and reducing sugars released were determined by Nelson Somogy’s method (Hawk et al ., 1965 ). Glucose was used as standard and degree of hydrolysis was expressed as milligrams of glucose liberated from food after correction for blank values (Moulishwar et al., 1993).
3.5
SHELF LIFE OF SEED FLOUR
3.5.1 Storage quality 3.5.1.1 Packaging and storage Twenty five grams of seed flour was weighed and packed in food grade polyethylene pouches (80 gauge) and heat sealed. The storage quality was assessed for 6 months (November, 2006 to May, 2007) both in refrigerated and ambient conditions.
3.5.1.2 Analysis of stored samples The stored samples were drawn at monthly intervals for six months and moisture percentages were determined, according to the procedure outlined in 3.2.1.1
3.5.2 Sensory Quality Any change in the visible sensory parameters of the stored seed flours was evaluated by expert panels and changes if any were recorded.
3.6
UTILISATION OF SEED FLOUR IN CONVENIENCE FOOD
The jack seed flour was utilized in the preparation of convenience food viz., non-katai biscuits at different proportions to assertain the acceptable level of incorporation. The wheat flour, fat, salt, baking powder and sugar were procured from local market. The biscuits were prepared using the standardized method of Bakery Unit, UAS, Dharwad. The detailed protocol of biscuits of standard recipe is mentioned below: Refined wheat flour (100g) was weighed Kneaded with 40g of hydrogenated fat Other ingredients viz., sugar (7g), salt (3g) and baking powder (1.5g) were mixed well
Homogeneous mass was prepared using curds to form required consistency Batter was rolled out to the thickness of 0.5 cm
Different shaped pieces were cut out using biscuit cutter Placed in the baking trays and baked at 150˚C for 10- 12 min
Biscuits were allowed to cool at room temperature for 8-10 min
Packed in the polyethylene cover and sensory evaluation was done after 24 hrs
3.6.1 Sensory evaluation of biscuits The biscuits were evaluated for organoleptic characters like appearance, colour, texture, taste, aroma and overall acceptability by scoring method using 9 point hedonic scale. The evaluation was achieved by selected partially trained judges from Department of Food Science and Nutrition, UAS, Dharwad. The judges were given a score card (Appendix I), instructed individually and requested to evaluate the biscuits. The most acceptable proportion of jack seed flour biscuit was considered for the consumer acceptability trail. The experiment was conducted in duplicates.
3.6.2 Consumer acceptability The accepted proportion of jack seed flour biscuit by the panelists was considered to assess the level of consumer acceptability. Hundred girls aged between 18-25 years were considered for the evaluation of biscuits by scoring method using 9 point Hedonic Scale.
Table 1. Level of incorporation of flours Treatments
Refined Wheat Flour
Jack seed flour
Control
100
-
I
90
10
II
80
20
III
70
30
IV
60
40
V
50
50
Fig. 1. Colour values of Minolota Colour meter
3.6.3 Physical characters of biscuits Physical characters viz., weight, diameter, thickness, spread ratio and colour of the biscuits was determined before and after the replacement of jack seed flour using Vernier Callipers and Minolta Colour meter (Fig.1).
3.7
STATISTICAL ANALYSIS
The data collected on physical properties, chemical composition, functional qualities of seed flour were statistically analysed. Completely randomized design (CRD) was applied to test the storage quality and significant difference in quality parameters. The limit of probability fixed for the test significance was P = 0.05 and P = 0.01, whenever, the significant result was obtained, the critical test was used (Steel and Torrie, 1960).
4. RESULTS Jackfruit is considered as poor man’s fruit. A good source of protein and carbohydrates, the seeds have several potentialities for value addition. The results of the studies on jack seed flour in terms of physical and functional properties, nutritional composition, in-vitro digestibility, storage quality, standardization and consumer acceptability of value added product are presented in this chapter.
4.1 PHYSICAL AND FUNCTIONAL PROPERTIES OF SEED FLOUR The physical and functional parameters considered are as follows.
4.1.1 Yield The observations related to the yield data of jack seed flour is presented in the Fig. 2 and Appendix II. It is evidenced that, 100 grams of jack seed consisted of 21 fresh seeds. After removal of white arils, the weight of the seeds reduced to 98 grams conversely, two per cent reduction in seed weight was observed. The weight of the brown spermoderm recorded eight grams, thus reducing the seed weight to 90 grams. The lye peeled and dried seeds were milled into flour, the weight of the flour recorded 78 grams. The total crude yield of the flour, exclusive of weight of the white arils, brown spermoderm and handling losses represented 78 per cent. Therefore, the total yield of the f lour was recorded as 68 per cent.
4.1.2 Functional properties of jack seed flour Seeds are generally processed to yield typical functional, nutritional or organoleptic characteristics in the resultant flours. The functional properties are important in the food systems for the creation of new products. Results of the experiments to assess the water and oil absorption capacities, dispersibility, swelling power and per cent solubility of jack seed flour is depicted in the Table 2. The mean value for the water absorption capacity of the flour recorded 112.00ml/100g where as, higher value (126.90 ml/100g) was recorded for oil absorption capacity. The dispersibility of the seed flour noted 30 per cent. The swelling power (3.62 g/g ) of the seed flour was higher than the per cent solubility (1.80 %). The viscosity is an important determinant of knowing pasting temperature at which the first detectable gelled starch is measured using Brooke field viscometer. This property helps in the food applications. Observations of Table 3 shows that, the cooked paste viscosity of 5 per cent jack seed flour paste got lower value (27.10 % ) compared to 10 per cent paste (51.40 %) at ambient temperature. Similar observations were also prevailing at hot temperature (90°c ), the 5 per cent slurry was less viscous (19.20 % ) than the 10 per cent (40.80 %) slurry. As expected, the cold pastes got the higher viscosity values compared to hot slurries. It is interesting to note that when temperature was considered as a variable, a difference of 10 per cent in viscosity was observed at both 5 and 10 per cent concentrations.
4.2
NUTRIENT COMPOSITION OF SEED FLOUR
Jack seed has a great potential in the product formulation. Data in Table 4, documents the range and mean values for proximate composition of jack seed flour. The moisture content recorded a mean of 14.07 per cent. On the other hand, the values of 9.03 per cent of crude protein, 1.10 per cent of fat, 2.25 per cent of crude fibre and of 3.01 per cent total mineral matter were recorded. The total carbohydrates documented was 70.26 per cent. The calorific value per 100 grams of jack seed flour was documented as 327 K. calories when computed using Atwater figures, where as higher value (376 K.cal) was recorded when energy was analysed using Bomb Calorimeter.
4.3
NUTRITIONAL QUALITY OF JACK SEED FLOUR
In-vitro studies are the appropriate methods for analyzing the nutritional quality of any food material. There are several direct and indirect methods employed in assessment of nutritional quality. In the present investigation the nutritional qualit y was assessed in terms of
Weight after removal of white arils Weight after removal of brown spermoderm Crude Passed
8.16 2
13.34 13.46
Fig. 2. Yield of jack seed flour
Fig. 2. Yield of jack seed flour
A – Dred jack seed chips B – jack seed flour
A – Dred jack seed chips B – jack seed flour
Plate 2. Processed jack seed products
Table 2. Functional properties of jack seed flour
Properties
Values
Water absorption capacity (ml/100 g )
112.00 ± 0.20
Oil absorption capacity (ml/100 g)
126.90 ± 0.60
Dispersibility (%)
30.00 ± 0.20
Swelling power (g/g)
3.62 ± 0.02
Per cent solubility (%)
1.80 ± 0.20
* Average of three replications
Table 3. Viscosity of jack seed flour Concentrations Hot slurry (90°C) 5% 10% Cold paste (25°C) 5% 10%
cps
%
384 816
19.2 40.6
541 1028
27.1 51.8
* Average of triplicates. Table 4. Proximate composition of jack seed flour (g/100 g) Composition* Moisture Protein (g) Fat (g) Crude fibre (g) Total mineral matter (g) Total carbohydrates (g) Calorific value (K. cal) Computed Analysed
% 14.07 ± 0.04 9.03 ± 1.09 1.10 ± 0.11 2.55 ± 0.09 3.01 ± 0.01 70.26 327 376
* Mean of triplicates Expressed on dry weight basis. Table 5. Nutritional quality of seed flour
In vitro digestibility
Percentage
Protein
78.17
starch
30 min
57.28
60 min
69.30
* Mean of triplicates
in-vitro digestibility of starch and protein using enzymatic method and documented in the Table 5.
The protein in-vitro digestibility documented 78.17 per cent. The starch digestibility of the seed flour observed was higher (69.30 %) at the withdrawal of 60 minutes compared to withdrawal of sample at 30 minutes (57.28 %).
4.4
STORAGE QUALITY OF JACK SEED FLOUR
The existence of any product without any change in the quality and sensory profile of the product can be analysed by the process of storage study. In the present investigation storage property of jack seed flour considered for six months.
4.4.1 Moisture Moisture content is one of the important parameters which interferes in the quality of the flour during the storage. In the Figure 3 and Appendix III, it is clearly depicted that, there was an increase in the moisture content from the initial value (7.16 %) to 8.04, 8.13, 8.41, 8.78, 9.64 and 11.03 per cent in ambient temperature and 7.31, 7.55, 7.63, 7.81, 8.03 and 8.39 per cent in refrigerated conditions, respectively with the intervals of a month. Peak increase in the st th th moisture level was observed at 1 (8.04 %), 5 (9.64 %) and 6 (11.03%) months of storage at ambient temperature. On the other hand, a gradual increase in moisture level was noticed in the samples stored under refrigerated condition. Significant difference was observed between the ambient and refrigerated condition (P < 0.01).
4.4.2 Sensory profile of stored jack seed flour The increase in moisture level in the stored samples did not reveal any change in sensory profile in terms of colour, flavour and texture during six months.
4.5 VALUE ADDED CONVENIENCE FOOD OF JACK SEED FLOUR Jack seeds are perishable and season bound. To enhance the utility and to make them available year through seeds can be processed into flour which can be used in different value added products. Value addition not only enhances proper utilization during glut, but extends the shelf life of seeds in processed form.
4.5.1 Preliminary trials A study on the standardization of jack seed based biscuits was conducted in two successive stages. In the first phase, standardization of control biscuit trials were conducted. Ingredient proportions were modified to develop satisfactory product using 25, 50, 75 and 100 per cent jack seed flour in terms of sensory parameters. The basic experiment approach consisted of developing satisfactory level of jack seed flour incorporated non-katai biscuits based on organoleptic qualities in terms of colour and appearance, texture, taste, aroma and overall acceptability as assessed by expert and trained panelists on 9 point Hedonic scale. The sensory profile of biscuits are depicted in the Figure 4 and Appendix IV. The colour and appearance of 25 per cent seed flour incorporated biscuits scored highest (8.00) value for its extremely good colour and appearance whereas, the control biscuits scored 7.66. Similarly, very good score (7.33) was recorded by 50 per cent seed flour incorporated biscuits. Conversely, the 75 and 100 per cent seed flour based biscuits scored the similar value (7.00) for their very good colour and appearance. However, the statistical test revealed that the mean scores of biscuits with different levels of incorporation of jack seed flour were not significant at 5 per cent level of si gnificance. The 25 per cent jack seed flour incorporated biscuits recorded (6.33) moderately good texture profile whereas the 50 per cent seed flour based biscuits recorded the higher value (7.00) for its very god texture as that of control. The 75 per cent seed flour based biscuits documented (5.66) moderately good texture. Though, 100 per cent seed flour incorporated biscuits scored the least value of 5.00 with good texture profile. However, the ‘F’
Ambient condition (24-26°C)
12
Refrigerated condition (8-10°C)
10
8 ) % ( e r u t s i o M
6
4
2
0 0
1
2
3
4
5
6
Months
Fig. 3. Moisture content of stored flour
Fig. 3. Moisture content of stored flour
9
8
8
7
7
6 s r e t 5 e
6 s r e t e
m a r a 4 p y r o s n 3 e S
m5 a r a p y r o 4 s n e S
s
3
2
2
1
1
0
0 control
25
50
75
control
100
25
Level ofincorporation
50
75
100
Level of incorporation
Colour and appearance
Texture
8
8
7
7
6
6
s 5 r e t e m a r a p 4 y r o
s 5 r e t e m a r a p 4 y r o
3
3
s n e S
s n e S
2
2
1
1
0
0 control
25
50
Level of incorporation
75
100
control
25
50
Levelof incorporation
75
100
9
8
8
7
7
6 s r e t 5 e
6 s r e t e
m a r a 4 p y r o s n 3 e S
m5 a r a p y r o 4 s n e S
s
3
2
2
1
1
0
0 control
25
50
75
control
100
25
Level ofincorporation
50
75
100
Level of incorporation
Colour and appearance
Texture
8
8
7
7
6
6
s 5 r e t e m a r a p 4 y r o
s 5 r e t e m a r a p 4 y r o
3
3
s n e S
s n e S
2
2
1
1
0
0 control
25
50
75
100
control
25
Level of incorporation
50
75
Levelof incorporation
Taste
Aroma
8
7
6
5 s r e t e m a r a p y r o s n e S
4
3
2
1
0 control
25
50
75
100
Level of incorporation
Overall acceptability
Fig. 4. Sensory scores of jack seed based biscuits (initial tri als)
100
test revealed that the mean scores of biscuits with different levels of incorporation of jack seed flour were not significant at 5 per cent of significance level. The taste of control biscuits scored highest value of 7.00 compared to different levels of jack seed flour incorporated biscuits. The 25 per cent seed flour based biscuits scored 6.66 for their good taste. The 50 per cent seed flour based biscuits recorded the good taste with the value of 4.66. The 75 and 100 per cent seed flour based biscuits recorded very fair and poor taste with the values of 3.00 and 1.66, respectively. With respect to aroma of biscuits, 25 per cent seed flour based biscuits scored the value of 6.66 with very god aroma as that of control (7.00). The 50 per cent seed flour incorporated biscuits recorded the value of 5.33 for its good aroma. The 75 and 100 per cent seed flour based biscuits recorded the scores, 2.33 and 1.66 for their poor and very poor aroma. The overall acceptability of biscuits showed that, the control biscuits scored higher value (7.33) with very good acceptability. The 25 per cent seed flour based biscuits recorded the value of 6.33 for its moderately good acceptability. The 50 per cent seed flour incorporated biscuits documented the score, 4.66 with good overall acceptability. The 75 and 100 per cent seed flour incorporated biscuits recorded the values of 2.66 and 1.66 for their very fair and poor overall acceptable quality.
4.5.2 Dough forming properties of jack seed flour The observations related to the dough forming properties of jack seed flour at different levels of incorporation is presented in the Table 6. The absorption of curds by control dough was lower (20 ml) compared to all other Seed flour incorporated doughs. The 10 per cent seed flour incorporated dough absorbed 21 ml of curds (4.76% absorption) followed by 20, 30, 40 and 50 per cent seed flour based dough absorbed the curds 23, 26, 30 and 32 mililitres, respectively with 13.04, 23.07, 33.30 and 37.50 per cent absorption levels. There was clear evidence of increase in the weight of the fresh dough with an increase in the seed flour incorporation level. The weight of fresh dough of control was recorded as 218 g. There was a visible trend observed that an increase in fresh weight of dough with increase in the proportion of jack seed flour. The 10 per cent seed flour incorporated dough documented 221 grams with 1.35 per cent increase in the weight. Further, the 20 per cent seed flour based dough recorded the weight of 225 g. with 3.11 per cent increase in the weight. Similarly, the 30, 40 and 50 per cent seed flour incorporated dough documented the weight of 228, 232 and 235 grams, respectively with 4.38, 6.03 and 7.23 per cent increase in the weight of fresh dough.
4.5.2.1 Weight of biscuits Similar to seed flour incorporated dough characteristics, the biscuits with varied proportion of jack seed flour exhibited similar trend of increase in weight with increase in jack seed flour in the product. The baked weight of the control biscuits recorded 155 grams. The 10 per cent seed flour based biscuits weighed 157 grams with 1.27 per cent increase in the weight (Table 7). Similarly, the 20 per cent seed flour based biscuits recorded the weight of 159 grams, with 2.51 per cent increase in the baked weight. Further, 30, 40 and 50 per cent seed flour incorporated biscuits documented the weight of 162, 165 and 167 grams, respectively with increase in the baked weight of biscuits 4.32, 6.06 and 7.18 per cent, respectively.
4.5.3 Standardization of jack seed flour incorporated biscuits Preliminary trials indicated that, incorporation with jack seed flour to obtain acceptable biscuits is possible only below 50 per cent. Hence, further experiments were planned to incorporate jack seed flour between 10 to 50 per cent with an intervals of 10 per cent. Biscuits were evaluated for sensory attributes and physical parameters such as diameter, thickness and colour (top and bottom). The sensory profile of the biscuits with an incorporation level of 10 to 50 per cent with jack seed flour were shown in Figure 5 and Appendix V.
Table 6. Dough characteristics
Variable Absorption of curds (ml) % increase in curds Weight of fresh dough (g) % increase in weight
Control 20 218 -
% incorporation of jack seed flour 10 20 30 40 21 23 26 30 4.76 13.04 23.07 33.30 221 225 228 232 1.35 3.11 4.38 6.03
50 32 37.50 235 7.23
% incorporation of jack seed flour 10 20 30 40 157 159 162 165 1.27 2.51 4.32 6.06
50 167 7.18
Table 7. Physical parameters of biscuits
Variable Weight of biscuits (g) % increase in the weight of biscuits Number of biscuits
Control 155 18
18
18
18
19
19
The colour and appearance of control biscuits recorded the highest value of 7.14 for its very good colour and appearance. Even though 10 and 20 per cent seed flour based biscuits scored the lower values (6.57 and 7.00, respectively) but recorded very good colour and appearance as that of control. It is interesting to note that the 30 and 40 per cent seed flour incorporated biscuits recorded the similar value of 6.57 for their very good colour and appearance. The 50 per cent seed flour based biscuits scored the value of 5.85 for its moderately good colour and appearance. However, the statistical test revealed that, there were no impact of substitution of jack seed flour upto 50 per cent and all the proportions of biscuits are not significant with each other at 5 per cent level of significance. The texture scores of biscuits with 10 per cent seed flour recorded the similar value of 6.71 as that of control for their very good texture profile. Further, the 20 and 30 per cent seed flour based biscuits recorded the values of 6.42 and 5.00, respectively for their moderately good and good texture. The 40 and 50 per cent seed flour based biscuits documented the values of 4.71 and 3.85, respectively and recorded fair texture profile. The statistical test revealed that significant difference was observed between the control and 30 per cent seed flour based biscuits. The non-significant diff erence was observed between 20 and 30 per cent and 30 and 50 per cent seed flour based biscuits. The taste of 10 per cent seed flour incorporated biscuits recorded the similar value of 6.71 as that of control biscuits. Further, the 20 and 30 per cent seed flour based biscuits recorded the values of 6.14 and 5.14 for their moderately good and good taste. The 40 per cent seed flour based biscuits recorded the value of 4.14 and 50 per cent seed flour based biscuits scored the value of 3.85 for their fair taste. The statistical test revealed that, the significant difference was observed between the control and 30 per cent seed flour incorporated biscuits. The 20 and 30 per cent and 30 and 50 per cent seed flour based biscuits were not significant with each other at 5 per cent level of significance. The aroma of control biscuits recorded the highest value of 7.14 and 10 per cent seed flour based biscuits documented the value of 7.00 for their very good aroma. The 20 per cent seed flour based biscuits documented the moderately good (6.28) aroma. Further, the 30 per cent and 40 per cent seed flour incorporated biscuits recorded the value of 5.00 and 4.14 for their good and fair aroma, respectively. Though the 50 per cent seed flour based biscuits scored the least value of 3.85 recorded the fair aroma as that of 40 per cent seed flour based biscuits. The statistical test revealed that, significant difference was observed between control and 30 per cent seed flour based biscuits. Similarly, the significant difference was observed between the 20 and 40 per cent seed flour incorporated biscuits. The overall acceptability of biscuits showed that, the control biscuits scored the highest overall acceptability value of 6.28 for its moderately good acceptability. The 10 per cent seed flour incorporated biscuits scored the value of 6.42 and recorded moderately good acceptability. It is interesting to note that the 20 per cent seed flour based biscuits scored
8
8
7
7
6
s r e t e
6
5
m a r a p y r o s n e S
5
3
s r e t e m a r a p4 y r o s n e S
2
2
1
1
4
3
0
0 control
10
20
30
40
50
control
10
20
30
40
50
30
40
50
Level ofincorporation Level ofincorporation
Colour and appearance Texture
8
8
7
7
6
6
s 5 r e t e m a r a p 4 y r o s n e S
3
s 5 r e t e m a r a p 4 y r o s n e S
2
2
1
1
3
0
0 control
10
20
30
40
50
control
10
20 Level of incorporation
Level of incorporation
Aroma
Taste
7
6
5 s r e t e 4 m a r a p y r o s 3 n e S
2
1
0 control
10
20
30
40
Level of incorporation
Overall acceptability
Fig. 5. Sensory scores of jack seed based biscuits
50
even though the lower value (5.71) than the control and 10 per cent jack seed flour based biscuits, recorded the moderately good acceptability. Further, the 30 per cent and 40 per cent seed flour based biscuits recorded good over all acceptability with the values of 5.23 and 4.78, respectively. The 50 per cent seed flour based biscuits documented the least value of 3.28 for its very fair acceptability. However, the statistical test revealed that, the significant difference was observed between control and 50 per cent seed flour based biscuits. There was non-significant difference was observed between 40 and 50 per cent seed flour based biscuits.
4.5.4 Physical parameters of jack seed flour incorporated biscuits The physical parameters viz., diameter, thickness and colour (top and bottom) of biscuits incorporated with different levels of jack seed flour were determined and the results are presented in this section. The observations related to the diameter and thickness of biscuits incorporated with jack seed flour at different levels is presented in the Table 8. The diameter of the biscuits gradually increased with increase in the proportion of jack seed flour. The control biscuits documented the diameter of 4.13 cm. The 10, 20 and 30 per cent jack seed flour incorporated biscuits documented lower diameter scores of 4.06, 4.08 and 4.09cms, respectively. It is observed that the 40 per cent seed flour based biscuits scored the same value (4.13cm) as that of control. It is interesting to note that the 50 per cent seed flour based biscuits documented higher value (4.21cm) compared to control. However, the statistical test revealed that, the mean scores of diameter of biscuits with different levels of incorporation of jack seed flour were not significant at 5 per cent signifi cance level. The thickness of control biscuits recorded 1.03cm. It is observed that 10 per cent jack seed flour based biscuits documented (1.04cm) higher thickness compared to control. Further, the 20 and 30 per cent seed flour based biscuits recorded the thickness of 0.93 and 0.88 cms, respectively. Similarly, the 40 per cent seed flour incorporated biscuits scored the same value (0.88cm) of thickness as that of 30 per cent seed flour incorporated biscuits. It is observed that, 50 per cent seed flour based biscuits documented lower thickness (0.81cm) compared to that of control and other different levels of seed flour incorporated biscuits. However, the ‘F’ test revealed that, the thickness of biscuits with different proportions of jack seed flour were not significant with each other at 5 per cent significance. The spread ratio of the biscuits gradually increased as the seed flour incorporation level increases. The 10 per cent seed flour based biscuits documented lower (3.90 cm) spread ratio than the control (4.00 cm). The 20, 30, 40 and 50 per cent seed flour incorporated biscuits documented the values as 4.38, 4.64, 4.68 and 5.19 cm, respectively. The observations related to the colour (top and bottom layer) of biscuits incorporated with jack seed flour at different levels is presented in the Table 9. The top side of all different levels of jack seed flour incorporated biscuits documented the higher values with respect to l, a, b colours compared to bottom side of biscuits. The top ‘l’ coluor values of biscuits were not significant with each other upto 30 per cent seed flour incorporation. Significant difference was observed between 40 and 50 per cent seed flour incorporated biscuits and these differed significantly with rest of the biscuits. All the seed flour incorporated biscuits differed significantly differed with control. With respect to top side the 10 per cent jack seed flour based biscuits scored the higher ‘l’ values (71.58) compared to 20 and 30 per cent seed flour based biscuits (72.46 and 72.67, respectively) with lesser whitish colour. Further, the 40 per cent seed flour based biscuits documented the lower ‘l’ values (68.83 and 68.63, respectively)with less whitish coloured compared to 10, 20 and 30 per cent seed flour incorporated biscuits. The top side of 10 per cent seed flour incorporated biscuits documented the lower ‘a’ value (1.04) with light brownish colour compared to other levels of seed flour incorporated biscuit. It is interesting to note that, the top layer of 20 and 40 per cent seed flour based biscuits recorded the same ‘a’ value (1.55). Further, the 30 per cent seed flour based biscuits scored ‘a’ value of 1.21. The 50 per cent seed flour incorporated biscuits scored highest ‘a’ value (3.05) with darker brownish colour compared to rest of the samples. The top layer ‘a’ colour values of biscuits with 20 per cent seed flour based were not significant with control, 30
Table 8. Physical characteristics of jack seed flour incorporated biscuits Particulars Diameter Thickness Spread ratio
Control 4.13 1.03 4.00
10 4.06 1.04 3.90
20 4.08 0.93 4.38
30 4.09 0.88 4.64
40 4.12 0.88 4.68
50 4.21 0.81 5.19
A – Top layer of biscuits B – Bottom layer of biscuits
Plate 3. Jack seed (40%) based biscuits and 40 per cent seed flour incorporated biscuits. The 10 per cent seed flour based biscuits were not significant with 30 per cent seed flour incorporated biscuits. The 50 per cent seed flour based biscuits were significantly differed with rest of the seed flour incorporated biscuits. The top layer of 20 per cent seed flour based biscuits documented the ‘b’ value of 27.00 with dark yellowish in colour compared to 10, 30,40 and 50 per cent seed flour incorporated biscuits with ‘b’ values 26.20, 25.72, 23.98 and 23.78, respectively. The statistical test revealed a non-significant difference between 40 and 50 per cent seed flour incorporated biscuits. The control and rest of the seed flour incorporated biscuits significantly differed with each other. With respect to bottom layer, the 30 per cent seed flour based biscuits scored the higher ‘l’ value (68.62) with whitish bottom layer. Similarly, the 10 and 20 per cent seed flour incorporated biscuits documented the ‘l’ values of 62.79 and 61.97, respectively. It is observed that the 40 and 50 per cent seed flour based biscuits scored lesser ‘l’ values (58.88 and 58.11, respectively) with dull whitish colour. The bottom ‘l’ colour values of control and 30 per cent seed flour incorporated biscuits showed significant difference with other seed flour based biscuits. The 10 and 20 per cent and 40 and 50 per cent seed flour incorporated biscuits were not significant with each other. The ‘a’ value (8.33) of 20 per cent seed flour based biscuits was higher with dark brownish in colour compared to all other seed flour incorporated biscuits. The 40 and 10 per cent seed flour based biscuits scored the ‘a’ values (7.99 and 6.33, respectively) with light brown colour. Further, the 50 per cent seed flour incorporated biscuits scored the ‘a’ value of 5.51. The least ‘a’ value (3.96) was documented by 30 per cent seed flour based biscuits with light brown coloured bottom layer. The bottom ‘a’ colour value of control biscuits statistically significant with rest of the seed flour incorporated biscuits. The 10 and 40 per cent, 20 and 40
per cent, 10 and 50 per cent and 30 and 50 per cent seed flour incorporated biscuits were not significant with each other at 5 per cent level of significance. The bottom layer of 20 per cent seed flour incorporated biscuits documented the highest ‘b’ value (29.52) with dark yellowish in colour compared to 10, 30, 40 and 50 per cent seed flour based biscuits with ‘b’ values of 28.12, 27.02, 26.85 and 23.11, respectively. The bottom ‘b’ colour value of control, 20 and 40 per cent seed flour based biscuits were significantly differed with each other. The 10 and 30 per cent and 30 and 40 per cent seed flour based biscuits were not significant with each other at 5 per cent level of significance. Data in Table 10, presents the consumer acceptability scores in terms of sensory parameters of 40 per cent seed flour based biscuits. The colour and appearance of biscuits recorded the score of 7.04 for its very good colour and appearance. The texture of the biscuits documented moderately good score (6.15). It is observed that the taste and aroma of biscuits scored very good score (6.96 and 6.90, respectively). The biscuits were accepted with very good overall acceptability score of 7.00. Table 9. Colour values of jack seed flour biscuits
Biscuits layer Top L A B Bottom L A B
10
Level of jack seed flour incorporation 20 30 40 50
Control
71.58a 1.04b 26.20b
72.46a 1.55a 27.00c
72.67a 1.21ab 25.72b
68.83b 1.55a 23.98d
63.63c 3.05d 23.78d
76.60d -1.62a 18.48a
62.79b 6.33ac 28.12a
61.97b 8.33b 29.52b
68.62c 3.96d 27.02ac
58.88d 7.99ab 26.85c
58.11d 5.51cd 23.11d
72.83a -0.96e 21.31e
Average of six biscuits. Identical alphabets denote non-significant differences between means. •
Table 10. Consumer acceptability of seed flour based biscuits N = 100 Biscuits Colour and appearance Texture Taste Aroma Overall acceptability •
9 point Hedonic scale.
40% seed flour incorporated 7.04 6.15 6.96 6.90 7.00
5. DISCUSSION The seeds are the main produce of a plant containing large number of nutrients. These nutrients interact with each other during product development and play an important role in determining the final quality of the products. Protein, fat, carbohydrates and fibre are the major constituents of seeds. There is a need for studying the functional properties such as water and oil absorption capacities which determines its utilization in developing convenience foods. Limited studies have been conducted to utilize seeds from vegetable and fruits sources for nutrient enhancement and value addition in product development. The tender jack fruit is utilized as vegetable in curries, the fruit is used in varieties of dishes, suitable to the pallet of residing population. The fruit is also adequately exploited for value addition in terms of chips, papads, pulp, preserves, concentrates and leather etc. at an industrial sector. As fairly large jack fruit is embedded with 200-300 seeds, are generally boiled or roasted for consumption at domestic sector. As seeds are perishable, left over ones are used as animal feed or wasted. Recently, the seeds are utilized for industrial purposes based on the composition. Conversely, the composition of seed has been investigated by several authors. Bobbio et al. (1978), Kumar et al. (1988), Rajarajeshwari and Jamuna (1999), Tananuwong et al. (2002) and Odeomelam (2005) to be a good source of carbohydrates, protein and energy. As seeds are bland with no untoward flavour, there is potential opportunity for utilizing the seed in the form of flour for value addition in the industrial sector. Hence, an investigation was undertaken to determine the physico- chemical properties of seed with specific objective of utilizing as a convenience food. The important results are critically discussed in the present section. The jack seed being seasonal and perishable, need proper processing protocol for its extended shelf life. Generally, seeds are utilized as boiled or baked and restricted to domestic usage. If jack seed needs to gain revenue, it is required to add value for commercial produce. Due to jack seed’s compositional benefit i.e., being rich in protein and carbohydrates it is pertinent to convert seed into flour to be used in several convenience foods. However, conversion to flour follow several steps such as lye peeling to remove spermoderm and to prevent flour becoming brown in colour and adequate drying and milling and obtaining desired particle size flour. The results of the present study revealed 67-50 per cent recovery of flour inclusive of handling losses. Tananuwong et al. (2002) documented much lower yield (36.40 %) of jack seed flour. Though lye peeling procedure followed was similar, the flour was passed through 70 micron mesh while, in the present study the flour was recovered in 105 micron mesh, thus the difference.
5.1
FUNCTIONAL PROPERTIES OF SEED FLOUR
The functional properties of food depend on its components such as protein, fat and carbohydrates and play an important role in sensory profile of the product. The results of water absorption of the flour in the present study (112.00ml/100g) was much lower than the value cited by Odeomelam,2005 (230.00 ml/100g), Rajarajeshwari and Jamuna; 1999 (210.00 ml/ 100g) and Tananuwong et al . (2002), (205 ml/100g). The noticeable differences observed may be due to variety and particle size of the flour, which are found varied in different studies. Nevertheless, it is interesting to note that, the water absorption property of melon seed flour was nearer (130.00 ml/100g) to jack fruit seed flour cited by Akubor (2004). However, the seed flour of tomato; 325 ml/100g (Carlson et al., 1981) and pumpkin; 340 per cent (Gaimi and Bekebain, 1992) registered much higher water absorption ratio, this may be due to differences in chemical composition of flours. The fat absorption is an important property in food product development because it imparts flavour and mouth feel to foods. The oil absorption capacity of jack seed flour in the present study registered lower value (126.90 ml/ 100g) than reported value of several authors (280 and 160 ml % according to Odeomelam, 2005 and Rajarajeshwari and Jamuna, 1999, respectively). However, Tananuwong et al.(2002) reported lower value (92.60 %) than the value of present investigation. The variation in observation may be attributed to processing, particle size and varietal differences of the jack seed flour.
The property of dispersibility determines the tendency of flour to move apart from the water molecules and reveals its hydrophobic action. The dispersibility of jack seed flour recorded 30 per cent, which was much lower than the documented values of Quality Protein Maize (71.00 %) and DMH-2 maize variety (68.70 %) as reported by Guria Punita (2006). The data on jack seed flour on the above parameter is not available. Viscosity is a property of flour to resist free flow tendency. It was observed that, the viscosity increased with increase in concentration of the jack seed flour as expected (Table 3). However, there were no reported studies for comparison in terms of the concentration or nature of flour.
5.2
CHEMICAL COMPOSITION OF SEED FLOUR
The composition analysis of jack seed flour reveals its importance as a source of protein (9.03 %), carbohydrates (70.26 %), crude fibre (2.25 %) and total mineral matter (2.01 %). However, the analysis of protein content of jack seed flour by Tananuwong et al. (2002) documented higher (11.17 % ) i.e., two per cent more than the value of present study. However, it is interesting to note that, Rajarajeshwari and Jamuna (1999) documented extraordinarily high (21.30 %) protein content in jack seed flour. On the contrarily Kumar et al. (1988) reported lower value of 6.75 per cent of protein in jack seed flour. These variations may be attributed to processing and varietal variations. Like jack seed, several fruit seeds have been explored for utilization in product development and nutrient composition of these seeds are investigated by several scientists. The protein content of melon seed documented 25- 36 per cent according to Lazos (1986), Oyenuga (1975) and Akubor (2004), values are higher than the jack seed flour. Similarly, cashew nut kernel flour recorded the protein content of 20-25 per cent by Amoo (2005) and Aremu (2006). The pumpkin seed flour documented 32.00 to 28.00 per cent of protein according to Gaimi and Bekebain (1992) and Lazos (1986). Conversely, Egusi seeds recorded 28.44 per cent of protein as reported by Akobundu; (1982). The above all values of protein from different seeds are nearly three times higher than the protein value observed in the jack seed. There are few seeds like mango seed which has documented much lower protein value (5.00 %) than jack seed flour as reported by Dingra and Kapoor (1984). These variations are obvious, as the seed is from different sources. However, the commonly used cereals in India viz., jowar (10.40 %), maize (11.40 %), rice (6.40%), ragi (7.30 %) and wheat (11-12 % ) documented slightly higher content compared to jack seed flour except rice and ragi according to Gopalan et al. (1989). On the similar line, the protein content of all the pulses was double than documented value of jack seed flour. The jack seed flour can be comfortably incorporated in cereal/pulse based products to enhance the nutritional quality. The analysis of fat content of jack seed flour by Bobbio et al . (1978); Kumar et al. (1988) and Tananuwong et al. (2002) documented the values of 0.5, 0.78 and 0.99 per cent of fat, respectively which are slightly lower than the value of present study. However it is interesting to note that Rajarajeshwari and Jamuna (1999) documented much higher (2.73 %) value than the others. The composition of other seed flour are known to vary from jack seed flour such as tomato seed in terms of fat content. Tomato seed documented 22.00 to 28.00 per cent according to Carlson et al. (1981) and George and Boskou (1975), the values are much higher than the jack seed flour. Conversely, the pumpkin seed flour recorded higher fat content (45.00 -47.00 %) as documented by Lazos (1986) and Gaimi and Bekebain (1992). The melon seed flour documented the fat content (53.80- 56.90 % ) much higher than rest of the fruit seed as reported by Gabriel (1999), Lazos (1986), Oyenuga (1975) and Akubor (2004). Similarly, the egusi seed flour documented the fat content, 52.00 per cent as reported by Akobundu (1982). Further, the Amoo (2005) and Aremu (2006) documented the fat content of cashew kernel flour as 42.80 and 52.00 per cent, respectively. The above values of f at from different seeds are much higher than the jack seed flour. The mango seed which has documented much lower fat content (7.00 %) than other fruit seed flours but higher than the jack seed flour (Dingra and Kapoor, 1984). In general, the fat content of cereals viz., ragi (1.30 %) and pulses viz., black gram dhal (1.40 %), green gram (1.30 %), moth bean and peas (1.10 %) documented the values which are on par with jack seed flour. However, the
higher fat per cent has been recorded by maize (3.60 %) and soybean (19.50 %) and lower values of fat documented by rice (0.40 %) and horse gram (0.50 %) than the jack seed flour. The crude fibre content of jack seed flour documented the value of 1.67 per cent as recorded by Tananuwong et al. (2002) was slightly lower (<1%) than the value of present study. It is observed that, Rajarajeshwari and Jamuna (1999) documented higher value of 5.69 per cent crude fibre in the jack seed flour. The other fruit seeds viz., tomato seed documented much higher crude fibre value of 18.30 to 21.40 as recorded by George and Boskou (1975) and Carlson et al. (1981). The pumpkin and melon seed flour documented the crude fibre content, ranging between 2.10 to 3.10 per cent and 2.40 to 3.10 per cent according to Lazos (1986) and Gaimi and Bekebain (1992) and Oyenuga (1975), Gabriel (1999) and Akubor (2004). Further, egusi seeds documented 2.70 per cent of crude fibre as recorded by Akobundu in the year, 1982. All the above values of crude fibre are on par with value of jack seed flour as recorded in the present study. The lower value of crude fibre recorded by cashew nut kernel flour ranged between 1.40 to 1.20 per cent according to Amoo (2005) and Aremu (2006). Conversely, the common cereal and millets viz., jowar (1.60 %), rice (0.20 %), wheat (1.20 %), bajra (1.20 %), maize (2.70 %) and ragi (3.60 %) recorded slightly lower values of crude fibre compared to jack seed flour except maize and ragi according to Gopalan et al. (1989). With respect to pulses, most of them viz., bengal gram (3.90 %), green gram (4.10 %), horse gram (5.30 %) and cowpea (3.80 %) recorded higher crude fibre content except black gram dhal (0.90 %), lentil (0.70 %) and red gram dhal (1.50 %) compared to jack seed flour. The composition analysis of total mineral matter of jack seed flour documented the value of 3.92 per cent by Tananuwong et al. (2002) which is slightly higher than the value presented in the study. Whereas, Rajarajeshwari and Jamuna (1999) documented the value of 2.00 per cent and Kumar et al. (1988) recorded the value of 1.27 per cent which are lower than the value of present study. The other fruit seeds which are explored for their utilization viz., tomato seed flour recorded much higher total mineral matter value ranged between 5.40 to 3.85 per cent as recorded by George and Boskou (1975) and Carlson (1981). Further, the pumpkin seed flour documented the total mineral matter values of 4.70 to 4.65 per cent according to Gaimi and Bekebain (1999) and Lazos (1986). The melon seed flour recorded slightly higher (i.e., 1%) values of total mineral matter ranged between 2.40 to 4.20 per cent recorded by Gabriel (1999), Lazos (1986) and Oyenuga (1975) than the jack seed flour. The cashew nut kernel flour documentd 2.80 to 4.40 per cent of total mineral matter as per the values of Amoo (2005) and Aremu (2006). The commonly used cereals and millets viz., jowar (1.60%), maize (1.50%), ragi (2.70%), wheat (1.50%) and pulses viz., black gram dhal (3.20%), cowpea (3.10), green gram (3.50%), Bengal gram (3.00%) recorded the values which are on par with jack seed flour except jowar, maize and wheat. The total carbohydrate content of jack seed flour recorded by Tananuwong et al. (2002) documented 12 per cent higher value (82.25) than the value in the present study. Further, Rajarajeshwari and Jamuna (1999) documented six per cent lower value (63.85) than the value in this study. It is interesting to note that, Kumar et al. (1988) and Bobbio et al. (1978) documented much lower values which ranged between 28.01 to 25.10 per cent of total carbohydrates than the value presented in this study, these difference may be due to the procedure applied for the isolation of starch or varietal differences or maturation of seeds. Other fruit seeds which are documented much lower values of total carbohydrate content viz., pumpkin seed flour which recorded 5.55 to 12.90 per cent as per the values documented by Lazos (1986) and Gaimi and Bekebain (1992). The melon seed flour also documented much lower per cent of carbohydrates which ranged between 2.80 to 17.75 according to Akubor (2004), Gabriel (1999), Lazos (1986) and Oyenuga (1975). The cashew nut kernel flour recorded much higher value of carbohydrate than the above seed flours and at the same time recorded much lower value ranged between 24.10 to 26.80 per cent according to Amoo (2005) and Aremu (2006) than the value of jack seed flour in the present study. Conversely, the commonly used cereals and millets viz., jowar (72.60%) and rice (79.00%), bajra (67.50%), maize (66.20%), wheat (71.20%) and ragi (72.00%) recorded slightly higher values of carbohydrate compared to jack seed flour except maize and bajra.
The pulses viz., black gram dhal (59.60%), Bengal gram (60.90%), green gram (56.70%) and peas (56.50%) recorded lower values of carbohydrate than the value of jack seed flour in the present study according to Gopalan et al. (1989).
5.3
SHELF-LIFE OF FLOUR
The jack seed flour was packed in polyethylene pouches and stored at ambient and refrigerated temperature. The jack seed flour was stored without deterioration for the period of six months with no untoward changes in sensory and apparent visible changes. However, there was a gradual increase in moisture level over the period of extended life, higher increase in the samples stored at ambient temperature (Fig. 3 and Appendix III). Similar study conducted on jowar flour at ambient temperature (Reddy Madhavi, 2001) revealed that sorghum flour could be stored only for 28 days, further lost its functional qualities for making rotis. The extended life of jack seed flour beyond the period of six months (the sample was good from sensory point of view even after 10 months of storage) may be due to its lower fat value (1.10%) compared to sorghum flour (1.90%). However, there were no studies available on seed flour with respect to storage.
5.4 UTILIZATION FOODS
OF
SEED
FLOUR
IN
CONVENIENCE
The bakery products such as biscuits and bread have become very popular in India in all socio-economic section of population. Thus for potential and economic exploitation, jack seed flour in biscuit preparation is more practical and hence an effort was made to blend wheat flour with jack seed flour. The preliminary product development studies indicated use of non-gluten flour in biscuit beyond 50 per cent was not acceptable though lower level of gluten protein is adequate for acceptable biscuit texture profile. However, Table 15 indicates that, gluten level of 75 per cent jack seed flour has gluten content of only 2.60 per cent which is inadequate. Conversely, an attempt was made to blend 10-50 per cent jack seed flour for biscuit preparation on wheat flour replacement basis. The Table 6 reveals a very interesting and noticeable trend with respect to total protein, fibre and gluten proteins, there was reduction of total protein and gluten protein with in vary non-gluten flour with wheat flour conversely increase in proportion in minerals and fibre. The physico-chemical properties of biscuits prepared from blend flour revealed a decrease in weight, thickness and diameter of biscuits with increase in replacement of jack seed flour, more pronounced with 50 per cent blend flour. Similar observations have been made with the biscuits prepared with millet flour and sesame seed flour (Alobo, 2000). Similarly, the sensory quality scores biscuit flax with seed flour incorporated with wheat flour decreased with increase in the substitution of flax seed flour according to Hussain et al. (1999) as that of jack seed flour incorporated biscuits. Another important bakery product, bread fortified with tomato seed meal revealed a slight increase in loaf weight after baking due to the enhanced absorption of water. The crust and crumb of the breads fortified with 5 per cent tomato seed meal were golden and at higher levels of supplementation breads were darker and the taste scores decreased as the level of tomato seed meal increased according to Yaseen et al. (1991). The diverse combinations of texture and taste have made biscuits an universal appeal and gain unique status. Thus, but it is natural for any food scientist to attempt and appreciate the utilization of jack seed flour in making biscuits. The bland flour of jack seed and wheat upto 50 per cent did not make any significant difference between each other with respect to colour and appearance when evaluated by sensory profile. However, the ‘l’ value recorded by colour meter revealed a significantly different picture. The control biscuits were significantly whiter than the rest and biscuits upto 30 per cent jack seed flour replacement made very little difference. While, biscuits with 40 and 50 per cent seed flour incorporated biscuits were significantly darker than the rest. As the judges were partially trained minute difference was not identified between the samples. Further, ‘l’ values varied with respect to top and bottom sides of the biscuits. The ‘l’ values were significantly higher in top side than
Table 11. Computation of composition in different levels of incorporation of jack seed flour with refined wheat flour
Variables
Protein
Fat
Minerals
Crude fibre
Carbohydrates
Energy K.Cal.
Gluten
Control
11.62
41.70
0.76
0.30
81.15
746.00
10.40
J-10%
11.42
41.72
1.00
0.52
80.78
749.00
9.36
J-20%
11.26
41.82
1.25
0.75
80.48
753.00
8.32
J-30%
11.20
42.00
1.52
0.97
80.23
758.00
7.28
J-40%
11.13
42.18
1.80
1.20
79.99
763.00
6.24
J-50%
10.99
42.28
2.05
1.42
79.69
767.00
5.20
the bottom surface of the biscuits. This change is due to higher temperature perforated in the bottom side of the biscuits. Similar trend w as seen in ‘b’ and ‘a’ values. Though acceptable, the texture values varied between control and upto 50 per cent replacement in biscuits with jack seed flour. The texture was similar to control upto 20 per cent seed flour replaced biscuits. While rest of the biscuits were harder than the rest. But these observations are obvious (Table 11) because the protein and gluten content decreased with higher replacement of non-glutenous flour such as jack seed flour. The gluten content upto 8 per cent seemed adequate for good texture of biscuits, further decrease made biscuits harder. The flavour characteristics of biscuits viz., taste and aroma recorded similar picture. Both sensory parameters did not make difference upto 20 per cent of seed flour incorporation. This is particularly true with flour such as jack seed flour is bland with insipid. It was interesting to notice that upto 40 per cent incorporation of jack seed flour, the overall acceptability did not make negative impact and hence 40 per cent incorporation was considered for consumer trial. The adolescent girls in consumer trial liked the biscuits considering the product being very good. Based on the above observations, it can be concluded that jack seed flour can be a good substitute upto 40 per cent in salt and sweet biscuits and can comfortably enter commercial bakery sector. The seed being perishable can be converted into flour and used potentially in bakery industry. However, following indepth studies are required for optimum utilization. 1.
Pasting behaviour of jack seed flour at different level of incorporation
2.
Utilization in non-bakery industry
3.
Out reach activities for popularizing the utilization of jack seed flour at household level.
6. SUMMARY An investigation pertaining to the nutritional quality and value addition to jack fruit seed was undertaken during 2006-07 with the objectives to document the physical and functional properties, proximate composition, nutritional quality, shelf-life and utilization of seed flour in convenience food. Jack fruit seeds were procured from the markets of Dharwad and North Canara districts during the season. White arils of the seeds were removed manually and further lye peeled to remove the Gawn spermoderm. Seeds were dried and milled into flour. The functional properties viz., water and oil absorption capacity, flour dispersibility, swelling power and per cent solubility of the jack seed flour were documented using standard procedures. The proximate composition of the seed flour were analysed by standard AOAC methods. The nutritional quality of seed flour was assessed in terms of starch and protein digestibility. The seed flour was packed in food grade polyethylene cover, heat sealed and stored both at ambient temperature and refrigerated conditions for six months. The moisture content and sensory quality of the stored seed sample was assessed using standard procedure and descriptive method. The seed flour was utilized in the preparation of convenience food viz., non-katai biscuits at different proportions to ascertain the acceptable level of incorporation by sensory parameters. The physical parameters viz., diameter, thickness and spread ratio were assessed using Vernier calipers. The colour (top and bottom) of biscuits was assessed using Minolta color meter. The maximum accepted proportion of jack seed flour based biscuit was considered for the consumer acceptability analysis. The salient points of the study are summerised below. •
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The total yield of the flour exclusive of weight of the white arils (2%), brown spermoderm (8.16%), handling losses represented 13.34 per cent and when passed through 105 m mesh flour yield was documented as 67.50 grams. The functional properties of jack seed flour had 112.00 ml/100 g of water absorption and 126.90 ml/100 g of oil absorption capacity with 30 per cent of flour dispersibility. The swelling power of the seed flour documented higher value (3.62 g/g) than the per cent solubility (1.80%). The cooked paste viscosity of 5 per cent jack seed flour recorded lower value (27.10%) compared to 10 per cent paste (51.4%) at ambient temperature (25°C). Similar observations were also noticed at hot temperature (90°C). The analysed value for proximate composition of seed flour were as follows 14.07 of moisture, 9.03 protein, 1.10 of fat, 2.25 of crude fibre, 3.01 of total mineral matter and 70.26 of carbohydrates. The calorific value of seed flour was less in computed value (327 k.cal) compared to analysed energy value (376 K.cal). The protein
in vitro digestibility
of seed flour recorded 78.17 per cent.
The starch in vitro digestibility of seed flour was higher (69.30%) at 60 minutes of withdrawal of sample compared to 30 minutes of digestion (57.28%). The seed flour packed in polyethylene pouches were able to store upto six months. There was an increase in the moisture content during the storage period both at ambient and refrigerated conditions. There was no visible change in sensory profile of the flour during the storage period both at ambient and refrigerated conditions. The sensory quality of jack seed flour based biscuits decreased with increase in incorporation level of seed flour. The incorporation above 50 per cent in biscuits was not acceptable by sensory quality parameters as assessed by panel of judges.
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The dough forming properties such as absorption of curds by control dough was lower (20 ml) compared to all other seed flour incorporated biscuits whereas 50% seed flour based dough absorbed (32 ml) higher of quality cards. There was a visible trend observed that an increase in fresh weight of dough with increase in the proportion of jack seed. The biscuits with varied proportion of jack seed flour exhibited similar trend of increase in weight with increase in jack seed flour in the product. The 20 per cent seed flour incorporated biscuits were on par with control with respect to sensory qualities. The 50 per cent seed flour based biscuits scored lowest values for all the quality parameters. The overall acceptability of biscuits with jack seed flour below 50 were judged as very good. The diameter of biscuits gradually increased with increase in the proportion of seed flour. It is observed that, 50 per cent seed flour based biscuits scored highest diameter (4.21 cm) whereas control biscuits recorded the diameter, 4.13 cm. The thickness of 10 per cent seed flour based biscuits was higher (1.04 cm) than the control (1.03 cm) biscuits. The lowest thickness (0.81 cm) was documented by 50 per cent seed flour based biscuits. The spread ratio of the biscuits gradually increased as the seed flour incorporation level increases. The 10 per cent seed flour based biscuits documented (3.90 cm) lower spread ratio and 50 per cent seed flour based biscuits scored higher (5.19 cm) value of spread ratio. The colour of the biscuits with respect to ‘l’, ‘a’ and ‘b’ values, the control biscuits were significantly whiter than the rest and biscuits upto 30 per cent jack seed flour replacement made very little difference. The ‘l’ values were significantly higher in top side than the bottom side of the biscuits. The adolescent girls in consumer trial liked the biscuits considering the product being very good.
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Appendix I. Score card for evaluation of value added products Name of the Product: Name of the Judge: Date: 1
2
3
4
5
COLOUR AND APPERANCE Excellent Extremely good Very good Moderately Good Good Fair Very fair Poor Very Poor TEXTURE / CONSISTENCY Excellent Extremely good Very good Moderately Good Good Fair Very fair Poor Very Poor TASTE Excellent Extremely good Very good Moderately Good Good Fair Very fair Poor Very Poor AROMA Excellent Extremely good Very good Moderately Good Good Fair Very fair Poor Very Poor OVER ALL ACCEPTABILITY Excellent Extremely good Very good Moderately Good Good Fair Very fair Poor Very Poor
Remarks :
Signature
Appendix II. Yield of jack seed flour Parameters Weight of fresh jack seeds No. of jackseeds in 100 g Weight after removal of white arils Weight after removal of brown spermoderm Weight of jack seed flour Crude flour Passed through 105 µ mesh
Grams 100.00 21.00 98.00 90.00
% of reduction 2.00 8.16
78.00 67.50
13.34 13.46
Appendix III. Moisture content (%) of stored jack seed flour Moisture (%) Storage temperature
Stored in Aluminium
Storage period (months) 0
1
2
3
4
5
6
7.16
8.04
8.13
8.41
8.78
9.64
11.03
7.16
7.31**
7.55**
7.63**
7.81**
8.03**
8.39**
box at ambient condition (24-26°C) Refrigerated condition (8-10°C) Filled in polyethylene pouches, heat sealed. Average of three replications. ** The values are significantly different at 1% point of distribution of F.
• •
Appendix IV. Sensory scores of jack seed flour based biscuits (initial t rials)
Particulars Control Incorporation levels (%) 25 50 75 100 • • •
Colour and appearance 7.66 8.00 7.33 7.00 7.00
Sensory parameters Texture Taste Aroma 7.00
7.00a
7.00a
Overall acceptability 7.33a
6.33 7.00 5.66 5.00
6.66a 4.66ab 3.00bc 1.66cd
6.66a 5.33a 2.33b 1.66b
6.33ab 4.66bc 2.66cd 1.66d
9 point Hedonic scale. In duplicates. Identical alphabets denote non-significant differences between means (P < 0.05).
Appendix V. Sensory profile of jack seed flour based biscuits Sensory parameters Particulars
Colour and appearance
Texture
Taste
Aroma
Overall acceptability
7.14
6.71a
6.71a
7.14a
6.28ab
10
6.57
6.71a
6.71a
7.00a
6.42ab
20
7.00
6.42ab
6.14a
6.28ab
5.71ab
30
6.57
5.00bc
5.14ab
5.00bc
5.23ab
40
6.57
4.71cd
4.14b
4.14c
4.78abc
50
5.85
3.85cd
3.85b
3.85c
3.28c
Control Incorporation levels (%)
• • •
9 point Hedonic scale. In duplicates. Identical alphabets denote non-significant differences between means (P < 0.05).
