FST254
EXPERIEMENT 7: EFFECT OF SLICING THICKNESS TO THE DRYING RATE RATE AND SENSORY ATTRIBU ATTRIBUTES TES OF POTATO POTATO CRACKERS CRAC KERS
NO 1. 2. #. 4. 5. !.
NAME ASMAA’ SYUHADA BT AMINUDDIN AFINA RAHMANI BT RA"ALI NIK ELFIKA BT NIK POH $ NIK A"MI NUR NADIA NAFISAH BT ADAM MALICK NUR NUR SYAH SYAHIR IRAH AH BT ABDUL MALEK LEK ABDUL ABDU L FATAH ATAH HAKIMIN HAKIM IN B BAHARUDDIN
GROUP: AS11! 4B1 DATE EXPERIMENT: 20&02&2017 DATE SUBMISSION: 0#&0#&2017 LECTURER NAME: NADYA BT HA'AR
MATRIC ID 2015!7272 20152#2772 2015!!7!2 20157%5! 2015 5%! ! 2014414#14
INTRODUCTION
Potato crisps are popular products commonly consumed as a snack Worldwide. Worldwide consumption of potato and potato products has been increasing in the last few decades. Potato crisps can be defined as thin potato slices that are dehydrated by deep-fat frying to a moisture content of ≥2%. Crisps can also be defined as thin slices of peeled and washed potato tubers, deep -fried until crunchy and to which edible salt, whether powder or brine, or permitted food grade spices, colour and flaour may be added. !rying of potato products is often selected as a method for creating uni"ue flaours, colours and te#tures in processed foods and is intended to improe oerall palatability. !ood drying or food dehydration is a method of remoing water from food. $he main reasons for dehydrating food are to presere food to decrease the weight and bulk or to make conenience products. rying is one of the most widely used methods of preseration, in which water is remoed from the food to the leel at which microbial spoilage and deterioration reactions are greatly minimi&ed. $his proides longer shelf life and lighter weight for storage. 'se of a cabinet dryer is an alternatie drying method that both decreases the drying time and improes the "uality of the final product. $he process of food drying inoles simultaneous heat and mass transfer. $he drying conditions affect the rate of heat and mass transfer and the dried food "uality. (umidity, temperature, air elocity and pressure are the main enironmental factors that influence drying rates and final product moisture. )ormally, lower humidity, higher temperature and higher air elocity increases the drying rate. !ood properties also affect the drying rate and dried product "uality. $hese properties include the product si&e, solute concentrations, initial water content, cellular structure, surface hardening, thermo-plasticity, porosity, and any chemical changes that during drying. *eeral physical and chemical changes can occur during food drying. *urface hardening can happen during baking or drying. $he high surface temperatures cause the outer layers to dry "uickly and form a hard skin layer, which seerely decreases the drying rate. OBJECTIVES
1. To learn the processing method for production of potato crackers. 2. To study the eect of slicing thickness to dehydration rate and texture after frying.
INGREDIENTS
Fish 1kg, potatoes 1kg, tapioca our 1kg, salt 40g, sugar 40g and ater !actual amount of ater used is "ased on the smoothness of the dough# PROCEDURE
1. $ll ingredients as prepared or eighted. 2. The skin of the potatoes as ashed. The potatoes ere "oiled for a"out 1% minutes, the skin mashed as remo&ed. '. Fish meat, tapioca our, salt, sugar and potatoes ere minced in a "ol chopper ere mixed ell. (ater as added sloly during mixing to form smooth dough. 4. The dough as put in roll ith plastics )lm to form cylindrical shape. *t as steamed for 1 hour until all the starch had "een completely gelatinised. *t as lea&ed to cool at room temperature. %. The dough as keeping in refrigerator o&ernight for easy slicing. The dough as sliced using slicing machines at dierent thickness !0.%, 1.0 and 2.0 mm#. +. The crackers ere arranged on a drying tray and then it as placed in the ca"inet dryer set at 40o o&ernight for three days.
RESULTS
-oisture content !# / (eight loss
x 100
*nitial eight inear expansion / iameter after frying iameter "efore frying
T()*+ 7.1: -oisture content of potato crackers !ay 1#
licing thickness
(eight !g# *nitial
$fter drying
(eight oss
-oisture content !#
!mm# 0.%
1.3
0.+%
1.'2
+.00
1.0 2.0
2.%3 1.%4
1.0+ 1.%0
1.%' 0.04
%3.0 2.+0
T()*+ 7.2: -oisture content of potato crackers !ay 2#
licing thickness
(eight !g# *nitial
$fter drying
(eight oss
-oisture content !#
!mm# 0.%
1.3
0.+4
1.''
+.%1
1.0 2.0
2.%3 1.%4
0.31 1.1
1.+5 0.'
+4.5+ 24.0'
T()*+ 7.#: -oisture content of potato crackers !ay '#
licing
(eight !g#
-oisture content !#
thickness
*nitial
!mm# 0.% 1.0 2.0
$fter
1.3
drying 0.%+
2.%3 1.%4
0.54 1.0
(eight oss 1.41
1.%
1.% 0.4
+.% '0.%2
T()*+ 7.4: inear expansion of potato crackers
licing
iameter !mm#
thickness
inear expansion
6efore frying
$fter frying
!mm# 0.%
20.0
40.0
2.00
1.0 2.0
20.0 24.0
''.0 '0.0
1.+% 1.2%
T()*+ 7.5: ensory e&aluation of potato crackers
licing thickness !mm#
rispiness
0.% 1.0
8ery crispy -oderate
2.0
crispy ess crispy
ensory attri"utes Taste
7&erall
9ot salty alty
accepta"ility -ost accepted -oderate
alty
accepted $ccepted
3oisture content s ays of drying 1 0 / ./ mm
3oisture content 4%5
+. mm
2. mm
2 +
+
2
ays of drying
DISCUSSION:
From the experiment, the processing method for production of potato crackers rate and the slicing thickness to the dehydration rate and texture after frying is determined. *n potato crackers making process, tapioca our is mixed ith )sh and other ingredients and then kneaded to o"tain dough. The dough is formed to a cylindrical shape and then cooked "y "oiling or steaming. The cooked dough is cooled and cut to certain thickness hich is 0.% mm, 1.0 mm and 2.0 mm of potato crackers and then dried in ca"inet dryer. The dried cracker o"tained is then fried in hot cooking oil to measure the linear expansion. -oisture content is de)ned as the percentage of ater in a product. -oisture in some form and amount is found in almost e&erything and can ha&e dierent eects on dierent products. :ence the moisture content measured in 0.% mm, 1.0 mm and 2.0mm are 1.% , +.% , and '0.%2 respecti&ely. From the graph constructed, the moisture content is slightly decreases from 0.% mm to 2.0 mm and increased "ack to '0.%2 of moisture content in 2.0 mm of potato cracker slicing thickness. -eanhile, through the result o"tained the moisture content decreases as the thickness of potato crackers increases. -eanhile, the drying rate of potato crackers "ecome shorter as the thickness of potato crackers is larger. This is "ecause product
structure and composition also play an important role in relationship "eteen cracker thickness and drying rate. inear expansion is the increase of a planar dimension, measured "y the linear elongation of a sample hich is exposed to to gi&en temperatures hich is "efore frying and after frying. inear expansion of )sh crackers is aected "y many factors such as frying time, oil temperature moisture content and etc. From the result o"tained, linear expansion of 0.% mm, 1.0 mm and 2.0 mm is 2.00, 1.+% and 1.2% respecti&ely. From the result, it can conclude that the higher the linear expansion, the smaller the thickness of potato crackers. This is "ecause; air cell is formed during frying that lead to expansion. (hen cracker contacts the hot oil, the moisture is e&aporated and forms pores in the cracker that ill increases the linear expansion of the crackers. $t the end of experiment, sensory e&aluation of potato crackers is determined as it is important in order to determine the accepta"ility of the customers. The sensory e&aluation that in&ol&ed is including the crispiness and also the taste "efore comment on o&erall accepta"ility can "e made. Through the result, 0.% mm of potato crackers sho that the crispiness is lighter and &ery crispy, hile the taste e&aluation shoing that the taste as not too salty. astly, the o&erall accepta"ility shoing that it is the most accepted. (hile the crispiness, taste, and o&erall accepta"ility of 1.0 mm potato crackers thickness is moderate crispy, salty and can "e moderate accepted respecti&ely. -ost of the e&aluator e&aluate that 1.0 mm slicing thickness is most suita"le than other thickness. racker crispiness, taste and o&erall accepta"ility is also aected "y some factors that occur during frying, and also the ra material used. Through the experiment, there are some source error that may aect the accuracy of the result and also the sensory e&aluation of potato crackers. For example, the eight of tapioca our, salt and )sh is not measured correctly, the dough also not exactly steamed according to the time gi&en as the longer the time that it supposed to "e. $ll of this error may aect the sensory e&aluation of potato crackers especially the taste. ertain thickness of the potato crackers is also not constant as it depends on the e
*n conclusion, the larger the thickness of potato crackers, the loer the moisture content and the shorter the drying rate. Thus, the hypothesis is accepted. REFERENCES
1. >. impai"oon. !2011#. ?ects of Temperature and lice Thickness on rying >inetics of @umpkin lices 2. $ishah,(.!200#.@rinciples of Food @reser&ations @ractical -anual in Food Technology. Ani&ersiti Teknologi -ara. '. . httpsBCCpdfs.semanticscholar.orgC230C5''%'22e3a'ed054f23+aaf "44+"4f'04%.pdf . 6an 7rsdel, W.8 !ood ehydration, 6ol. +. 769. Westport. C$. +:0 /. 7guilera, ;. 4215 !ood 3aterails *cience principles and practice )ew
