SUMMARY
Yogurt ogurt is a food product product that that are made made up by fermentin fermenting g the milk milk with other other various various ingredients in order to get the right texture, color, flavor and creaminess. Apart of being known and existed for quite amount of time, it is only being popular and widely taken starting from 30 !0 years back, due to the improvisation made towards the yogurt in terms of flavor, fruits flavor is introduced into the market and yogurt are known as one of the healthy low fat products. "ecause of that particular reason, the manufacturers are taking this opportunity to widen the market by introducing more unique flavors and various type of yogurt meeting the growing demands of the consumers themselves. #ven for those that are known to be lactose intolerant can consume this, this is because the milk once it turns to be a yogurt, it became generally aldehydic flavor and free from lactic acid due to the fermentation process. $here are a few parameters that needed to be cover in order to consider this experiment is successful or not which is p% of each type of the yogurt, p% is a numeric scale that are widely used and known to identify the acidity and the alkalinity of the product. $he process of making the yogurt is not that complicated, generally they contain milk, sugar, a starter culture to help the fermentation process, &antham gum to increase the viscosity of the yogurt itself, plain water and a bit of flavor that could be from fruits, chocolates and other flavors that could be envision. $he composition of the milk must be modified by adding the concentrated milk, milk powder and evaporate some of the water in order to increase the amount of solid content and fat content is reduced and minimi'ed. $he procedure for making a plain yogurt is ( liter of )%$ milk been added with (00 g of powder milk and the mixture mixture been heated until *0+.After *0+.After that the mixture mixture achieve achieve *0+, the mixture been bottle inside glass bottle and cooled until it reached !-+ to -0+. lightly after the mixture cool, -ml of culture / Lactobacillus Vulgaricus Vulgaricus been added into the mixture. 1ext the mixture was been shake until the mixture homogeni'ed homogeni'ed with culture then incubated at !3+2 (+ for at least hours. 4astly the mixture been coagulated, the mixture been transfer into chiller which the temperature was -+ for cooling down.$he result for this pro5ect is the yogurt A contain only plain yogurt with -.36 p% value and (78 brix content that was calculated using refractometer. $he taste of yogurt a little bit sour and not sweet at all. Yogurt " was added with -0 gram of grape cordial. $he taste of yogurt " was changed from scale ( to 3 as it is too sweet. $he total soluble sugar inside cordial makes brix content of yogurt " increased to !08 and p% value was decreased into !.69. $hen, in yogurt , -00 gram of water, (00 gram of sugar and -0 gram of ice
were added and blending all together. $he brix content is then calculated and it increasing by (08 from yogurt " into -08 as well as p% value also increased by 0.!. $aste of yogurt is kind of sweet and sour blending. :or fourth formulation, formulation, yogurt ; was added with -0 grams of xantham gum dissolved in 700 ml water. p% value and brix content of yogurt ; was decrease by -8.$here is few error which which is human error for a brix brix reading because some of the yogurt is too high and to low so it is quite difficult difficult to read the blue line in a brix equipment. $hen the student have put a little bit more plain yogurt during process so it cause the yogurt is too stench. o it is highly recommended to follow the lab manual accurately and do not add on without technician permission. 1ext for brix reading do swipe a little onto it to test wheter this type of brix is suitable or not for reading.
INTRODUCTION
Yogurt is a food product that are made up by fermenting the milk with other various ingredients in order to get the right texture, color, flavor and creaminess. ;espite of that, yogurt origins was an accident that happened thousand years ago in
t is usually the measure of the molar concentration of the hydrogen ions in the solution, which suits the name itself that are stands for power of %ydrogen /p%. $he higher the concentration of the hydrogen ion, it is more alkaline and the lower the hydrogen ion, the more acidic the product. Apart from the p%, the other parameter is the "rix percentage, "rix is the percentage of the sugar content inside an aqueous solution. >t is usually tested in a sugar, carbonated beverages, fruit 5uices, honey and even wine, this is important as these products usually high content of sugar which could be very dangerous to the health of the consumers that did not know. >t is widely used in the food industries especially the brewing industry. 4ast but not least, the tasting panels which is very crucial in all of the food productions, in which the product will not get any reviews if it does not taste good. o, the usual taste panels used are the hedonic scale as the consumers have various preferences on how their food should taste and such.
$he process of making the yogurt is not that complicated, generally they contain milk, sugar, a starter culture to help the fermentation process, xantham gum to increase the viscosity of the yogurt itself, plain water and a bit of flavor that could be from fruits, chocolates and other flavors that could be envision. $he composition of the milk must be modified by adding the concentrated milk, milk powder and evaporate some of the water in order to increase the amount of soli solid d conte content nt and and fat fat cont conten entt is redu reduced ced and and minim minimi' i'ed ed.. $he $he modi modifi fied ed milk milk was was then then pasteuri'ed beforehand to produce a delightful yogurt, and also to denature the whey protein that is present inside the milk in order to associate with the casein which will contributes to the gel network as when the casein precipitate, the whey protein will tag along thus strengthening the gel network and providing the texture for the yogurt afterwards. Also, during the heating process the milk will be homogeni'ed where the fat globules will break down into smaller fractions resulting smoother and creamier yogurt. After it is cooled to touch, the starter culture is added into to the pasteuri'ed milk in abo ut 7 8 to the amount of milk. >t was then placed into an incubator incubator for a few days, which will give the bacteria some time to metaboli'es each compound in the milk which will produce the characteristic flavor of the yogurt itself which will have lactic acid as the byproduct. After it reaches a certain level of acidity it is kept inside the refrigerator to cool it down, which explains the common sour taste inside the plain yogurt. After it is refrigerated, it is improvised to add some flavor to the plain yogurt, also some color to make it more attractive. >t was done in such a way of stated in table 7, each of the yogurt are tasted and then tested for the p% and the brix percentage and recorded.
PROCEDURE
Table 1: $he ingredient used to make plain yogurt. NO. 1 2 3
INGREDIENT
AMOUNT ( liter (00 gram - ml
4ow :atmilk ?owder milk ulture / Lactobacillus / Lactobacillus Vulgaricus Vulgaricus
STEP a) (. 7. 3.
Procedu Procedure re or or !a"#$% !a"#$% &'e (la#$ (la#$ o%ur& o%ur& $he ( liter liter of )%$ milk been added added with with (00 g of powder powder milk. milk. $he mixtur mixturee been been heat heated ed unti untill *0+ *0+ After the the mixture mixture achieve achieve *0+, the the mixture mixture been bottle bottle inside inside glass glass bottle bottle and cooled cooled
until it reached !-+ to -0+ !. light lightly ly after after the the mixtur mixturee cool, cool, -ml of cultu culture re / Lactobacillus Lactobacillus Vulgaricus Vulgaricus been added into the mixture. -. $he mixture mixture was was been shake shake until until the mixtur mixturee homogeni'ed homogeni'ed with with culture. culture. . After been been shake, shake, the mixture mixture been incubate incubated d at !3+2 (+ (+ for at least least hours. hours. 6. After the the mixture mixture been coagulat coagulated, ed, the mixture mixture been been transfer transfer into into chiller chiller which which the temperature was -+ for cooling down.
Table 2: $he ingredient of the yogurt for the sensory evaluation of the yogurt
$ype
Yogurt A
Yogurt "
Yogurt
Yogurt ;
?lain yogurt I$%red#e$&
?lain yogurt
?lain yogurt
?lain yogurt
/-0g @ grape
/-0g @ grape
/-0g @ grape
cordial /-0g
cordial /-0g @
cordial /-0g @
water /-0g @
water /-0g @
sugar /(00g @
sugar /(00g @
ice /(0g
ice /(0g @ &antan gum /-0g
b) Procedure Procedure or &'e *e$*or *e$*or e+aluao$ e+aluao$ o &'e o%ur& /$he evaluation been done to (0 panelists and the questionnaire been attached at the
(. 7. 3. !.
appendix section $he yogur yogurtt A been taste taste for for ( spoon spoon.. $he yogurt yogurt " been been tast tastee for for ( spoon. spoon. All of the ingredi ingredient ent been been blended blended and been taste taste for for ( spoon. spoon. All of the ingredi ingredient ent been been mixed mixed and been been taste taste for for ( spoon. spoon.
RESU,TS
roup ( 7
p% -.36 !.69
"rix /8 (7 !0
$aste /((0 ( 3
omment
3 !
-.7-.06
-0 !-
! 3
DISCUSSIONS
Yogurt is produced by bacterial fermentation. )nlike cheese production, rennet is not used. >ngredients for yogurt are !00ml of low fat milk and !00g powdered milk that heated and stirred until temperature hit *0B. $he yogurt is then being put in the bottle and was left in cool temperature. After it cool, 7 spoons of culture media were add ed. $he thick consistency of yogurt is due to the decreased solubility of casein in the acid produced by the yogurt culture and by additional ingredients. tarch, pectin and gelatin are often added to commercial yogurt to give it a thick consistency. :or our yogurt, powdered milk is added to provide this thicker consistency. ugar is added to flavor the finished yogurt and to provide additional carbohydrate for the 4A". 4A" can ferment lactose /milk sugar and sucrose /table sugar. )nlike cheese, yogurt does not use the en'yme rennet to aid in gel formation. $he heat treatment of *-+ for 70 minutesC aids in the formation of a smooth gel /coagulum by denaturing whey proteins present in the milk. Dhey proteins are not present in high concentrations in milk /like casein nor are they sensitive to acid /like casein. Dhen sub5ected to moderately high temperatures, they denature, or unfold, which helps to trap water and forms a smooth coagulum. "uttermilk is heat treated for the same reasons. All yogurts requir requiree two bacter bacteria ia which which 4actobac 4actobacil illus lus ;elbru ;elbrueck eckii ii p. Eulga Eulgaric ricusa usand nd strept streptococ ococcus cus thermophilus. $hese two 4A" together produce acid and typical yogurt flavor. $hese two 4A" isthermophilic, which is why the fermentation temperature for yogurt is much higher than the temperature used for cheese or buttermilk. =ther bacteria are often added to yogurt for health reasons, particularly in the last few years. $hese bacteria are called probiotic bacteria, and they aid in digestion and intestinal health /but play no role in the production of yogurt. $he two
bacteria most commonly used for this purpose are 4actobacillus acidophilus and "ifidobacterium 4ongum. n this case, a few teaspoonful of the storebought yogurt will adequately act as the starter culture. 4ater, the yogurt was divided using four formulations with labeled A, ", and ; were tested the p% value and percentage brix of sugar. Yogurt A contain only plain yogurt with -.36 p% value and (78 brix content that was calculated using refractometer. $he taste of yogurt a
little bit sour and not sweet at all. Yogurt Yogurt " was added with -0 gram of grape cordial. $he taste of yogurt " was changed from scale ( to 3 as it is too sweet. $he total soluble sugar inside cordial makes brix content of yogurt " increased to !08 and p% value was decreased into !.69. $hen, in yogurt , -00 gram of water, (00 gram of sugar and -0 gram of ice were added and blending all together. $he brix content is then calculated and it increasing by (08 from yogurt " into -08 as well as p% value also increased by 0.!. $aste of yogurt is kind of sweet and sour blending. :or fourth formulation, yogurt ; was added with -0 grams of xantham gum dissolved in 700 ml water. p% value and brix content of yogurt ; was decreased by -8. "ased on the results obtained, the taste was better but the texture of yogurt was thickened as xantham gum increased the value of viscosity and decreased syneresis sample. Hesults of the experiment experiment on p% and percentage of sugar of yogurt sample sample showed that samples had a normal normal decrease in value during storage. $he decrease of p% was due to the formation of lactic acid by certai certain n bacteri bacteriaa of yogurt yogurt.. &anthan &anthan gum used used as thicken thickening ing agent agent to control control syneresis syneresis of fermented milk.
CONC,USIONS
$he yogurt was divided using four formulations with labeled A, ", and ; were tested the p% value and percentage brix b rix of sugar. Yogurt Yogurt A contain only plain yogurt with -.36 p% value and (78 brix content that was calculated using refractometer. $he taste of yogurt a little bit sour and not sweet at all. Yogurt " was added with -0 gram of grape cordial. $he taste of yogurt " was changed from scale ( to 3 as it is too sweet. $he total soluble sugar inside cordial makes brix
content of yogurt " increased to !08 and p% value was decreased into !.69. $hen, in yogurt , -00 gram of water, (00 gram of sugar and -0 gram of ice were added and blending all together. $he brix content is then calculated and it increasing by (08 from yogurt " into -08 as well as p% value also increased by 0.!. $aste $aste of yogurt is kind of sweet and sour blending. :or fourth formulation, yogurt ; was added with -0 grams of xantham gum dissolved in 700 ml water. p% value and brix content of yogurt ; was decreased by -8. $o be conclude that based on the results obtained, the taste was better but the texture of yogurt was thickened as xantham gum increased the value of viscosity and decreased syneresis sample. Hesults of the experiment on p% and percentage of sugar of yogurt sample showed that samples had a normal decrease in value during storage. $he decrease of p% was due to the formation of lactic acid by certain bacteria of yogurt. &anthan gum used as thickening agent to control syneresis of fermented milk. $here is few error which is human error for a brix reading because some of the yogurt is too high and to low so it is quite difficult difficult to read the blue line in a refractometer refractometer equipment. equipment. $hen the student have put a little bit more plain yogurt during process so it cause the yogurt is too stench. o it is highly recommended to follow the lab manual accurately and do not add on without technician permission. 1ext for brix reading do swipe swipe a little onto it to test whether this type of refractometer is is suitable or not for a reading.
RE-ERENCE
(. $amime $amime,, A.Y A.Y.I Hobisons, Hobisons, H.J. /7006 /7006 hapter hapter ( %istorical %istorical backgrou background. nd. >n Tamime and Robinson’s Robinson’s Yogurt: Yogurt: Science and Technology Technology,, 3rd 3rd ed. Doodhe odhead ad ?ubl ?ublis ishi hing ng 4$;K ambridge, )J. pp. (L(0. 7. %elferich, %elferich, D. and ;. Desthoff esthoff./(990 ./(990 Yogurt: All About It.
3. %ui, %ui, Y.%. /(997 /(997 Dairy Science and Technology Technology Handboo. 1ew Handboo. 1ew YorkK YorkK Diley Diley E%. !. Hobins Hobinson, on, H.J. H.J. /(990 /(990 Mnack Mnack :oods :oods of ;airy ;airy =rigin. =rigin.MM >n Snac !ood. #dited by ordon H. "ooth. 1ew YorkK YorkK Ean Ean 1ostrand Heinhold. pp. (-9(*7. -. Hobinson, Hobinson, H.J and A.Y A.Y. $ami $amime. me. /(9* Hecent Hecent developments developments in yoghurt yoghurt manufacture manufacture.. >n "odern >n "odern Dairy Technology. Technology. #dited #dited by ".N.: ".N.:.. %udson. %udson. 4ondonK 4ondonK #lsevie #lsevierr Appli Applied ed cience ?ublishers. pp (3.
SENSORY EA,UATION O- T/E YOGURT Sa!(le
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