Etiket Arşivleri: What happens during fermentation of yogurt?
1-) Names of m/o.’s used in yogurt fermentation? Lactobacillus bulgarıcus – supply a.a. Streptococcus aureus – produce formic acid
2-) What’s symbiosis? For two m/o’s – both benefıt to each other
3-) Reason of heating milk at 85 – 90 C for 30 min? For supply pasteurization of milk M/o’s are killed To obtain correct viscosity and consistency – denature the coagulable proteins – water binding capacity will increase. To concentrate milk solids The denaturation process makes the protein more accesible to S.C.
4-) Why is it necessary to cool coagulum after fermentation? After fermentation we reduce temperature to stop the fermentation.
5-) What happens during fermentation of yogurt? To observe decrease of lactıc acıd and ph 6-) What should be optimum Ph, lactic acid and solid content? Optimum temperature of milk ıs 42 C ( 40 – 45 ) and ph ıs between 4.5 – 4.7
PURPOSE: To determine the effect of solid content and inoculation rate on the fermentation time of yogurt.
Milk is heated to 85-90°C and held at that temperature for 30 min. After cooling to 45 °C under top water, add inoculum’s, previous day yogurt,
1. Group 1, do not add skim milk powder, inoculum rate 4%
2. Group 2, do not add skim milk powder, inoculum rate 2%
3. Group 3, add 5% skim milk powder, inoculum rate 2%
4. Group 4, add 10% skim milk powder, inoculum rate 2 %
Incubate milk at 42°C for 3 h. Refrigerate samples.
RESULT AND DISCUSSION
Measure the lactic acid and pH of the milk before fermentation. Do same measurements after fermentation was completed and overnight storage. Discuss the effect of inoculum rate and solid content on the pH and lactic acid production rate clearly.
Research the following topics;
Names of microorganisms used in yogurt fermentation.
What is symbiosis?
Reason of heating milk at 85-90°C for 30 min. Why is it necessary to cool coagulum after
What happens during fermentation of yogurt?
What should be the optimum pH, lactic acid and solid content of yogurt?