Yogurt Fermentation

1. Yogurt Fermentation Molly Landon

2. milk • cream • nonfat dry milk • stabilizers (alginates, gelatins, gums, pectins, and starch) • sweeteners Ingredients in Yogurt

3. Adjust milk composition and blend ingredients. • Pasteurize milk at 85°C for 30 minutes. • Homogenize. • Cool milk to 42°C. • Inoculate with starter cultures. • Hold at 42°C until a pH of 4.5 is reached. • Cool to 7°C. • Add fruit and/or flavors. • Package. Process

4. The principal cultures in yogurt include Lactobacillus bulgaricus and Streptococcus thermophilus. They are used to ferment lactose to produce lactic acid, which causes the milk to clot and form yogurt. • Lactobacillus acidophilus, Lactobacillus subsp, casei, and Bilfido-bacteria may also be added to improve digestion and the immune system. Bacterial Cultures

5. This bacteria is used for the production of yogurt but also found in several other fermented foods. • It was first discovered in 1905 by Stamen Grigorov. • It feeds on lactose to make lactic acid in order to preserve milk. • The bacterium requires a low pH to grow effectively, which is why the product must be held in step 6 before it is used. Lactobacillus bulgaricus

6. This lactic acid bacterium is found in fermented milk products. • It also turns lactose into lactic acid for yogurt. • Its ideal growth rate is at 45 °C, another reason milk products must be cooled before adding the bacterium. Streptococcus thermophilus

7. Cultured milk products date back to 2000 BCE. • In the Indian and Iran cultures around 500 BCE, yogurt was referred to as “the food of the gods.” • Yogurt was not brought to the United States until the twentieth century and it wasn’t until much later in the century that it became a common food. • Yogurt with additional fruit preservatives was patented in Prague by RadlickáMlékárnadairy. • People who are lactose-intolerant can eat yogurt with no sideaffects. • Fermentation formula: C6H12O6+ 2ATP + 2ADP + 4NADH 2C2H5OH + 2CO2 +4ATP + 2H2O + 4NAD+. Yogurt History