Question

In which food would you find lactic acid bacteria? Mention some of their useful applications.

Answer 1

Lactobacillus and other microorganisms, known as lactic acid bacteria (LAB), develop in milk. They convert lactose sugar from milk into lactic acid. Lactic acid causes casein, a milk protein, to coagulate. Milk is processed into curds, yogurts, and cheese.

1. Curd: Indian curd is made by inoculating cream and skimmed milk with Lactobacillus acidophilus at temperatures of around 40°C or below.
2. Yogurt: It is made by fermenting milk with Streptococcus thermophilus and Lactobacillus bulgaricus. It tastes of lactic acid and acetaldehyde. It is frequently sweetened and flavored with fruits.
3. Cheese: It comprises milk curd separated from the liquid portion. Lactic acid bacteria help to curdle milk for making raw cheese.

The LAB also plays an important function in preventing microbes that cause illness in our stomach.

Answer 2

Lactic acid bacteria (LAB) grow in milk and change it into curd. As they multiply, they release acids that cause the milk proteins to thicken and also break them down partly. They enhance the nutritional value of curd by increasing its vitamin B₁₂ content. In our digestive system, LAB are also helpful because they prevent harmful microbes from growing.