While microbes are causal agents of most of the infectious diseases, they have also been in use by humans and nature in many important processes in homes, industries, agricultures and sewage treatment. Rather, microbes become part of many useful articles used by early humans like fermented honey (alcoholic drink mead), wines, bread, curd, cheese, separation of plant fibers, etc.
1. Dairy Products:
Lactic acid bacteria (LAB) like lactobacillus are added to milk. It changes lactose sugar of milk into lactic acid. Lactic acid results in coagulation and little digestion of milk protein casein. Milk is changed into curd, yoghurt and cheese.Millions of LAB are contained inthe starter or inoculum used in preparation of milk products.
Indian curd is made by vaccinating skim and cream milk with Lactobacillus acidophilus at a temperature of concerning 40°C or less. Curd is additional alimentary than milk because it contains variety of organic acids and vitamins as well as B12. LAB curd additionally checks growth of malady inflicting microbes in abdomen and alternative components of GI tract. Curd is eaten as such, salted or sweetened. Curd is churned to prepare lassi.
It is produced by curdling milk with the help of Streptococcus thermophiles and Lactobacillus bulgaricus. The temperature is maintained at about 45°C for four hours. Yoghurt is often sweetened and mixed with fruit.
(iii) Butter Milk:
It is acerbated product which is produced by inoculating skimmed milk with beginning culture of Streptococcus cremoris, S. lactis, Lactobacillus acidophilus, Leuconostoc species at 22°C for 18 hours. Acidulated liquid left after churning of butter from curd is also called butter milk.
(iv) Sour Cream:
Cream obtained by churning of milk is inoculated with Sterptococcus lactis for producing lactic acid and Leuconostoc cremoris for imparting the characteristic flavor.
It is one of the oldest milk products made with microbes. The curd is segregated from liquid part to form cheese. Depending upon water content, cheese is of three types -soft, semi hard and hard.
Selected strains of Baker’s Yeast, Saccharomyces cerevisiae, are grown on molasses. When enough growth is done, Baker’s Yeast is harvested and changed into either powder or cakes. A small amount of Baker’s Yeast is also added to wheat flour. The same is needed.
3. Dosa, Uppma and Idli:
They are substance preparation of rice and Black Gram. The two are allowed to ferment for 3-12 hours with air borne Leuconostoc and Streptococcus species of bacteria. CO2 formed in the course of fermentation results in the puffing up of the dough.
The semi-liquid dough of fine flour of Wheat is fermented with yeast, fried in the form of coils and dipped in sugar syrup to obtain Jalebi. Imriti is similarly prepared from Black Gram flour.
5. Other Foods:
Tempeh (Indonesia), Tofu (Japanese) and Sufu (Chinese) are fermented foods obtained from soybean. Soy sauce is brown flavored salty sauce fermented from soybean and wheat. Sauerkraut is finely chopped fermented and pickled cabbage.
It is a traditional drink of some parts of South India which is made by fermentation of sap of palms. It’s a refreshing drink which can be heated to produce palm sugar or jiggery.