cultures and fermentation

1.   What are starter cultures?

Starter cultures are mostly bacteria alone and sometime in combination with yeast, which are used in the production of fermented and cultured dairy products such as dahi, mishti doi, lassi, mathaa, shrikhand, chaach, yoghurt and cheese. Starter cultures may be a single strain or multiple strains. Commonly, sourness in fermented milk products is due to the production of lactic acid by starter cultures. In some fermented milk product such as Kefir and Kumis, yeast and bacteria in combination are used as starter.

2.   What roles starter cultures play in food fermentations?

The major role of lactic starter culture is to produce lactic acid by converting milk sugar, lactose. Besides, cultures can also contribute towards aroma, flavor, body, texture, alcohol content and keeping quality of the product by producing antimicrobial compounds.

3.   Can any bacteria be a starter culture?

No, only selective bacteria can be starters. Almost all starter cultures are members of a group of bacteria known as Lactic Acid Bacteria (LAB). Most of the members of LAB enjoys generally regarded as safe (GRAS) status, which implies that they are safe for consumption. Only those cultures which enjoy GRAS status, have history of safe usage or declared safe after safety assessment studies can be used as starter cultures.

4.   What is difference between Paneer and Cheese?

In the process of paneer manufacturing there is no role of starter cultures to play. Milk is curdled by externally adding coagulating agents such as lactic acid, sour milk, and citric acid etc. However in Cheese after coagulation with rennet enzyme, bacterial cultures are added to get desired flavor after ripening. Generally paneer is known as “soft cheese”.

5.   Is there any difference between a starter and probiotic culture?

Yes. A fermented or cultured dairy product may or may not be probiotic. Probiotic are additional bacteria which hardly play any role in fermentation and other activities alike that of starter. A fermented or culture product cannot be obtained without the use of lactic acid bacteria, however it can be made without probiotic. Mostly probiotic cultures are added into the product to get additional health benefits over inherent nutritional value of the products.

6.   Are all Lactic Acid Bacteria are probiotic?

No. Probiotic attributes are strain specific. It means that only a strain for which probiotic attributes have been established following specified guidelines can be used as probiotic.

7.   Is there are any guidelines for probiotic in India?

Yes. Department of Biotechnology (DBT) and Indian Council of Medical Research (ICMR) task force has framed guidelines for evaluation of probiotics in foods. These guidelines can be accessed from the following link:

8.   Where from one can obtain starter culture?

Starter cultures for application in milk and milk products are mostly obtained from dairy products only. There are reports on isolation of these cultures from, feces, plants and vegetation etc. For commercial application starter cultures can be obtained from National Collection of Dairy Cultures (NCDC), National Dairy Research Institute, Karnal, National Dairy Development Board (NDDB) and other research centers and universities. There are various commercial suppliers who supply culture in direct vat set format.

9.   Is there any Indian probiotic culture used in probiotic dairy products?

As of now, none of the Indian probiotic cultures is used in dairy products. Leading research labs at Anand Agriculture University and National Dairy Research Institute in Karnal are working to come-up with such cultures.