Starter Cultures and Nutritional Importance of Fermented Milks

Fermented milks have a history of thousands of years. They are enjoyed everywhere in the world for their characteristics refreshing acid taste. Most of them use the lactic acid fermentation by lactic acid bacteria, but some also use additional alcohol fermentation due to yeasts or lactic fungi to prevent bacterial and mould contamination  and improve storage properties. This characteristics as a preserved food is one reason for their success, but with the diversification of the diet in recent years and their image as health foods, not only plain fermented milks, but also fermented milks in liquid or frozen form, and with all kinds of fruit juice or added fruit, have appeared in the market.

Research into the health-giving effects of fermented milks has flourished since Metchnikoff developed his hypothesis on longevity, and the physiological significance of fermented milk and of lactic acid bacteria is continuing to become clearer. Clinical trials are also already showing beneficial results, and fermented milks are now recognized as health foods as well as being pleasant preserved foods. The starter cultures of today used for bringing about fermentative changes in milk in the form of a variety of fermented milks comprise special types of lactic acid bacteria. This useful group of bacteria include lactococci, lactobacilli, Leuconostocs, pediococci,and propionic acid bacteria along with some common yeasts and moulds which are now extensively used in the preparation of several types of fermented products.