Chapter 6 - Enumeration and Identification of Probiotic Bacteria in Food Matrices

Abstract

Probiotic bacteria are increasingly applied in the food industry, such as milk, vegetables, or meat products. According to FAO/WHO (2002) recommendation, to exert their positive effect on the host, they must be ingested in adequate amount, that is, probiotic bacteria should be 106–109CFU/g in the product at the time of ingestion. Moreover, the positive effect on the host is connected with the specific strain of bacteria, not the genus or species. The correct species identification of bacteria is of paramount importance from the technological, ecological, and safety point of view. So far there is no standard method for the identification of probiotics. Therefore, the need to develop fast and efficient methods of probiotic identification in food matrices occurs. The aim of the work is to provide different methods of enumeration and identification of probiotic bacteria in food according to the culture-dependent and culture-independent techniques, such as phenotyping, biochemical, physical, immunological, and molecular biology methods. In particular, the direct identification potential of molecular tools, such as DNA, RNA, and peptide analysis will be highlighted.