Starter cultures

The production of fermented foods and beverages is one of the oldest biotechnological practices, dating back 7,000 years or more. Throughout human history, many different substrates of animal or plant origin have been fermented, including milk, meat, fish, various vegetables, and soybeans. The manufacture of fermented foods, although rooted in practices developed over many thousands of years, is today a major biotechnological activity which is valued at many billions of dollars. The success of such a large and diverse process is critically dependent on the activity of microorganisms, particularly the lactic acid bacteria (LAB). These are the microbes for which the term “starter culture- was specifically coined, as they are added deliberately to a substrate to start a given fermentation process. This chapter provides a detailed examination of the LAB, outlining their key functional properties. The historical development of starter cultures, their composition, the formats in which they are commercially available, and the particular issues pertaining to the use of starters in a modern, high-throughput industrial setting are discussed. The more recent advances in the analysis of phage-host interactions is also reviewed. Finally, the challenges relating to the use of starters in the production of fermented foods are examined, particularly as they relate to strain diversity and the generation of new products with modified flavor, texture, and health attributes.