Starter cultures for dairy products

Starter cultures used in the production of dairy products comprise a great variety of lactic acid bacteria. Most common are species within the genera Lactococcus, Streptococcus, Lactobacillus and Leuconostoc. Non-lactic acid bacteria of the genera Bifidobacterium and Propionibacterium are commonly used in Swiss-type cheeses and so-called health cultures . 

Traditionally, commercial starter cultures were only specified on genus or species level, therefore the composition of starter cultures, i.e. number of strains and strain variety, was generally unknown. Recently, cultures composed of pure, single strains have been introduced to the market. This avoids strain dominance and greatly stabilises performance. 

1 Purpose of using starter cultures. Preservation of food by fermentation is one of the oldest methods known to humankind. Products and microorganisms from ancient times are the predecessors of the variety of fermented milk products and cultures we have today. 

Nowadays most fermented milks are manufactured under controlled and sanitary conditions. As in the past, the main purpose of using starter cultures is to preserve the milk, but other reasons for using starter cultures in modern dairy industry are diverse and may be summarised as follows  

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