MICROBIAL STARTER CULTURES IN FERMENTATION

The success of many food and beverage based fermentation industries depends heavily on the availability of the microorganisms which drive the fermentation process. The type or types of microorganisms used, the quality and volume of inocula used in the fermentation process is crucial in the fermentation industries. In reality, most of the food or beverage based fermentation industries use pure or mix cultures for their fermentation depending on the type of fermentation carried out. Some fermentation requires the use of mono cultures while there are food or beverage fermentations that require the contribution of a number of species of microorganisms for the fermentation to be successful.

The microorganisms used in the various food and beverage fermentations were in fact historically isolated from the ' natural contaminants' which occur on the decomposing or naturally fermented foods!

The use of starter cultures is not new. In traditional fermentations traditional starter cultures have always been used in the fermentation though many do not realize it. Some of these starter cultures used are obtained from:

1 Remnants or residuals of past fermented food and beverage
2 Original flora that existed naturally on wrappings used in the fermentation such as banana leaves
3 Inocula that occur naturally in the substrate of the fermentation such as grapes used in wine making
4 Traditionally made 'kojis' used in many soy sauce or tuak fermentation

It is only now in the modern, sanitary, stainless steel fermentors of modern fermentation industries are ' starter cultures' used to start the desired fermentation process. Starter cultures are specially isolated and selected strains of microorganisms used in the fermentation which are massively cultivated under strict and scientific control to give the best and optimized fermentation which are not often seen in traditional food fermentations

Before the first cultures entered the market,traditional fermented food producers tended to rely on their own cultures. However, inadequately characterised cultures and inadequately defined compositions generally variability in the quality of the fermented products which is regarded not satisfactory in the market.

The development of such cultures requires the expertise and experience of specialists microbiologists, biochemists and food technologists as not all combinations are suitable for all products. The use of different strains in the same microbial starters must not result negative influence on each other. Usually in any microbial starters it is not wise mix more than four different species in a culture,”



The advantages of using industrially prepared starter cultures for food and beverage fermentation are:
1 Use only the microorganisms responsible for the fermentation
2 No other microbial contaminants that can cause diversion from the optimal fermentation
3 Can use the best strains specifically designed for the particular fermentation
4 Use of large inocula of starter cultures will result in better and faster fermentation
5 Quality and stability of the fermentation will be maintained
6 Taste, texture, colour stability and shelf life are mainly determined by microorganisms involved in the maturation, i.e. fermentation, of the product.