Quality and food safety aspects

Soya fermentation processes have a strong impact on the evolution of miCTobes in the product. This may be positive in the case of natural fermentations, but sometimes it may constitute a hazard. Knowledge of the parameters and microorganisms involved is useful in controlling optimum quality and consumer safety. Environmental factors (Nout, De Dreu, Zuurbier, Sonants-Van Laarhoven, 1987) that impact 

Britting or salting increases the NaCl concentration to levels that are inhibitory to most microorganisms (Han, Sesenna, Beumer, Nout, 2005). Only halotolerant or halophilic bacteria or yeasts would have the opportimity to (slowly) grow and cause effects. 

The type of starters used can vary from defined single-strain starters to traditional mixed starters. Defined single or mixed starters, such as used for natto and sufu, have been selected for their specific properties, and in order to draw appropriate profit from their addition, they need to be provided with optimum conditions for growth including absence of competing microbiota and the control of temperature, pH and water activity. Natural mixed microbiota 

Yeasts occur in fermented soya foods, but have not been reported in connection with hazardous situations. 

Several genera of bacteria have positive effects on the quality of fermented soya foods. Lactic acid bacteria (LAB) are important for flavour as well as for protection against pathogenic contaminants. The addification by LAB was shown to inhibit the growth 

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