**3.3 Soy sauce**

Cultures of *Aspergillus oryzae* are also used as starter for the production of soy sauce. The manufacturing of soy sauce is carried out as follows (Fukushima, 1979). Soybeans, or defatted soybean flakes, are moistened and cooked under pressure until they are sufficiently soft. The cooking was done in a batch type or a continuous cooker which allows a high pressure. On the other hand, the wheat is roasted by continuous roasting and then cracked into four to five pieces. The cooked soybean and wheat are mixed and then inoculated with a pure culture of *Aspergillus oryzae* to make koji. After two or three days, the well fermented koji is mixed with yeasts, lactic acid bacteria in the presence of more than 18% salt water which excludes undesirable microorganisms in the second period fermentation. The pH drops from an initial value of 6.5-7.0 down to 4.7-4.8. After fermentation, the product is filtered, pasteurized and packaged as soy sauce. The salt concentration of soy sauce from different country ranges from 10-21% (Stute et al., 2002).
