**2.2 Soy sauce**

Soy sauce is recognized as Jiang-you in China, Shoyu in Japan and Ganjang in Korea. There are two types of soy sauce based on the color. One type of soy sauce is an all purpose liquid seasoning, characterized by a strong aroma, a myriad flavor, and a deep red-brownish color. The other type is in a lighter brown color used mainly for cooking when the original flavor and color of the foodstuff need to be preserved. The difference in aromas observed between Japanese and Chinese styles of soy sauce are ascribed to the different ratios of wheat and soybeans used and the existence of pasteurized process (Fukushima, 1979). The salt concentration of soy sauce is around 16-17%, and the pH is around 4-5 (Shibasaki and Hesseltine, 1962).
