ABSTRACT
Amino acids are the principal organic components, comprising almost 25% of the total soluble solids. They are followed by carbohydrates, 13%; polyalco hols, 5%; and organic acids, nearly 3%. Of the total nitrogen, about 40-50% are amino acids, 40-50% peptides and peptones, 10-15% ammonia, and less than 1% protein. There are 18 amino acids present, and glutamic acid and its salts are the principle flavoring agents. Sugars present are glucose, arabinose, xylose, maltose, and galactose, whereas sugar alcohols are glycerol and man nitol. Organic acids found in shoyu are lactic, acetic, succinic, citric, formic, and pyroglutamic. In addition, there exist trace amounts of organic bases, such as ardenine, hypoxanthine, xanthine, quanine, cytosine, and uracil, all of which are believed to be metabolites of nucleic acids (Yokotsuka, 1986).
