Comparison of Physicochemical Characteristics of Traditional and Commercial Kochujang during Fermentation

Physicochemical characteristics of traditional kochujang fermented for 6 months and commercial kochujang were compared. Tested kochujang included 18 kinds of Sunchang kochujang prepared with glutinous rice, 10 kinds of Boeun kochujang prepared with barley and 17 kinds of Sachun kochujang prepared with wheat, and 10 kinds of commercial kochujang. Major free sugar was found to be glucose both in traditional and commercial kochujang. Fructose, maltose, and sucrose were also detected in small amounts. The contents of free sugars in traditional kochujang was approximately one fourth of those presented in commercial kochujang. Commercial kochujang showed the highest level of total free amino acids followed in decreasing order by Sachun, Sunchang, and Boeun kochujang. The most abundant free amino acid was serine in Sunchang kochujang and aspartic acid both in Boeun and Sachun kochujang. On the other hand, glutamic acid was the most abundant amino acid in commercial kochujang. Volatile organic acids in various kochujang were determined and acetic, propionic, butyric, and 3-methyl butanoic acids were found in traditional kochujang. However, 3-methyl butanoic arid was not found in commercial kochujang. The most abundant volatile acid was acetic acid in both tradtional and commercial kochujang. Analysis of non-volatile organic acids showed that large amounts of lactic, oxalic, and succinic acids were found in traditional and commercial kochujang. In addition to these, small amounts of itaconic, malic, malonic, and pyroglutamic acids were found in commercial kochujang.