Determination of the physiochemical characteristics of traditional doenjang produced in Chungnam region in South Korea

Traditional doenjang characteristically differs from commercial doenjang, as the former involves a long and natural fermentation process. This study determined the physiochemical characteristics of traditional doenjang produced in Chungnam region. Two commercial and thirteen traditional doenjang products were characterized in terms of color, moisture content, pH, °Brix, salinity, acid value, titratable acidity, NH₂-N content, alcohol content, and total and reducing sugar contents. The traditional samples significantly differed from the commercial samples in terms of color, moisture, °Brix, acid value, and in alcohol, NH₂-N content, and total sugar contents (p < 0.05), and the traditional samples were characteristically similar to those previously analyzed. Moreover, the samples produced in different cities could be clustered based on their physiochemical characteristics. The observed differences among the traditional samples were attributed to fermentation conditions, namely, duration and temperature, as these differences were not correlated with ingredient ratio.