Effects of turmeric (Curcuma longa L.) on the physicochemical characteristics of kochujang during fermentation

Abstract

Physicochemical properties of kochujang prepared with different concentration of turmeric were compared. The number of yeast and bacteria in the kochujang were low in the group with more than 1% of turmeric while the amylase and protease activity increased in the group with less than 1% of turmeric. The L- and b-values increased as the concentration of turmeric increased, however a-value decreased. The titratable acidity was low in the high percentage of turmeric added group. Oxidation-reduction potential increased in the later stage of fermentation with decrease in Aw. Reducing sugar and alcohol were high in than higher turmeric added group. Amino- and ammonia-type nitrogen were the highest in the 0.5% turmeric added group. The overall acceptability of kochujang was significantly more favorable (p <0.05) in the 0.25% turmeric added group than over 1% turmeric added one.