Fermentation Properties of Low-salted Doenjang Supplemented with Licorice and Mustard

Licorice (Glycyrrhiza glabra) and mustard (Brassica juncea) were added to doenjang to reduce salt content in traditional Korean doenjang and solve problems related to abnormal fermentation during the storing process. After supplementing the low-salted doenjang (6.3% salt) with licorice and mustard (LM), a number of fungi were reduced and lactic acid bacteria increased. Protease activity increased in the 6.3% salted doenjang regardless of additives. The amino nitrogen content increased as much as that in the low-salted doenjang. pH decreased and acidity increased at day 10. A sensory evaluation was conducted after doenjang was stored for 40 days. The 6.3% + LM had very high taste quality. LM added to low-salted doenjang suppressed fungal growth, and promoted the growth of lactic acid bacteria. The results indicate that the salts content of doenjang could be lowered to 6.3% by adding LM with improved quality and taste, and without abnormal fermentation.