Antioxidant Activity and Contents of Total Phenolic, Monacolin K, GABA and Citrinin of Monascus-Fermented Soy Sauce

In this study, antioxidant activity, contents of total phenolic, monacolin K, GABA, and citrinin as well as sensory evaluation of Monascus-fermented soy sauces were investigated. The soy sauces included tradtional soy sauce (S1), soy sauce fermented with commercial red mold (S2) and soy sauce fermented with lab-cultivated red mold (S3). The final DPPH free radical scavenging activity of soy sauces S1, S2 and S3 were 92.2%, 94.8% and 95.0%, respectively. The total phenolic content in soy sauces S1, S2 and S3 were 724.6, 800.2, and 885.7 μg gallic acid/mL, respectively. Total phenol contents soy sauce increased as fermentation time increased. Contents of monacolin K in S1, S2 and S3 were 0.00, 97.0 and 57.62 μg/mL. The content of GABA in S1, S2 and S3 were 14.46, 35.47 and 36.37μg/mL. The citrinin was not detected in all soy sauce samples.