Abstract:

With soybean meal and wheat as the raw materials, base soy sauce was produced by low-salt and solid-state fermentation in the pond with spraying-extraction, and then its aroma was enhanced by using Rhizopus sp. esterifying enzyme. Via single-factor test and response surface analysis, the effects of esterifying enzyme amount, esterifying temperature and time on the sensory and physical-chemical quality of the soy sauce were investigated. The results showed that the addition of Rhizopus sp. esterifying enzyme significantly enhanced the volatile ester content, and made the soy sauce mellow and fragrant. The optimized Rhizopus sp. esterifying enzyme amount, esterifying temperature and time were 1.0%, 45 ℃, and 72 h, respectively. Under these conditions, the total volatile ester content was 7.512 mg/100 ml, which was 36.3% higher than that in the base soy sauce.

Key words: Rhizopus sp. esterifying enzyme, soy sauce, aroma enhancement, optimization