本文以米渣蛋白(RDP)为主要原料酿制酱油，探讨发酵过程中氮素变化规律与过程调控的相关性。通过动态监测RDP酱油30 d的发酵过程中氨基态氮、总氮、可溶蛋白质、氮转化率的变化规律，优化酱醪的发酵温度、盐水浓度、盐水添加量等控制条件。对相同试验条件下所得RDP酱油和大豆酱油的氨基酸态氮和总氮含量进行了比较，并初步评价了RDP酱油的抗氧化活性。结果表明，50 ℃发酵2 d氮素转化即可达到最高值，35 ℃发酵持续时间长且有利于氮素转化，产品品质好；酱醪盐浓度为11%时有利于RDP的氮素转化；在盐水倍数为2.2、2.5、2.8时，对总氮和氨基态氮含量没有明显影响，但较高的盐水量可以促进RDP蛋白质的降解，有利于提高RDP酱油的总氮转化率。综合分析，确定RDP酱油发酵的优化控制条件为不超过35 ℃条件下添加2.8倍曲料质量的盐水，使酱醪盐浓度达到11%，可获得RDP总氮转化率70%以上的酱油产品。RDP酱油的总氮和氨基态氮含量均明显高于大豆酱油，RDP酱油具有显著的抗氧化活性。

Rice dreg protein (RDP) was used as the main material for fermentation to produce sauce, and the correlation between the process control and nitrogen transformation pattern during the fermentation was investigated. The fermentation temperature, salt concentration, amount of added brine, and other control conditions were optimized via dynamic monitoring of the changing patterns of total nitrogen content, amino nitrogen content, soluble protein, and total nitrogen conversion rate in RDP sauce during a 30-d fermentation. The amino nitrogen and total nitrogen contents of RDP sauce and soy sauce obtained under the same conditions were compared, and the antioxidant activity of RDP sauce was evaluated preliminarily. The results showed that the conversion of nitrogen in RDP sauce peaked on the second day of fermentation at 50 ℃; fermentation at 35 ℃ required a longer duration, favored the conversion of nitrogen, and yielded a high-quality product. Moromi with a salt concentration of 11% was conducive to conversion of nitrogen. When the amount of brine was 2.2, 2.5, and 2.8 times as much as the koji weight, no significant effects on the total nitrogen and amino nitrogen contents were observed, while a higher amount of brine promoted the degradation of RDP protein and increased the total nitrogen conversion rate in RDP sauce. Based on this comprehensive analysis, the optimized processing conditions were as follows: the amount of added brine was 2.8 times the koji weight; the fermentation temperature was below 35 ℃; and the salt concentration of the moromi was 11%. Under these conditions, an RDP sauce with a total nitrogen conversion rate of over 70% was obtained. The amino nitrogen and total nitrogen contents of RDP sauce were significantly higher than those of soy sauce, and RDP sauce possessed significant antioxidant activity.

国家自然科学基金面上项目（31371741）