原粒酱油渣脱酸工艺研究

以原粒大豆为主要蛋白质原料酿造的传统酱油，其剩余酱油渣中油脂氧化和酸败形成的大量游离脂肪酸，降低了酱油渣的利用价值。该研究通过正交试验设计研究酱油渣乙醇脱酸处理工艺，得出最佳脱酸条件为：酱油渣和95%乙醇1∶4（g∶mL），处理时间3 h，处理温度60 ℃。在此条件下进行3次平行试验，酱油渣中游离脂肪酸含量降至1.41%，此时酱油渣酸价为6.26 mg KOH/g，与没脱酸处理酱油渣比较，降低了71.4%。通过气相色谱-质谱测定，脱酸处理酱油渣中7组游离脂肪酸特征成分峰的峰面积明显减小，除了3号成分峰的脱除率为52.2%外，其他6组成分峰的脱除率均达到61%以上。结果表明，乙醇在此工艺条件下，对原粒酱油渣脱酸效果明显。

Deacidification process of whole-soybean soy sauce residue

The traditional Chinese-type soy sauce was made from whole soybeans. After brewing, there was a large quantity of free fatty acids from lipids-oxidative rancidity remaining in the residue, which leaded to diminishing in the application value of the soy sauce residue. The deacidification technology of soy sauce residue was developed by orthogonal experiments, and the optimum parameters were soy sauce residue: 95% ethanol 1∶4 (g∶ml), treatment time 3 h, temperature 60 ℃. Under these conditions, the content of free fatty acids remaining in soy sauce residue decreased to 1.41%, and the acid value of soy sauce residue was 6.26 mg KOH/g, which decreased 71.4% compared with untreated soy sauce residue. Furthermore, 7 kinds of free fatty acids were analyzed by GC-MS, which indicated that each peak area of free fatty acid obviously decreased. All the removal rates of six components were over 61% by deacidification, apart from the removal rate of the NO. 3 peak was 52.2%. The results showed that ethanol was significantly effective to reduce the free fatty acids of soy sauce residue under above conditions.