pH值对成熟期小麦酱油理化指标的影响

Effects of pH Values on Physical and Chemical Indexes of Mature-stage Wheat Soy Sauce

pH值直接影响美拉德反应和酶促反应的反应效率,因此pH值对酱油品质有明显影响。文章探讨了pH值对高盐稀态小麦酱油在发酵成熟期(40～70天)的色泽、总氮、氨氮、总酸、总糖、还原糖和风味的影响规律。研究结果表明:发酵过程中将酱油pH值稳定在6.5左右,可导致酱油的红色指数和黄色指数分别提高9.76%和7.25%,谷氨酰胺酶酶活力提高30%左右,发酵70天后,小麦酱油中游离谷氨酸含量上升38.56%,但酱油的总氮和氨基酸态氮含量略有下降。感官评价表明:酱油的鲜味和苦味均有明显提高,甜味和酸味下降。

The pH value directly affects the reaction efficiency of Maillard reaction and enzymatic reaction,so the pH value has a significant influence on the quality of soy sauce.The effects of pH values on color,total nitrogen,ammonia nitrogen,total acid,total sugar,reducing sugar and flavor of high salt diluted wheat soy sauce during the maturation period of fermentation(40~70 days)are investigated.The results show that the pH values of soy sauce are stable around 6.5 during the fermentation process,which result in the increase of red index and yellow index of soy sauce by 9.76%and 7.25%respectively.After 70 days'fermentation,free glutamic acid content in wheat soy sauce increases by 38.56%,but the total nitrogen and ammonia nitrogen content of soy sauce decrease slightly.The sensory evaluation shows that both the umami and bitterness of soy sauce are significantly improved,while the sweetness and sourness are decreased.