外源蛋白酶对腐乳后发酵理化和感官特性的影响

通过对分别添加木瓜蛋白酶、皱胃酶的腐乳与不加酶腐乳在后发酵阶段pH值、水分、总酸、氨基态氮、硬度和感官品质的测定，评定外源蛋白酶的添加对腐乳成熟的影响。结果表明：腐乳后发酵过程中，外源蛋白酶添加组的pH值在5?d后均高于空白组；外源蛋白酶的添加对腐乳的含水量和总酸含量影响不明显；4%木瓜蛋白酶、2%和4%皱胃酶的添加使腐乳氨基态氮含量明显增加；4%木瓜蛋白酶和4%皱胃酶的添加能够明显降低腐乳硬度；外源蛋白酶的添加能改善腐乳的口感和内部颜色，提高香味和鲜味，但木瓜蛋白酶的添加会产生一定的苦味。

Effect of Exogenous Protease on the Physiochemical and Sensory Properties of Sufu during Post-Fermentation

To evaluate the impact of adding exogenous protease on sufu ripening, the pH, moisture, total acid content, amino nitrogen content, hardness and sensory quality were determined during the post-fermentation of sufu with no enzyme, papain or rennet added. The results showed that addition of exogenous proteases increased the pH of sufu compared with the control group after 5 days of ripening but it had no significant effect on moisture or total acid content. Addition of 4% papain, 2% or 4% rennet remarkably promoted the production of amino nitrogen. Hardness was decreased by adding 4% papain or 4% rennet. The results of sensory evaluation showed that exogenous proteases improved the taste, internal color, aroma and umami of sufu, but bitterness was formed as a result of the hydrolysis of soybean protein with papain.