本研究将酶解不同时间( 3、12 和 24 h) 得到的大豆分离蛋白酶解产物( SPIH) 添 加至自制酸奶中，通过测定 3 种 SPIH( SPIH-A3、SPIH-A12、SPIH-A24) 的酶解特性、酸奶 的发酵特性和贮藏品质，研究 SPIH 对酸奶发酵和贮藏品质的影响． 结果表明: 酶解时间 越长，SPIH 水解度越高; 3 种 SPIH 均能促进酸奶发酵，抑制酸奶贮藏期间的后酸化，减少 乳清析出，降低杆菌活菌数; 将促发酵效果最显著的 SPIH-A12 进行超滤分离，发现 4ku 以 下的 SPIH-A12-L4 组分具有更多的疏水性氨基酸和不带电亲水性氨基酸，更能提高酸奶 球菌活菌数和表观黏度，降低乳清析出率; 适度酶解得到的 SPIH 可以有效促进酸奶发 酵，改善酸奶贮藏品质，进一步超滤分离得到的小分子组分作用更显著

Soybean protein isolate hydrolysate ( SPIH) obtained at different enzymatic hydrolysis times ( 3，12 and 24 h) were added to homemade yoghurt． The effects of SPIH on the fermentation and storage quality of yoghurt were studied by measuring the enzymatic hydrolysis characteristics，fermentation characteristics and storage quality of SPIH ( SPIH-A3，SPIH-A12 and SPIH-A24) ． The results show that the longer the enzymatic hydrolysis time，the higher the degree of SPIH hydrolysis． All SPIH can promote yoghurt fermentation，inhibit post-acidification during yoghurt storage，reduce whey precipitation，and reduce the number of viable bacteria． Ultrafiltration separation was carried out on SPIH-A12，which has the most significant effect of promoting fermentation． It was found that the SPIH-A24 component below 4 ku had more hydrophobic amino acids and uncharged hydrophilic amino acids，which could improve the number of live bacteria and the apparent viscosity of yoghourt coccus and reduce the whey precipitation rate． Appropriate enzymatic hydrolysis of SPIH can effectively promote yoghurt fermentation，improve yoghurt storage quality． In the meantime，small molecular fraction obtained by ultrafiltration demonstrated a more pronounced effect．