浸泡介质及浸泡条件对豆浆中抗营养因子及品质的影响

为了最大程度降低豆浆中抗营养因子含量的同时保证品质优良,以干豆制浆为对照,利用不同浸泡介质(水、柠檬酸溶液、NaHCO_3溶液)及不同浸泡条件,探究前处理工艺条件以及介质的改变对豆浆中抗营养因子及营养品质的影响。结果表明:浸泡处理能有效降低豆浆中胰蛋白酶抑制因子活性和植酸含量,但不同介质对不同抗营养因子的效果不同。经浸泡处理后的胰蛋白抑制因子的最低活性为30.88±1.35 TIU·mg^-1,相对于未处理组降低了54%;植酸最低含量为3.46±0.15 mg·mL^-1,相对于未处理组降低了77.4%;而经浸泡处理后的单宁含量却显著上升(P<0.05)。从降低胰蛋白酶抑制因子活性的效果来看,NaHCO_3>水>柠檬酸;从降低单宁含量的效果来看,柠檬酸>NaHCO_3>水;从降低植酸含量的效果来看,柠檬酸>水>NaHCO_3。除抗营养因子外,豆浆的品质指标也发生了显著变化,NaHCO_3浸泡组的总体品质最优,除了个别品质指标(蛋白质含量)与水浸泡组相比差异不显著(P>0.05),其它品质成分含量均显著高于水浸泡组,而柠檬酸浸泡组的品质为3组中最差。选取NaHCO_3溶液作为浸泡介质进行正交工艺优化,当浸泡温度为25℃,浸泡时间为16 h,浸泡豆水比为1∶4,NaHCO_3浓度为0.45%时,豆浆的抗营养因子的去除效果最好,品质最优。

Soaking Medium and Pretreatment Conditions on Main Anti-nutritional Factors and Nutritional Quality in Soybean Milk

In order to minimize the content of anti-nutritional factors, and to ensure its excellent quality. This study explored the effects brought by some changes in pre-treatment on anti-nutrition factors in soybean milk with different soaking media(including water, citric acid solution and sodium bicarbonate solution) and soaking conditions, also, soybean milk made from dried soybeans was the control group. The results showed that soaking effectively reduced trypsin inhibitor and phytic acid in soybean milk. However, different soaking media had various effects on anti-nutritional factors. The minimum content of trypsin inhibitor in soaked soybeans was 30.88±1.35 TIU·mg^-1, 54% lower than the control group. The minimum content of phytic acid was 3.46±0.15 mg·mL^-1, 77.4% lower than the control group. However, the content of tannin in soaked soybeans was increased significantly(P<0.05). The capabilities of reducing trypsin inhibitor content were decreasing from sodium bicarbonate solution to water to citric acid solution. The capabilities of reducing tannin content were decreasing from citric acid solution to water to sodium bicarbonate solution. The capabilities of reducing phytic acid content were decreasing from citric acid solution to water to sodium bicarbonate solution. In addition to anti-nutritional factors, the quality index of soymilk also changed significantly. The results showed that the overall quality of the NaHCO3 soaking group was the best, except for the individual quality indicators(such as protein content), which was not significantly different from the water-immersed group(P>0.05), while the quality of the citric acid soaking group was the worst among the three groups. Finally, the NaHCO3 solution was selected as the soaking medium for orthogonal process optimization. The results showed that when the soaking temperature was 25 ℃, the soaking time was 16 h, the soaking bean water ratio was 1∶4, and the NaHCO3 concentration was 0.45%, the anti-nutritional factor of soybean milk had the best removal effect and the best quality.