不同HLB值的表面活性剂对核桃仁酶解特性的影响

Effects of the Hydrophile-Lipophile Balance Value of Surfactants on the Characteristics of Enzymatic Hydrolysis in Walnut Kernels

摘要:

本文主要研究了表面活性剂不同HLB值对水酶法提取核桃油和制备抗氧化肽过程中油提取率、酶解清液析出率、乳化层形成率、酶解清液还原力和蛋白回收率的影响，并通过测定酶解清液的肽分子量分布和乳化层的粒径分布及其组成进一步探讨了其作用机理，研究发现：随着表面活性剂HLB值的逐渐增大，油提取率逐渐降低，乳化层形成率及酶解清液中>5000 u和>3000 u的肽段含量逐渐升高，而酶解清液析出率和蛋白质回收率则呈现出先减小后增大最后又减小的趋势。与空白相比，表面活性剂HLB值为1.0时，核桃油提取率可提高5%左右；表面活性剂HLB值为13.5时，可显著解析界面蛋白和多肽，增大乳化层中的脂肪球粒径，显著提高酶解清液中的蛋白回收率，且不会对核桃肽的抗氧化活性造成显著影响。

Abstract:

The effects of the hydrophile-lipophile balance (HLB) value of surfactants on the oil extraction rate, enzymatic hydrolysate supernatant yield, emulsified layer formation rate, protein recovery, and protein reducing power of walnut hydrolysates were examined in this research. And the molecular weight distribution of the peptides in the enzymatic hydrolysate, the droplet size distributions in the emulsified layer, and the composition of the emulsified layer were determined to further investigate the underlying mechanisms. The results showed that the oil extraction rate decreased gradually as the HLB value increased. The emulsified layer formation rate and the contents of proteins or peptides with molecular weights higher than 5000 or 3000 Da increased gradually as the HLB value increased. In addition, the yields of enzymatic hydrolysate supernatants and proteins initially tended to decrease, then increased, and finally decreased. Compared with the blank control, the oil extraction rate was increased by five percent at an HLB value of one. When the HLB value was 13.5, the contents of surface proteins and peptides in the emulsified layer decreased significantly, the particle sizes of the fat globules in the emulsified layer increased, and protein recovery in the enzymatic hydrolysate supernatant improved significantly. However, the antioxidant activity of the walnut hydrolysate was not significantly altered.