Niu Rui-Hao, Chen Fu-Sheng, Zhao Zi-Tong, Xin Ying, Duan Xiao-Jie, Wang Bing-Yi
College of Food Science and Technology, Henan University of Technology.
J Oleo Sci. 2020 Jun 4;69(6):617-625. doi: 10.5650/jos.ess19297. Epub 2020 May 14.
This study investigated the effect of papain on the demulsification of peanut oil body emulsion extracted using an aqueous enzymatic method and the associated mechanism. The highest free oil yield using papain (92.39%) was obtained under the following conditions: an enzymatic hydrolysis temperature of 55°C, sample-to-water ratio of 1:3, enzyme concentration of 1400 U/g, and an enzymatic hydrolysis time of 3 h. Papain degraded the peanut oil body protein to small-molecular-weight peptides (≤ 14.4 kDa). Compared to the emulsion before enzymatic hydrolysis, the amino acid content in the aqueous phase was higher after enzymatic hydrolysis, the viscosity of the oil body emulsion was lower, and the particle diameter of the emulsion was significantly larger. The following demulsification mechanism was derived. Papain degrades the protein on the peanut oil body and dissolves it in water. The outer side of the oil body loses the protection of electrostatic repulsion and steric hindrance provided by the membrane protein. This causes the viscosity of the emulsion system and the molecular steric hindrance to decrease. As a result, the oil droplets gather and eventually demulsify. The results of this study provide the theoretical basis for the instability in oil body emulsions and are expected to promote the application of enzymatic demulsification in industry.
本研究考察了木瓜蛋白酶对水相酶法提取的花生油体乳液破乳的影响及其相关机制。在以下条件下，使用木瓜蛋白酶获得的最高游离油产率为92.39%：酶解温度55℃、料水比1:3、酶浓度1400 U/g、酶解时间3 h。木瓜蛋白酶将花生油体蛋白降解为小分子量肽（≤14.4 kDa）。与酶解前的乳液相比，酶解后水相中的氨基酸含量更高，油体乳液的粘度更低，乳液的粒径显著增大。由此得出以下破乳机制。木瓜蛋白酶降解花生油体上的蛋白质并将其溶解于水中。油体外侧失去了膜蛋白提供的静电排斥和空间位阻保护。这导致乳液体系的粘度和分子空间位阻降低。结果，油滴聚集并最终破乳。本研究结果为油体乳液的不稳定性提供了理论依据，有望推动酶法破乳在工业中的应用。
