Chen Yeming, Chen Yajing, Zhao Luping, Kong Xiangzhen, Yang Zhaoqi, Hua Yufei
State Key Laboratory of Food Science and Technology, Jiangnan University, China; School of Food Science and Technology, Jiangnan University, China.
State Key Laboratory of Food Science and Technology, Jiangnan University, China; School of Food Science and Technology, Jiangnan University, China.
Food Chem. 2018 Feb 15;241:443-451. doi: 10.1016/j.foodchem.2017.09.020. Epub 2017 Sep 7.
Peanut seeds are rich in oil, which exists as oil bodies (OBs). By extraction, peanut crude OBs are obtained and can be used as a food ingredient. In a previous study, it was found that the crude OBs contained an unknown protease, which hydrolyzed the oleosins. This would disrupt the integrity of OBs, and therefore, affect their physical and oxidative stability. In this study, the protein composition of crude OBs and some properties of the unknown protease were examined. The results showed that the protease was a two-chain (32 and 9kDa) aspartic protease, which showed high affinity for OBs. The optimal pH and temperature for oleosin hydrolysis by the protease were pH 4.0 and 60°C. Interestingly, the aspartic protease not only hydrolyzed OB intrinsic proteins (oleosin, caleosin, and steroleosin), but also extrinsic proteins (especially Ara h 1 allergen and 26-30kDa arachin).
花生种子富含油脂，以油体（OBs）的形式存在。通过提取可获得花生粗油体，其可用作食品成分。在先前的一项研究中，发现粗油体中含有一种未知的蛋白酶，该酶可水解油质蛋白。这会破坏油体的完整性，进而影响其物理稳定性和氧化稳定性。在本研究中，对粗油体的蛋白质组成以及未知蛋白酶的一些特性进行了检测。结果表明，该蛋白酶是一种双链（32 kDa和9 kDa）天冬氨酸蛋白酶，对油体具有高亲和力。该蛋白酶水解油质蛋白的最适pH值和温度分别为pH 4.0和60°C。有趣的是，这种天冬氨酸蛋白酶不仅能水解油体内在蛋白（油质蛋白、钙结合油体蛋白和固醇结合油体蛋白），还能水解外在蛋白（尤其是Ara h 1过敏原和26 - 30 kDa的花生球蛋白）。
