13-羟基过氧十八碳二烯酸对米蛋白结构和功能特性的氧化修饰作用。

Effects of oxidative modification by 13-hydroperoxyoctadecadienoic acid on the structure and functional properties of rice protein.

机构信息

College of Food Science and Engineering, Central South University of Forestry and Technology, Changsha, Hunan 410004, China; National Engineering Laboratory for Rice and By-product Deep Processing, Changsha, Hunan 410004, China.

出版信息

Food Res Int. 2020 Jun;132:109096. doi: 10.1016/j.foodres.2020.109096. Epub 2020 Feb 11.

DOI:10.1016/j.foodres.2020.109096

PMID:32331648

Abstract

13-hydroperoxyoctadecadienoic acid (13-HPODE) was selected as lipid peroxidation primary products during rice ageing to investigate the effects of lipid hydroperoxide modification on the structural characteristics and functional properties of rice protein. Incubation of rice protein with 13-HPODE resulted in protein carbonylation and loss of protein sulfhydryl groups in a concentration-dependent manner. FT-IR evaluated the effects of 13-HPODE on rice protein, and the results indicated increasing concentration of 13-HPODE resulted in continuous loss of α-helix, β-turn and random coil structure, and increase in β-sheet content and amino acid side chains. The content of soluble protein aggregates gradually increased, accompanied by protein crosslink via disulfide bonds. 13-HPODE had a negative impact on the solubility, water holding capacity, foaming capacity, and foam stability of rice protein. 13-HPODE could promote oil holding capacity of rice protein. With the concentration of 13-HPODE below 0.1 mmol/L, emulsifying activity index (EAI) and emulsifying stability index (ESI) of rice protein gradually increased, which due to gradual increase in rice protein surface hydrophobicity and flexibility. However, at relatively high concentration of 13-HPODE (above 1 mmol/L), the adverse effect in EAI and ESI was observed, which might be attributed to a decrease in surface hydrophobicity and protein aggregates formation.

摘要

13-羟基过氧十八碳二烯酸（13-HPODE）被选为稻米老化过程中脂质过氧化的初级产物，以研究脂质氢过氧化物修饰对稻米蛋白结构特征和功能特性的影响。用 13-HPODE 孵育稻米蛋白会导致蛋白羰基化和巯基损失，且这种作用具有浓度依赖性。傅里叶变换红外光谱（FT-IR）评估了 13-HPODE 对稻米蛋白的影响，结果表明，随着 13-HPODE 浓度的增加，α-螺旋、β-转角和无规卷曲结构不断减少，β-折叠含量和氨基酸侧链增加。可溶性蛋白聚集体的含量逐渐增加，同时伴随着二硫键的蛋白质交联。13-HPODE 对稻米蛋白的溶解度、持水力、起泡能力和泡沫稳定性有负面影响。13-HPODE 可以促进稻米蛋白的吸油性。当 13-HPODE 的浓度低于 0.1mmol/L 时，稻米蛋白的乳化活性指数（EAI）和乳化稳定性指数（ESI）逐渐增加，这是由于稻米蛋白表面疏水性和柔韧性逐渐增加。然而，在相对较高浓度的 13-HPODE（高于 1mmol/L）时，EAI 和 ESI 的不利影响被观察到，这可能归因于表面疏水性的降低和蛋白质聚集体的形成。