羟自由基氧化对鹰嘴豆蛋白质结构及功能性质的影响

Effects of hydroxyl radical oxidation on the structure and functional properties of chickpea protein

中文关键词:  鹰嘴豆  羟自由基  氧化蛋白  结构及功能性

英文关键词:chickpea  hydroxyl radical  oxidation protein  structure and functionality

中文摘要:

      目的 探究羟自由基氧化对鹰嘴豆蛋白质结构及功能性的影响。方法 以鹰嘴豆为研究对象, 用羟自由基体系氧化鹰嘴豆蛋白, 分别测定不同氧化程度氧化蛋白的羰基、内源荧光、溶解度、乳化性、乳化稳定性、起泡性、泡沫稳定性、凝胶持水性和硬度等指标并分析与表征。结果 随着氧化蛋白浓度的增加, 羰基值显著增加, 从1.82 nmol/mg增至6.95 nmol/mg; 溶解度显著下降(P＜0.05); 鹰嘴豆蛋白内源荧光λmax强度从141.24降低到70.37, 最大荧光峰位发生蓝移; 乳化性和乳化稳定性均呈显著下降的趋势, 但最后又略有上升; 起泡性和泡沫稳定性在H2O2体系中整体呈现先增加后降低的趋势; 蛋白凝胶硬度和持水性也随氧化程度的增加而显著下降(P＜0.05), 其中5 mmol和10 mmol氧化蛋白凝胶硬度的下降程度最大, 而0 mmol的氧化蛋白凝胶的硬度下降程度最小。结论 鹰嘴豆蛋白对羟自由基比较敏感, 且氧化程度越高, 对蛋白质功能性的影响越大。

英文摘要:

      Objective To investigate the effect of hydroxyl radical oxidation on the structure and function of chickpea protein. Methods Chickpeas were used as the research object, and the chickpea protein was oxidized by hydroxyl radical system. The carbonyl group, endogenous fluorescence and solubility, emulsification and emulsifying stability, foaming and foam stability, gel water holding capacity and hardness of the oxidized proteins with different oxidation degrees were determined, analyzed and characterized. Results With the increase of the concentration of oxidized protein, the carbonyl value was increased significantly, from 1.82 nmol/mg to 6.95 nmol/mg, the solubility was decreased significantly(P＜0.05), the endogenous fluorescence λmax intensity of chickpea protein was decreased from 141.24 to 70.37, and the maximum fluorescence peak was blue shifted. Emulsification and emulsifying stability were decreased significantly, but were increased slightly at last. In the H2O2 system, the foaming property and foam stability firstly increased and then decreased. The hardness and water holding capacity of the protein gel were also significantly decreased with the increase of oxidation degree (P<0.05), and the hardness of the 5 mmol and 10 mmol oxidized protein gel were decreased the most, while the hardness of the 0 mmol oxidized protein gel was decreased the least. Conclusion Chickpea protein is sensitive to hydroxyl radical, and the higher the degree of oxidation, the greater the effect on protein function.