pH偏移协同热处理对燕麦分离蛋白的结构和乳化特性的影响

Effect of pH offset synergistic heat treatment on the structure and emulsification properties of oat isolated proteins

本实验首先探究了燕麦蛋白的最优提取参数。以燕麦粉作为研究对象,通过碱提酸沉法提取燕麦蛋白,结合正交试验分析方法,探究不同条件下的提取pH、料液比、温度,以及提取时间等对燕麦蛋白质提取率的影响。结果表明:料液比16∶1、pH10、提取时间为100 min、提取温度为50 ℃是最优提取条件,在此情况下燕麦蛋白质提取率为66.16%。进而研究了不同pH偏移协同热处理对燕麦分离蛋白结构及乳化特性的影响。燕麦蛋白质的二级结构结果显示,由于pH提高,蛋白质的二级结构中的β-折叠含量发生显著降低,α-螺旋的含量显著提高。内源性荧光光谱显示,在蛋白质等电点附近荧光强度最低。燕麦蛋白质的乳化性及乳化稳定性结果显示:燕麦蛋白的乳化性随着pH的增加呈现先降低后增加的趋势,乳化稳定性在等电点处达到最小值。当pH升高,乳化稳定性逐渐增大。本研究为改善燕麦蛋白的性质,以期为食品工业生产提供新的思路及新的理论依据,扩展蛋白类产品,特别是燕麦蛋白产品在食品深加工领域的进一步应用。

This experiment explored the optimal extraction parameters of oat protein.Using oat powder as the research object,oat protein was extracted by alkali extraction acid sedimentation method.Combined with orthogonal test analysis method,the effects of extraction pH,liquid ratio,temperature and extraction time on the protein extraction rate of oat under different conditions were explored.The results showed that the liquid ratio of 16∶1,pH value of 10,extraction time of 100 min and 50℃ were the optimal extraction conditions,and the oat protein extraction rate was 66.16%.The effect of different pH offset on protein structure and emulsification characteristics of oat was also studied.The secondary structure results of the oat protein showed that the beta-folding content in the secondary structure of the protein was significantly reduced and the beta-helix content increased significantly due to the increased pH value.Endogenous fluorescence spectra revealed the lowest fluorescence intensity was near the isoelectric points of the protein.The results of the emulsification and emulsification stability of oat protein showed that the emulsification of oat protein decreased first then increased with the increase of pH value,and the emulsification stability reached the minimum value at the isoelectric point.When the pH value increased,the emulsification stability gradually increased.This study aims to improve the nature of oat protein,in order to provide new ideas and new theoretical basis for food industry production,and expand the further application of protein products,especially oat protein products in the field of food deep processing.