焙烤对绿豆蛋白结构和功能性质的影响

本文以绿豆为原料，测定了不同焙烤温度对绿豆蛋白的结构及功能性质的影响。用碱法提取绿豆中的总蛋白，并对蛋白质的二级结构以及多种功能性质进行分析。结果表明，当焙烤温度升高时，除乳化稳定性外其他性质均有显著（P<0.05）提高，乳化性最高达到38.46 m2/g，在180℃下起泡性最高达到了26%，溶解性增加了47.72%，而乳化稳定性则明显下降。相比较，在180℃时绿豆蛋白各项功能性质最佳。在电泳分析中，焙烤加工使得绿豆蛋白各个部分发生不同程度的降解，各个范围的条带均变浅，Ⅰ、Ⅳ、Ⅴ条带几乎消失。在180℃时，第Ⅲ条亚基带颜色加深与功能性质在180℃增强相呼应。通过测定傅里叶红外光谱发现，在1640 cm-1处的峰在110和180℃分别出现红移，其他温度下蛋白与生蛋白相比该峰值出现蓝移，在150和180℃蛋白图谱中1050 cm-1波长处出现明显的峰值。焙烤加工后蛋白二级结构中β-折叠结构含量显著（P<0.05）增加，α-螺旋结构、β-转角结构含量显著（P<0.05）降低。综上，经过高温焙烤热处理后的绿豆蛋白结构会发生改变，基础功能特性会更加优异，180℃ 20 min的焙烤强度可使绿豆蛋白功能性质提升到最佳。

Effects of Baking on the Structure and Functional Properties of Mung Bean Protein

Using mung beans as raw materials.In this paper,the structure and functional properties of mung bean protein extracted at different temperatures were determined.The total protein in mung bean was extracted by alkaline method,and the secondary structure and various functional properties of the protein were analyzed.The research results showed that when the baking temperature increasing,all the properties except the emulsification stability were significantly(P<0.05)improved.The emulsification was up to 38.46 m 2/g.The foamability at 180℃was up to 26%.The solubility increased by 47.72%.And the emulsion stability was significantly reduced.In comparison,mung bean protein had the best functional properties at 180℃.In the electrophoretic analysis,the roasting process causes various parts of mung bean protein to degrade in varying degrees.All the bands became shallow,and bands I,IV,and V almost disappeared.At 180℃,the deepening of the color of article II subunit bands echoes the enhancement of functional properties at 180℃.By measuring Fourier infrared spectroscopy,it was found that the peaks at 1640 cm-1 showed red shifts at 110 and 180℃,respectively.At other temperatures,the peaks of the protein showed blue shifts compared to the raw protein.At 150 and 180℃protein maps,there are obvious peaks at 1050 cm-1 wavelength.From the perspective of protein functional maintenance and regulation after thermal processing.After baking,the contents ofβ-folding structure increased significantly,while that ofα-helix structure andβ-angle structure decreased significantly.In conclusion,after high temperature baking,the structure of mung bean protein would change,and the basic functional properties would be more excellent.The baking strength at 180℃for 20 min could improve the functional properties of mung bean protein to the optimal level.