不同酶解条件下大豆分离蛋白结构特性及起泡性研究  

Effect of Enzymatic Hydrolysis on Structure and Foamability of Soybean Protein Isolate

作　　者：齐宝坤[1] 王英 李子玉 张小影 王帅[1] QI Baokun;WANG Ying;LI Ziyu;ZHANG Xiaoying;WANG Shuai(College of Food Science,Northeast Agricultural University,Harbin 150030,China)

机构地区：[1]东北农业大学食品学院,哈尔滨150030

出　　处：《农业机械学报》2024年第5期431-439,共9页Transactions of the Chinese Society for Agricultural Machinery

基　　金：国家重点研发计划项目(2021YFD2100301)。

摘　　要：以大豆分离蛋白(SPI)为原料,采用碱性蛋白酶(Alcalase)进行酶解(0~180 min),通过凝胶电泳、傅里叶红外光谱(FT-IR)和内源荧光光谱等方法探究酶解产物的结构变化;通过表面张力、界面蛋白吸附量等指标说明酶解产物的界面行为,并分析结构变化和界面行为对泡沫性质的影响。经酶解后,蛋白中7S和11S典型条带消失并有新条带产生(约24 ku);与SPI相比,水解物中α-螺旋含量减少,β-转角和无规则卷曲含量增加;荧光波长发生红移。以上结果说明蛋白结构展开,进而促进蛋白功能性的改变。结果发现,酶解90 min时样品起泡性最好(起泡性指数143.20%),可能由于此时水解物平均粒径最低(208.10 nm),溶解度较高(90.44%),表面张力最低,有利于提升水解物在空气-水界面的吸附速率,但由于酶解作用产生较小的肽段失去了蛋白质网络结构的能力,因而对泡沫稳定性有负面的影响。此外,酶解作用大大提高了蛋白抗氧化性。通过酶解可以有效地改善SPI的起泡性,拓宽了酶解后的SPI作为一种有效的起泡剂在食品中的应用范围。Soybean protein isolate(SPI)was used as raw material for hydrolysis with Alcalase(0~180 min).The structural changes of enzymatic hydrolysis products were investigated by gel electrophoresis,Fourier transform infrared spectroscopy(FT IR)and intrinsic fluorescence spectra.The interfacial behavior of enzymatic hydrolysis products was described by surface tension and adsorption of interfacial protein,and the influence of structural changes and interfacial behavior on the foam properties was analyzed.After enzymatic hydrolysis,the typical 7S and 11S bands disappeared and new bands were produced(about 24 ku).Compared with SPI,the content of α-helix was decreased,the content of β-turn and random coil was increased in hydrolysate,and the fluorescence wavelength was red shifted.These results indicated that the protein structure was unfolded,which in turn promoted the change of protein function.The results showed that the foamability of the sample was the best(143.20%)at 90 min,which may be due to the lowest average particle size(208.10 nm),high solubility(90.44%)and lowest surface tension of the hydrolysate at this time,which was conducive to improving the adsorption rate of the hydrolysate at the air water interface.However,due to the small peptides produced by enzymolysis,the ability of protein network structure was lost,which had a negative impact on foam stability.In addition,the antioxidant activity of the protein was greatly improved by enzymatic hydrolysis.The foamability of SPI can be effectively improved through enzymatic hydrolysis,and the application range of SPI as an effective foaming agent in food was expanded.

关 键 词：大豆分离蛋白 碱性蛋白酶 界面行为 起泡性 抗氧化 

分 类 号：TS214.2[轻工技术与工程—粮食、油脂及植物蛋白工程]