超声辅助提取对藜麦麸皮蛋白结构及功能特性的影响

Effect of Ultrasound-Assisted Extraction on the Structure and Functional Properties of Quinoa Bran Protein

采用超声辅助碱溶酸沉法制备了藜麦麸皮蛋白(Quinoa Bran Protein,QBP),并考察了超声辅助对其结构及功能特性的影响。基于单因素试验,采用Box-Behnken响应面试验分析优化了QBP的制备工艺,对比了超声前后QBP的溶解度、持水性、起泡性及起泡稳定性、乳化性及乳化稳定性、分子量及微观结构等的差异。结果表明:QBP的最优提取工艺为超声功率为400 W,超声时间为26 min,温度为46℃,pH为10,料液比为1∶22,此时蛋白纯度为80.74%,与常规碱法提取相比,QBP的提取率提高了5.51%;QBP的氨基酸含量十分丰富,疏水性氨基酸的比例约占氨基酸总量的1/3以上,采用凝胶成像系统观察到其分子质量主要在10.0 kDa~66.0 kDa范围内;超声辅助提取的QBP的亚基分布无明显改变,但功能特性有所改善,粒径减小并出现较多球状小颗粒结构,说明超声辅助能够改善QBP的结构及功能特性。本文研究为超声技术在藜麦麸皮深加工中的应用提供了理论支持,并可为食品工业废料资源的综合利用提供参考。

The aim of this study was to prepare the quinoa bran protein(QBP)by the ultrasound-assisted alkaline solution-acid precipitation method,and to investigate the effects of ultrasound-assisted extraction on the structure and functional properties of QBP.Based on single factor experiment,Box-Behnken response surface methodology was used to analyze and optimize the preparation process of QBP.The changes of functional properties of QBP,such as solubility,water retention,and foaming properties,and the differences of protein molecular weight and microstructure before and after ultrasound were compared.The results show that the optimal extraction process of QBP is as follows:ultrasonic power is 400 W,ultrasonic time is 26 min,temperature is 46℃,pH is 10,solid-liquid ratio is 1∶22,the purity is 80.74%.Compared with conventional alkali extraction,the extraction rate of QBP is increased by 5.51%.QBP is rich in amino acids,the proportion of hydrophobic amino acids accounts for more than 1/3 of the total amino acids.The molecular weight is observed in the range from 10.0 kDa to 66.0 kDa by gel imaging system.The subunit distribution of ultrasound-assisted extraction of QBP does not change significantly,but the functional properties are improved,the particle size is reduced and more spherical small particle structures appears.This indicates that ultrasound-assisted can improve the structural and functional characteristics of QBP.This study provides theoretical support for the application of ultrasonic technology in the further processing and utilization of quinoa bran,and has reference value to the comprehensive utilization of food industrial waste resources.