空化射流条件下酶法制油豆渣蛋白结构与理化特性研究

Effect of Cavitation Jet on Structure and Physicochemical Properties of Soybean Residue Protein Produced by Enzymatic Oil Production

为运用空化射流处理技术有效提高酶法制油豆渣中可溶性蛋白含量、改善其理化特性,采用二维和三维荧光、十二烷基硫酸钠聚丙烯酰胺凝胶电泳及扫描电镜解析了不同空化射流处理时间(0、5、10、15 min)对豆渣蛋白结构的影响及形态变化,并采用溶解性、乳化性、氨基酸分析、粒度分布及ζ-电位对其理化及功能特性进行表征,最终明确了空化射流处理对酶法制油豆渣蛋白结构及理化特性的影响规律。结果表明:空化射流可促进豆渣蛋白结构解折叠,使分子间相互作用增强,其亚基结构由高分子量向低分子量转化;当空化射流处理10 min时,豆渣蛋白粒度分布稳定,且体积平均粒径D[4,3]达到最低值(470.10±8.70)nm,ζ-电位绝对值达到最大(27.4±0.83)mV,溶解特性及界面性质最佳;经氨基酸分析发现,酶法制油豆渣蛋白和大豆分离蛋白(SPI)的氨基酸组成相似,其疏水性氨基酸质量分数达33.03%。

Aiming to use the cavitation jet treatment technology to effectively increase the soluble protein content and improve the physicochemical properties of the soybean residue produced by enzymatic oil production,two-dimensional,three-dimensional fluorescence,sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDSPAGE),and scanning electron microscopy were used to analyze the effects of different cavitation jet treatment times(0 min,5 min,10 min and 15 min)on the structure and morphological changes of soybean residue protein,and its solubility,emulsification,amino acid analysis,particle size distribution andζ-potential were used to characterize its physicochemical and functional characteristics,and finally the cavitation jet effect on the structure and physicochemical properties of protein from soybean residue produced by enzymatic method was clarified.The results showed that the cavitation jet can promote the unfolding of the soybean residue protein structure and the intermolecular interaction was enhanced,and its subunit structure was transformed from high molecular weight to low molecular weight.When the cavitation jet was treated for 10 min,the particle size distribution of the soybean residue protein was stable and the volume average particle diameter D[4,3]reached the lowest value(470.10±8.70)nm,the absolute value ofζ-potential reached the maximum value(27.4±0.83)mV,and the dissolution characteristics and interfacial properties were the best;in particular,amino acid analysis revealed that the amino acid composition of the enzyme-made oil soybean residue protein and soy protein isolate(SPI)was similar,with hydrophobic amino acids reached 33.03%.