食品科学 ›› 2017, Vol. 38 ›› Issue (11): 18-24.doi: 10.7506/spkx1002-6630-201711004

• 基础研究 • 上一篇    下一篇

红外光谱研究超声促聚集作用对大豆蛋白-磷脂结构与功能的影响

毕 爽,张巧智,丁 俭,隋晓楠,王中江,齐宝坤,江连洲,李 杨   

  1. 东北农业大学食品学院,黑龙江 哈尔滨 150030
  • 出版日期:2017-06-15 发布日期:2017-06-19

Infrared Spectroscopic Analysis of the Effect of Ultrasound-Promoted Aggregation Behavior on Structural and Functional Properties of Soybean Protein-Lecithin System

BI Shuang, ZHANG Qiaozhi, DING Jian, SUI Xiaonan, WANG Zhongjiang, QI Baokun, JIANG Lianzhou, LI Yang   

  1. College of Food Science, Northeast Agricultural University, Harbin 150030, China
  • Online:2017-06-15 Published:2017-06-19

摘要: 大豆分离蛋白和大豆卵磷脂在中性条件下(pH 7.0)复合后,可自发组成蛋白质-磷脂复合体系,但仍有部分未自组装的蛋白质和磷脂存在于溶液中。为实现蛋白质-磷脂最大程度复合,解析复合体系功能性质与大豆蛋白二级结构间的构效关系,本研究采用“超声改性-结构变化-功能表达”的研究理念,采用傅里叶变换红外光谱法研究体系结构变化,测定持水性、持油性、凝胶质地剖面并分析其功能性质。结果表明:超声处理会显著改善大豆蛋白-磷脂复合体系的功能性质,超声时间较短时,持水性、持油性等功能性质随功率的增加先升高后降低;超声时间较长时,功能性质随功率的增加持续降低。傅里叶变换红外光谱分析发现低、中功率条件下,大豆蛋白二级结构中β-折叠相对含量较多而α-螺旋结构相对含量较少,说明大豆蛋白与磷脂间的交互作用更明显。超声波作用下复合体系凝胶质地剖面分析表明,功能性质与蛋白质的二级结构改变具有一定的关联性。以上结果说明,适当的超声处理有助于改变大豆蛋白-磷脂复合体系的结构并提升其功能性质。

关键词: 大豆蛋白, 卵磷脂, 功能性质, 结构性质, 傅里叶变换红外光谱

Abstract: Soybean protein isolate (SPI) and lecithin can be self-assembled into a complex system at neutral condition (pH 7.0), while the unassembled compounds are still present in the solution. In an effort to achieve maximum complexation between SPI and lecithin and to elucidate the relationship between the functional properties of the complex system and the secondary structure of soybean proteins, we examined the structural variability of the system by Fourier transform infrared spectroscopy and measured its water-holding capacity, oil-holding capacity, gel texture characteristics and functional properties under ultrasound irradiation. The results showed that ultrasonic treatment significantly improved functional properties of the soybean protein-lecithin complex. Water-holding capacity and oil-holding capacity increased firstly then decreased with increasing ultrasonic power after a short irradiation time, but these functional properties continuously decreased with increasing ultrasonic power after a long irradiation time. Fourier transform infrared spectroscopic analysis revealed that the secondary structure of SPI contained a lower content of α-helix and a higher content of β-structure after ultrasonic irradiation at low and medium powers, indicating stronger protein-lecithin interactions. There was a certain relationship between the gel texture characteristics of the complex system and the secondary structure of SPI. The structure of soybean protein-lecithin system could be changed by proper ultrasonic treatment, thus improving its functional properties.

Key words: soybean protein, lecithin, functional properties, structural properties, Fourier transform infrared spectroscopy

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