Effects of Ultrasound Pretreatment on the Enzymatic Hydrolysis of Soy Protein Isolates and on the Emulsifying Properties of Hydrolysates
Effects of Ultrasound Pretreatment on the Enzymatic Hydrolysis of Soy Protein Isolates and on the Emulsifying Properties of Hydrolysates
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DOI：
10.1021/jf103771x
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发表时间：
2011-03-23
影响因子：
6.1
通讯作者：
Zhao, Mouming
中科院分区：
文献类型：
--
作者：
Chen, Lin;Chen, Jianshe;Zhao, Mouming
采用超声预处理（200w、400w、600w）和控制木瓜蛋白酶水解对大豆分离蛋白（SPI）进行改性，研究了大豆分离蛋白水解产物SPIH和超声预处理大豆分离蛋白USPIH的乳化性能。对SPIH和USPIH形成的乳剂的平均液滴大小和成乳指标的分析表明，在静态储存过程中，部分USPIH的乳化能力和乳化稳定性显著提高。与对照SPI和SPIH-0.58%水解度（DH）相比，USPIH-400W-1.25% （USPIH在400W超声条件下预处理，水解至1.25% DH）在较低浓度（3.0% w/v）下能够形成稳定的细乳液（d(43) = 1.79 μ m）。研究了USPIH-400W产品的各种物理化学和界面性能与DH和乳化性能的关系。SDS-PAGE结果表明，超声预处理可以显著提高大豆蛋白中α - 7s和A-11S亚基对木瓜蛋白酶水解的可达性，导致USPIH-400W的DH、蛋白溶解度（PS）、表面疏水性（H-0）和二级结构发生变化。与对照SPI和SPIH-0.58%相比，USPIH-400W-1.25%具有更高的蛋白质吸附分数（F-ads）和更低的饱和表面负荷（Gamma(sat)），这主要是由于其PS和随机线圈含量较高，这可能是其乳化能力显著提高的原因。本研究表明，超声预处理与酶解控制相结合是一种有效的球形蛋白功能修饰方法。
Soy protein isolate (SPI) was modified by ultrasound pretreatment (200 W, 400 W, 600 W) and controlled papain hydrolysis, and the emulsifying properties of SPIH (SPI hydrolysates) and USPIH (ultrasound pretreated SPIH) were investigated. Analysis of mean droplet sizes and creaming indices of emulsions formed by SPIH and USPIH showed that some USPIH had markedly improved emulsifying capability and emulsion stabilization against creaming during quiescent storage. Compared with control SPI and SPIH-0.58% degree of hydrolysis (DH), USPIH-400W-1.25% (USPIH pretreated under 400W sonication and hydrolyzed to 1.25% DH) was capable of forming a stable fine emulsion (d(43) = 1.79 mu m) at a lower concentration (3.0% w/v). A variety of physicochemical and interfacial properties of USPIH-400W products have been investigated in relation to DH and emulsifying properties. SDS-PAGE showed that ultrasound pretreatment could significantly improve the accessibility of some subunits (alpha-7S and A-11S) in soy proteins to papain hydrolysis, resulting in changes in DH, protein solubility (PS), surface hydrophobicity (H-0), and secondary structure for USPIH-400W. Compared with control SPI and SPIH-0.58%, USPIH-400W-1.25% had a higher protein adsorption fraction (F-ads) and a lower saturation surface load (Gamma(sat)), which is mainly due to its higher PS and random coil content, and may explain its markedly improved emulsifying capability. This study demonstrated that combined ultrasound pretreatment and controlled enzymatic hydrolysis could be an effective method for the functionality modification of globular proteins.