不同热处理大豆分离蛋白凝胶冻藏特性  

Gel properties of soybean isolate protein with different heat treatments during frozen storage

作　　者：陈振家[1,2] 施小迪 杜昱蒙 姚美伊[1] 郭顺堂[1] 

机构地区：[1]中国农业大学食品科学与营养工程学院,北京100083 [2]山西农业大学食品科学与工程学院,太谷030801

出　　处：《农业工程学报》2016年第11期283-289,共7页Transactions of the Chinese Society of Agricultural Engineering

基　　金："十二五"农村领域国家科技计划课题资助项目(2012BAD34B04-2);国家自然科学基金资助项目(31471582)

摘　　要：为探究冻藏过程中不同加热温度处理大豆分离蛋白(soybean isolate protein,SPI)凝胶特性变化及评估不同热处理对SPI凝胶冻藏特性的影响。该文以65、90和135℃3个不同温度处理所得SPI为研究对象(分别记为65SPI、90SPI和USPI),采用离心法、质构分析法、可溶蛋白含量测定和电泳等方法对其冻藏过程中的凝胶持水性、凝胶硬度、凝胶弹性、可溶蛋白含量及亚基组成和凝胶作用力进行了分析研究。结果表明:随冻藏时间延长,不同温度处理SPI凝胶持水性、凝胶弹性和凝胶可溶蛋白含量呈下降趋势,而凝胶硬度呈增大趋势。凝胶持水性、弹性的下降和凝胶硬度的升高标志着凝胶品质的劣变。不同温度处理对SPI凝胶的冻前凝胶特性和冻藏特性有较大影响,65和90℃的温度处理降低了冻前SPI凝胶的持水性,增强了冻前SPI凝胶硬度,有更多的β和B亚基参与了凝胶形成,冻藏前后的亚基组成没有变化;超高温瞬时加热(ultra high temperature,UHT)处理则降低了冻前SPI凝胶硬度,冻藏过程中可溶蛋白含量大幅下降且可溶蛋白中β和B亚基含量下降。3种温度处理SPI的凝胶劣变程度均高于未处理SPI。加热处理会造成SPI发生部分或完全变性,变性后疏水基团的暴露会加快蛋白凝胶形成过程中聚集速率,进而增大粗糙凝胶结构形成的几率,而粗糙凝胶网络在冻藏过程中其劣变程度更甚于未加热SPI。由此可知,加热处理尽管在一定程度上增大了凝胶硬度,但会加速其凝胶品质冻藏劣变。This phenomenon that water in the foods transforms into ice crystals during frozen storage, might have influence on the gel properties of soybean isolate protein（SPI） and sensory quality of frozen foods. In addition, heat effect generated during sterilization, which is the important procedure to process SPI, would change gel properties of SPI. Therefore, the effects of different heat treatments on the gel properties of SPI during frozen storage were carried out using Texture Analyzer and SDS-PAGE to provide a theoretical basis for endowing SPI-containing foods with better quality during frozen storage. In this study, three types of SPI, which were prepared by three different heat treatments, namely low temperature with long time（65 ℃, 30 min）, high temperature with short time（90 ℃, 10 min） and ultra-high temperature sterilization（135 ℃, 15 s）, hereafter were referred to as 65 SPI, 90 SPI and USPI. The changes in gel properties of three types of SPIs were investigated during frozen storage at-18 ℃. The SPI without any heat treatment was regarded as the control. The results showed that the gels of 65 SPI and 90 SPI had higher hardness with lower elasticity and water holding capacity（WHC）, compared to the control SPI gel, while for USPI gel, the hardness, elasticity and WHC were relatively low. On the other hand, before freezing, 65 SPI and 90 SPI had more proteins incorporated into the gel network than the control SPI, whereas less protein of USPI participated in the formation of gel network. SDS-PAGE results further revealed that almost all β subunits and basic polypeptides（B） of 65 SPI and 90 SPI were incorporated into the gel network before freezing, while for USPI and SPI, only part of β and B subunits took part in the formation of gel network. However, no marked changes were detected in the values of chemical interactions of gels formed from three types of SPI before freezing. After freezing, the hardness of gels was increased continuously with the increase of frozen storage t

关 键 词：加工 温度 冷藏 大豆分离蛋白 温度处理 凝胶特性 

分 类 号：TS201.7[轻工技术与工程—食品科学]