菜籽蛋白的制备及其体外模拟消化

Preparation and in vitro digestibility of rapeseed protein

采用响应面法(RSM)优化了菜籽蛋白提取的3个影响因素(pH、温度、液料比),同时对大豆蛋白(SPI)、菜籽蛋白(PPI)及其12S组分(RP-12S)、2S组分(RP-2S)进行模拟体外消化,结合SDS-PAGE分析和可溶性氮释放量评价了菜籽蛋白消化率。结果表明,在pH12.0、液料比19∶1、55.0℃下提取菜籽粕30 min,重复2次,最大提取率可达78.85%,酸沉pH为5.0。经胃蛋白酶、胰蛋白酶体系消化,PPI、RP-12S、RP-2S的可溶性氮释放量分别为84.51%、78.33%、80.39%,均比SPI的可溶性氮释放量高。说明菜籽蛋白拥有比大豆蛋白更好的消化性,是适合人类食用的优质蛋白质。

The influence factors of pH, extraction temperature and ratio of solution to solid for rapeseed protein extraction were optimized by response surface methodology. The in vitro digestibility of soybean protein isolate （ SPI）, rapeseed protein （ PPI）, 12S - and 2S - rich rapeseed protein （ RP - 12S and RP -2S） were also investigated by SDS- PAGE and nitrogen release. The results indicated the highest extraction yield （78.85%） of rapeseed protein was obtained, when the rapeseed meal was extracted twice for 30 min at 55.0 ℃, ratio of solution to solid 19：1 and pH 12. 0. The maximum yield of precipitated rapeseed protein was obtained at pH 5.0. Under the sequential pepsin and trypsin digestion model, the nitrogen releases of PPI,RP - 12S and RP -2S were 84.51% , 78.33% and 80.39%, respectively, and all were higher than that of SPI. The digestibility of PPI was superior to SPI, and the PPI was an high - quality protein source.