摘要
研究不同质量浓度的花青素与大豆分离蛋白(soy protein isolate,SPI)在漆酶条件和碱性条件下的共价交联机制,以及两者在共价交联后对蛋白结构及营养吸收特性的影响。采用三维荧光光谱研究花青素与SPI在不同共价交联条件下的复合程度,并揭示被花青素交联后的SPI的结构构象变化;后采用胃蛋白酶、胰蛋白酶及Caco-2细胞对SPI与花青素-SPI共价复合物进行模拟人体胃肠消化及吸收,探究消化过程中水解度、抗氧化性、多肽渗透率等指标。结果表明:花青素对SPI的交联可以降低蛋白荧光值,使蛋白多肽链解折叠从而改变蛋白的三级结构。同时,蛋白的消化率和抗氧化性因花青素的交联而升高,花青素质量浓度越高,这种改善现象越明显,尤其是在漆酶条件下。值得注意的是,花青素对蛋白多肽的渗透率有抑制作用,且花青素含量越高,抑制作用越强烈。添加同质量浓度花青素时,漆酶条件下的花青素对多肽渗透率的抑制作用比碱性条件下的花青素更强。
In this paper we studied the covalent cross-linking mechanism of soy protein isolate (SPI) with different concentrations of anthocyanins in the presence of either laccase or alkali, and we also investigated the effect of this cross-linking on protein structure and absorption. The degree of cross-linking as well as the resulting conformational change of SPI was evaluated by three-dimensional fluorescence spectroscopy. The gastrointestinal digestion and nutritional absorption of anthocyanins-SPI conjugates were simulated using pepsin, pancreatin, and Caco-2 cells. And we also evaluated the degree of hydrolysis, antioxidant capacity, and the permeability of peptides during the digestion process. The results showed that the fluorescence intensity of SPI was reduced, and polypeptide chain unfolding and consequently tertiary structure changes occurred after cross-linking with anthocyanins. At the same time, the cross-linking increased the digestibility and antioxidant capacity of the protein and this effect was positively correlated with anthocyanin concentration, especially in the presence of laccase. It is worth noting that anthocyanins had an inhibitory effect on the permeability of peptides in a concentration- dependent fashion, which was stronger in the presence of laccase than in the presence of alkali at the same concentration of anthocyanins.
作者
刘英杰
蒋悦
黄国
王宁
刘春峰
王天雪
李婧
刘贵辰
隋晓楠
江连洲
LIU Yingjie;JIANG Yue;HUANG Guo;WANG Ning;LIU Chunfeng;WANG Tianxue;LI Jing;LIU Guichen;SUI Xiaonan;JIANG Lianzhou(College of Food Science,Northeast Agricultural University,Harbin 150030,China)
出处
《食品科学》
EI
CAS
CSCD
北大核心
2019年第12期1-8,共8页
Food Science
基金
国家自然科学基金青年科学基金项目(31601475)
关键词
大豆分离蛋白
花青素
漆酶条件
碱性条件
结构
营养吸收
soybean protein isolates (SPI)
anthocyanins
laccase
alkali
structure
nutritional absorption