摘要
本研究旨在对超高压处理作用于乳清浓缩蛋白后结构的影响进行验证,通过体外模拟消化探究其进入人体消化过程后功能性的变化。通过SDS-聚丙烯酰胺凝胶电泳(SDS-PAGE)、圆二色谱、荧光光谱及紫外吸收光谱分析超高压对乳清浓缩蛋白结构的影响,再通过SDS-PAGE、粒度及Zeta电位分析其体外模拟消化后乳清浓缩蛋白分子变化,再对其体外模拟消化产物进行抗氧化性分析(ABTS^(+)自由基清除率、DPPH自由基清除率及Fe^(3+)还原力测定法)及对动物双歧杆菌BB-12的增殖效果的研究,确定最佳超高压条件及探究其消化前后功能性变化。结果表明,超高压处理对于乳清浓缩蛋白的三级结构有明显影响,在600 MPa、30 min对其三级结构的改变最大,而对于其一、二级结构的影响并不明显;证明在肠消化完成后乳清浓缩蛋白被完全水解为小分子肽或氨基酸,且超高压处理对于其胃消化后的分子量并无显著影响,与未消化样品无明显差异;随着体外模拟消化过程的进行,乳清浓缩蛋白粒度先减少后增大,Zeta电位绝对值先减小后增大;随着压力和时间的增加,未消化的乳清浓缩蛋白抗氧化性逐渐增强,胃消化和肠消化后的样品抗氧化性先增强后减弱;且未消化的样品在500 MPa、15 min促进双歧杆菌BB-12生长的效果最好,胃消化后的样品在200 MPa 30 min、300 MPa 30 min对其生长有促进效果,肠消化后的样品均对其生长有抑制作用。本研究结果为超高压技术应用乳品工业提供了进一步的理论基础。
The purpose of this study was to verify the effect of ultra-high pressure treatment on the structure of whey protein concentrate,and to explore its functional changes after entering the human digestive process through simulated digestion in vitro.The effects of ultra-high pressure on the structure of whey protein concentrate were analyzed by SDS-polyacrylamide gel electrophoresis(SDS-PAGE),circular dichroism,fluorescence spectrum and ultraviolet absorption spectrum.Then,the molecular changes of whey protein concentrate after simulated digestion in vitro were analyzed by SDS-PAGE,particle size and Zeta potential.Then the antioxidant activity of its simulated digestion products in vitro(ABTS^(+) free radical scavenging rate,DPPH free radical scavenging rate and Fe^(3+) reducing power)and the proliferation effect of animal Bifidobacterium BB-12 were studied to determine the optimal ultra-high pressure conditions and explore the functional changes before and after digestion.The results showed that,UHP treatment had a significant effect on the tertiary structure of whey protein concentrate,and the 600 MPa for 30 min had the greatest change in the tertiary structure,but the effect on the primary or secondary structure of protein was not significant.The whey protein concentrate was completely hydrolyzed into small peptides or amino acids after intestinal digestion,and the ultrahigh pressure treatment had no significant effect on the molecular weight of the stomach after digestion,and there was no significant difference between the whey protein and the undigested sample.With the simulated digestion process in vitro,the particle size of whey protein concentrate first decreased and then increased,and the absolute value of Zeta potential first decreased and then increased,the antioxidant activity of undigested whey protein concentrate gradually increased with the increasing of pressure and time,the antioxidant activity of samples after gastric digestion and intestinal digestion firstly increased and then decreased with the increase of pressure and time,and the effect of undigested samples on promoting the growth of Bifidobacterium Bb-12 at 500 MPa for 15 min was the best.The samples after gastric digestion could promote its growth at 200 MPa for 30 min and 300 MPa for30 min,and the samples after intestinal digestion could inhibit its growth.The results of this study would provide a further theoretical basis for the application of ultra-high pressure technology in dairy industry.
作者
马寅龙
郭锐斌
孔祥丽
滕国新
许晓曦
MA Yinlong;GUO Ruibin;KONG Xiangli;TENG Guoxin;XU Xiaoxi(Key Laboratory of Dairy Science and Education,College of Food Science,North East Agricultural University,Harbin 150030,China;Inner Mongolia Mengniu Dairy(Group)Co.,Ltd.,Hohhot 011500,China)
出处
《食品工业科技》
CAS
北大核心
2022年第8期93-104,共12页
Science and Technology of Food Industry
基金
内蒙古自治区科技计划资助(201903202203)。
关键词
乳清浓缩蛋白
功能性
超高压技术
体外模拟消化
抗氧化性
whey protein concentrate
functionality
ultra high pressure technology
simulated digestion in vitro
antioxidation
