摘要
为了建立多糖的带电特性与蛋白质复合体系的关系,以壳聚糖(CS)和酪蛋白为试验对象,通过荧光光谱法、紫外-可见吸收光谱法、傅里叶红外吸收光谱法及流变黏态分析法研究CS与酪蛋白的复合机制及流变特性。结果表明:荧光光谱中,CS对酪蛋白的猝灭方式是静态的。在温度303 K和313 K条件下,高脱乙酰度壳聚糖(HDCS)的结合位点数分别为1.29和1.36;低脱乙酰度壳聚糖(LDCS)的结合位点数分别是1.47和1.44。此外,pH 6.0时,HDCS-酪蛋白间的相互作用主要为静电相互作用,LDCS-酪蛋白则主要为疏水相互作用。紫外-可见吸收光谱中,LDCS的加入未改变酪蛋白中酪氨酸(Tyr)的微环境,而HDCS的加入使得酪蛋白中Tyr的微环境发生改变,使其极性升高,多肽链伸展。傅里叶红外光谱显示,CS中的-NH3+基团和酪蛋白中-COO-基团发生相互作用。流变稳态黏度分析表明,CS-酪蛋白复合溶液的黏度随CS脱乙酰度的增加而增大。
In order to establish the relationship between the charged characteristics of polysaccharides and protein complex systems,in this paper,the composite mechanism and rheology of CS and casein were characterized by fluorescence spectroscopy,ultraviolet-visible absorption spectroscopy,Fourier infrared absorption spectroscopy and rheological viscosity analysis.The results showed that the quenching of casein by CS was static in the fluorescence spectrum.At 303 K and 313 K,the binding sites of high deacetylation chitosan(HDCS)were 1.29 and 1.36,the number of binding sites for low deacetylation chitosan(LDCS)were 1.47 and 1.44,respectively.At pH 6.0,the interaction between HDCS-casein was mainly attributed to electrostatic interaction,LDCS-casein mainly ascribed to hydrophobic interaction.In the UV-visible absorption spectrum,the addition of LDCS did not change the microenvironment of tyrosine(Tyr)in casein.However,the addition of HDCS changed the microenvironment of Tyr in casein,increasing its polarity and stretching the polypeptide chain.Fourier transform infrared spectroscopy showed that the-NH3+group in CS interacted with the-COO-group in casein.In the rheological steady-state viscosity analysis,the viscosity of the CS-casein complex solution increased with the increase of CS deacetylation degree.
作者
张超
傅玉颖
沈亚丽
陈国文
张豪
靳冰
Zhang Chao;Fu Yuying;Shen Yali;Chen Guowen;Zhang Hao;Jin Bing(College of Food and Biotechnology Engineering,Zhejiang Gongshang University,Hangzhou 310018;Hangzhou College of Commerse,Zhejiang Gongshang University,Hangzhou 310018)
出处
《中国食品学报》
EI
CAS
CSCD
北大核心
2021年第2期63-71,共9页
Journal of Chinese Institute Of Food Science and Technology
基金
浙江省自然科学基金项目(1110KZN0418025G)。
关键词
壳聚糖
酪蛋白
脱乙酰度
带电特性
相互作用
chitosan
casein
degree of deacetylation
charged property
interaction
