title: Covalent complexation and functional evaluation of (-)-epigallocatechin gallate and α-lactalbumin.
abstract: The covalent complexation between (-)-epigallocatechin gallate (EGCG) and α-lactalbumin (α-La), and the effect of EGCG on the antioxidative activity and emulsifying properties of α-La were investigated. The turbidity of a solution of 1% α-La and 0.2% EGCG decreased after 24h reaction at pH 8.0 and 60°C, less than the value of α-La alone. The interaction between α-La and EGCG at pH 8.0 was more pronounced than that at pH 6.0 or 7.0, as evidenced by the reduced amplitude of amide A, and I, and II bands of α-La by FT-IR and the increase in the total phenolic content and denaturation temperature. These results implied that EGCG was covalently linked to α-La at pH 8.0. In addition, compared with the control of α-La, α-La-EGCG complexes had significantly increased antioxidative activity. The emulsions stabilized by α-La-EGCG complexes, compared with that by α-La alone, had much smaller droplet sizes, which indicated the emulsifying property of α-La was improved.
authors.affiliation: Beijing Key Laboratory of Functional Food from Plant Resources, College of Food Science & Nutritional Engineering, China Agricultural University, Beijing 100083, China. Electronic address: wangxiaoyayani@163.com.
authors.forename: Xiaoya
authors.initials: X
authors.lastname: Wang
authors.affiliation: Beijing Key Laboratory of Functional Food from Plant Resources, College of Food Science & Nutritional Engineering, China Agricultural University, Beijing 100083, China. Electronic address: 121931053@qq.com.
authors.forename: Jiao
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Beijing Key Laboratory of Functional Food from Plant Resources, College of Food Science & Nutritional Engineering, China Agricultural University, Beijing 100083, China. Electronic address: 791540130@qq.com.
authors.forename: Fei
authors.initials: F
authors.lastname: Lei
authors.affiliation: Beijing Key Laboratory of Functional Food from Plant Resources, College of Food Science & Nutritional Engineering, China Agricultural University, Beijing 100083, China. Electronic address: 382766127@qq.com.
authors.forename: Chunxuan
authors.initials: C
authors.lastname: Liang
authors.affiliation: Beijing Key Laboratory of Functional Food from Plant Resources, College of Food Science & Nutritional Engineering, China Agricultural University, Beijing 100083, China. Electronic address: yuanfang0220@163.com.
authors.forename: Fang
authors.initials: F
authors.lastname: Yuan
authors.affiliation: Beijing Key Laboratory of Functional Food from Plant Resources, College of Food Science & Nutritional Engineering, China Agricultural University, Beijing 100083, China. Electronic address: gyxcau@126.com.
authors.forename: Yanxiang
authors.initials: Y
authors.lastname: Gao
mesh_terms: D000975:Antioxidants / Q000737:chemistry; D002392:Catechin / Q000031:analogs & derivatives* / Q000737:chemistry; D004655:Emulsions / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007768:Lactalbumin / Q000737:chemistry*; D011485:Protein Binding; D011487:Protein Conformation; D013696:Temperature
chemical_list: D000975:Antioxidants; D004655:Emulsions; D002392:Catechin; D007768:Lactalbumin; C045651:epigallocatechin gallate
keywords: Antioxidative activity; Covalent complexation; EGCG; Emulsifying property; α-La