Improvement of protein emulsion stability through glycosylated black bean protein covalent interaction with (−)-epigallocatechin-3-gallate

• Published in: RSC advances 2021-01, Vol.11 (4), p.2546-2555
• Main Authors: Wang, Jubing, Zheng, Huanyu, Zhang, Shenyi, Li, Jishu, Zhu, Xiuqing, Jin, Hua, Xu, Jing
• Format: Article
• Language: English
• Subjects: Chemistry; Coordination compounds; Covalence; Covalent bonds; Emulsions; Fourier transforms; Interface stability; Oxidation; Polyphenols; Protein adsorption; Proteins
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/d0ra08756d

This study investigated the effects of covalent conjugates combined by glycosylated black bean protein isolate (BBPI-G) and (−)-epigallocatechin-3-gallate (EGCG) on the emulsion stability. Fourier transform infrared (FTIR) spectroscopy showed that covalent binding of EGCG with BBPI-G made the protein molecule unfolded. Besides, the emulsifying properties of BBPI-G were increased after combined with EGCG. BBPI-G-EGCG emulsion had lower mean particle size and higher content of interfacial protein adsorption (AP), which resulted in thicker and more impact oil-water interface. Therefore, the stability of emulsions was significantly improved. Furthermore, the emulsions prepared by BBPI-G-EGCG compounds exhibited considerable stability in storage, oxidation, thermal treatments, freeze-thaw and freeze-dried powders resolubility. This study demonstrated that the covalent bond of glycosylated protein and polyphenols could advance the emulsifying performance of protein, and BBPI-G-EGCG covalent complex was an effective emulsifier for preparing high stability emulsions. Stability improvement of emulsions stabilized by covalent conjugation with glycosylated black bean protein and EGCG (BBPI-G-EGCG) was studied through structure changes of proteins and emulsion properties.