Issue 10, 2019

Fabrication of surface-active antioxidant biopolymers by using a grafted scallop (Patinopecten yessoensis) gonad protein isolate–epigallocatechin gallate (EGCG) conjugate: improving the stability of tuna oil-loaded emulsions

Abstract

The oxidation of unsaturated fats generally occurs at the oil–water interface of emulsions, so surface-active antioxidants are needed for inhibiting lipid oxidation. In this study, a scallop gonad protein isolate (SGPI)–epigallocatechin gallate (EGCG) conjugate was fabricated and characterized as an amphiphilic surface-active antioxidant in improving the physicochemical and oxidative stability of tuna oil-loaded emulsions via a free-radical grafting method. The covalent binding of EGCG to SGPIs was verified by using electrophoresis and gel permeation chromatography. Meanwhile, the structural, physical, thermal, as well as the in vitro antioxidant properties of the SGPI–EGCG conjugate were further characterized. The results indicated that the SGPI–EGCG conjugate contained more β-sheet but less α-helix than SGPIs, leading to the changes of the secondary and tertiary conformation stability after conjugation. The radical scavenging and oxygen radical absorbance capacity of SGPIs were significantly increased by 4.9 times and 7.4 times, respectively, after the EGCG-grafting reaction. Compared with that stabilized by SGPIs, tuna oil emulsions emulsified by the SGPI–EGCG conjugate exhibited a smaller particle size and better storage stability. Furthermore, the SGPI–EGCG conjugate inhibited lipid and fatty acid oxidation during storage more significantly in tuna oil emulsions than SGPIs due to its higher interfacial accumulation and antioxidant activities. These results suggested that the SGPI–EGCG conjugate could be utilized as an efficient surface-active antioxidant and emulsifier for the encapsulation and protection of unsaturated lipids.

Graphical abstract: Fabrication of surface-active antioxidant biopolymers by using a grafted scallop (Patinopecten yessoensis) gonad protein isolate–epigallocatechin gallate (EGCG) conjugate: improving the stability of tuna oil-loaded emulsions

Supplementary files

Article information

Article type
Paper
Submitted
30 Jul 2019
Accepted
04 Sep 2019
First published
05 Sep 2019

Food Funct., 2019,10, 6752-6766

Fabrication of surface-active antioxidant biopolymers by using a grafted scallop (Patinopecten yessoensis) gonad protein isolate–epigallocatechin gallate (EGCG) conjugate: improving the stability of tuna oil-loaded emulsions

J. Han, Y. Du, W. Shang, J. Yan, H. Wu, B. Zhu and H. Xiao, Food Funct., 2019, 10, 6752 DOI: 10.1039/C9FO01723B

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements