Antioxidant activity and stability of α‐tocopherol, resveratrol and epigallocatechin‐3‐gallate in mixture and complexation with bovine serum albumin

• Published in: International journal of food science & technology Vol. 56; no. 4; pp. 1788 - 1800
• Main Authors: Dong, Huanhuan, Yin, Xin, Wusigale, Cheng, Hao, Choijilsuren, Narangerel, Chen, Xing, Liang, Li
• Format: Journal Article
• Language: English
• Published: Oxford Wiley Subscription Services, Inc 01.04.2021
• Subjects: antioxidant activity; Antioxidants; bioactive compound; Bioactive compounds; Biological activity; Bovine serum albumin; complex; Complexation; Coordination compounds; Encapsulation; Epigallocatechin gallate; Functional foods & nutraceuticals; Ligands; Proteins; Resveratrol; Scavenging; Serum albumin; stability; Structural stability; Tocopherol; Vitamin E
• ISSN: 0950-5423; 1365-2621
• DOI: 10.1111/ijfs.14804

Intermolecular interactions among α‐tocopherol, resveratrol and EGCG appear to be antagonistic based on antioxidant activity but improve their structural stability and preserve antioxidant property. These bioactive compounds interact with BSA to form tri‐ligand complexes. Such tri‐ligand complexes maintain structural integrity and antioxidant property of a‐tocopherol, resveratrol and EGCG simultaneously and to a greater degree than is observed for mono‐ligand complexes with BSA. Summary Ligand‐binding proteins were proposed as ideal carriers for the co‐encapsulation of bioactive compounds. Multiple compounds co‐encapsulated in food formulation may give rise to different effects on bioactivity and stability. The protein effect on the interplay between bioactive compounds was investigated for selecting suitable co‐encapsulation strategy. α‐Tocopherol, resveratrol and epigallocatechin‐3‐gallate (EGCG), as model compounds, interacted with bovine serum albumin (BSA) to form tri‐ligand complexes when added in the sequence. For ferric‐reducing antioxidant power, the mixtures of α‐tocopherol and resveratrol,α‐tocopherol and EGCG, resveratrol and EGCG were respectively additive, antagonistic and synergistic, while their ternary mixture were antagonistic. For ABTS+ scavenging capacity, all pairs were antagonistic. BSA improved FRAP of α‐tocopherol, resveratrol and EGCG mixture but decreased their ABTS inhibition. Although structural stability and antioxidant activity of resveratrol decreased when alone interacted with BSA, they were improved when α‐tocopherol and EGCG were co‐presented. Mixing the antioxidants improved their stability and the complexation with BSA can further stabilise them. BSA could thus be a suitable carrier for co‐encapsulation/protection of α‐tocopherol, resveratrol and EGCG in functional foods.