Whey protein and phenolic compound complexation: Effects on antioxidant capacity before and after in vitro digestion. (July 2020)

• Record Type: Journal Article
• Authors: de Morais, Francielli P.R.; Pessato, Tássia B.; Rodrigues, Eliseu; Peixoto Mallmann, Luana; Mariutti, Lilian R.B.; Netto, Flavia M.
• Is Part Of: Food research international. Volume 133(2020)
• Publication Date: 2020-07
• Subjects: Bioactivity -- Simulated digestion -- Mass spectrometry -- Phenolic acids -- Flavonoids -- Protein-phenolic interaction; Food -- Analysis -- Periodicals; Food industry and trade -- Periodicals; Food industry and trade -- Canada -- Periodicals; Food Technology -- Periodicals; Food -- Periodicals; Food-Processing Industry -- Periodicals; Aliments -- Industrie et commerce -- Périodiques; Aliments -- Industrie et commerce -- Canada -- Périodiques; Aliments -- Recherche -- Périodiques; Food industry and trade; Canada; Periodicals; Electronic journals; 664.005
• DOI: 10.1016/j.foodres.2020.109104
• Languages: English
• ISSNs: 0963-9969

Abstract

Graphical abstract: Highlights: WPI was complexed with caffeic acid (CA) or epigallocatechin gallate (EGCG) Complexation with CA led to larger changes in WPI conformation than with EGCG. Complexation with WPI protected CA and EGCG during in vitro digestion. Protein digestion pattern was dependent on the pH of complexes preparation. Abstract: Whey protein isolate (WPI) interactions with (-)-epigallocatechin gallate (EGCG) and caffeic acid (CA) at pH 3.5 and 7.0 were investigated concerning complex formation and antioxidant capacity, before and after simulated digestion. Complex formation was evidenced by protein structural changes when WPI was associated with CA or EGCG. Reducing capacity and FRAP values increased as the phenolic compound concentration increased while ORAC values remained unchanged. In general, compared to the isolated compounds, complexation suppressed the antioxidant capacity possibly due to hydrophobic interaction and H-bonding between these compounds. Protein:phenolic complexation in 1:0.5 M ratio did not affect the digestibility compared to WPI (83%), except for WPI:CA at pH 7.0 (73%). The hydrophilicity profile of the digested samples suggested that pH of complexation and type of phenolic affected the protein cleavage pattern. Furthermore, the phenolic compounds were more stable when associated with the protein since they were protected from the simulated gastrointestinal environment.