Environmental factors and blueberry anthocyanin-induced conformational changes modulate the interaction between myofibrillar proteins and fishy compounds and their mechanism, specifically aldehydes and alcohols.

Abstract

This study investigated the impact of blueberry anthocyanin (BA) on the interaction between tilapia myofibrillar protein (MP) and fishy compounds (hexanal, octanal, nonanal, trans-2-nonenal, and 1-octen-3-ol). Results indicated that at a protein concentration of 5 mg/mL and fishy compounds at 5 μg/mL, MP effectively adsorbed these compounds at 4 °C, pH 7.0, and 0.6 mol/L Na⁺. Increasing BA concentration (0.03-0.24 mg/mL) enhanced the α-helix content of MP from 30 % to 60 %, with a blue shift in the maximum fluorescence emission peak (333-337 nm), suggesting that BA promotes protein structural folding and stability. In MP and fresh fish models, BA addition significantly decreased hexanal (from 50.2 % ± 1.6 % to 29.0 % ± 9.5 %), octanal (from 97.8 % ± 1.6 % to 38.7 % ± 1.8 %), and nonanal (from 69.4 % ± 7.7 % to 39.0 %). Conversely, higher BA concentrations led to increased release of 1-octene-3-ol (from 104.1 % ± 4.4 % to 120.4 % ± 1.1 %). Overall, the findings highlight the correlation between BA's effects on protein folding and stabilization and its influence on the controlled release of fishy compounds, underscoring the significance of polyphenols in protein-flavor interactions. This research offers valuable insights into flavor management and establishes a theoretical basis for flavor regulation in tilapia meat products, contributing to the broader study of quality control and flavor enhancement in meat products through natural pigment active ingredients.