Structural and functional characteristics of β-lactoglobulin/C-phycocyanin/ starch composite gels induced by pressure

Abstract

High-pressure processing (HPP) has emerged as a key sustainable green alternative for food treatment, effectively preserving food’s sensory and nutritional properties. This study investigated the potential of HPP to develop β-lactoglobulin (BLG) gels in the presence of starch and the bioactive blue protein C-phycocyanin (C-PC). Various compositions of binary (BLG/C-PC and BLG/starch) and ternary (BLG/C-PC/starch) systems were subjected to high-pressure (HP) conditions at 4500 bar. BLG, C-PC, and starch concentrations were maintained at 180, 10, and 5 g/L. HP-induced hydrogels preserve C-PC colour and partial preservation of secondary and tertiary structures, as evidenced by visible absorption and CD spectroscopy. SAXS data at the high-Q range revealed that C-PC induces the unfolding of BLG within binary system gels. In contrast, the ternary system gel maintained the BLG tertiary structure better. C-PC and starch affected the nano and microstructures of BLG HP-induced gels by increasing the pore size, as demonstrated by SAXS (at low Q-range) and SEM analysis. This increase in pore size further influenced the resulting gels’ rheological behaviour and texture profile. C-PC enhanced the protein solubility and antioxidant activity of the HP-induced gels, potentially boosting the bioactive and nutritional value of the developed gels