Complex characterization and formation mechanism of scallop (Patinopecten yessoensis) protein hydrolysates/κ-carrageenan/konjac gum composite gels

This study aimed to investigate the effects of κ-carrageenan (KC) and konjac gum (KGM) on gelaiton and microstructural properties of scallop male gonads hydrolysates (SMGHs) as well as the governed intermolecular interactions. The G' values of SMGHs/KGM/KC significantly increased by 3.6- and 108.5-fold in comparison to that of SMGHs/KC and KGM/KC gels at 0.1 Hz, with corresponding melting temperature increasing from 27.9 (KGM/KC) and 30.0 (SMGHs/KC) to 33.7 °C (SMGHs/KGM/KC), respectively. In addition, the decrease in the relaxation time T₂₃ and intensity enhancement of hydroxyl group vibrations of SMGHs/KGM/KC compared with controls indicated strong interactions between SMGHs and KGM/KC. Moreover, the ternary mixture of SMGHs/KGM/KC formed a condensed and compact network structure with thick walls as well as showed a rougher structure with more aggregation due to the generation of macromolecular biopolymers. Furthermore, electrostatic and hydrophobic interactions were found to be the main interaction forces, while hydrogen bonds were secondary in the gelation of SMGHs/KGM/KC gels. This study is expected to provide theoretical basis for modification of marine-based protein hydrolysates by binary gum, as well as fabrication of food ingredients with better gel properties, which promote SMGHs to be relevant to controlled design and production processes in future food industry application.