Design and characterization of low salt myofibrillar protein-sugar beet pectin double-crosslinked gels pretreated by ultrasound and konjac glucomannan: Conformational and gelling properties

The purpose of this study was to investigate the influence of two-step sequential cross-linking induced by laccase and heat treatment on the conformation and gelling properties of low-salt myofibrillar proteins (MP) modified by konjac glucomannan (KGM) and ultrasound treatments. Adding sugar beet pectin (SBP), irrespective of laccase crosslinking, significantly decreased the fluorescence intensity of low-salt MPs (MP, UMP, UMP-KGM). Laccase crosslinking caused the exposure of hydrophobic and Tyr residues, induced moderate aggregation of MPs, and enhanced rheological properties and gel strength of composite MP gels, especially in the UMP-KGM sample. This result could also be corroborated by the highest WHC, improved textural characteristics, enhanced intermolecular interactions, and increased percentage in t-g-g conformation of S–S bridges in the SBP modified UMP-KGM gel after laccase crosslinking. Therefore, the dual crosslinking could be used to regulate the protein-protein and protein-polysaccharide interactions and improve the gel properties of low-salt meat products.