Exploration of the crude polysaccharides derived from Lentinus squarrosulus and their impact on the rheology, physicochemical properties, and microstructure of threadfin bream ( Nemipterus hexodon ) surimi gel

Summary This research examined the influence of subcritically-treated crude polysaccharide powder (SCP) obtained from Lentinus squarrosulus on threadfin bream (Nemipterus hexodon) surimi gel characteristics. Physicochemical properties analyzed included rheology, color values, gel strength, water holding capacity, secondary structures, and microstructures by confocal laser scanning microscopy. The antioxidant properties were evaluated through the DPPH and FRAP assays. The storage modulus (G′) values were significantly greater than the loss modulus (G″) throughout the temperature range of 5-90°C. Surimi gel with SCP demonstrated a significant increase in G′ and G″ values, as well as gel strength (P < 0.05), and enhanced water holding capacity. The microstructure revealed that the polysaccharide phase was randomly distributed within the protein structure as the SCP concentration increased. The addition of SCP enhanced the total phenolic content (TPC) and improved antioxidant properties, while incorporation of SCP improved the surimi gel characteristics, with increased levels of bioactive compounds.