Effect of deproteinization of polysaccharides from Auricularia auricula-judae on the gel properties of sodium alginate

Abstract

Natural polysaccharides have gained increasing attention in the food industry due to their exceptional biological activity, physical, and chemical properties, particularly in preparing food gels for individuals with dysphagia. The aim of this study was to investigate the feasibility of Auricularia auricular-judae polysaccharides and sodium alginate (SA) for developing dysphagia-friendly food and elucidate the potential mechanism before and after deproteinization of A. auricular-judae polysaccharides in enhancing the properties and swallowing performance of SA gels. Achieving high-value utilization of Auricularia auricula. The results indicated that deproteinized A. auricular-judae polysaccharides (DAAP) exhibited greater rheological properties and texture compared to non-deproteinized polysaccharides (AAP) and the SA composite gel. The biggist elastic modulus value (221.4pa) and hareness (197.4 g) with a 1:1 mass ratio of DAAP and SA. According to the IDDSI, DAAP-SA and AAP-SA could be qualified as level 5-minced/moist dysphagia diets, proved suitable for dysphagia patients. The addition of DAAP enabled the formation of dense and regular microstructures within the DAAP-SA complex compared to the AAP, owing to the strong hydrogen bonding and electrostatic interaction between DAAP and SA, which was confirmed by FT-IR and gel force analysis results. Moreover, the decrease of XRD intensity was observed with high DAAP and AAP content, and thermal analysis demonstrated that A. auricular-judae polysaccharides notably improved the gel thermal stability, indicating that A. auricular-judae polysaccharides content and deproteinization affected the properties of SA gel. The research findings provide valuable insights for developing and processing A. auricular-judae polysaccharide gel products tailored to diverse consumer needs, particularly individuals with dysphagia.