Effect of Hot Air Drying on Processing Characteristics and Antioxidant Activity of Pleurotus eryngii Polysaccharide-Protein Complex
Fruiting bodies of Pleurotus eryngii were dried by hot air,and then the fruiting bodies were determined for color difference value,browning degree,intermediate index,and UV-visible absorption spectrum to analyze the degree of Maillard reaction.After that,polysaccharide-protein complex was extracted from the dry heat treated P.eryngii and then analyzed for basic components,processing characteristics(solubility,relative viscosity,foaming property,emulsification,hardness,cohesion,elasticity,chewiness,and gel strength)and antioxidant activity.The results showed that the color difference value of fresh P.eryngii was the highest,and the lowest value was detected at 24 h of drying.Both browning index and intermediate index were the lowest in fresh P.eryngii and reached the highest at 24 h of drying.The polysaccharide-protein complex of fresh P.eryngii took longer time to dissolve than that of dry heat treated P.eryngii,and the dissolution time was relatively short at 18 h and 24 h of drying.Relative viscosity was the highest in the polysaccharide-protein complex of P.eryngii dried for 24 h,and the lowest in the polysaccharide-protein complex of fresh P.eryngii.Both emulsifying and foaming properties were the best in the polysaccharide-protein complex of P.eryngii dried for 24 h.The polysaccharide-protein complexes of P.eryngii dried for 12 h,18 h,and 24 h remained good emulsion stability,and the polysaccharide-protein complex of P.eryngii dried for 18 h also showed good foam stability.The polysaccharide-protein complex of P.eryngii dried for 24 h showed the highest hardness,cohesiveness,elasticity,chewiness and gel strength.For antioxidant activity,the polysaccharide-protein complexes of P.eryngii dried for 18 h and 24 h showed higher activities on scavenging DPPH and inhibiting polyphenol oxidase than P.eryngii polysaccharide-protein complexes from other drying time.The P.eryngii polysaccharide-protein complex of 24 h drying also had the highest hydroxyl radical scavenging rate and superoxide anion scavenging rate.The results provided a reference for the development and utilization of P.eryngii in the future.
Hot air dryingPleurotus eryngiipolysaccharide-protein complexprocessing characteristicsantioxidant activity