Study On The Preparation Of ?-PGA Hydrogel And Its Application In Apricot Storage

?-PGA is a high molecular polymer produced by the fermentation of Bacillus subtilis,which is biodegradable,non-toxic and edible.The hydrogel obtained by?-PGA through cross-linking reaction has good water absorption and biocompatibility,and has a wide range of applications in food,agriculture,medicine and other fields.It mainly studies the preparation and properties of?-PGA raw materials and?-PGA hydrogel,and the application of?-PGA hydrogel in the preservation of apricots.The results of the study on the effect of surfactants on the synthesis and secretion of?-PGA showed that the addition of 5g/L of Tween 80 at the 36th hour can significantly promote the fermentation and production of?-PGA by Bacillus subtilis,with a yield of 30.3g/L.The results showed that D4006(3%)resin combined with ultrafiltration(pressure difference 0.2MPa,temperature 40?and ultrafiltration times6)had good decolorization effect on?-PGA fermentation broth,and the decolorization rate was 96.8%.Using?-PGA and pectin as raw materials,a hydrogel was prepared by cross-linking polyethylene glycol diglycidyl ether.Explore the effects of the ratio of?-PGA to pectin,p H,and crosslinking agent concentration on the rheological properties,swelling properties,and water retention properties of hydrogels.The results show that the optimal conditions for preparing hydrogels are:the ratio of?-PGA to pectin is 24:3,the p H is 6,and the crosslinking agent concentration is 20%.The hydrogel prepared under this condition has good rheological properties,with a swelling degree of 99.2 and a water retention rate of 64.1%.The application effect of?-PGA hydrogel in the storage and preservation of apricots was studied.The results showed that the?-PGA hydrogel coating treatment group compared with the uncoated control group,the?-PGA hydrogel coating treatment group can significantly inhibit the decay rate and weight loss rate of big apricots during storage,hardness,V_C,titratable acid content and other quality indicators.Among them,?-PGA hydrogel combined with 1-MCP treatment has the best effect,can maintain good storage quality,and delay the senescence and softening process of apricot storage.