Study On Edible Films Of Chitosan Gallic Acid Derivatives Study On Preparation,properties And Application In Food Storage

Chitosan is a natural polysaccharide with excellent film-forming properties,biodegradability and biocompatibility,and can be widely extracted from nature,so it is widely used in the development of edible films.However,because of its limited antioxidant and antibacterial properties,it needs to be improved in a targeted manner.Accordingly,in this paper,we prepared chitosan-gallate derivatives from chitosan and gallic acid,characterized their properties,and added them to pure chitosan edible membranes in the form of additives to prepare chitosan-gallate derivatives edible membranes,and after characterizing the chitosan-gallate derivatives edible membranes,we applied them to antioxidant research of fats and oils in order to provide a scientific basis and a basis for the development of new The study aims to provide scientific basis and theoretical foundation for the development of new edible membranes..(1)Chitosan-gallate derivatives were prepared by combining gallic acid with chitosan in the form of covalent grafting using chitosan and gallic acid as raw materials,and the redox system was constructed with H₂O₂and ascorbic acid to study the effects of different factors on the grafting rate of gallic acid.The experimental results showed that the grafting rate of gallic acid was higher when the reaction time was 12 h,the addition amount of gallic acid was 1%,the addition amount of H₂O₂was0.50%and the addition amount of ascorbic acid was 2.50%.(2)The performance of chitosan-gallate derivatives was characterized,and the experiments showed that the DPPH radical scavenging rate of the chitosan-gallate derivative solution at a concentration of 0.3 mg/m L was 28.13%and 4.00%higher than that of the control chitosan and chitosan/gallate blend,respectively;the Fe³⁺reducing power of the chitosan-gallate derivative solution at a concentration of 1 mg/m L was 79.46%and 16.07%higher than that of the control chitosan and chitosan/gallate blend,respectively;the chitosan-gallate derivative solution at a concentration of 1%was 79.46%and 16.07%higher than that of the control chitosan.+reducing power of chitosan-gallate derivative solution at a concentration of 1 mg/m L was 79.46%and 16.07%higher than that of chitosan and chitosan/gallate mixture as the control,respectively;the inhibition ability of chitosan-gallate derivative solution at a concentration of 1%was higher than that of chitosan and chitosan/gallate as the control for E.coli and S.aureus,and the inhibition rate for E.coli was 69.77%and 54.77%higher than that of chitosan and chitosan/gallate mixture,respectively.The inhibition rate of E.coli was 69.77%and 54.52%higher than that of chitosan and chitosan/gallate mixture,respectively;the inhibition rate of S.aureus was 80.43%and 62.63%higher than that of chitosan and chitosan/gallate mixture,respectively.(3)The antioxidant,antibacterial,mechanical and physical properties of the chitosan-gallate derivative edible membranes were characterized,and the experimental results showed that the inhibition ability of the chitosan-gallate derivative edible membranes at a concentration of 1%was higher than that of the chitosan edible membranes and chitosan/gallate blend edible membranes as the control items.The inhibition rate of E.coli was 18.77%and 9.50%higher than that of chitosan edible film solution and chitosan/gallate blend edible film solution,respectively;the inhibition rate of Saureus was 16.58%and 9.31%higher than that of chitosan edible film solution and chitosan/gallate blend edible film solution,respectively;the inhibition rates of chitosan/gallate blend edible film and chitosan-gallate derivative edible film were higher than those of chitosan edible film and chitosan-gallate blend edible film,respectively.The tensile strength of chitosan/gallate blended edible film and chitosan-gallate derivative edible film decreased by 9.29%and 88.80%,respectively,compared with that of chitosan edible film;the tensile strength of chitosan/gallate blended edible film and chitosan-gallate derivative edible film decreased by 68.18%and 87.50%,respectively,compared with that of chitosan edible film;the swelling of chitosan/gallate blended edible film was higher than that of chitosan/gallate blended edible film and chitosan-gallate derivative edible film,respectively.The swelling of chitosan/gallate blended edible film was 2.96 times and 14 times higher than that of chitosan and chitosan-gallate derivative edible film,respectively;there were significant differences(P<0.05)in color values L*,a*,b*,?E and C between chitosan/gallate blended edible film and chitosan-gallate derivative edible film compared with chitosan edible film.The color of chitosan edible films became heavier regardless of the addition of pure gallic acid or chitosan-gallic acid derivatives;chitosan-gallic acid derivatives edible films were more resistant to external moisture than chitosan/gallic acid co-blended edible films and chitosan edible films.(4)Peanut oil and peanut oil emulsion were stored closed using chitosan-gallate derivative edible film as the sealing material and tested for their use.The experimental results showed that compared with the control group,the acid values of peanut oil sealed with chitosan edible film,chitosan/gallate blended edible film and chitosan-gallate derivative edible film were reduced by 16.79%,30.53%and38.93%,respectively,on the 40th day of storage at 50?;the malondialdehyde values were reduced by 16.60%,23.10%and 27.19%,respectively;and the peroxide values were reduced by 35.19%,respectively.The peroxide values decreased by 35.67%,50.28%and 62.27%,respectively.Compared with the control group,the acid values of peanut oil emulsions covered with chitosan edible film,chitosan/gallate co-mingled edible film and chitosan-gallate derivative edible film decreased by32.17%,34.25%and 39.74%,respectively,on day 15 under storage conditions at 35?;malondialdehyde values decreased by 19.40%,35.86%and 40.51%,respectively;peroxide values decreased by 35.67%,50.28%and 62.27%,respectively.The peroxide values decreased by 14.29%,42.86%and 57.14%,respectively...