Preparation,Characterization Of Edible Collagen/Curcumin Film With Sustained Release Activity And Its Mechanism Of Grass Carp Fillets Preservation

Edible food packaging film is an important branch of food packaging materials,has become a hot topic for food companies,universities and research institutes in various countries.However,pure bio-based edible packaging film has limited bio-activities.At present,the modification of protein or biological polymer based edible films is an important way to improve film performances,mainly by adding natural active substances,such as tea polyphenols,plant essential oil,curcumin,and so on.The film fabricated by combining substrate materials with untreated active substances has a fast release of active substances,and the film maintain its activity for a short time.Therefore,it is very important to prepare edible active packaging films with sustained release performance.The research contents of this study are as follows:(i)In order to improve the water solubility,stability and bioavailability of curcumin,it was combined with?-cytodextrin(?CD)to prepare CUR/?CD emulsion called as an oil-in-water emulsion,and the optimum ratio of CUR to ?CD was determined to be 1:4.(ii)Fish skin collagen was extracted from silver carp skin using hot water method in our own laboratory,and it was defined as gelatin(GL).The GL-CUR,GL-?CD and GL-?CD-CUR films were prepared by casting method.The light barrier property,water vapor permeability,microstructures and heat sealing properties of gelatin-based films were investigated.At the same time,the antioxidant property and its stability and sustained-release properties of films were studied.Compared with GL-?CD film,the GL-?CD-CUR film had better optical barrier properties,water vapor resistance and oxidation resistance.Compared with the GL-CUR film,the antioxidant stability property was improved for GL-pCD-CUR film.The results of SEM showed that the gelatin based films had smooth surfaces and intact cross-section structures.(iii)Using silver carp skin gelatin as matrix material combined with CUR/?CD emulsion,we prepared edible coatings with antioxidant and sustained-release properties and studied the preservative effects and mechanism of the coatings on grass carp fillets during storage at 4?,mainly including the weight loss,pH,total volatile base nitrogen(TVB-N),peroxide value(PV),TBA,protein degradation,free amino acids and microorganisms.The results showed that the coatings can effectively inhibit the lipid oxidation and the degradation of grass carp fillets.All these findings indicated that combing fish skin collagen with CUR/?CD emulsion is a promising way to maintain the fish freshness and prolong the shelf life of fish fillets.