Antibacterial Properties Of Asparagus Cellulose Films And Its Application In Preservation Of Strawberry Fruit

In order to solve the current situation of large waste of asparagus in China and meet the increasing demand for natural,safe and multifunctional food packaging materials,this paper used cellulose obtained from asparagus waste to prepared cellulose and cellulose derivative films,and evaluated the characteristic and antibacterial property of films.Besides,the preservation effects of cellulose derivative films on postharvest strawberry fruit were also explored.1?Study on the characteristic evaluation and antibacterial application of asparagus cellulose films.The cellulose films were obtained by phase inversion method,as the concentration of cellulose solution increased from 0.008 g/m L to 0.01 g/m L,the swelling ratio(SR),quercetin loading rate(QLR),pore size of films increased.But when the concentration of cellulose solution increased from 0.01 g/m L to 0.05 g/m L,the SR,QLR,pore size of films decreased.The x-ray diffraction(XRD),fourier transform infrared spectroscopy(FTIR),and thermal gravimetric analysis(TGA)indicated that the asparagus cellulose belongs to cellulose I,the Li Cl/DMAc solvent has no effect on the structure of cellulose,and the quercetin loaded cellulose films were successfully prepared.Compared with QUE-AC0.008(the film prepared by 0.008 g/m L cellulose solution,same as below)and QUE-AC0.025 films,the QUE-AC0.01 film exhibited an excellent antimicrobial activity against E.coli and S.aureus.As a result,the quercetin/asparagus cellulose films prepared by asparagus waste displayed a better antibacterial activity.2?Preparation of hydroxyethyl cellulose/sodium alginate edible film and its preservation effects on postharvest strawberry fruit.Firstly,the ethanol extract and cellulose were obtained from asparagus waste,and the asparagus cellulose was used to synthesis hydroxyethyl cellulose(HEC)by quaternization and etherification.Then,the ethanol extract as antibacterial materials were added in HEC and sodium alginate(SA)solutions to prepared 1.5%HEC,1.5%SA and 1.0%HEC/0.5%SA coatings,and recorded as HEC1.5,SA1.5 and HEC1.0/SA0.5,respectively.Compared to HEC1.5 and SA1.5 films,the HEC1.0/SA0.5 film displayed increased porosity and heterogeneity characteristics.The HEC1.0/SA0.5 film also presented an excellent antifungal activity against 1×10~4CFU/m L Penicillium italicum spore suspension.Moreover,the HEC1.0/SA.5 film significantly delayed the color change,weight loss,and oxidative decomposition of total phenols and total flavones of postharvest strawberry fruit.As a result,the edible and biodegradable HEC/SA film prepared by asparagus waste showed a desirable preservation effects on postharvest strawberry fruit.