Pickering Emulsion Of Bacterial Cellulose Stabilized Cinnamon Essential Oil And Its Application In Gelatine Film

Gelatin edible film has the advantages of biodegradability and low cost,but it has no antibacterial and antioxidant activity and can not effectively prevent food spoilage.Cinnamon essential oil is made of natural materials,and has antibacterial and antioxidant activities,so it can be used as an ideal additive.However,blending gelatin and cinnamon oil directly into the film increases the risk of deoiling.Pickering emulsions are formed by encapsulating essential oils with solid particles to protect them from the outside environment.Bacterial cellulose can be used as an excellent encapsulation material because of its unique nano size,high purity and reproducibility.In this study,bacterial cellulose(BC)film was prepared by fermentation of K.xylinus CGMCC 2955,which was screened and stored in the laboratory.The BC nanofibers were prepared by cutting BC film into pieces and treated by fiber distributor and high pressure homogenizer.The carboxylated BC nanofibers(TOBC)were obtained by TEMPO/Na Cl O/Na Br oxidation system.Dialdehyde BC nanofibers(DAC)were prepared by selective oxidation of BC with sodium periodate.Furthermore,a certain concentration of BC,TOBC and DAC nanofiber dispersion solutions were mixed with cinnamon essential oil in a certain proportion,and emulsified in a high-speed homogeneous manner to obtain O/W-type Pickering emulsion.The micromorphology,particle size distribution,stability,rheological properties,controlled release and bacteriostatic properties of Pickering emulsions were investigated.The results showed that Pickering emulsion with 1.0 wt%TOBC stabilized cinnamon essential oil had better comprehensive performance,smallest average particle size and more uniform,and had the best controlled release effect on essential oil.TOBC/gelatin antibacterial emulsion film was prepared by solvent pouring method using Pickering emulsion and gelatin with a concentration of 1.0 wt% TOBC.TOBC/gelatin antibacterial emulsion film has smooth surface,compact and continuous cross section,and shows excellent antibacterial properties(Figure 2-9).When Pickering emulsion was added in a large amount,the water vapor barrier performance of the emulsion film was weakened because the emulsion destroyed the network structure of gelatin.With the increase of Pickering emulsion content of cinnamon essential oil,the tensile strength of the emulsion film decreased and the elongation at break increased.The water content,water solubility,swelling and water absorption of the emulsion film decreased with the increase of Pickering concentration(Figure 2-10).In addition,the prepared TOBC/gelatin emulsion film had good antibacterial performance and antioxidant activity.Adjusting the amount of Pickering emulsion could regulate the antibacterial and antioxidant activity of the film.It provides a new idea for the application of gelatin edible film in food packaging field in the future.