| To solve the problems of volatile,poor hydrophilicity and rapid release of Cinnamon essential oil（CEO）during the preparation and storage of food packaging film.In this study,Tenebrio molitor protein-Chitosan（TMP-CS）Pickering emulsifier was used to encapsulify CEO.Pickering emulsions（PEs）with high encapsulation efficiency and good stability were obtained by response surface optimization.Moreover,PEs was added to Chitosan/fish gelatin（CF）to prepare active composite film,and the effects of PEs with different mass fractions on physicochemical properties of CF films were investigated.Finally,the active CF-based emulsion films were used to preserve fresh-cut apples to explore their application value in preserving fresh-cut fruits.The main findings are as follows:（1）The average particle size of TMP-CS nanoparticles was 181.37±0.29 nm.There were hydrogen bonds and electrostatic interactions between TMP and CS.CS extended as a shell to the surface of TMP particles.The addition of CS improved the high temperature resistance of TMP-CS.（2）The optimal process conditions for PEs preparation were obtained by single-factor and response surface optimization tests.When the mass ratio of TMP/CS was 10:10,the p H value of the system was 4,and the amount of oil phase was 40%,the encapsulation rate of PEs was 82.90±0.27%.The PEs prepared under this condition had a uniform spherical shape with a particle size of 1～3μm,and no oil-water separation was found in the storage of PEs within one month.When the ionic strength increased from 0 m M to 100 m M,the average size of the droplets did not change significantly within 3 d.At the same time,the PEs had good centrifugal stability and temperature stability.（3）The PEs optimized above was added to CF with different mass fractions（0,0.5%,1%,2%and 3%）to explore its influence on physicochemical properties of CF-based films.The results showed that the mechanical,barrier and antioxidant properties of the film increased with the increase of PEs,while the light transmittance,water content and swelling rate of the film decreased.When the amount of PEs added was 1%（w/v）,the tensile strength and elongation at break of the film were 25.16±1.98 MPa,89.73±5.86%,respectively.Transmission coefficient of water vapor and oxygen were（1.80±0.09）×10-10g·m·m-2·s-1·Pa-1and（4.92±0.47）×10-12g·m·m-2·s-1·Pa-1,respectively.The free radical scavenging rates of DPPH and ABTS were 56.14±1.14%and 81.27±2.78%,respectively.Compared with the films prepared by traditional emulsions,the PEs-containing films showed stronger sustained release of CEO in 95%ethanol food simulation solution.At the same time,there were hydrogen bonds between PEs and CF matrix.The addition of PEs increased the surface roughness and thermal stability of the films,but did not affect the compact structure of the films.（4）The CF/1%PEs film was used for the preservation tests of fresh-cut apples,while polyethylene film and CF film were used as control groups.It was found that fresh-cut apples packaged in CF/1%PEs film maintained relatively good sensory and quality during storage.After 5 d of storage,the browning index of fresh-cut apples packaged in CF/1%PEs film was44.15±1.40%and the weight loss rate was 4.61±0.79%.The hardness decreased by 16.65%,the total soluble solid and titratable acid were well retained,and the total phenolic content was57.44±0.98 mg/GAE 100g.The total number of bacteria,yeast and mold was 2.60±0.07 log CFU/g and 1.21±0.08 log CFU/g,respectively.In general,the CF/1%PEs film has the best preservation effect on fresh-cut apples,indicating that CF/1%PEs film has a certain preservation effect on fresh-cut apples. |
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