Effects Of Ginger Essential Oil On Functional Characteristics Of Fish Sarcoplasmic Protein-Chitosan Composite Edible Films

Edible films are degradable films made from one or more edible bio-macromolecule materials(proteins,polysaccharides and lipids)which have a certain barrier function and can be used in food packaging and other fields instead of petroleum source plastic films.The edible films prepared from a single raw material have poor mechanical and barrier properties,and they are difficult to meet the packaging needs of different foods.Mixing two or more materials with complementary advantages at a certain ratio can prepare composite films with good performances.In order to improve the utilization of resources,a type of protein that is not fully utilized in the aquatic processing process-fish sarcoplasmic protein,and blends chitosan were used as film-forming substrates in this paper.The effect of the amount of ginger essential oil on the mechanical properties,barrier properties,micro-structure and other properties of composite films were studied.After that,taking the sea bream fillet as the research object,the differences of fresh-keeping performance of different composite films were explored.This paper with a view to providing theoretical basis and technical support for the research and application of composite edible films.The main conclusions are as follows:Ginger essential oil was directly added and explore the effect of the amount of ginger essential oil(0,0.5%,1.0%,1.5%,2.0%,3.0% v/v)on the performances of SP-CH composite films.The results show that the light transmittance,tensile strength,and water solubility of the composite films decrease with the increase in the amount of ginger essential oil,and the ductility and water resistance of the composite film are best when the amount of ginger essential oil is 1%.Scanning electron microscopy images showed that when the ginger essential oil was added in excess of 1%,the composite films had uneven structures with holes,which eventually led to the decrease of the composite films in the barrier properties and tensile strength.Therefore,blending an appropriate amount of ginger essential oil can improve the performance of the composite films at a certain extent.Based on ginger essential oil oil-in-water emulsion,nanoemulsion was prepared by high-pressure homogenization method.And the effect of particle size and addition amount ofginger essential oil emulsions on the mechanical properties,water vapor permeability,micro-structure,and antioxidant and antibacterial properties of SP-CH composite films.were investigated.In addition,the effect of ginger essential oil on the moisture distribution and infrared spectrum of composite films were explore at molecular level.The results showed that the ginger essential oil nanoemulsion had better compatibility with the film-forming matrix,so the micro-structure of the composite film was compact and uniform,which increased the ductility and water vapor barrier.The antioxidant and antibacterial properties of composite films increased with the increase of the emulsion concentration.There were interactions between ginger essential oil and the film-forming substrate,which affected the moisture distribution of the composite films.The fresh-keeping effect of the composite films containing ginger essential oil on real sea bream fillets was compared by comprehensively analyzing the water retention,pH,TVB-N,TBA,total number of colonies,and sensory scores of the fish fillets.The results showed that the composite film containing ginger essential oil can obviously inhibit the growth of microorganisms,slow down the process of protein degradation and fat oxidation,and prolong the shelf life of fish fillets.