Study On The Preparation And Properties Of Citurs Pericarp-based Antibacterial Film And Application In Chilled Fresh Pork

As people’s environmental consciousness increase,the packaging materials which made of natural biomaterial are widely used in food packaging.Biodegradable packaging materials become hotspot,because edible packaging materials have many advantages that non-pollution,raw material sources,etc.Fruit and vegetable films which are made of fruit and vegetable purees are meaningful to the develoption of biodegradable packaging and the multipurpose use of fruit and vegetable.Ta pe casting was applied to prepare a citrus pericarp based antibacterial film using sodium alginate and carboxymethyl cellulose as a thickening agent,glycerin as a plasticizer,tween as an emulsifier and carvacrol as a antimicrobial.A series of experiments were carried out on the optimized preparation,performance testing,the application of pork,pecific study content and results are as follows:(1)The influence of different concentrations of citrus pericarp,sodium alginate,carboxymethyl cellulose,and glycerin on the mechanical and barrier properties of the film were investigated by the single factor tests.The appropriate adding ranges of the factors above were obtained.Based on the results,chose the tensile strength as index and orthogonal experimental design was used to perform the statistical analyses,through which we got the following results: The main influence factor of the tensile strength of citrus pericarp based film was glycerin> citrus pericarp> carboxymethyl cellulose> sodium alginate.The optimal technology parameters were: citrus pericarp mass concentration was 1.5%,sodium alginate mass concentration was 0.1%,carboxymethyl cellulose mass concentration was 0.2% and glycerin mass concentration was 0.2%.(2)On the basis of the optima formula,carvacrol with 0%,0.5%,1%,1.5% and 2% concentrations was added.In order to make carvacrol better dissolve,0.3% Twain-80 was added as emulsifier,and the performance of different concentratio n of carvacrol antibacterial films was measured and compared.The results showed that:with the increase of the concentration of the carvacrol,the tensile strength of the antibacterial film decreases,the elongation at break increases,the water vapor permeab ility and oxygen permeability coefficient increase,the film thickness increases,and the transmittance decreases.According to SEM,with the increase of the concentration of the carvacrol,degree of crystallinity,rough surface was increased.The antibacterial ability was enhanced gradually with the increase of carvacrol.(3)Antimicrobial film still had good antibacterial activity in the 7th week by determination of carvacrol concentration and inhibitory circle experiment.The carvacrol content slowly decreased along with time.The antibacterial activity of the film with 1.5% carvacrol was better than that with 2% or higher carvacrol content.The optimal concentration of carvacrol was 1.5% based on the comprehensive performance.(4)The study used 1.5% carotene antibacterial film to preserve fresh meat.The pH value,the content of volatile base nitrogen and the total number of colonies were used as evaluation indicators.The results showed that the antibacterial film extended the shelf life of chilled fresh pork from 4-5 days to 8 days.