| Today's economy is developing rapidly and people's quality of life is improving.Most of the plastic wraps that are ubiquitous in the market are not easily degraded.After these plastic wraps are used,if they are not processed in time,they will cause great damage to the environment.How can we not only ensure food health and safety,but also pay attention to environmental protection.In view of this situation,the use of low-cost and abundant materials to prepare an environmentally friendly,hygienic,and degradable cling film is an important direction of current academic research.However,some degradable cling films have the disadvantages of high water permeability or poor tensile strength.These shortcomings make the degradable plastic wrap cannot be widely used in the field of food packaging.In this paper,chitosan,polyvinyl alcohol and glycerol,three degradable substrates have been used as film-forming materials to prepare degradable cling film to make up for the shortcomings of single-component film.At the same time,buckwheat trypsin inhibitor has been added to perform degradable cling film.Modification optimization,through the experiment of degradable preservative film,to study its practical application effect.The main results are as follows:(1)Study on the preparation and properties of degradable preservative film.Through single factor test,we determined the addition amount of chitosan,polyvinyl alcohol and glycerin.The response surface optimization was performed,and the optimization results were that the concentration of chitosan was 1.16%,the concentration of polyvinyl alcohol was 4.00%,and the concentra otionf glycerol was 1.78%.The actual water vapor transmission coefficient of the degradable preservative film was 1.1462±0.0078{g/(Pa·h·m)},the tensile strength was 3.4033±0.0165 MPa,and the elongation at break was 61.12±0.46%.(2)Preparation and characterization of BTI degradable CS and PVA cling film.The results showed that: the release rate of fixing BTI by blending method was higher than that of fixing BTI by combination method,so the direct blending method has been used to fix BTI.Through observation,the film was found to be smooth and dense,without bubbles and holes.Infrared analysis of the intermolecular forces between the components of the degradable cling film was confirmed by the content of the previous chapter.At the same time,it was confirmed that the addition of Nisin and BTI did not affect the performance of the film.It ensured that the degradable preservative film had good mechanical properties and good water resistance,which provided a theoretical basis for the next chapter.(3)The fresh-keeping effect of the biodegradable preservative film with BTI on sea bass.Take ordinary preservative film as a control to investigate the fresh-keeping effect of 1?2?3?4 film on meat.The 2?3?4 membrane treatment group can keep the sample meat in a suitable state,smell and color for a longer time;the 2?3?4 membrane can effectively inhibit the increase in the number of microorganisms and slow down the TVB-N value compared with the normal membrane of the control group.Increased while maintaining a low juice loss rate.The degradable cling film prepared in this study was safe,had low water vapor permeability,suitable mechanical properties,and was degradable.It was expected to be a substitute for traditional cling film and had certain economic and food safety benefits. |
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