Research On The Preparation And Analysis Of Antibacterial And Mildew-proof Packaging Paper And Application In Food Packaging

Paper packaging materials have the characteristics of low cost,rich source,recyclable,easy degradation and so on.They are promising green packaging materials.However,the existing packaging paper does not have antibacterial and mildew-proof functions,and there is no antibacterial packaging paper applied to food on the market.In order to prolong the shelf life of food,food manufacturers usually add a certain amount of preservatives directly to the food,which can inhibit the growth and reproduction of microorganisms.How to prolong the shelf life of food without adding preservatives and keep the flavor and safety of food has become a research hotspot in the food packaging industry.In view of the above problems,a kind of antibacterial and mildew-proof packaging paper was prepared by coating polyvinyl alcohol(PVA)and antibacterial agent on kraft paper under specific conditions,and then drying.The antibacterial and mildew-proof packaging paper can control the growth of microorganisms in the packaging environment by slowly releasing the components with antibacterial and mildew-proof effects.Different from other antibacterial plastic film packaging,PVA and kraft paper used in this study can be degraded,which belong to environment-friendly packaging materials and will not pollute the environment.The application of the packaging paper can effectively reduce or even not add preservatives to the food,ensure the quality of food,and do not need to store under the conditions of low temperature,air conditioning and so on.Furthermore,the operation is simple,and is conducive to improving people's quality of life.In this paper,we first developed a method to prepare antibacterial and mildew-proof paper,and tested its antibacterial and packaging properties(barrier and mechanical properties).Then,we applied antibacterial and mildew-proof paper to the packaging of semi-dried grass fish fillet and baked food(toast),measured the relevant quality indicators and compared them.The research contents and results are as follows:(1)Potassium sorbate,sodium dehydroacetate and sodium benzoate were used as antimicrobial agents to prepare three kinds of antimicrobial solutions,which were respectively dissolved in polyvinyl alcohol solution,and then coated on kraft paper to prepare antibacterial and mildew-proof paper for packaging.The inhibition effect of three kinds of antibacterial and mildew-proof paper on Escherichia coli and Staphylococcus aureus was tested by the inhibition zone method.The best antibacterial and mildew-proof paper was selected for the follow-up test.The effects of coating antibacterial liquid on the tensile strength,tear strength,water vapor transmission coefficient,oxygen transmission and microstructure of the antibacterial and mildew-proof paper were studied.The results showed that sodium dehydroacetate was the best antibacterial agent.Compared with uncoated kraft paper,antibacterial and mildew-proof paper has improved tensile strength,tear strength,water vapor transmission coefficient and oxygen transmission.Its microstructure is more compact and uniform,and has good antibacterial performance.The antibacterial effect increases with the increase of the concentration of antibacterial agent.(2)The antibacterial solution was prepared by dissolving sodium dehydroacetate and sodium lactate in polyvinyl alcohol solution,and then coated on kraft paper.The fresh grass carp was made into fillets from its back meat,and dried after being pickled in certain conditions to obtain the fillets.Then,the fillets were packed with antibacterial and mildew-proof paper and PE film respectively.The changes of color difference,p H,TBA,TVB-N,total number of colonies and sensory quality of the fillets were compared.The results showed that the change of color difference of fish meat packaged with antibacterial and mildew-proof packaging paper was relatively small,the change of p H was also small,the rise of TBA value and TVB-N value was delayed,the growth of colony number was effectively inhibited,and the deterioration of sensory quality was also delayed.Compared with the common PE film,the antibacterial and mildew-proof paper can obviously slow down the quality deterioration of the semi-dried grass fish fillet.(3)Sodium dehydroacetate and sorbitol were dissolved in polyvinyl alcohol solution to prepare antibacterial solution,and then the antibacterial solution was coated on kraft paper to prepare antibacterial and mildew-proof paper for packaging.The texture,color difference,water activity,total number of colonies and enthalpy of toast were compared with toast using only PP film packaging and unpackaged.The results showed that the texture and color difference of toast packaged with paper plastic composite packaging were slower than those packaged only with PP film and without packaging,the water activity was reduced to some extent,the growth of colony number was effectively inhibited,and the rise of aging enthalpy was delayed.The composite material was used for toast packaging,which can effectively prolong the shelf life of toast without adding preservatives.The antibacterial and mildew-proof packaging paper prepared in this paper provides a theoretical basis for other food packaging applications.The base material and antibacterial agent used are low in price,good in antibacterial and fresh-keeping effect,and can be popularized on the market.