Research On Prepapation And Application Of Chinese Herb Extracts Antimicrobial Packaging Materials

This paper aims to study the preparation and the physical properties of antibacterial film which used herbal essential oils as antibacterial agents and NaAlg/WPU compound film as substrate,it was for the preservation of grapes which were characteristics of agricultural products in Tianjin,in order to reduce the amount of chemical preservatives and the use of hardly degradable plastic packaging materials.Firstly,according to their bacteriostatic action thyme oil and clove basil oil were choosed from 6 kinds of herbal essential oils,which include thyme oil,spearmint oil,tea tree oil,clove basil oil,forsythia suspansa oil and eucalyptus globulus oil.The main chemical components,the minimum inhibitory concentration and the optimal ratio of thyme oil and clove basil oil were analysed by gas chromatography-mass spectrometry?GC-MS?,increasing the concentration with an equal amount and fractional inhibitory concentration,respectively.Then,the herbal antibacterial film was prepared by flowing spread molding.In this antibacterial film,thyme oil and clove basil oil were antibacterial agent,NaAlg and WPU were the main film-forming Materials,glycerol was plasticizer and C_aCl₂ was crosslinking agent.Mechanical properties,thickness,transmittance,the oxygen permeability,water absorption and antibacterial property of compound films were tested to confirm the mass ratio of NaAlg and WPU,the concentration of herbal essential oils,glycerol and C_aCl₂.Using infrared spectroscopy and scanning electron microscopy characterized the structure of the herbal essential oils antibacterial film.Finally,muscat grapes were packaged by the herbal essential oils antimicrobial film,NaAlg/WPU compound film and PE film,respectively;muscat grapes unpacked was blank control group.Jufeng grapes had the same treatment as muscat grapes.The physical and chemical indicators of grapes which incloud sensory,weight loss rate,rot rate,total soluble solids,total acid content and vitamin C content were analysed to evaluate the preservation effect of these films.The results showed that the minimum inhibitory concentration of thyme oil to botrytis cinerea,penicillium,aspergillu were 0.786ul/ml,1.376ul/ml and 1.572ul/ml;the minimum inhibitory concentration of clove basil oil to botrytis cinerea,penicillium,aspergillu were 0.688ul/ml,1.376ul/ml and 1.474ul/ml;the optimal ratio of thyme oil and clove basil oil were 2:1?volume ratio?.A good compatibility existed among the film-forming components of herbal essential oils antimicrobial film;The combination property of herbal essential oils antimicrobial film was best when the mass ratio of NaAlg and WPU?the mass concentration of their mixture was 3%?was 9:1,the volume concentration of thyme oil and clove basil oil?their volume ratio was 2:1?was 1.2%,the volume concentration of glycerol was 1.5%and the mass concentration of C_aCl₂ was 2%.The herbal essential oils antimicrobial film had a good fresh-keeping effect on muscat grapes and Jufeng grapes.