Preparation And Properties Of Zein Antibacterial And Transportation Carrier

Food origin disease can be mainly attributed to the breeding of pathogenic bacteriumduring the foodstuff was being processed,transported and stored.Also, Food safety andquality has been the main concern of all kinds of food manufacturing industry. Many wayshave been tried to dissolve the food safety problem, like adding bacteriostatic agent into theraw material.In addition to that, packaging material that of bacteriostatic function in whichfoodstuff is wrapped is also one useful method to stop the content from being polluted. Thepurpose of this essay is to fabricate bacteriostatic agent loaded soluble nanoparticles withstrengthened surface hydrophobicity,gas and water resistant ability to prolong the shelf-lifeof the food stuff by preventing the pollution of the bacterium.The main contents can bedescribed as follow:(1) Synthesize thymol/nisin-loaded water-soluble zein/SC nanoparticles by using liqiudantisolvent technique. Zein and sodium casein act as matrix in which zein colloid particle loadhydrophobic antimicrobial agent (Thymol); while sodium caseinate nano-layer loadhydrophilic antibacterial agent (Nisn). Then we can get a kind of multiple antibacterialparticles which consist of both fast release kinetics and slow release kinetics. Besides，microscopic structure, encapsulation rate and the release kinetics of zein/SC nanoparticleswas studied. In addition, a method using headspace gas chromatography was established tomonitor the bacteriostatic effect. After analytical investigation,we found that the final productis uniformity spheroidal particle which is pale yellow. We did not only eliminate the excitantodour of thymol, but slao maintain long-term release, in the pH=7and pH=2liquidenvironment. The zein/SC nanoparticles have certain inhibitory effect in whole milk withListeria monocytogenes.(2) This work has explored a new kind of zein/carrageenan complex films usingself-assembly character of zein particles from the angle of material science. The ratio of zeinparticles to carrageenan can result in different films with different microstructure.Throughinvestigating the mechanical properties, oxygen permeability, water vapor permeability andsurface propertied of the composite film obtained. This article attempted to reveal therelationship between microstructure between microstructure and physical properties of the film and to study the possibilities of making films with the ability of encapsulating lysozymeand controlled releasing rate of loaded functional ingredients.The Results show that under the condition of60℃, RH40%, Zein/KC composite filmswith the ratio of1:1and1:2have good comprehensive performance.The Zein/KC compositefilm formed a kind of network in which K–carrageenan acts as matrix and homogeneousnanoparticles of zein is embedded. Such a hrydrophilic matrix (K-carrageenan) andhydrophobic (zein microsphere) structure has a good prospect of building controlled releaseof antibacterial material. Then added Lysozyme to the Zein/KC composite and studied theantimicrobial properties.of Zein/KC composite films and the release kinetics of lysozyme.(3)The barrier ability of sodium caseinate (SC) films was enhanced by using Zeincoatings and structural inversion approach. The effects of zein coatings on barrier properties(oxygen and water vapor) and surface properties (surface hydrophobicity, surface free energyand surface topography) of the flms were extensively investigated. Explore and reveal therelationship between surface microstructure and the barrier property. Zein coatings producedvia structural inversion approach enhanced the barrier of SC films against water vapor andoxygen, whereas the direct coating approach only decreased oxygen permeability (OP) of thefilms. The data pointed to a possible arrangement and orientation ofhydrophilic andhydrophobic moieties of zein on surface of SCfilms under different conditions. A schematicillustration of the formation pathway of zein coatings on SC films was proposed to relate itwith barrier and surface properties of the films.