| Zein is an alcohol-soluble complex protein derived from corn,which contains?-,?-,?-,?-zein and other components.Due to its special dissolution and self-assembly characteristics,it is widely used in food,medicine,biomedicine,packaging,textile fibers and other fields.At present,there are many researches on the physicochemical properties and applications of zein,but the research on the colloidal properties of zein single component is very limited.Therefore,this subject classifies zein to obtain three main components,such as?-zein,?-zein,and?-zein,and comparatively studies the basic physical and chemical properties of zein and its components and the interface and loading characteristics of self-assembled particles.,To provide a theoretical basis for promoting the further development and utilization of zein.The main conclusions obtained in this article are as follows:(1).The three components of zein,?-zein,?-zein,and?-zein were successfully isolated from corn.SDS-PAGE analysis results showed that commercially available commercial zein mainly contained?-zein components,and extractive zein mainly Contains?-zein and?-zein,the relative molecular mass of?-zein is 22 KDa and 24 KDa;the relative molecular mass of?-zein is 14 KDa,and contains a small amount of?-zein and?-zein;the relative molecular mass of?-zein is 16 KDa,and contains a small amount of?-zein.In terms of amino acid composition,the highest hydrophobic amino acid content of?-zein is 54.3%,and the lowest of?-zein is 38.2%.In terms of interface morphology,?-zein exists in the form of particles at the air-pure water interface,?-zein has a tight network structure,and?-zein forms a worm-like structure.(2)Colloidal particles of zein and its components were prepared by anti-solvent method under two buffer systems of pH=2.0 and pH=8.0,and their interface and emulsification characteristics were analyzed.Zein and its components can self-assemble into spherical particles of 100-1000nm under two pH systems.For zein 2.0 particles,commercial zein,?-zein,and?-zein particles with a large amount of adsorption at the oil-water interface have good emulsifying activity;while?-zein particles have almost no emulsification;?-zein shows more excellent Interface viscoelasticity.For zein 8.0 particles,?-zein has the strongest interface activity and emulsification;?-zein and?-zein have good interface activity,and?-zein has higher interface viscoelasticity;?-zein and?-zein The emulsion stability is poor.Compared with zein2.0 particles,zein8.0 particle emulsion has better acid and alkali resistance and salt resistance than zein2.0 particles.(3)Use zein2.0 particles and zein8.0 particles as V_E carriers to explore the load and release characteristics of zein and its components.As the amount of V_E added increases,the encapsulation rate of zein particles decreases,and when the ratio of V_E:zein reaches1:10,the encapsulation rate tends to be stable.When the ratio of V_E:zein is 1:10,the particle size is the smallest and the loading effect of the particles is the best.For zein2.0 particles,the highest encapsulation rate of commercial zein to V_E is 93.2%,and the lowest encapsulation rate of?-zein is 57.9%;for zein 8.0 particles,the highest encapsulation rate of commercial zein to V_E is 97.1%,extractability The minimum encapsulation rate of extractive zein is 60.0%.After 15 days of storage at 37?,the retention rate of V_E of zein2.0 and zein8.0 particles can still reach about 70%.The release rate and cumulative release amount of V_E-loaded zein 2.0 particles in simulated gastrointestinal fluid in vitro are significantly smaller than that of zein 8.0 particles.Under the condition of pH 2 antisolvent,extractable zein and?-zein can achieve better sustained release effect,and the loading effect of?-zein is the worst;Under the pH8anti-solvent condition,the sustained release effect of extractable zein and?-zein is more excellent;?-zein has the worst loading effect on V_E. |
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