Fabrication Of Litsea Cubeba Essential Oil Microcapsules And Its Application In Beef Preservation

Beef is favored by people because of its high protein,low fat,and delicious taste,but it is easy to spoilage during storage and transportation.Litsea cubeba essential oil has good antibacterial and antioxidant activity,but it is volatile and has a lemon odor.The microcapsule technology can shield its unpleasant odor and improve its stability.In this paper,gelatin and sodium alginate are used as composite wall materials,and Litsea cubeba essential oil is used as the core material.Litsea cubeba essential oil microcapsules are prepared by complex coacervation method.The preparation conditions are optimized through single factor and response surface tests;scanning electron microscopy(SEM),laser particle size analyzer,Fourier transform infrared spectrometer(FT-IR),thermogravimetry analysis(TGA),X-ray diffraction(XRD)are used to study the morphology,thermal stability,crystallization properties of the microcapsules prepared under the optimal conditions,and the effect of temperature and light on the slow-release performance of microcapsules are studied;the preservation effect of Litsea cubeba essential oil microcapsule on chilled beef is studied by sensory evaluation,color,drip loss,pH value,total number of colonies and total volatile basic nitrogen(TVB-N)changes.It includes the following aspects:(1)Preparation of Litsea cubeba essential oil microcapsules and optimization of technological conditionsUsing gelatin-sodium alginate as composite wall material,the essential oil of Litsea cubeba is embedded by the complex coacervation method.The effect of wall material concentration(w/v),wall material ratio(w/w),core-wall ratio(w/w),homogenization time and pH value on the embedding rate was studied by single factor and response surface test.The optimal preparation conditions of microcapsules areas fllows:wall material concentration 2%,wall material ratio 1.2:1,core-wall ratio 3:2,homogenization time 3 min,pH value 3.8,and the embedding rate is 61.85%.(2)Study on the properties and slow-release properties of Litsea cubeba essential oil microcapsulesThe surface morphology,size and properties of the microcapsules are studied by SEM,laser particle size analyzer,FT-IR,TGA,XRD,and the release rate under different temperature and light conditions is explored.The results show that the microcapsules of Litsea cubeba essential oil are off-white powder with a shrunken surface and irregular cysts,with an average particle size of 105.808 ?m;gelatin-sodium alginate can maintain the original properties of Litsea cubeba essential oil and improve its thermal stability within 250?.The most stable storage is under 4? dark conditions,and the release rate is 25.6%on the 18th day.(3)Study on the application of Litsea cubeba essential oil microcapsules to chilled beef preservationLitsea Cubeba essential oil microcapsules and its preparation solution are applied to the preservation of chilled beef,and the effect of the microcapsules and its preparation solution on sensory evaluation,color,drip loss and pH value,total number of colonies and total volatile basic nitrogen(TVB-N)of chilled beef are studied.Exploring the effect of Litsea cubeba essential oil microcapsules on chilled beef is compared with the blank control group and the empty microcapsules preparation solution group.The research results show that Litsea cubeba essential oil microcapsules can delay the decrease of sensory evaluation and color,and delay the increase of drip loss,pH value,total number of colonies and total volatile basic nitrogen(TVB-N),then it can extend the shelf life of chilled beef by 4-6 days.In conclusion,Litsea cubeba essential oil microcapsules has significant preservation effect on chilled beef.