Research On Citronella Oil Extraction And Application On The Preservation Packaging Of Fresh Beef

In this work,the citronella oil was used as botanical antimicrobial agent,and coating liquid and porous starch were used as raw material to prepare esessential oil microcapsule.The antimicrobial technology of the new green safe plant essential oil was designed and developed by combining with fresh water absorption cushion.It was applied to fresh keeping packaging of chilled beef,in order to realize that the essential oil can play the bacteriostatic action in different storage stages,thus the shelf life of chilled beef was extended.Citronella oil was extracted by using ultrasonic assisted steam distillation method and the extraction process was optimized by orthogonal experiment.The results show that when the solid-liquid radio was 1:20,the amount of Nacl was 10%,extraction time was 180 minuses,the yield of Citronella essential oil was 2.8%,under the premise of the power ultrasonic was 420W,the ultrasonic time was 30min.The main ingredients of citronella oil were analysed by using gas chromatography-mass spectrometry.The results showed that citronellal was the main antibacterial components of citronella oil,and the absolute content of that was 49.11mg/mL.The phase minimum inhibitory concentration of citronella oil on Escherichia coli,Staphylococcus aureus,Salmonella and Bacillus subtilis were 35?40?35?30?L respectively.The experimental results of gas phase inhibition mechanism of the essential oil show that,with the extension of time,essential oils can disrupt the normal life activities of the cell,destroy the integrity of the cell membrane,and then inhibit the growth and reproduction of the cell.Microcapsule core material combination which was prepared according to the best ratio(0.5:1)of citronella oil(mL)and porous starch(g)had excellent sensory evaluation.The embedding rate of microcapsule whose wall material dosage(mL)was 1.4 times of porous starch(g)achieved 98.1%.Take 2.5mL citronella oil dosage for example,The yield of microcapsules was 42.96%under the optimum proportioning condition.Scanning electron microscope of sample show that,the pores of the porous starch surface are further from the surface to the center.Most of the pores which adsorbed citronella oil in a full state,but internal essential oil can still be directly exposed to the air.When wall material was added,the pores in closed state and the surface of microcapsule was flat and smooth.With the fresh water absorption cushion,the fresh-keeping effect of different concentration of citronella oil on chilled beef was researched.The results showed that preservation effect of essential oil consumption of 90?L was relatively prominent.Compared with the control group,the shelf life of fresh beef was extended 6d.With 90?L of essential oil as the standard,the fresh keeping effect of combined body of porous starch adsorbing essential oil,essential oil microcapsule and compound application of antibacterial method on chilled beef were investigated separately.The results showed that:compared with the other two kinds of preservation methods,compound application of antimicrobial agents can better maintained the sensory quality of fresh beef,reduced the increasing rate of pH value,inhibited increase of total number of bacterial colony of fresh beef surface and delayed increase of lipid oxidation degree and TVB-N content.Compared with the control group,the shelf life of chilled beef can be prolonged 1 times.