Preparation Of Cinnamon Essential Oil Emulsion And Its Effect On Preservation Of Nanfeng Tangerine

Due to the problems of improper storage methods and low level of preservation technology in the process of storage,transportation and sales,the annual post-harvest loss of fruits in my country is as high as 80 million tons,accounting for about25%-30%of the total field.As one of the most popular fruits,Nanfeng tangerine has the characteristics of thin and juicy skin,high water content and rich nutrition,but it is prone to mechanical damage and decay during storage and transportation,resulting in great economic losses.Therefore,it is of great significance to study scientific and effective preservation methods for Nanfeng tangerine preservation to improve the economic benefits of fruit farmers.Cinnamon is a medicinal and edible plant.Cinnamon essential oil has good antibacterial activity,but because of its volatile,low water solubility,and sensitivity to light,heat and oxygen,it is widely used in the food industry.subject to certain restrictions.Encapsulation of cinnamon essential oil by nano-emulsification can effectively improve its water solubility and stability.In this study,cinnamon essential oil was used as the main raw material,and cinnamon essential oil emulsion was prepared by ultrasonic emulsification,and its stability,antioxidant activity and antibacterial properties were explored,and finally it was applied to the preservation of Nanfeng tangerine.The contents of each chapter are described as follows:The first chapter introduces the commonly used methods of fruit preservation,and summarizes the research progress and practical application of the biological activity of cinnamon essential oil.In the second chapter,to prepare a uniform and stable cinnamon essential oil emulsion,in this study,cinnamon essential oil and sodium caseinate were used as raw materials to prepare cinnamon essential oil emulsion.And the dosage of emulsifier,the p H of the system,the heating temperature,the heating time were optimized,and its microstructure,rheological properties,ionic stability,thermal stability and storage stability were characterized.The experimental results show that the optimal conditions for the preparation of cinnamon essential oil emulsion in this study are as follows:the dosage of emulsifier is 9.8%,the p H of the system is 8,the heating temperature is 80℃,and the heating time is 20 min.The influence degree of each condition on the particle size of cinnamon essential oil emulsion is as follows:emulsifier dosage>system p H>heating temperature>heating time.In conclusion,the cinnamon essential oil emulsion prepared in this study has good uniformity and stability.In the third chapter,to explore the antibacterial properties and antioxidant activity of the prepared cinnamon essential oil emulsion,this study determined the minimum inhibitory concentration(MIC),minimum bactericidal concentration(MBC)and the effects of different concentrations of cinnamon essential oil on the hydrophobicity and permeability of bacterial cell membranes to evaluate their antibacterial properties.The results of the antibacterial experiments showed that the cinnamon essential oil emulsion showed a certain bacteriostatic activity against the six tested bacteria,with MIC≥0.625μg/m L,MBC≥1.25μg/m L,and within a certain concentration range,the higher the concentration of cinnamon essential oil,the higher the concentration of cinnamon.The better the antibacterial properties of the essential oil lotion.The results of antioxidant experiments show that the DPPH scavenging rate of cinnamon essential oil emulsion can reach a maximum of 90%,the scavenging rate of hydroxyl radicals and ABTS~+can reach 80%,and the anti-lipid peroxidation ability can reach 70%.Therefore,the cinnamon essential oil emulsion prepared in this study has good antibacterial properties and antioxidant activity.In the fourth chapter,to explore the fresh-keeping effect of the prepared cinnamon essential oil emulsion on Nanfeng tangerine,the cinnamon essential oil emulsion was sprayed on the surface of Nanfeng tangerine,and the changes of its weight loss rate,soluble solids,total acid content and ascorbic acid content were measured.The research results showed that after spraying 0.25%cinnamon essential oil emulsion and storing it at room temperature for 18 days,the decay rate of Nanfeng tangerine was only 50.4%of the rot rate of the control group,indicating that cinnamon essential oil emulsion spraying can effectively slow down the decay rate of Nanfeng tangerine to a certain extent.In addition,after spraying the cinnamon essential oil emulsion,the decline rate of soluble solids,total acid and ascorbic acid in Nanfeng tangerine was effectively slowed down,indicating that the cinnamon essential oil emulsion can effectively inhibit the metabolic activity of Nanfeng tangerine to a certain extent.Therefore,the prepared cinnamon essential oil emulsion has a certain preservative and fresh-keeping effect on Nanfeng tangerine.To sum up,in this study,cinnamon essential oil,sodium caseinate and hydroxypropyl starch were used as the main raw materials to prepare a cinnamon essential oil emulsion with excellent stability and good fresh-keeping effect,which was applied to Nanfeng tangerine.And it provides new technical means for the preservation of Nanfeng tangerines.