Extraction And Purification Of Lycopene And Preparation Of Microemulsion And Its Degradation Kinetics

Lycopene is a kind of natural pigment which can be dissolved in non-polar solvent.It has attracted more and more attention because of its unique functional properties.In industrial production,lycopene is often extracted by organic solvent.The amount and volatility of organic solvent are very large.It is easy to have residues and cause damage to human body.It is not only waste but also damage the environment.The purity of lycopene extracted is low,and it can not be directly put into production,and its stability is poor.It is vulnerable to environmental factors,such as light,high temperature and so on,Therefore,it is very necessary to extract and prepare high purity lycopene,study its degradation mechanism and improve its stability,which is also an urgent problem to improve the commercial value of lycopene.In this experiment,lycopene was extracted from tomato powder by microemulsion instead of traditional organic solvent.The linoleic acid was selected as the oil phase of microemulsion.The best extraction conditions of lycopene were ultrasonic power 422 W,material to liquid ratio 1:13.80 g/g,ultrasonic extraction 22 min,the extraction rate was 76.79%,and the lycopene content was 519.90.μ This method has the advantages of green and environmental protection.Lycopene was purified by saponification recrystallization method.The ratio of saponification liquid to lycopene was 4:3:1:1 g/g.the purity of lycopene was 60.09%after saponification at 70℃ for 2 h and Recrystallization at 0℃ for 36 h.In order to increase the stability of lycopene,lycopene obtained from above optimal technological conditions was prepared into microemulsion.The best conditions for the preparation of microemulsions were obtained,that is,the best oil phase selection was lycopene,the most ethyl acetate with the strongest microemulsion ability,the surfactant Tween 60,the cosurfactant fixed anhydrous ethanol,the ratio of surfactants and cosurfactant(Km)was 2,the ability of forming microemulsion was the strongest,and the area of lycopene microemulsion was 53.97%.The average particle size of the microemulsion was 13.22 nm and PDI 0.348,indicating that the lycopene microemulsion belongs to the single phase system.The substructure of lycopene microemulsion was determined by measuring the conductivity of lycopene.The results showed that the water content of microemulsion was 0-25%,and its substructure was oil in water.When the water content reached 66%,its substructure was Bi continuous,and its water content was more than 66%.Its substructure was oil in water.The prepared lycopene microemulsion has good stability,which is:high speed centrifugation without lamination;heating to 80.At C,the microemulsion changed from clarification to turbidity,and the phase transition point was higher.Lycopene microemulsion had higher retention rate than lycopene crystal with higher temperature,and better storage stability.After 90 days,the retention rate of lycopene in microemulsion was 56.12%,and lycopene crystal was basically oxidized at ninetieth days.Taking lycopene crystal and lycopene microemulsion as the obj ect of study,the photo and thermal degradation pathways and the degradation of color in the process of degradation were studied.According to the calculation and linear equation,the R2 of the lycopene microemulsion was greater than 0.98,which accorded with the first order degradation kinetics law.The lycopene and the color degradation rate of lycopene microemulsion were far less than that of lycopene crystal and chroma degradation rate.The results showed that lycopene microemulsion had good stability and provided reference for improving the practical application of lycopene in the future.