Studies On Extraciton And Purification Of Carotenoids From Aril Of Gac(Momordica Cochinchinensis Spreng.) Fruit And Its Preparation Of Nanoparticles

Momordica cochinchinensis Spreng.(gac fruit)is a herb of Momordica charantia L..It has attracted much attention because of the abundant carotenoids in its aril.However,carotenoids are instable and indissolvable in water,which limits their application in the food industry.Therefore,it is necessary for us to study how to use these substances efficiently.In this study,carotenoids were extracted from aril of gac fruit by ultrasonic assisted solvent method.The optimal conditions of extraction and saponification were determined by single factor and orthogonal test methods.Then the purification was carried out by thin later chromatography and column chromatography.Ultimately,purified carotenoids nanoparticles were prepared by complex coacervation of gelatin and gum Arabic.The main results were as follows1.The optimal conditions of ultrasonic-assisted extraction were determined as follows:ultrasonic power was 60 W,ultrasonic temperature was 65,ultrasonic time was 60 min,solid to liquid ratio was 20:1 mL/g with the solvent is anhydrous ethanol/ethyl acetate(1:1)and extract once.The content of carotenoids was 2.232±0.11 mg/g under this condition.The antioxidant capacity of carotenoids was determined by measuring the ability of scavenging radical(DPPH and ABTS).The values of IC50 were 33.5 μg/mL and 26.13 μg/mL respectively,reflecting strong antioxidant activity of carotenoids2.Under the optimal conditions(3 mol/L of concentration,50℃ of temperature,150 min of time)of saponification interacted by KOH-ethanol solution,the saponification yield was 77.75±0.52%.The carotenoids after saponification contained lycopene,β-carotene,zeaxanthin and lutein with concentration of 5411.37 μ/g,4635.51μg/g,32.79μ/g and 87.62 μg/g respectively,The optimal eluent determined by thin layer chromatography was petroleum ether:ethyl acetate of 100:1.A fter purification by silica gel column chromatography,the content of carotenoids was increased from 1.02%to 3.28%,which indicated that the effect of purification by column chromatography was considerable.3.The paper researched that the optimum pH of complex coacervation was 4.89 with G-to-GA ratio of 1:1.This method was based on the properties of wall materials and complex coacervation process.The optimal preparation conditions of CAG-Ps were determined by particle size,polydispersity index(PDI),zeta potential and encapsulation efficiency.The results were as follows:concentration of wall materials was 0.5%,concentration of core materials was 0.5%,the concentration of Tween 80:Span 80(1:l,w/w)was 0.5%and the amount of curing agent was 15 U/g gelatin.The average particle size of the carotenoids capsule prepared under this condition was 318 nm.The PDI was 0.262 and the encapsulation effeciency was 89.3%.It also had a good spherical particle morphology observed by the SEM.In the test of stability of carotenoids in capsule,three factors of light,oxygen and temperature were all damage carotenoids in certain degree,especially light.While the carotenoids nanoparticles could effectively maintain its stability.