Preparation And Characterization Of Eudragit EPO-?-Carotene Nanoparticles

?-carotene is a natural antioxidant,which has good antioxidant activity and is widely used in food systems.However,?-carotene is insoluble in water at room temperature and only slightly soluble in oils.Furthermore,it is sensentive to light,heat and oxygen due to the presence of conjugated polyunsaturated double bonds and proen to oxidative degradation.The poor insolubility and unstability result of ?-carotene results in limited bioavailability and reduced application in food industries.The nano-system is an emulsified transport system with a particle size of 10-1000 nm,which can significantly improve the solubility and stability of bioactive substances.In this study,eudragit-EPO-?-carotene nanoparticles(EPO-CA-NPs)were prepared and their physicochemical properties,release behavior and stability in different pH buffers,simulated gastrointestinal fluids or simulated beverage were evaluated.The major results were listed as follows.(1)Eudragit-EPO and PVA were used as embedding material and emulsifier for the preparation of EPO nanoparticles(EPO-NPs),respectively.Through single-factor optimization and orthogonal optimization experiments,the the optimum conditions for preparing EPO-NPs with the smallest size and best dipersity index were obtained:EPO concentration 15 mg/mL,PVA concentration 3.5%,ultrasound time 60 s,volume ratio of EPO to PVA solution 1:3.The EPO-NPs obtained under the optimiezed conditions showed average diameter 236.1 nm and zeta potential 38.1mv.Scanning electron microscopy(SEM)shows that EPO-NPs are uniform nanospheres with diameter 200-400 nm.(2)The 5-carotene nanoparticles were prepared using solvent-volatile drying method to study the embedding rate and drug loading efficiency of ?-carotene.Meanwhile,the prepared EPO-CA-NPs were characterized by DLS,PDI,SEM,DSC,X-RD and FI-IR.The results showed that the embedding rate of ?-carotene was 88.50±074%,the drug loading efficiency was 1.73±0.24%,the average particle size disamter was 236.5 nm,the polymer dispersion index was 0.022 and The Zeta potential was 39.2mV.Scanning electron microscopy showed that the nanoparticles exhibited a relatively uniform spherical shape with a moderate size and a smooth and smooth surface.FI-IR,DSC and X-RD results showed that ?-carotene suggested that ?-carotene was successfully embedded the EPO-CA-NPs in an amorphous state.(3)The release behaviors and storage stability of EPO-CA-NPs in different pH buffers,at different heating temperatures,lights,and lyophilization conditions were investigated.Results showed that EPO-CA-NPs was relativel senentive to pH values,and was rapidly broken to release ?-carotene in an acidic environment with a release rate up to 94-98%.While in alkaline solution,alomost no release?-carotene was observed.EPO-CA-NPs showed relatively excellent stability to heat,light and lyophilization during long-term storage up to 90 days,with well dispersed uniform particles size and high retention rate over 90%.These results showed that the established EPO-CA-NPs showed pH response-release and great stability to heat,light during the storage.(4)The in vitro release characteristics of EPO-CA-NPs in simulated gastrointestinal fluid and stability in simulate beverage were investigated.Results showed that the release rate of ?-carotene reched 98.87%under simulated gastric conditions,while almost no release was observed in simulated intestinal conditions.Totally,the bioavailability of ?-carotene reached 91.03 ± 0.64%in vitro gastrointestinal models.Aftert added into simulated beverage,EPO-CA-NPs showed good stability with well dispersed nanoparticle size,and the retention rate was over 70%,during a 90-day storage.