Study On Extraction, Enrichment And The Microcapsule Of α-Linolenic From Hovenia Acerba Lindl Seed Oil

By employing modern high-tech food engineering technology,namely Soxlet extraction,supercritical CO₂ extraction,urea inclusion and microencapsulation techniques,the seed oil was extracted from Hovenia acerba Lindl seed,α-linolenic acid was enriched and purified from the obtained H.acerba seed oil,and then encapsulated successfully.This dissertation focused on the optimization of the extraction of H.acerba seed oil,the enrichment and purification ofα-linolenic acid from the obtained seed oil,as well as the micencapsulation of H.acerba seed oil rich inα-linolenic acid.The results are as follows:1.Conventional extraction of H.acerba seed oil:The comparative study on the extraction solvent and extraction strategies indicated that high-boiling petroleum ether was the best extraction solvent,while using Soxlet extraction could achieve higher extraction efficiency.The optimal conditions for the fatty acids extraction are as follows:microwave processing time 30s,ultrasonic treatment time 30 min,extraction time 7h,extraction temperature 90℃and sample/solvent ratio 1/8(w/v),with an extraction yield of 8.45%and aα-linolenic acid content of 56.96%.2.Supercritical CO₂ extraction of H.acerba seed oil:The optimized supercritical CO₂ extraction conditions are as follows:extraction pressure 36 MPa,extraction temperature 45℃,extraction time 120 min,separatorâ… pressure 10 MPa,with a fatty acid extraction yield of 12.1%and a linolenic acid content of 59.91%.3.Enrichment and purification ofα-linolenic acid from H.acerba seed oil:The process flow of the enrichment and purification ofα-linolenic acid from H.acerba seed oil was:H.acerba seed exracts→Saponification→Freeze crystallization Urea inclusion.With ethanol as saponification solvent,the best saponifying ratio, saponifying temperature and saponifying time of H.acerba seed oil were 1:6.0,45℃and 30 min,respectively.While the best inclusion conditions of H.acerba seed oil were:the rate of urea-acetone saturation solution to fatty acid ethyl ester 4.0:1, reactive temperature 0℃and reactive time 10 h.The purity ofα-linolenic acid was enhanced to 80.36%and recovery rate ofα-linolenic acid was over 60%under the optimal saponification and purification conditions.4.Microencapsulation of H.acerba seed oil rich inα-linolenic acid by spray drying method:the results of single factor experiment confirming that the best raw materials formula for microcapsules was as follows:gelatin/β-cyclodextrin 1:6,wall material / water 15:85,core material / wall material 1:3.5,and amount of complex additive 10%. In addition,the optimal spy-drying parameters of H.acerba seed oil were:ultrasonic emulsification time 10 min,homogenization pressure 30 Mpa,inlet temperature 160℃and outlet temperature 80℃,with an encapsulation yield of 88.89%and an encapsulation efficiency of 90.83%.The obtained microparticles were spherical,with a smooth surface,and a narrow particle size varied between 8-10μm.