Purification,Identification And Microencapslation Of Oligomeric Proanthocyanidins From Red Raspberry Seed

Red raspberry seed is the mature red raspberry seed of rosaceae,which is often abandoned,causing great waste of resources.Therefore,the development and utilization of raspberry seeds has become an important issue to ensure the development of the raspberry industry.Red raspberry seed was rich in proanthocyanidins,of which oligomeric proanthocyanidins have a variety of biological pharmacological activity and are a kind of natural active substances with great potential for development.In this study,red raspberry seed was used as experiment material.Ultrasonic combined with cellulase-assisted was used to extract proanthocyanidins of red raspberries seeds on the basis of organic solvent extraction.Proanthocyanidins oligomers compounds were separated,purified and a identified to obtain the purified Proanthocyanidins oligomers.Finally,the microencapsulation of purified oligomeric procyanidins was studied.Main conclusions were shown as follows:1.The process of ultrasound-enzyme assisted method of extracting proanthocyanidins from red raspberry seed was optimized by response surface methodology in this research.Based on Box-Benhnken design and taken extraction rate of proanthocyanidins as index,effects of crucial factors were investigated by response surface analysis.The optimal optimal process was: solid to liquid ratio1:31 g/mL,enzyme addition amount 0.8%,ultrasonic power 190 W and extraction time 39 min.Under these conditions,the maximum extraction rate of proanthocyanidins reached 16.42 mg/g.2.Combining use of macroporous resins with polyamide resins shows a good separation and purification effect.Macroporous adsorption resins were used topurify the crude extract of proanthocynidins from red raspberry seed,and then polyamide resins were used for secondary purification of the oligomeric procyanidins.The results showed that the macroporous resins,which adsorbed the crude extract of proanthocyanidins from red raspberry seed,obtained the oligomeric proanthocyanidins by 40% ethanol elution,and then high polymeric proanthocyanidins were obtained by 60% ethanol elution.The optimal extraction parameters for polyamide resins were determined as follows: polyamide number30-60,sample concentration 2 mg/mL,flow rate 1.5 mL/min,sample volume 100mL;70% ethanol concentration on desorption,flow rate 1.5 mL/min,eluent volume 150 mL.As a consequence,the purity of oligomeric proanthocyanidins increased from 52.36% to 71.09%.Simulated gastric digestion 0~2.5 h and intestinal digestion 0~3.0 h,The release of oligomeric proanthocyanidins and high polymeric proanthocyanidins gradually increased to 14.23,5.02 mg/g and 27.79,12.62 mg/g.The release of oligomeric proanthocyanidins was much higher than that of high polymeric proanthocyanidins,indicating that oligomeric proanthocyanidins were more beneficial to human body absorption and utilization.3.The purified oligomeric proanthocyanidins composition was analyzed and identified by UV,IR and LC-MS/MS technology.The characteristic absorption peak of proanthocyanidins at 504 nm exists in the UV scanning spectra of oligomeric proanthocyanidins.It was determined that the main structural unit of purified oligomeric proanthocyanidins was procyanidin by IR scanning.By LC-MS/MS technology it was identified four monomers,one dimmers,two phenolic acids and one unknown oligomer from oligomeric procyanidins which were gallic acid,epigallocatechin,B-procyanidin dimer,catechin,epicatechin,galloyl-HHDP-glucose,epicatechin gallate and unknown oligomersm respectively.4.A new method for preparation of microencapsulated oligomeric proanthocyanidins from red raspberry seed was established in order to improve the stability of oligomeric proanthocyanidins.The preparation of oligomeric microcapsuls of red raspberry seeds was made from oligomeric proanthocyanidinsas core material and gelatin and gum arabic as wall material and optimized by single factor and response surface test.The stability of the native and the microencapsulated oligomeric proanthocyanidins was compared.The optimal parameters of microcapsule technology of the oligomeric proanthocyanidins were shown as follows: wall material concentration 0.75%,wall material quality ratio(gelatin/gum)1:1,core/wall material quality ratio 1:1,curing temperature 10 ?,transglutaminase dosage 22.39 g/100 g gelatin.In these cases,the rate of embedding could reach 80.34%;in addition,the moisture content,repose angle,solubility and particle size of the microcapsules was 5.64%,36.4°,89.64% and 476 nm respectively.Under the influence of Vc,sodium bisulfite,temperature,pH and light,the stability degree of oligomeric proanthocyanidins microcapsules after the embedding was significantly higher than that before embedding.Therefore,microencapsulation technology improves the stability of oligomeric proanthocyanidins,which broadens the range of application of oligomeric proanthocyanidins from red raspberry seed.