The Development Of Ionic Liquids Extracting Agent On Procyanidins And The Processing Research

Procyanidins（PC）,existing in seeds,stems,leaves,fruits of the plants,are secondary metabolites in plants.Their high biological activities are mainly manifested in the ability of scavenging free radicals and antioxidant activity,leading to some functions,such as blood vessels protecting,anti-cancer,hypertension prevention,promoting the cell proliferation,keeping young and delaying senescence.PC are widely used in the fields such as food,cosmetics,health products.This paper worked on the development and utilization of procyanidin from the grape seeds.Firstly,the extraction process of procyanidin in cabernet gernischt grape seeds by alcohol aqueous solution was explored;extraction temperature,extraction time,liquid-to-solid ratio and ethanol concentration were investigated to manifest their effects on the extraction of the procyanidin.Response surface experiment analysis was utilized to optimize the process conditions for extracting PC.The results indicated that the optimizing conditions are as follows:extracting temperature 64.91℃,extracting time 69.03 min,liquid to solid ratio 6.14 and ethanol concentration44.47%.Under these optimized conditions,the concentration of the PC could be obtained 2.14 mg/g in theory,while the actual production rate compared with the theoretical value,the error was about 1%verified by the experiment.Then,some ionic liquids which have strong interaction to procyanidin under the optimal process of alcohol extraction to improve the effect of PC extraction were investigated and selected.[Bmim]PF₆,[Omim]PF₆,[Hmim]PF₆,[Bmim]Cl,[Hmim]Cl and[Omim]Cl were chosen to get a better efficiency.Considering the synthesis conditions and cost,[Bmim]Cl and[Bmim]PF₆ were chosen to extract the PC,physical and chemical properties of the two kinds of ionic liquids were studied in details.[Bmim]PF₆ and [Bmim]Cl were synthesized and used to extract PC.The optimizing process conditions of [Bmim]Cl were shown that[Bmim]Cl concentration 0.005 mol/L,ethanol concentration 95%,temperature 70.00℃,extracting time 83.03 min,liquid-to-solid ratio6.18,under which the extraction quantity of PC could be reached 13.9mg/g.The optimized conditions of [Bmim]PF₆:0.0005 mol/L[Bmim]PF₆,95%ethanol,temperature 71.27℃,extracting time 91.59 min and the liquid-to-solid ratio 9.69,under which the extraction quantity of PC could be obtained about 19.9 mg/g.Finally,five kinds of resin were used to purify the coarse products.D101 microporous resin showed a better effect in the extraction of PC among D101,AB-8,SP700,732 and D152.Further 95%ethanol was selected as the desorption agent through the experiment of desorption using different concentration of ethanol as the desorption agent.The best sample concentration and volume were 1.55 mg/mL and 120 mL.The adsorption kinetics of five kinds of resin D101,AB-8,SP700,732 and D152 were studied and the adsorption dynamics equations were obtained.As a little of ionic liquids were existed in the systems,the adsorption effect of [Bmim]PF₆ and [Bmim]Cl on the resin aforesaid were studied,the results showed that only D152 resin could adsorb these two kinds of ionic liquids.So the microporous resin D101 not only could be used to purify PC,but also to get rid of the ionic liquids.In this work,a complete set of PC extraction processes from the grape seeds with [Bmim]PF₆ and [Bmim]Cl as agents were obtained,after separation and purification,high purity of PC solid products were also got.The innovation of this work is to systematically choose two typical ILs which have strong interactions with PC.The extraction efficiency of the PC with the ILs as the assister is much higher than that under the same conditions with alcohol as the solvents lonely;methods of separation and purification system were found and the safe solid PC products were finally obtained.