Study On Extraction Of Procyanidins From Natural Products Using Subcritical R134A And Phase Equilibrium

Procyanidins was known as an antioxidant, which had wide application prospect in the area of medical and health care, thus a green and efficient extraction method had always been a focus of research. As a new type of refrigerant, R134a (1,1,1,2-tetrafluoroethane) has lower critical pressure (4.06MPa) and stronger dissolving property, nevertheless, the phase equilibrium data in subcritical R134a system was scarce and lacking in theoretical research. The subcritical extraction and solubility of solid solutes in R134a were studied as follows:The research on the extraction of procyanidins from hawthorn and ipuranol using subcritical R134a was investigated. The influence of operating variables, including extraction pressure (8-12MPa), extraction temperature (303-323K) and extraction time (40-80min), on the extraction rate of procyanidins was tested. Through orthogonal and single-factor experiment, the optimal extraction conditions and maximum extraction rate was obtained, in which the procyanidins was analysed by the molysite catalytic colorimetry method. Compared with the traditional solvent extraction, the method in this article had better selectivity and considerable extraction rate.Within the range of5.0-13.0MPa and308-328K, the solubility of pure and mixed solid solutes in the subcritical R134a was determined. The results indicated that the solubility varied by many factors including temperature, pressure, substituent group positions and molecular interaction of the solutes and solvent. Meanwhile, Gaussian03was used to calculate the molecular interaction between the solute and solvent molecules, which proved the variation of the solubility of solid solutes in subcritical R134a.Moreover, the experimental solubility of solid solutes in subcritical R134a was correlated by Chrastil, modified A-L, K-J and M-T models, and the model parameters and values of mean relative deviation were obtained, repectively.This research was supported by the foundation of National natural science foundation of China(21176012), Natural science foundation of Jiangsu province(BK2012595) and Science&technology projects of Changzhou (CJ20110013).