Study on Extraction and Determination of Procyanidins From the Grape Seed

Extraction and determination of procyanidins from the grape seed were systematically studied. Effects of solid-to-liquid ratio, extraction agent concentration, extraction temperature, extraction time on extraction of procyanidins were investigated, and by orthogonal experiment the optimum extraction conditions were determined as follows: solid-to-liquid ratio 1∶6, ethanol concentration 70%, extraction temperature 50 ℃, extraction time 60 min. The range analysis showed that the extraction temperature was major factor, the secondary factors were ethanol concentration, extraction temperature and solid-to-liquid ratio. The content of proanthocyanidins was determined by colormetry with ferric ion as catalyst. Effects of reaction time, reaction temperature, reaction medium, acid type, acid concentration, ferric ion concentration and metal ion type on the absorbency were researched. Through experimental analysis,the optimum conditions were determined as follows:using n-butanol and 5 mL hydrochloric acid as reaction medium,0.415 mol/L Fe3+ as a catalyst, reaction time 60 min, reaction temperature 60 ℃;under above conditions,the absorbency is the maximum.