The invention provides a method for extracting and purifying procyanidine from waste grape seeds and discloses a process
route with simpler and reasonable effects and low cost. The method comprises the following steps: carrying out water-bath
reflux extraction on
grape seed powder by using a
solvent containing 50%
alcohol and 4%
citric acid at a ratio of (3:1)-(5:1) at a material-
liquid ratio of (1:6)-(1:9) (m / v, the
mass-
volume rate), cooling, filtering, then carrying out rotary
evaporation, and recovering
alcohol; using the
alcohol for alcohol
precipitation, filtering alcohol-
precipitation liquid, then concentrating, recovering alcohol, adding
distilled water and uniformly mixing; extracting with normal
butanol, combining extraction liquid, and cleaning the extraction liquid with saturated
salt water; and carrying out rotary concentration and
drying on the extraction liquid, and recovering normal
butanol, thereby obtaining purpurin
powder. The method provided by the invention has the following advantages that waste grape seeds in the
wine brewing process are adopted as raw materials, so that not only are the wastes reasonably reutilized, but also the cost is low and the implementation benefit is obvious; alcohol is utilized for extraction, and normal
butanol is utilized for extraction treatment, so that the production safety is good; alcohol and normal butanol are recovered, and are recycled, so that the cost is reduced; the product is high in purity and good in yield; and the process is simple and the industrialization is easy.