Patent ID: 6855353

Claim:
A process for producing resveratol in the form of dried white crystals from peanut oil residue and/or from peanut stems comprising: (a) extracting a ground dried powder of the peanut oil residue and/or the peanut stems with 95% ethanol to obtain a crude extract; (b) mixing and filtering the crude extract to obtain a filtercake and filtrate; (c) refluxing the filtercake twice with 95% ethanol in a steam bath to obtain a refluxed extract; (d) concentrating the filtrate obtained in step (b) and the refluxed extract obtained in step (c) under reduced pressure, and recovering the ethanol and still residue therefrom; (e) extracting the still residue with a mixture of water and ethyl ether; (f) separating and recovering the ethyl ether and still residue from step (e); (g) adding hot water to the still residue obtained in step (f) in a steam bath to form a suspension; (h) cooling and filtering the suspension to obtain a filtrate; (i) adding active carbon to the filtrate obtained in step (h) in a steam bath with agitation; (j) removing the active carbon by filtration to obtain a filtrate; (k) concentrating the filtrate obtained in step (j) under reduced pressure, and cooling the concentrated filtrate; (l) crystallizing the concentrated filtrate by adding ethyl ether to the concentrated filtrate to obtain crystals; (m) collecting the crystals by filtration; (n) dissolving the crystals in 30% NaOH to form a solution; (o) decolorizing the solution by contacting the solution with active carbon; (p) concentrating the decolorized solution under reduced pressure to obtain white crystals; (q) collecting the white crystals by filtration; and (r) drying the white crystals under vacuum.