title: A biocatalyst for the removal of sulfite from alcoholic beverages.
abstract: The presence of sulfites in alcoholic beverages, particularly in wines, can cause allergic responses with symptoms ranging from mild gastrointestinal problems to life threatening anaphylactic shock in a substantial portion of the population. We have developed a simple and inexpensive biocatalytic method that employs wheatgrass (Triticum aestivum) chloroplasts for the efficient oxidation of sulfites in wines to innocuous sulfates. A sufficiently high rate of sulfite oxidation was obtained in the presence of ethanol at concentrations commonly found in most wines. Crude chloroplast preparations at a concentration as low as 5 mg/mL were capable of reducing sulfite in commercial white wines from 150 ppm to under 7.5 ppm within 3 hours. A 93% removal of sulfite in commercial red wines was observed with 1 mg/mL chloroplasts within 45 min. Optimal sulfite removal efficiency was observed at pH 8.5 and was promoted by illumination, indicating the participation of light-induced photosynthetic electron transport processes in sulfite oxidation. Overall, this work indicates that biocatalytic oxidation using wheatgrass chloroplasts can be employed to remove sulfites from beverages prior to consumption.
authors.forename: Sung-Chyr
authors.initials: SC
authors.lastname: Lin
authors.forename: George
authors.initials: G
authors.lastname: Georgiou
mesh_terms: D000434:Alcoholic Beverages / Q000032:analysis*; D002384:Catalysis; D002736:Chloroplasts / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D004579:Electron Transport / Q000528:radiation effects; D000431:Ethanol / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008029:Lighting; D010084:Oxidation-Reduction; D010788:Photosynthesis; D013447:Sulfites / Q000378:metabolism*; D013997:Time Factors; D014908:Triticum / Q000166:cytology; D014920:Wine / Q000032:analysis
chemical_list: D013447:Sulfites; D000431:Ethanol