Liquid-liquid extraction of tocopherols from corn oil deodorizer distillate

In this study, the use of liquid-liquid extraction technique was investigated in order to obtain high purity tocopherol vitamers from deodorizer distillate which is a by-product of corn oil production. For this purpose, first, acetonitrile was determined as the extraction solvent as it is not miscible with deodorizer distillate in any ratio. Some compositional and chemical properties (free fatty acid content, saponification number, peroxide number, iodine value and fatty acid composition) of corn oil deodorizer distillate were determined. The effects of the solvent/distillate ratio, presence of co-solvent, dilution with hexane, extraction time, the number of extraction stage and temperature were examined during the extraction of tocopherols form corn oil deodorizer distillate. Corn oil deodorizer distillate was found to be rich in linoleic (%49.41) and oleic acid (%28.60) while it has 51.9% free acidity, 52.0 mg KOH/g oil saponification number, 7.2 meq/kg oil peroxides and iodine number of 64.8. According to the results obtained from liquid-liquid extraction trials, it was determined that tocopherol recovery was increased with increasing solvent to distillate ratio. In order to determine the influence of the presence of co-solvent on tocopherol recovery, ethanol and isopropyl alcohol were used. With increasing ratio of both co-solvents in acetonitrile, tocopherol recovery was also increased. Results obtained from isopropyl alcohol were higher than ethanol alcohol in all ratios used. An inverse relationship were found between the amount of hexane in distillate phase and tocopherol recovery. In the multi-step extraction studies, the highest tocopherol recovery was achieved at the first stage, It was determined that temperature and extraction time had no significant effect on tocopherol recovery.