EXTRACTION AND QUANTITATION OF TOCOPHEROL IN RAW AND COOKED CHANNEL CATFISH

Using either saponification or sodium dodecylsulfate/ethanol/hexane extraction (SDS) extraction, similar recoveries of alpha-tocopherol added to either raw or cooked tissue were obtained. Significantly lower levels of alpha- and gamma-tocopherol (mu-g/g tissue) from both raw and cooked tissue were indicated using the SDS extraction method than with saponification. In particular, SDS extraction was ineffective in extracting tocopherols from tissue structurally modified by heat. Based on saponification data, cooking did not result in destruction of either alpha- or gamma-tocopherol in tissue samples.