Determinação de vitamina E na castanha de caju e sua relação com a recomendação nutricional em humanos

Abstract

Alpha-tocopherol is the most biologically active form of vitamin E. Its main function is related to the antioxidant activity, which protects the cell membranes from damage caused by free radicals. Given to the importance of adequate intake of this vitamin and the scarcity of Brazilian data on their contents in foods, this study aimed at determining the alpha-tocopherol concentration in cashew nuts, and these findings were compared with the vitamin E nutritional requirement. In this context, four brands of roasted cashew nuts purchased in supermarkets in Natal/RN were analyzed. The alpha-tocopherol was extracted from samples by lipid extraction, and its determination was performed by HPLC. The alpha-tocopherol values in the analyzed nuts were expressed as mean and standard deviation. The average concentration of alpha-tocopherol in 100 g of roasted cashew nuts was 0.96 ± 0.12 mg. The amount of this vitamin contained in the medium portion of cashew-nuts consumed by the interviewed population was equivalent to 3.6 % of the daily nutritional requirement for vitamin E. The analyzed toasted nuts cannot be considered as good sources of alpha-tocopherol, as they did not reach the percentage of 10 to 20 % of the daily nutritional requirement.