Stability of Tocopherols and Retinyl Palmitate in Snack Extrudates

Fish- and peanut-containing half-products were obtained by extruding and drying tocopherol- and retinyl palmitate-fortified mixtures of tapioca starch and minced fish or partially defatted peanut flour (PDPF 60:40, wet basis). Half-products were puffed by deep-fat frying. Vitamins were determined simultaneously at each step of snack production using a direct solvent extraction method. Extrusion significantly reduced the content of tocopherols and retinyl palmitate in both products. Reduction of retinyl palmitate in fish and peanut extrudates during snack production was 48% and 27%, respectively. Final products contained more tocopherol than intermediates because of the high tocopherol content in the frying oil and its uptake.