Menhaden oil was purified by column chromatography to remove minor componen
ts. The effect of alpha -tocopherol (alpha TOH) (50-500 ppm) on the rate of
formation of hydroperoxides in the original menhaden oil and in the purifi
ed menhaden triacylglycerol (TAG) fraction was studied at 30 degreesC in th
e dark. An increase in the initial rate of formation of hydroperoxides was
observed at alpha TOH concentrations above 100 ppm in both substrates. The
original menhaden oil oxidized more rapidly than the purified menhaden TAG
at all antioxidant levels tested, and the presence of minor components in t
he menhaden oil was found to contribute only to a limited extent to the per
oxidizing effect of alpha TOH. The alpha TOH did not display any prooxidant
activity at either of the concentrations tested when the control oil was t
he purified menhaden TAG. Addition of ascorbyl palmitate eliminated the ini
tial peroxidizing effect of alpha TOH, and this emphasizes the participatio
n of the alpha -tocopheroxyl radical in the reactions causing an accumulati
on of hydroperoxides at high concentrations of alpha TOH.