Malonaldehyde content of indigenous and imported foods and foodstuffs in Nigeria

Several types of imported and locally available foods and foodstuffs in Nigeria were analysed for their malonaldehyde concentrations. The malonaldehyde levels of imported canned fish products ranged from 0·32 to 3·32 mg/kg. Thermal treatment of mackerel (Scomber scombus) reduced its malonaldehyde level but increased the oncogenic substance of other fish samples. Freezing beef for 4 days increased the malonaldehyde level with a mean of 0·48 mg/kg. The extract from boiled liver had a higher malonaldehyde level than that from raw liver. Milk and milk products did not contain any detectable quantity of malonaldehyde. The need to determine the cumulative effect(s) of ingesting small quantities of malonaldehyde for long periods and further appraisal of all food items for this oncogene are discussed.