African Journal of Chemistry

African Journal of Chemistry ISSN 4391-3199 Vol. 7 (4), pp. 001-005, April, 2020. © International Scholars Journals

Full Length Research Paper

Occurrence of malondialdehyde and N- nitrosamines and their precursors in some Nigerian ice creams, yogurts, meat and fish species

Okafor, P. N1, Nwosu, O1, Chukwu, J1, Agbayi, J1 and Maduagwu, E. N2

1Department of Biochemistry, Michael Okpara University of Agriculture, Umudike, PMB 7267, Umuahia, Abia State, Nigeria.

2Department of Biochemistry, College of Medicine University of Malawi, Malawi.

Accepted 24 January, 2020

Abstract

The malondialdehyde (a deleterious by-product of lipid peroxidation) and N-nitrosamines and their precursors (nitrate and nitrite) content of seven (7) and three (3) brands of Nigerian yogurts and ice-creams respectively as well as that of some meat and fish samples were determined using chemical methods. Malondialdehyde and nitrite were estimated spectrophotometrically, nitrate after reduction to nitrite with cadmium column and N-nitrosamines after decomposition to nitrite using U.V irradiation. Malonaldehyde was detected in all the samples of both ice-creams and yogurts and in some meat and fish samples with mean concentration of 1.79 ± 0.13- 9.11 ± 2.67 µg/ml in the food drinks and 0.51±0.01 - 1.68 ± 0.03 µg/g and N.D – 12.95 ± 1.07 µg/g in fish and meat samples respectively. All the brands of ice-creams and yogurts (except Brand B) analyzed contained detectable amounts of nitrite. The mean values in µg/ml ranged 0.06 ± 0.01 – 0.2±0.01µg/ml for ice creams and 0.07 ± 0.01 – 0.04 ± 0.02 µg/ml for yogurts. Measurable concentrations of nitrate (0.64 ± 0.04 – 4.91 ± 0.51 µg/ml) and N-nitrosamines were also found in some of these food drinks. The toxicological implications of these findings are discussed.

Key words: Malondialdehyde, nitrate, nitrite, n-nitrosamines, ice creams, yogurts, fish, meat.