EFFECT OF SMOKING AND FRYING ON NUTRITIONAL QUALITY OF FOUR SPECIES OF FISH COMMONLY CONSUMED IN BENIN

Abstract

Fatty acids are vital for human health. The objective of the study was to evaluate the impact of processing and preservation processes on nutritional quality. Thus, 60 fish samples were used for fatty acids quantification through Gas Chromatography coupled with a Mass Spectrometer (GC-MS). It appears that total lipid contents were higher when fresh fish were fried in Coptodon guineensis and in Sarotherodon melanotheron than fresh, fried and smoked fish. The dominant saturated and monounsaturated fatty acids were respectively Palmitic and oleic acids. In Trachurus trachurus, Coptodon guineensis and Sarotherodon melanotheron, smoking significantly (p<0.05) reduced polyunsaturated fatty acid (PUFA) levels compared to fresh samples. Similarly, frying fresh fish lowered PUFA levels in brackish water species. All the fish had high linoleic acid levels after frying. DHA and EPA acids were higher in marine fish. DHA was higher in fresh Coptodon guineensis, Trachurus trachurus and Scomber scombrus. In all species DHA and EPA contents dropped after frying. Smoked marine fish showed a high level of DHA and EPA. The ratio H/H not exceeding 2 were obtained in smoked Scomber scombrus and fried Scomber scombrus. By contrast, the lowest atherogenicity index was obtained in fried Trachurus trachurus (0.35). Likewise, smoked Trachurus trachurus and Scomber scombrus had low thrombogenicity indices. Coptodon guineensis and Trachurus trachurus had higher Peroxidability Indices while all the fried fish had the lowest values. The control of variation parameters of essential fatty acids during the processes would guarantee a better nutritional quality to the consumer.