Effects of Roasting and Frying on the Proximate Composition, Mineral Content and Health Risks Due to Heavy Metals in Ethmalosa fimbriata (Bowdich, 1825)

Abstract

Aims: Effects of roasting and frying on the proximate composition, mineral content, and health risks due to heavy metals in Ethmalosa fimbriata were assessed. Place and duration of study: Food Science Laboratory of the University of Douala and Douala Foodstuffs Laboratory (Cameroon) between February and June 2025. Methodology: Fresh fish were purchased at the fishing port market of Douala and transported to the laboratory. After several washes, the fish were separated into three batches. One batch was analyzed fresh and the other two batches after frying and roasting. Proximate composition, mineral contents and heavy metals were analyzed by AOAC methods. Estimated Daily Intake (EDI), Targeted Hazard Quotient (THQ), Hazard Index (HI) and Carcinogenic Risk (CR) were assessed to estimate human health risk. Results: Roasting and frying increased proteins, ashes, energy values and some minerals such as Ca, P, K and Na levels in fish. A significant (p<0.05) drop in lipid contents was noted with roasting compared to fresh and fried fish samples. Moisture, carbohydrates and minerals such as Zn, Cu and Mn decreased with roasting and frying. Both methods increased significantly Cd, Pb, Hg, As, EDI, HI and CR compared to fresh samples. Roasting increased significantly heavy metals and health risk compared to frying. EDI values of all heavy metals studied were below acceptable limits while THQ of mercury in roasted and fried samples were above acceptable limits for human consumption. HI from roasted and fried samples suggested a non-potential carcinogenic effect while CR for cadmium suggested a carcinogenic risk. Conclusion: This study shows that E. fimbriata has good nutritional quality, but is subjected to the increase of metal residues during roasting and frying, leading to consumer’s health risks. Frying presents the lowest risk for consumption compared to roasting. It is therefore important to continuously monitor toxicological quality of fish from the Cameroonian coast.