Chemical composition and nutritional value of raw and cooked black scabbardfish (<i>Aphanopus carbo</i>)

Abstract

suMMarY: the objective of the present study was to follow the seasonal chemical changes and to study the effect of culinary treatments on the nutritional value of black scabbardfish (Aphanopus carbo). the proximate chemical composition of black scabbardfish (BsF) landed in sesimbra (Portugal) was followed for one year. the nutritional quality (proximate chemical composition, amino acid and fatty acid profiles, cholesterol and minerals) of raw, fried and grilled BsF was evaluated in one period of the year. BsF is a semi-fatty species, the protein content was 15-17.5% and the most abundant amino acids were glutamic acid, aspartic acid and lysine. the dominant fatty acids were monounsaturated (66%), followed by saturated (19%) and polyunsaturated (10%) ones. Potassium, phosphorus and sodium were the most abundant minerals. some dehydration occurred in cooked BsF but fat content was the most affected nutrient, particularly in fried fish. these results may suggest that the absorption of frying oil led to important changes in the fatty acid profile, and particularly in the linoleic acid level. the highest protein losses were recorded in fried BsF. in general, the nutritional quality of grilled fish seemed to be more balanced than that of fried fish.Keywords: black scabbardfish, raw, cooked, fatty acids, amino acids, cholesterol and minerals. resuMeN: Variación estacional de la composición química y del valor nutritivo de sable negro (AphAnopus cArbo) crudo y cocido. -el objetivo del presente trabajo fue seguir los cambios químicos y estudiar el efecto de los tratamientos culinarios sobre el valor nutritivo de sable negro (Aphanopus carbo). La composición química proximal de sable negro (BsF) desembarcado en sesimbra (Portugal) fue seguida durante un año. La calidad nutricional (composición química proximal, perfiles de aminoácidos y ácidos grasos, colesterol y minerales) del pescado crudo, frito y asado fue evaluada en un período del año. BsF es una especie semi-grasa, el contenido de proteína fue de 15 y 17,5% y los aminoácidos más abundantes fueron glutámico, aspártico y lisina. Los ácidos grasos dominantes fueron los monoinsaturados (66%), seguidos por saturados (19%) y polinsaturados (10%). Potasio, fósforo y sodio son los minerales más abundantes. se observó alguna deshidratación en el BsF cocinado, pero el nutriente más afectado fue la grasa, sobre todo en el pescado frito. estos resultados permiten concluir que la absorción de aceite de freír da lugar a importantes cambios en el perfil de ácidos grasos, en particular en el nivel de ácido linoleico. Las máximas perdidas de proteinas se observaron en el BsF frito. en general, la calidad nutricional del pescado a la parrilla parece estar más equilibrada que la del pescado frito.

Chemical composition and nutritional value of raw and fried allis shad (Alosa alosa)

“…In fact, it has been recognised (Jacquot, 1961;Murray & Burt, 1979) that before spawning fish usually stops feeding and expends its lipidic and proteic reserves for migration and gonadal maturation. These results are in accordance with those reported for other fish species (Garc ıa-Arias et al, 2003;Rosa et al, 2007;T€ urkkan et al, 2008;Bandarra et al, 2009). Table 3 shows the proximate chemical composition of raw and fried MS allis shad.…”

“…This value ranged between 40.5% in the RS females and 15.4% in the RS males. This inverse relationship between moisture and lipid content has been reported for other fish species (Grigorakis, 2007;Bandarra et al, 2009). Between males and females of each stock, there were no significant differences (P > 0.5) in the content of each constituent.…”

Effect of processing treatments (frozen, frying) on contents of minerals in tissues of ‘frutti di mare’

“…Water loss as a result of frying might have contributed to a considerable increase in the contents of these elements in the fried products, compared with the frozen ones. As shown by the analysis of minerals in tissues of seafood presented in fresh weight (García‐Arias et al ., ; Gokoglu et al ., ; Kalogeropoulos et al ., ; Rosa et al ., ; Bandarra et al ., ). Increment in concentration of microelements (fresh weight), iron and zinc in particular, after frying was reported by Ganbi () in their study with fish ( Hammour ).…”

“…Investigations conducted by Bandarra et al . () also demonstrated a significant increase in the concentration of these elements in fried black scabbardfish ( Aphanopus carbo ), which was explained by the authors as a loss of water during thermal treatment. Research presented by Ersoy & Özeren () suggest that some minerals in fresh weight after thermal treatment (cooking, frying or treatment in the microwave) are increased, while some of them are reduced.…”

New tools to assess toxicity, bioaccessibility and uptake of chemical contaminants in meat and seafood

“…However, the studies performed so far to compare the availability of chemical contaminants in raw and cooked/processed seafood products highlighted strong variations according to the cooking procedure and species (Table 2). Such variations may be due to: (a) decrease in weight of foodstuff resulting from loss of water, volatiles, and to a lesser extent of other gross sample constituents (lipids, carbohydrates and proteins); (b) volatilization or solubilisation of contaminants, as heat from cooking (except frying) melts some fat in seafood, thus allowing contaminated fat to drip away and to decrease the content of contaminants in the edible part; and c) migration of chemical contaminants like PAH in canned bivalves to the vegetable oil used (Bandarra, Batista, & Nunes, 2009;Devesa et al, 2001;Rey-Salgueiro, Martínez-Carballo, García-Falcón, & Simal-Gándara, 2009). The degree of accumulation or removal of contaminants from seafood products strongly vary according to species, e.g.…”