Deep-Fat Frying Modifies High-Fat Fish Lipid Fraction

Abstract

The lipid composition of three high-fat fishes (sardines, mackerel, and salmon) was analyzed to study the effect of deep-fat frying with sunflower oil and warmholding (65 °C, 3 h). Only sardines increased total fat content with cooking. Saturated fatty acids content decreased, especially in sardines and mackerel, mostly because of the palmitic acid reduction. Raw sardines and mackerel presented an important content of ω-3 polyunsaturated fatty acids (24.0 and 16.6 g/100 g of fat, respectively), but it decreased significantly during frying (6.6 and 5.4 g/100 g of fat, respectively). Salmon, despite having the lower amount of eicosapentaenoic acid and docosahexaenoic acid in raw samples, was the best source of these fatty acids after frying (1.7 g/100 g of food). The ratio of total ω-6 fatty acids to total ω-3 fatty acids increased with cooking from 0.12 to 1.07 in salmon, from 0.12 to 6.19 in mackerel, and from 0.07 to 5.98 in sardines. Cholesterol content was differently affected by frying: it increased in salmon and mackerel and decreased in sardine. Fatty acid and cholesterol were slightly affected by warmholding in all fishes. Keywords: High-fat fishes; frying; warmholding; lipids

Essential long chain polyunsaturated fatty acids in muscle tissue of freshwater fish Labeo calbasu under different cooking processes

“…Increase in fat content of the fried Labeo calbasu fish indicates absorption of oil during the frying process. Similar results were found for sardines fried in sunflower oil [13,18]. The author has concluded from his observations that increase in fat content is due to the penetration of oil on the food after water is partially lost by evaporation.…”

“…However, owing to the thermal sensitivity of a broad number of fish constituents and nutrients several detrimental effects due to cooking have been reported: i.e., heat degradation of nutrients, oxidation of vitamins and lipids, leaching of water-soluble vitamins, minerals and proteins, and toughening and drying of sensitive protein tissues [10,11]. Meanwhile, the long-chain PUFA such as EPA and DHA, are considered to be especially susceptible to oxidation during heating and other culinary treatments [12,13,14,15] .…”

Effects of pan-frying in margarine and olive oil on the fatty acid composition of cod and salmon

“…Also Al Saghir et al (2004) found that the exchange between salmon and olive oil is marginal and mostly detectable as a slight modification in the fatty acid profile. On the other hand, Candela et al (1998) reported that deep fat-frying of salmon did not significantly affect the fat content, as also did Mai et al (1978) for other species of fatty fish. Sanchez- Muniz et al (1992) found equal results for sardines after deep frying with different culinary fats (olive oil, sunflower oil and lard).…”

“…Several studies were undertaken to determine the effects of different cooking methods on the fatty acids of fish species, in particular deep fat-frying and oven-baking (Agren & Hanninen, 1993;Aro et al, 2000;Candela, Astiasaran, & Bello (1997, 1998 ;Gall, Otwell, Koburger, & Appledorf, 1983;Mai, Shimp, Weihrauch, & Kinsella, 1978;Mustafa & Medeiros, 1985;Sanchez-Muniz, Viejo, & Medina, 1992). Yet, less information on the effect of pan-frying can be found.…”

“…Using these two species, in the same setting made it also possible to investigate the effect of the fat content on the compositional changes of fish fillets during processing. Candela et al (1997Candela et al ( , 1998) studied the effect of processing on these species, but only looked at the effects of deep-fat frying. In Belgium, pan-frying is another popular cooking method to prepare fish and fish derived foods.…”