Effects of Different Cooking Procedures on Lipid Quality and Cholesterol Oxidation of Farmed Salmon Fish (Salmo salar)

Abstract

Salmon fillets were steamed, or pan-fried without oil, with olive oil, with corn oil, or with partially hydrogenated plant oil. The exchange between the salmon and the pan-frying oils was marginal, but it was detectable as slight modifications in the fatty acid pattern and the tocopherol contents according to the oil used. Primary and secondary oxidation products were only slightly increased or remained unchanged, which indicated a slight lipid oxidation effect due to the heating procedures applied. The same was observed for tocopherol levels, which remained almost stable and were not affected by the oxidation process. The sum of cholesterol oxidation products (COPs) increased after the heating processes from 0.9 microg/g in the raw sample to 6.0, 4.0, 4.4, 3.3, and 9.9 microg/g extracted fat in pan-fried without oil, with olive oil, corn oil, partially hydrogenated plant oil, and steamed, respectively. A highly significant correlation was found between the fatty acid pattern and the total amount of COPs (r2 = 0.973, p < 0.001). No change has been determined in the n-3 fatty acids content and in the polyunsaturated/saturated-ratio of the cooked salmon fillets. Moderate pan-frying (6 min total) and steaming (12 min) of salmon did not accelerate lipid oxidation but significantly increased the content of COPs. The highest increase of COPs was found through steaming, mainly due to the longer heat exposure. The used frying oils did not influence the outcome; no significant difference between heat treatment with or without oil has been determined.

From farm to fork: lipid oxidation in fish products. A review

“…The significant differences in peroxide content in both cases seem to depend on the first oxidation state and degree of unsaturation of the frying oils. Indeed, as reported by Al-Saghir et al (2004) olive oil has a high initial PV (11.8 6 0.03 meq O 2 /kg), which provides the explanation for the increased PV of salmon after frying with olive oil.…”

“…This fact is mostly evident for frying which seems to lead a wide variety of changes. Figure 1, as an example, reports data from Al-Saghir et al (2004) for Atlantic salmon and rainbow trout, respectively. Salmon fried with olive or corn oil at 180 C increase its PV 3 or 2 times, respectively, whilst sunflower frying doubled PV in rainbow trout.…”

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

“…Not surprisingly, MUFA forms the largest fraction of the used olive oil, which shows that there must be interaction between the salmon fillets and the culinary fat. 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.…”

“…Yet, less information on the effect of pan-frying can be found. Only Agren and Hanninen (1993), Al Saghir et al (2004) and Mai et al (1978) have studied the effects of pan-frying on the fatty acid profile of lake trout, white sucker, bluegill, rainbow trout, vendace, pike and salmon. Pan-frying is a frequently applied method and gives flavour characteristics to the food that are highly appreciated by the consumers.…”

Distribution of Lipids and Oxidative Changes Therein in Particularized Parts of Rainbow Trout Fillets

“…Zwłaszcza skład lipidów, a tym samym przydatność technologiczna i wartość żywieniowa, jest zależny m.in. od cyklu biologicznego ryby [13], środowiska bytowania i sposobu hodowli, a także sposobu przetworzenia [2,3,7]. Rodzaj i stopień przetworzenia ryby, a także czas i sposób przechowywania w istotny sposób wpływają na jakość lipidów, szczególnie na stopień ich hydrolizy i utlenienia.…”