Muscle Thiobarbituric Acid Reactive Substance of the Atlantic Herring (Clupea harengus) in Marinades Collected in the Market Network

Fish fat belongs to highly specific nutritious elements especially due to its high content of polyunsaturated fatty acids. The aim of the present study was to determine the content of 2-thiobarbituric acid reactive substances in over-the-counter cold and warm marinades in which the base fish material consists of the Atlantic herring (Clupea harengus). Fifty six marinated fish products stored at refrigeration temperatures were analyzed before their expiration date. Their fat content was determined by means of the Soxhlet method and the TBARS validated fluorimetric micromethod. Lowest TBARS values were characteristic of warm baked marinades (1.17 ± 0.40 mg MDA/ kg muscle) and in case of cold marinades for the rolled herring fillets with pepper (5.03 ± 0.54 mg MDA/kg muscle) whereas the highest TBARS values were observed in warm cooked marinades (16.48 ± 4.22 mg MDA/kg muscle) and in roll mops sold over the counter (7.61 ± 3.87 mg MDA/kg muscle). The results showed that fat content is not always critical for herring TBARS determination in marinades. For the consumer safety it is essential to pay attention to cold marinades in brine sold over the counter and baked marinades in aspic before their expiration date. Marinated fish, fat, lipid oxidation, TBARS, baked and cold marinade Fish fat belongs to highly specific nutritious elements especially due to its high content of polyunsaturated fatty acids which play an important role in prevention of cardiovascular and other diseases. Sea fish present the main source of these acids. The most serious cause of a decrease in the nutritive value of fat in all fish species is oxidation occurring in the organism in vivo. Post mortem oxidation is accelerated due to new pro-oxidation factors, such as the presence of atmospheric oxygen and various technological procedures or storage conditions (Undeland et al. 1998; Undeland and Lingnert 1999). Methods detecting the present fatty acids or oxidation products are generally used for lipid oxidation determination. One of the frequent methods is determination of TBARS, the 2-thiobarbituric acid reactive substances (Decker et al. 2005; Guillén-Sans and Gurmán-Chozas 1998). The method determines aldehydes formed by degradation of hydroperoxide, including malonaldehyde (MDA) which is used as a standard. Experimental animal studies and biochemical research lend support to the hypothesis that lipid oxidation products ingested with food present a health risk (Esterbauer 1993). The aim of the experiment was to determine TBARS using fluorimetric micromethod in selected cold and warm market marinades before their expiration date, in which the fish material is of the Atlantic herring (Clupea harengus). Materials and Methods The following consumer packages of marinades available on the market were purchased for the purpose of the analysis: A, cold marinades: Rolled herring fillets with pepper – 10 packages: marinated herring 120 g, oil, salt 5% max, acetic acid, sugar, saccharine, cabbage, onion, carrot, gherkin, pepper 0.05%, potassium sorbate, sodium