Naslov
Changes in oxidation stability of fish oil during thermic treatment and storage under poor conditions

Autori
Šimat, Vida ; Čagalj, Martina ; Vlahović, Jelena ; Skroza, Danijela ; Ljubenkov, Ivica ; Generalić Mekinić, Ivana

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
46th WEFTA Conference / - Zagreb, 2016, 145-145

Skup
46th WEFTA Conference

Mjesto i datum
Split, Hrvatska, 12.11.2016. - 14.11.2016

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Cod liver oil ; Oxidation stability ; Peroxide value ; p-anisidine value ; TBARS

Sažetak
Oxidation stability of cod liver oil during five hours cooking at 95 °C and poor storage conditions (direct sun exposure and high summer temperatures) over three months was determined. Deterioration of the oil and its oxidation stage were determined through analyses of peroxide value, p-anisidine value, thiobarbituric test, free fatty acids (FFA) and composition of fatty acids. Additionally, total oxidation value, nutritional lipid indices and uncertainty of listed analytical methods were determined. The results showed increasing oxidation of the cooked oils and high peroxide values (> 40 mmol O2/kg). This was not the case in oil stored in poor conditions ; it showed an increase of p-anisidine value. Fatty acid composition did not vary much between the samples ; however, dissolution of polyunsaturated fatty acids measured trough polyene index was the highest (2.21) in oil sample cooked for five hours. The percentage of the most important omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) was not significantly changed during thermic treatment nor poor storage conditions. The share of the total monounsaturated fatty acids in cooked oil samples decreased from the average 46% to 31% after 5 hours at 95 °C. Opposite to that, the total polyunsaturated fatty acid increased after 5 hours of cooking from an average of 32% to 46%. Relative standard deviation (RSD) of ten parallel analyses of oil samples was used to determine the uncertainty of methods. Analytical methods for peroxide value, p-anisidine value and thiobarbituric test showed more certainty at higher concentrations of analyte, while average RSD for FFA was 18.89%, which is relatively high thus >4 repetitions are needed to get accurate results.

Izvorni jezik
Engleski

Znanstvena područja
Prehrambena tehnologija

Napomena
This work was partially supported by Croatian Science Foundation grant number 6897 BioActCom.

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