Influence of frying oil type and chill storage on the nutritional quality of farmed great sturgeon (Huso huso)

Abstract

OBJECTIVE: The objective of this study was to investigate the effect of frying oils (canola, hydrogenated sunflower and soybean oils) available commercially and chill storage on the proximate and fatty acid composition of fried slices of farmed great sturgeon (Huso huso). METHODS: Slices of farmed great sturgeon were fried for four minutes at 160ºC in a deep-fryer using different frying oils (canola, hydrogenated sunflower and soybean oils). The oil-to-slice ratio was 2:1. After frying, the slices were allowed to be air cooled for two minutes prior to analysis. For performing the analysis, each of the abovementioned batches was divided into two groups: one group was analysed immediately after frying and the second group was chill-stored at 4ºC for three days and then analysed. RESULTS: After frying, the moisture content decreased while that of fat increased. Fatty acid composition of the slices is affected by type of frying oil. Frying increased the omega-6-to-omega-3 (n-6:n-3) fatty acid ratio while decreased Eicosapentaenoic Acid (C20:5 n-3) and Docosahexaenoic Acid (C22:6 n-3) contents. Proximate and fatty acid composition of raw slices did not change after chill storage. However, in fried- and chill-stored slices, Eicosapentaenoic Acid and Docosahexaenoic Acid contents decreased, while linoleic acid content increased. CONCLUSION: The fatty acid composition of the fried slices tended to resemble that of the frying oils, indicating fatty-acid equilibrium between oils and slices and, during chill storage, it is influenced by the type of frying oil. Slices fried with canola oil had omega-6-to-omega-3 ratios in the ranges recommended for human health.