Vitamin retention during the canning of swordfish (Xiphias gladius) with different filling media

Swordfish (Xiphias gladius) is an economically and nutritionally important fish. The aims of this study were to determine the effects of the various steps of the canning process and of different filling media (olive oil, corn oil, sunflower oil, and high oleic sunflower oil) on the fat- and water-soluble vitamin contents of swordfish. An HPLC-based method was used for this purpose. The canning process led to loss of some vitamins, particularly of vitamin D₃ . Loss of this vitamin mainly occurred during storage and although important (89.34% to 91.36%), canned swordfish can be considered a good source of vitamin D₃ , providing between 50% and 64% of the RDI. The frying process also caused significant loss of vitamin B₉ (73.7%). However, the vitamin E content increased due to contributions from the frying and filling oils. The canned swordfish packed in olive oil had lower vitamin A (107.35 µg/100 g) and E (1.58 mg/100 g) contents than the fish packed in sunflower oil (193.28 µg/100 g and 2.28 mg/100 g, respectively). The swordfish packed in sunflower oil also had the highest B₂ (0.036 mg/100 g) content. The swordfish packed in corn oil had the lowest vitamin A (80.17 µg/100 g) and B₂ (0.012 mg/100 g) contents, while the samples packed in high oleic sunflower oil had the lowest contents of vitamins B₉ (0.14 µg/100 g) and B₁₂ (2.37 mg/100 g). PRACTICAL APPLICATION: Swordfish (Xiphias gladius) is consumed worldwide and is economically very important in the seafood industry. The canning process caused losses of some vitamins, particularly of vitamins D₃ and B₉ ; however, the vitamin E content increased due to the frying and filling oils. The study findings may contribute to increasing knowledge about how processing, storage and the filling medium influence the composition of canned fish.