A new study published in the journal Food Research International has said that the healthiest way to fry fish is to use extra virgin olive oil, especially if this is done in the microwave. The study was conducted by researchers from the University of the Basque Country in Spain.
Their research says that the frying techniques, the nature of the oil used and the fish species have been shown to exert a great influence on the changes that take place during the process. Researchers say that the choice of cooking oil is hugely important owing to its impact on the lipid profile in the fish and on the possible generation of toxic compounds in the oil during frying, which can influence food safety and human health.
Filets of European sea bass, or Dicentrarchus labrax, and gilthead seabream, or Sparus aurata, were shallow-fried in a frying plan and in a microwave oven using extra virgin olive oil and refined sunflower oil. Proton Nuclear Magnetic Resonance Imaging H-1 NMR, was used to study the changes that took place in the lipid composition of the fish and of the frying oil.
Fish lipids migrate to the frying oil and the components of the oil are also transferred to the fish. As a result, the composition of the oil used for frying is modified. It is enriched by the acyl groups, or fatty acids, that are present in a higher concentration in the fish fat than in the original oil, and simultaneously it is depleted in the acyl groups present in a higher concentration in the original oil than in the fish fat. So after having been used for frying, the extra virgin olive oil was richer in omega-3, omega-1 acyl groups, linoleic and saturated fats, from the fish, and poorer in oleic, which is the main acyl group in olive oil.