Posts Tagged ‘frying’

What is the Best Oil for Frying Fish?

Friday, July 22nd, 2016

Logos 005

A new study published in Food Research International concluded that using extra virgin olive oil is the best choice for frying fish because of the changes that take place in fish lipids and in the oil during the frying process. The frying techniques, nature of oil uses in frying, and the fish species show a great influence on changes that take place during the process and cooking oil is v4ery important because of its impact on the lipid profile in the fish and on the possible generation of toxic compounds in the oil during frying, that can influence food safety and human health.

In the study fillets of European seabass and gilthead seabass were shallow-fried in a frying pan and microwave oven using extra virgin olive oil and refined sunflower oil. Changes taking place in the lipid composition of the fish and the frying oil were studied using the Proton Nuclear Magnetic Resonance Imaging (H-1 NMR). During the shallow-frying of the fish the fish lipids migrate to the frying oil, and and the components of the oil are also transferred to the fillet of fish. Subsequently, the composition of the oil used for frying is modified as follows: first it is enriched by the acyl groups (fatty acids) that are present in a higher concentration in the fish fat than in the original oil, and then, simultaneously it is depleted in the acyl groups present in a higher concentration in the original oil than in the fish fat. Thus, after being used for frying,theĀ  extra virgin olive oil was richer in omega-1 acyl groups, linoleic and saturated fats (from the fish) and poorer in oleic, which is the main acyl group in olive oil. Also, after being used for frying, the sunflower oil was richer in all the acyk group types (coming from the fish) except linoleic, which is the majority acyl group in sunflower oil. In addition, after frying, both types of oil were enriched by small amounts of cholesterol (from the fish). The fat composition in the fish fillets also changed during the frying process and became enriched by the acyl groups present in higher concentrations in the frying oil than in the fillet.

In addition, because oils were subjected to high temperatures during frying certain small scale oxidation may take place. Although it did not take place when frying with olive oil, secondary oxidation took place when frying with sunflower oil and some potential toxins were formed that could affect human health. These toxins did not form when fried in the microwave or with olive oil.

Researchers concluded that the study showed the frying techniques, the type of oil used and the fish species exert a great influence on the changes that take place during the frying process. Thus, it is important to select the proper oil to prevent potential toxic compounds during the frying process.