Which oil is better to fry - refined or unrefined? The ambiguous answer of scientists

The debate about which oil is better to fry, have not subsided for many years. Nutritionists in this matter advocate for refined (although from the point of view of science, not everything is so simple). Ordinary citizens also prefer this option. Only representatives of the older generation, in the old fashioned way, buy amber-yellow unrefined oil, using it as a universal product - both for frying and in salads.

What is the difference?

When people only learned how to extract oil from various cultures, they used it in its natural form. However, in those distant days they did not even suspect such a method of processing meat, dough and vegetables as frying - vegetable fats, as well as animals, were cooked with ready-made porridge and liquid dishes. The fact that over time the oils acquired an unpleasant odor and bitterness in the taste was considered an inevitable process.

With the development of science, it was found out: the cause of damage lies in undesirable impurities. They enter the oil during the spin cycle and are part of the seeds used to make “liquid gold”. These are phospholipids, coloring and aromatic substances, waxes. After this discovery was made, people came up with a cleaning process called refining. It is constantly being improved and in our time consists of four stages:

1. Degumming - removal of mucus.
2. Whitening - disposal of excess natural pigments (chlorophyll, carotenes and others).
3. Winterization - this is what technologists call the freezing process, during which wax-like substances come out of the oil (it is they that cause turbidity and sedimentation in unrefined oils).
4. Deodorization - Some volatile oil components, under the influence of high temperature, evaporate from the pan, and then settle on the surfaces in the kitchen. Deodorization by distillation is designed to save consumers from such trouble.

A little later, another fact became known - those components of vegetable fats that contribute to their spoilage can not only make oil reserves unusable, but also harm human health. True, this happens only under certain conditions.

Benefit and harm

At temperatures close to natural (a record of + 58.6 ° C has so far been recorded on planet Earth), crude oils are only beneficial for humans. Of course, if you use them in reasonable quantities. The worst thing begins during strong heating - then carcinogens (substances that cause cancer) are formed in the oil. It should be noted that these same carcinogens, but in much smaller quantities, can also appear after storage of oil in open containers or under direct sunlight. Therefore, it is most dangerous to eat foods that have been fried in stale, rancid oil.

Refined oil, from which all "garbage" components were extracted, does not have such negative properties. However, with prolonged heating to very high temperatures, it is also able to secrete carcinogens.

Among the chemical compounds that occur in oil during frying, there are 4 most dangerous:

• Aldehydes - toxic substances that accumulate in the body.
• Free radicals - penetrate into the lungs when inhaled smoky air. Cause premature aging, provoke heart attacks and strokes.
• Acrylamide - a component of everyone's favorite crisp. Destroys the nervous system, disrupts the liver.
• Acrolein - irritating to the mucous membranes of the nose and eyes, damages the respiratory tract.

Difficulty choice

It would seem that it makes no difference which oil to fry - refined or unrefined, if they both pose a threat to health. In fact, it is. Vegetable fat should be selected not by the inscriptions on the bottle and not by the processing method, but by the smoke temperature. The mentioned indicator got its name for a reason, because the appearance of a temperature threshold is indicated by the appearance of a gray haze above the pan. It is from this moment that the active release of carcinogens begins.

It is important to know that in oils made from different types of plants, the smoke temperature is significantly different, and in refined oils it will be much higher than in natural ones. However, this does not mean that any refined oil is by default suitable for frying more than unrefined. So, for example, unrefined corn starts to burn at 178 ° С, and refined sesame - at 177 ° С.

Fans of fried foods may be disappointed, but you can use quite expensive refined oils of plant origin without harm to health:

• avocado - it can withstand up to 270 ° C;
• mustard - warms up to 250 ° C;
• olive - depending on the region where it was produced, and on the method of extraction shows indicators from 200 to 243 ° C;
• soybean - begins to smoke at 234 ° C.

The usual sunflower oil lags behind the leaders - refined remains safe at temperatures up to 227 ° C, and unrefined - only at 160 ° C.

Other nuances

Do not forget about the pan. It is she who determines to what extent its contents will heat up. When using a gas stove, the metal from which the frying equipment is made is heated to 600 ° C. In the case of an electric burner, the temperature will be two times lower. And this suggests that, even using relatively pure oils with a high smoke temperature, you can not turn on the heating device at full power. It should be cooked on moderate, or even completely on low heat.

And here another difficulty arises, because with this method of processing products it is difficult to get a truly fried piece of meat with a crust or to make crispy fries. In addition, the lower the temperature, the more oil the food absorbs - that is, its calorie content increases, which also does not have the best effect on human health.

Summing up, we can say that refined oils are most suitable for frying, but not all, but only those that have a very high smoke temperature. It is also important that even the best oil will not save the situation if the pan is heated more than the physico-chemical properties of the fat used allow. And in terms of taste, products cooked at a low temperature noticeably lose in that they were fried in the usual way.