Olive & Oil 07/01/2013

The extra virgin olive oil will contribute to sales of seed oils

The olive oil is renowned for its healthy virtues. Underway to exploit these features in order to increase the added value of palm oil and soybean oil

The extra virgin olive oil is especially appreciated in the world for its health benefits and nutritional virtues. These are properties that represent a flywheel marketing of undoubted value and that the industries of other vegetable oils do not want to miss.

It 's so they are multiplying and developing studies that intend to take advantage of the extra virgin to improve the characteristics of other oils instead have little fame nutraceutical.

And it's the case of palm oil, often used in frying, but which presents an induction all'inracidimento very high to high temperatures, on the contrary oil from olives.

For this reason the University of Molise has decided to show by a Rancimat test, the effect of an addition of extra virgin olive oil mixed with palm oil. Although the induction time to degrading were always higher than palm oil extra virgin olive oil, a decrease was noted for mixtures even if the content of extra virgin olive oil had to be well over 20%, a where there was no significant difference compared to a pure palm oil. According to Alessandra De Leonardis, oxidation stability to heat would be attributed mainly to the fatty acid composition. In particular, a ratio of 1 between saturated and unsaturated fatty acids would be optimal, with significant losses of polyunsaturated fatty acids, during the thermal increase, and formation of short chain fatty acids. According to the research, moreover, does not reveal a clear and obvious contribution of phenols in oxidative stability.

One Portuguese study, conducted by the Polytechnic Institute of Bragança, has instead put its attention on the use of polyphenols, obtained from the leaves of the olive, to confer greater stability soybean oil during heating, in particular in the microwave. This type of oven is an increasingly popular around the world and increasingly used for the preparation of the dishes, even in professional kitchens. The heating through microwave, however, leads to the loss of important nutritional qualities, especially when, as is for the soybean oil, the stability to oxidation by heat is low. The work conducted by Ricardo Malheiro has determined the oxidative stability of soybean oil, with addition of phenols of the leaf of the olive, at different steps of heating, from 0 to 15 minutes, with the microwave power set to 1000 W. The differences were measured according to the following parameters: peroxides, K232, K270. The study has determined that, with the simple soybean oil, already three minutes were sufficient to cause serious nutritional losses which instead is lowered significantly in the samples to which was added the olive leaf extract. The test would indicate that the increased availability of vitamin E would reduce the formation of oxidation compounds, in particular protecting from degradation polyunsaturated fatty acids.

Ricardo Malheiro concludes that the use of natural antioxidants could be an effective way to protect soybean oil, one of the most important crops worldwide, from oxidation.

di Ernesto Vania