The use of an inert gas during the olive oil bottling: shelf life evalutation.

The extra virgin olive oil has precious characteristics that may be lost during the commercialization because oxidative and hydrolytic reactions may occur. It is possible to obtain a reduction of the oxidative process by storing oil in dark and closed bottles.

In this paper we have studied the effect of the composition of the bottles' headspace and its influence on the shelf life of the product. The oils that have origin from different industrial storage conditions were bottled and the headspace filled with air and with nitrogen. Then the samples were stored under conditions similar to those found in supermarkets for six months. The oils were examined before bottling and after 30, 60, 90, 120, 150 and 180 days on the shelf. Each sample was examined for free acidity, peroxide value, specific extinction coefficients K-232 e K-270, total phenol content. Its stability was measured periodically using a Rancimat apparatus at 120 degrees C (20 1/h). The best results were obtained from the oils stored in industrial refrigerated tanks saturated with nitrogen and then the headspace of bottles was filled up all the way with nitrogen.