Oil quality and sensory evaluation of almond (Prunus amygdalus) stored after electron beam processing

The changes in the lipid fraction and the deterioration of its quality were studied in almonds (Prunus amygdalus) of the variety Guara after treatment with accelerated electrons at doses of 3, 7, and 10 kGy, during a storage period of 5 months. In almond oil, the most significant difference from the nutritional point of view was seen in the fatty acid linolenic (18:3), which shows at 3 kGy a maintenance of the initial content during the whole storage period, whereas, at 7 and 10 kGy, the content in 18:3 disappears from the first moment. The quality indices of the oil (K(232), K(270)) decreased at all doses and remained stable during the time of storage. The peroxide value did not show changes at the doses of 3 and 7 kGy, in non-irradiated samples, but significantly increased when the maximum dose of 10 kGy was applied. These changes were reflected in the sensory analysis, in which the tasters did not find sensory differences between the controls and those irradiated at doses of 3 or 7 kGy, whereas almonds irradiated at 10 kGy exhibited a rancid flavor and a significant decrease in general quality.