Determination of the Shelf Life of High-Oleic Fried Peanuts Prepared by the ‘Deep-Fried Process’ with the Addition of Humulus lupulus or Origanum vulgare Oil in the Frying Oil

Abstract

Vegetable oil is widely used in deep-frying, but its deterioration affects the shelf life of food. In contrast, the use of oregano essential oil (OEO) and hops essential oil (HEO) decreases this deterioration. Thus, the objective of this work was to determine the effects of the addition of OEO and HEO in the frying oil on the shelf life of fried high-oleic peanuts (FP). Sunflower oil with OEO, HOP and BHT (0.02% w/w) and a control oil without added antioxidants were used. High-oleic peanuts were fried at 170 °C during an 8-h frying process with samples taken at 0, 2, 4, 6 and 8 h. Totox value and the main OEO and HEO compounds were determined. The FP was stored in non barrier containers at 25 °C for 3 months from peanuts obtained at 0 and 8 h. Conjugated dienes, peroxide, nonanal, 2-undecenal and oxidation intensity were determined. OEO and HEO were present in the frying oil up to hour 6, and protection was found in these treatments during the whole deep-frying process. Storage of OEO and HEO treatments doubled the shelf life compared to the control. The use of OEO and HEO in deep-frying prolongs the shelf life of FP.