Determination in the efficiency of the use of essential oils of oregano and hop as antioxidants in deep frying processes

Abstract

The aim is to evaluate the antioxidant efficiency of oregano essential oils (OEOs) and hops essential oils (HEOs) in a deep frying process of high‐oleic peanuts in high‐oleic peanut oil. There is no information available regarding the antioxidant behavior in deep frying. A combined vegetable oil/food system with high levels of lipids is susceptible to oxidation. High‐oleic peanut oil and high‐oleic peanuts are susceptible to oxidation involved in frying. The antioxidant effect of HEO and OEO was proved in frying peanut process (170°C) in peanut oil enriched at 0.02% p/p and compared with butylated hydroxytoluene (BHT) (0.02%) and control (without additives) during 8 h. Chemical oxidation indicators and volatile compounds were measured. 2,5‐Dimethylpyrazine (2,5‐DMP) and descriptive sensory analysis were measured in fried peanuts. High‐oleic peanut and oil are very stable in a frying process. OEOs and HEOs protected against the deterioration of the high‐oleic peanut oil: Peroxide value was 3.7, 2.8, 3.1, and 1.3 meq O2 kg−1 for control, BHT, HOP, and OEO, respectively. The addition of essential oils (EO) maintained the 2,5‐DMP in the fried peanuts. The use of EO of oregano and hop improves the stability of high‐oleic frying oil.Practical Application: Deep frying processes generate the deterioration of the vegetable oils used for cooking food. This deterioration reduces the shelf life of the frying oil and the quality of the food, even generating compounds that are toxic to the health of consumers. Antioxidants are used as measures that can help to reduce spoilage, but synthetics are being questioned. Natural products offer an alternative and essential oils, due to their high hydrophobic interaction with the oils, generate a strong interaction, remaining in the frying oil for its protection even at high‐temperature thermal processes. This alternative is a possibility because of the protection it generates in the deep frying process.