Use of Humulus lupulus and Origanum vulgare as Protection Agents Against Oxidative Deterioration in “Deep-Fried Process”: Frying Model Assay with Sunflower Oil and High-Oleic Peanuts

Abstract

Sunflower oil and peanuts are susceptible to oxidation reactions during the frying process. This study aimed to evaluate the efficacy of hop and oregano essential oils in protecting sunflower oil and peanuts during frying. The sunflower oil was enriched with oregano and hop essential oils (0.02% w/w). These treatments were compared to sunflower oil enriched with BHT (0.02% w/w). All treatments were subjected to a temperature of 170 °C for 8 h. Samples were collected at 0, 2, 4, and 8 h. Chemical oxidation indicators, oxidation volatile compounds, and 2,5-dimethyl pyrazine were measured. Also, a descriptive sensory analysis of fried peanuts was carried out. Oregano and hop essential oils enhanced the oxidative stability of the sunflower oil, while preventing the development of undesirable flavours in the fried peanuts. However, this protection led to the formation of 2,5-dimethyl pyrazine, which is responsible for desirable flavours.