Oxidation protection efficiency of the combination of Minthostachys mollis K. and Origanum vulgare L. essential oils with "chain-breaking" and "termination-enhancing" antioxidant mechanisms.

Abstract

The use of antioxidants is known to reduce lipid oxidation. This study aimed to assess the interaction of two antioxidant mechanisms, namely, "chain-breaking" and "termination-enhancing" by combining natural antioxidants derived from "oregano" (Origanum vulgare L.) and "peperina" (Minthostachys mollis K.) essential oils (EOs) in an accelerated oxidation process of sunflower oil at 60°C. Concentrations of 0.05% w/w (1) and 0.02% w/w (2) of the combined oregano and peperina EOs were evaluated. Chemical and volatile oxidation markers were determined in comparison with the pure compounds, an antioxidant-free control, and a BHT-treated sample (0.02% w/w). Although the combinations exhibited lower oxidation indicator values (Anisidine≈136) compared to the control (Anisidine≈213), no evidence of a synergistic effect was observed (Anisidine: Oregano 1≈52; Oregano 2≈199; Peperina 1≈155; Peperina 2≈153), indicating that the combination did not enhance their antioxidant activity beyond that of the pure EOs. Thus, evaluating these combinations in other food matrices is important. PRACTICAL APPLICATION: Food oxidation is one of the main causes of food spoilage, and the search for natural antioxidants has become a necessity for society's increasing food knowledge and consumption preference. The research is focused on demonstrating that not only natural phenolic compounds with a "chain-breaking" mechanism have efficient antioxidant activity but also non-phenolic terpenes using the "termination enhancer" mechanism are efficient, but also the combination of them, which provides more alternative antioxidants for industrial applications.