Effect of Thymus vulgaris and Bunium persicum essential oils on the oxidative stability of virgin olive oil

Abstract

Natural antioxidants are becoming a major focus because natural food ingredients are safer than synthetic types. The aim of this study was to investigate the protective effects of Thymus vulgaris and Bunium persicum essential oils (EO) on the oxidation of virgin olive oil (VOO) during accelerated storage. The antioxidant activities of EOs were compared with those of α-tocopherol and BHT. GC/MS analyses revealed that thymol (28.50%), p-cymene (27.14%), carvacrol (18.36%), and γ-terpinene (4.97%) are the main components of T. vulgaris EO, while cuminaldehyde (32.81%), γ-terpinene (16.02%) and p-cymene (14.07%) are the main components of B. persicum EO. Both EOs provided protection for the VOO, inhibiting the formation of primary and secondary oxidation products although T. vulgaris EO showed greater protection against the oxidation process than B. persicum EO. The effect of T. vulgaris essential oil on the oxidation inhibition of VOO was similar to that of BHT. α-Tocopherol showed no measurable effect on improving the oxidative stability of VOO. This study suggests that T. vulgaris and B. persicum EOs can be used to improve the oxidative stability of VOO.

Keywords

• bunium persicum
• oxidation
• thymus vulgaris
• tocopherol
• virgin olive oil