Essential oil Storage conditions affect the chemical composition in cultivated Mentha spicata

Spearmint (Mentha spicata) is widely utilized in traditional medicine and folk remedies. The fresh and dried plants and their essential oils are widely used in food, cosmetic, confectionary, chewing gum, toothpaste, and pharmaceutical industries. In this research the essential oil of air-dried samples was obtained by hydrodistillation and was analyzed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). Changes in essential oil compositions were detected during storage for 3 months in refrigerator (4), freezer (−20 ℃), and at room temperature (25 ℃). Results indicated that at room temperature, the proportions of the compounds with lower boiling temperatures such as 1,8-Cineole (3.78-3.34%), limonene (7.33-6.61%), and Germacrene D (6.26-1.90%) decreased significantly. Furthermore, the essential oil composition showed the least alterations and Mentha spicata L. kept its primary quality when stored at low temperatures, particularly in a freezer, and Carvone showed a significant increase in all treatments.