Effect of drying temperature and storage time on Ocimum gratissimum Linn. leaf essential oil from Central Highlands, Vietnam

Abstract Essential oil of Ocimum gratissimum Linn. leaf is widely used in folk medicine. Extraction yeild, compositions and antioxidant activity of clove basil essential oils could be affected by several factors including drying temperature and storage conditions. The present work evaluated the influence of storage conditions and drying temperature different of Ocimum gratissimum leaves on essential oils from Central Highlands, Vietnam. In this research, fresh leaves were preserved at 4°C for 10 days and dried and then stored at room temperature. Essential oil of Ocimum gratissimum L. was extracted by hydrodistillation and steam distillation methods. The composition of essential oil was determined by using GC-MS, antioxidation activities were conducted by the DPPH method. Drying the material at 45°C only 1% Decrease extraction yield, the extraction yield of essential oil at 45°C is still high (2.5%); the color of the oil when the material is fresh in yellow, characteristic odor, drying at 45°C is pale yellow, mild characteristic odor; Antioxidation resistance change is negligible; Drying the material at 45°C, the content of eugenol (77.389%) increased 3 fold compared with fresh material (24.84%), while the drying loss of some components small proportion in oil.