Abstract

The oil of Alpinia galanga (L.) Willd in Phu Tho was obtained by steam distillation and dried with Na₂SO₄. By Gas chromatography-mass spectrometry (GC-MS) method, 29 components in the oil were predicted by comparing their retention times and molecular weights with the standards’. In particular, there were 10 hydrocarbons such as monoterpenes: 29.15%, sesquiterpenes: 21.06%, and 19 oxygenated components like aldehydes (7.29%), alcohols (32.43%), ketones (1.09%), and esters (7.57%). Physico-chemical properties, antioxidant activities as well as antimicrobial activities of the oils were also analyzed. The density (at 20°C), acid index and ester index of the oil were 0.812 g/ml; 0.653 mg KOH/g and 0.728 mg KOH/g, respectively. The antioxidant activity was determined by using 1,1-diphenyl-2-picrylhydrazol (DPPH) radical percentage inhibition and it was 47.15±0.34%. Antimicrobial activity against Salmonella typhi, Bacillus cereus, Staphylococcus aureus and Escherichia coli of the oil was identified by agar diffusion method.

Key words: Oil of Alpinia galangal (L.) Willd in Phu Tho-Vietnam, components, physico-chemical, biological activity.