Abstract
The oxidative stability is reported of herbal oil samples containing fresh rosemary leaves or basil leaves which were exposed to bright sunlight for 14 days. POV, the radical scavenging activity (analyzed by the DPPH method), the total polyphenol content and the tocopherol content were each measured. POV of all the herbal oil samples did not exceed 20 meq/kg untill 70 days had elapsed. The contents of α-tocopherol and polyphenol in the oil samples decreased slightly during the initial 14 days when exposed to bright sunlight. The radical scavenging activity of the basil oil was substantially decreased. Although the contents of chlorophyll and carotenoid were decreased in the oil samples exposed to direct sunlight, these contents were increased in the oil samples stored in the dark. No oxidation of the herbal oil samples was apparent in any cases. It is therefore considered favorable to prepare herbal oils in the dark.
