Seasonal variation in yield and composition of Thymus zygis L. subsp. sylvestris essential oil

摘要: The seasonal variation in the yield and composition of essential oil from collective samples Thymus zygis L. collected North Portugal is reported. Essential was obtained by steam distillation a modified Clevenger apparatus. Analysis performed GC GC–MS. showed maximum at flowering stage (0.9–1.4%) minimum during dormancy period (about 0.15%). also different patterns phases vegetative cycle. At rich thymol geraniol. p-Cymene presenting (post-flowering period). Aiming use as food ingredient, most interesting post-flowering period, this time being 21%), geranyl acetate 17%) geraniol 13%), with p-cymene lower levels. Copyright © 1999 John Wiley & Sons, Ltd.