Effects of Different Harvesting Time on Essential Oil, Phenolic Compounds and Antioxidant Activity in Sage (Salvia officinalis L.)

This research aimed to determine the effect of different harvest timesrepresenting 12 months of a year on the herba and leaf yields, leaves essential oil contentand composition, extract of total phenols by the folin–ciocalteu colorimetric method,phenolic components, antioxidant activities according to free radical scavenging activitydpph and ferric ion reducing antioxidant power (frap) methods in common sage (salviaofficinalis l.). fresh herb yield between 500.0 and 961.0 kg/da, dry herb yield between223.4 and 556.6 kg/da, dry leaf yield between 129.6 and 367.2 kg/da, essential oilcontent between 0.83 and 3.33%, total phenolics between 14.54 and 30.83 mg/g werechanged in common sage during the harvest periods of growing season. herb and leafyields, essential oil contents and yields, and total phenolics were found higher in thesummer and autumn harvests in comparison to the winter and spring harvests. the maincomponents of common sage essential oil were 1,8‐cineole (11.93‐31.87 %), α‐thujone(15.72‐26.26%), β‐thujone (4.51‐27.67%), and camphor (3.65‐23.02%). while the ratiosof 1,8‐sineol and camphor of the common sage leaves essential oil were the least in springseason, the ratios of α and β‐thujone were the highest in the same season. the mostimportant phenolic compounds in the common sage extracts were rosmarinic acid(15.15‐100.57 mg/g), naringin (9.59‐41.81 mg/g), hesperidin (9.80‐53.26 mg/g), andrutin (0.73‐10.04 mg/g). the highest antioxidant activities of the leaves were found in theplants harvested in may and june, and the lowest antioxidant activities of the the leaveswere found in the plants harvested in march and april.