Ontogeny of volatile leaf and peel oils of Citrus limon L. Burm. f

Volatile essential oils are nondrying oils widely used as flavoring agents in beverages, foods, pharmaceuticals, and other industrial products. Lemon oils, used principally as flavors and fragrance, are of commercial importance. Changes in volatile leaf and fruit peel oils of Citrus limon L. Berm. f. were observed during ontogeny. Effects of tree to tree variations, shade, diurnal and nocturnal variation on the composition of lemon leaf and peel oils were also observed. Total oil yields in leaves were highest in the month of December while, in peel oil samples, yields were highest in the month of September. Limonene was the major component in both leaf and peel oils and showed comparative variations during ontogeny. Other terpene components also changed during ontogeny. Monoterpene hydrocarbons were higher in the beginning, and than decreased with time in leaf oils. A consistent trend of changes in monoterpenes of peel oil was not observed. Sesquiterpenes in both leaf and peel oils were in less amount in beginning but gradually increased during ontogeny. Plant to plant variations for total oil and components were also observed in both leaf and peel oils. Reciprocal relationship between linalool and For shade effects, oil yield was found highest in both leaf and peel sampled from the outside of the canopy. Differences were also observed in the quantity of some oil components of leaf and peel of C. limon and were attributed due to shade effects.Diurnal variations were observed in qualitative and quantitative amounts of volatile leaf and peel oils of C. limon. Total oils were higher at 1 am in leaves and at 1 pm in peel samples. Components of both leaf and peel oils showed some response to diurnal variations. A reciprocal relationship was also observed in some components of volatile leaf oils but not in peel oils.