LIMONENE CONCENTRATION IN LEMON (CITRUS-VOLKAMERIANA) PEEL OIL AS A FUNCTION OF RIPENESS

The dependence of the limonene content of lemon (Citrus volkameriana) peel oil on the degree of ripeness of the fruit has been studied by us ing steam distillation and cold pressing to extract the oils from lemo n fruit peel at different stages of maturation (green, greenish-yellow , and yellow-orange peel coloration). Samples of essential oils were a nalyzed by high resolution GC and GC-MS, using tetradecane as internal standard for quantitation. Forty components were detected; thirty eig ht were positively identified by comparison of their mass spectra (El, 70 eV) and Kovats retention indexes (determined using a non-logarithm ic scale on capillary columns coated with both polar (DB-Wax) and non- polar (DB-1) stationary phases) with those of standards and with data reported in the literature. The limonene concentration reached a maxim um level of 79.4% when the fruit was in the intermediate maturation st age characterized by greenish-yellow coloration.