The content of bergamottin, 5-geranyloxy-7-methoxycoumarin, citropten and bergapten in Calabrian bergamot essential oil was determined by HPLC. 128 genuine bergamot essential oils, cold-pressed during the year 1992, were analysed; for each sample the date and area of production of the fruits is known.The percentage of bergamottin ranges between 1.02% and 2.75%. 5-geranyloxy-7-methoxycoumarin between 0.08 and 0.22%, citropten between 0.14% and 0.35%, bergapten between 0.11 YO and 0.32%. The mean content of bergamottin and 5-geranyloxy-7-methoxycoumarin did not vary during the production period, while that of citropten and bergapten decreased considerably from January to March. There does not seem to be any evident correlation between the production areas of the fruits and the coumarin composition. The presence of some peaks absent in genuine bergamot essential oils, has been detected in three bergamot oils, available on the market, probably because of lime oil addition.

The composition of 432 samples of bergamot essential oil, absolutely genuine and produced in Calabria using a 'pelatrice' (peel machine) during the 1986/87 and 1987/88 seasons, has been studied by HRGC.The results obtained, together with those of 409 samples produced in the 1984/85 season, establish that the quantitative composition of bergamot essential oil (1) shows peculiar and reproducible variations for some compounds during the whole productive season and (2) greatly depends on the provenance of the fruit, the latitude but not the altitude being the determining factor.The ranges of the compounds studied are wider than those observed previously for lemon and mandarin essential oils.The results obtained help in the determination of genuineness and the quality of bergamot essential oils.