In nineteenth century the flowers producers distilled the flowers directly in small alembic with straight flame. Larger distilling flasks later were used with indirect heating (water jacket, coils, etc.), or by external steam injection. The most common procedure in the Mediterranean countries was the hydro distillation, without the distilled or cohobated water recycle, at low pressure inside the alembic, for three hours. The average yield of oil, by this procedure was about 1 %o (Igolen, 1946; Guenther, 1949; Gildmeister and Hoffmann, 1959).
Recently, it was evaluated how different technological parameters (e.g. the flowers load in relation to the alembic volume; the presence or absence of water contact with the flowers; the temperature and pressure in the alembic; the total time of the extraction process) would influence the yield, the chemical composition and the sensory characters of the oil. For example, the use of saturated steam and an internal pressure higher than 0.8 bar, improves about 0.2%o the oil yield, reducing, at the same time, the length of the process, and therefore production cost. This also limited some chemical changes such as the hydrolysis of linalyl acetate, and the formation of alcohols such as a-terpineol (Rolet etal., 1998).
From the fresh distilled waters after the neroli oil separation, is prepared the bitter orange flower water absolute, by counter current extraction by hexane. The yields from the waters is of about 0.25—0.35%«. This product is particularly rich in methyl anthranilate (Pecout, 1973).
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