The processing of
Essentially, there are three essential oil extraction methods: the first is to operate on the entire fruit prior to juice extraction; the second is to operate on the peel after juice extraction; the third method consists on the extraction of juice and oil simultaneously.
Extraction of essential oils
The procedures for essential oil extraction can be classified on the basis of the type of action applied to the fruit:
- By folding, compressing the surface of the peel with traditional Sicilian machinery denominated "sfumatrice". The latter exploits the natural pressure exerted by the essential oil inside the oil glands, which causes it to spurt when the peel is folded and compressed
- By abrasion ("Pelatura") of the citrus surface which contains the essential oil glands with traditional Sicilian machinery denominated "pelatrice"
- By pressure of fresh citrus fruits by continuous presses "Torchiato";
- By pressure of fresh citrus fruits by the machinery “FMC”.
The extraction of juice can be obtained: by "Birillatrice" machine before passing the peels to the "Sfumatrice" machine or subsequently to the extraction of essential oil by "Pelatrice" machine, or simultaneously to the extraction of the essential oil by FMC or by continuous presses (Torchi)
Concentrated and terpeneless oils
The concentrated and terpeneless oils are characterized by a higher solubility in alcohol and by a remarkable stability. These oils are obtained by separation of the less perfumed terpenes and sesquiterpenes called respectively deterpenation (terpeneless oils) and desesquiterpenation (sesquiterpeneless oils)
The production of distilled oils ("Peratoner") has a complementary role and it is limited exclusively to obtaining oils present in very dense emulsions and hardly recoverable by centrifugation.
Furthermore, for the recovery of oils from flowers, twigs and leaves of citrus fruits, the most commonly applied procedure is steam distillation.
The most important oils are "Neroli Bigarade" and the various "Petitgrain" (Bigaradier, Bergamotier, Citronnier and Mandarinier), obtained respectively, from the flowers and from the twigs and leaves.