The genus Cinnamomum

KETTLE
FURNACE
Harvesting, Processing, and Quality Assessment of Cinnamon Products 139
STILL PRE COOLER
Figure 5.8 Diagram of a traditional cinnamon leaf oil distillation unit.
Cinnamon leaf oil
STATIC CONDENSER
Leaf oil distillations are normally carried out in large distillation vessels (200–500 kg)
(Fig. 5.8). Cinnamon leaves are obtained as a by-product of the cinnamon industry.
When the shoots are harvested for bark, the leaves and twigs are trimmed in the field.
Before distilling the leaf oil, the trimmed leaves are allowed to remain in the field for
three to four days. Traditional leaf oil distillation units consist of a wooden still body
with a copper goose neck lid. The condensing system is similar to the bark oil-distilling
unit. The steam is generated in a separate kettle like external boiler. The condensed
distillate is collected in a series of Florentine vessels (Fig. 5.8). Due to the low solubility
of leaf oil in water it turns milky white in colour. Oil separated water is kept stored for
days before complete separation of oil from the water. Since leaf oil is heavier than
water, oil collects at the bottom of the Florentine vessel. Due to oxidation and to reactions
with copper or steel vessels, the oil turns usually dark brown in colour. It takes
about six to seven hrs to distill one batch of leaf, normally a yield of 1.0% oil on dry
weight basis is obtained. After months of operation, a dark resinous material is found
in condenser tubes. This is removed by burning condenser tubes in open fire.
Cinnamon leaf oil is graded according to the eugenol content (CS 184, 1972).
Supercritical fluid extraction (SCFE) of cinnamon
SCFE is a versatile tool for addressing the disadvantages of the conventional extraction
technologies of essential oils and oleoresins. In this process the ground spice is brought
into contact with a supercritical solvent at a relatively high pressure ranging from
60–300 bar at a temperature 35–70 °C. The supercritical solvent, after getting
enriched with the solute, is passed through a micrometer valve or pressure reducing
valve, where the pressure on the separator side is much less and the temperature much
lower due to the adiabatic expansion of the supercritical solvent. This results in lower
solubility of the solute leading to the separation of the solute from the solvent.
Once the material is separated the gas is compressed back to extract the material