Removal of Calamus Odour from Patchouli Oil
During distillation of cured leaves of four different strains of patchouli namely Java, Johore, Indonesian and Malaysian, it was observed that the oil obtained from Java strain, gave calamus odour which is not desirable for Patchouli oil as it masks true Patchouli odour. The presence of calamus odour in patchouli leaves (Java strain) and it's removal by strong fermentation has been reported. The present study describes an approach for the removal of calamus odour by the distillation method since the oil obtained from strongly fermented leaves still had the calamus odour.
MATERIALS AND METHODS
Leaf samples for distillation of oil were collected from about six month old plants of above strains of Patchouli (Pogostemon patchouli Pellet), maintained at the experimental plots of the Indian Institute of Horticultural Research, Hessaraghatta.
Twigs containing first four to five pairs of leaves were harvested during morning hours. Leaves were stripped off the twigs and were shade dried in the laboratory for about a week. During drying the leaves were turned frequently to ensure uniform drying. After the leaves had dried, they were packed and stored in paper bags.
For fermentation, the leaves from Java strain, after stripping from the twigs were heaped and allowed to dry and were not turned frequently. 100 g of dried leaves were distilled in a clevenger appartus for 8 hours and the percentage of oil in each case was recorded (in triplicate).
In another set of experiment, during distillation of the dried leaves oil fractions were collected separately at one hour interval upto 8 hours. The oil obtained from each strain and also the eight fractions from each strain were tested for calamus odour by comparison with Acorus calamus oil. Also the oils were tested for the presence of b asarone by TLC method, since it is reported that the calamus odour is apparently due to b asarone. The percentage of b-asarone in Patchouli oil was estimated by the method of Chopra.
RESULTS AND DISCUSSION
The yield of oil and asarone content of different strains of unfermented and strongly fermented leaves of Java strain of patchouli are given in the table 1. Marked differences were observed in the essential oil content among the four strains; leaves from Malaysian strain, recorded the highest oil content (3.4%) and that from Java strain lowest (1.2%). Strongly fermented leaves of Java straisn recorded higher oil content (1.8%) compared to unfermented leaves (1.2%).
Essential Oil and b-asarone Content of Patchouli (Pogostemon Patchouli Pellet)
|Essential oil content ml/100g.(%)
|b-asarone mgl 100 ml of oil
It is clear from the table that the oil obtained by distillation of unfermented and strongly fermented leaves of Java strain has calamus odour. The calamus odour could not be detected in the oil from other strains. The presence of b-asarone could be detected in the oil from Java strain and not in the oil obtained from other strains. While the b-asarone content was highest in the oil from unfermented leaves of Java strain (9.8%) and that from fermented leaves was lowest (2.3%).
Among the eight fractions of patchouli oil obtained by the distillation of fermented and unfermented leaves of Java strain collected at hourly intervals, the calamus odour and b-asarone could be detected only in the first fraction and not in the latter fractions indicating that the b-asarone was remove during the first hour of distillation.
Recent investigations have revealed ca:r cinogenic properties o b-asarone (Cis, 2, 4, 5-trimethoxy, 1-propenyl benzene). The Food and drug Administration Department of USA has prohibited the use of calamus in any form (root, extract or oil). Also the presence of b-asarone masks the true odour of patchouli oil. In the light of above findings we recommended the rejection of the oil fraction obtained during first hour distillation of Patchouli leaves (Java strain which contains b-asarone in order to obtain Patchouli oil free from calamus odour.