Impact of Harvesting Cycle, Maturity Stage, Drying and Storage on Essential Oil Content of Patchouli Leaves Grown in Northeast Region of India

Abstract:

The effect of harvesting regime, drying mode and storage period on quantity of essential oil in the leaves of Patchouli (Pogostemon cablin) grown under humid tropical conditions of Northeast India is reported for the first time. Leaf samples of first year harvests had the highest oil content (g/100g of dry weight) as compared to subsequent year's harvests. All the three harvests of second year showed considerable yield reduction whereas third year harvests yielded the lowest oil. Further, first harvests of leaves during the entire three years crop cycle yielded the maximum oil. Declining trend in oil yield was recorded in second and third harvests of subsequent years. Leaf maturity stage also had significant effect on oil content. Out of the three maturity stages viz. full vegetative, semi-mature and fully mature; semi matured leaves had the highest oil content. Spread followed by heap drying of patchouli leaves resulted highest yield of oil. Storage of well dried leaves up to 135-150 days produced highest oil yield. Based on the studies, it is concluded that the essential oil profile of patchouli leaves greatly influenced by harvesting cycle, post-harvest drying mode and storage period.

Key words::

• Patchouli leaves
• Harvesting regime
• Drying mode
• Storage period
• Essential oil