Cost Effective Essential Oil Extraction from Surplus Betel (Piper betle L.) Leaves

The betel leaf production in West Bengal, India is facing a serious decline due to recurrent storms and drastic weather fluctuation. A low-cost essential oil extraction process from the decomposed betel leaves could assist the farmers in partial recovery from the huge financial loss. ‘Sada Bangla’ cultivar of betel leaf collected from betel-vine of South 24 Parganas district was used for betel leaf essential oil (BLEO) extraction. A modified steam distillation process involving Clevenger apparatus was used for increasing oil recovery with different treatments. The process involving pre-grinded leaves in 10% cooking salt-based brine was found best for optimum oil extraction with a solute: Solvent ratio of 1:1 with a continuous time period of 3 hr with a 100°C initial and 80°C constant temperature after boiling of the mixture. The process is effective with both fresh and partially decomposed leaves with oil recovery of 1.82 ml and 1.72 ml respectively from 1 kg betel leaf sample. The removed fresh petioles as well as 10 days old petiole samples yielded 0.91ml /kg and 0.84 ml/kg of oil respectively. The process leads to 9 times reduction of de-oiled leaf-waste showing the viability of the process in profitable agri-waste management and the waste could be reused for further oil extraction. The fragrance and volume of essential oil remain intact for 6 months in airtight amber bottle in room temperature or 4°C chamber of refrigerator. The byproduct fragrant water extracted in the process could be utilized as taste enhancer or re-extraction of oil. This technique could be effectively utilized by the betel farming families for additional income generation and development of rural cottage production unit of BLEO.