Influence of Various Drying Methods on the Extraction of Alpinia galanga (L.) Willd. Essential Oil for Evaluating Yield Efficiency: A Comparative Study

Aims: This study aims to evaluate the effectiveness of oil extraction through galangal rhizomes from various drying methods i.e. fresh, oven dried and shade dried rhizomes by using hydro distillation method. Study Design: Experimental study comparing essential oil yields from three different samples of Alpinia galanga rhizomes. Place and Duration of Study: Alpinia galanga rhizomes harvested from the Germplasm Conservatory cum Herbal Garden of Silviculture and Forest Management Division, at the Forest Research Institute, Dehradun. Further the oil extraction from rhizomes through hydro distillation has carried out in Non-Timber Forest Products laboratory, Forest Research Institute, Dehradun, from the time period between January 2023 to June 2024. Methodology: Three types of Alpinia galanga rhizome samples (fresh, oven-dried, and shade-dried) were used. Each sample (400 grams) was immersed in 1000 ml of water in a boiling flask and subjected to hydro distillation for 4–5 hours. A Clevenger-type apparatus was used to separate the oil and water components. The oil-water mixture underwent multiple extractions using a separatory funnel to isolate the essential oil. The extracted oil was transferred to vials and allowed to evaporate completely in a well-ventilated area. The final oil content was weighed to determine extraction yield. Results: The highest essential oil yield was obtained from the shade-dried rhizome sample, with a yield of 0.09%. Fresh and oven-dried samples yielded lower amounts of essential oil. Using these yield percentages, the estimated essential oil extraction from one kilogram (1 kg) of Alpinia galanga rhizome can be calculated. Conclusion: Shade drying was found to be the most effective method for optimizing essential oil yield from Alpinia galanga rhizomes. This finding is significant for commercial production, as shade drying enhances oil recovery and could improve industrial-scale essential oil extraction efficiency.