EFFECT OF AIRFLOW RATE ON THE EXTRACTION OF WHITE PEPPER (PIPER NIGRUM L.) ESSENTIAL OIL USING THE MICROWAVE AIR-HYDRODISTILLATION METHOD

Abstract

This study examines the effect of airflow rate on the extraction of white pepper (Piper nigrum L.) essential oil using the Microwave Air-Hydrodistillation (MAHD) method. The research aimed to optimize the extraction process by varying the airflow rate (1, 2, 3, 4, and 5 L/min) while maintaining a microwave power of 450 W and an extraction time of 100 minutes. The results indicate that airflow rate significantly influences essential oil yield, with the highest yield (2.4590%) obtained at 1 L/min airflow. Increasing airflow beyond this rate led to a decline in yield due to excessive volatilization and incomplete condensation of essential oil components. The extracted essential oil was analysed for color, density, ethanol miscibility, and acid number and compared with ISO 3061:2008 standards. The oil exhibited a blue color, a density of 0.8814 g/mL (within the ISO range of 0.861– 0.885 g/mL), and an acid number of 1.2732 mg KOH/g, indicating good quality. However, the miscibility test deviated slightly, requiring 4–5 mL of ethanol instead of the standard 3 mL, suggesting possible differences in chemical composition. These findings confirm that MAHD is an efficient extraction method, offering shorter processing times and improved efficiency compared to conventional hydrodistillation. The study highlights the importance of optimizing airflow rate to balance yield, condensation efficiency, and volatile compound retention. Further research is recommended to refine extraction conditions for enhanced quality and industrial applicability.