Microwave-Assisted Drying Pretreatment for Enhanced Avocado Oil Quality

Abstract

This study evaluates microwave-assisted drying as a pretreatment for avocado oil extraction, focusing on drying efficiency, oil quality, and scalability. Microwave-assisted drying for 12.5 min yielded 63.42% oil, comparable to 63.83% obtained by conventional drying at 50 °C for 300 min, while significantly reducing processing time. Oils produced using microwave-assisted drying pretreatment retained higher levels of bioactive compounds, including carotenoids (140.44 ppm), vitamin E (392.35 ppm), and chlorophyll (20.79 mg pheophytin a/kg), compared to conventional drying (97.19 ppm, 192.40 ppm, and 5.77 mg pheophytin a/kg, respectively). Improved oxidative stability was observed, with a peroxide value of 4.68 mequiv/kg versus 20.32 mequiv/kg and a p-anisidine value of 0.89. Fatty acid composition remained stable (∼44–45% oleic acid). Pilot-scale processing (10 kW, 7 kg) confirmed feasibility, demonstrating a rapid and effective approach for high-quality avocado oil production.