Abstract
This study evaluates the impact of ultrasound (US), ethanol (ET), and combined ultrasound-ethanol (ET/US) pretreatments on the drying efficiency and quality of Rosa damascena petals during hot air drying. All pretreatments significantly reduced the drying time and specific energy consumption (p < 0.05). The highest reduction in drying time (52.38%) and specific energy consumption (64%) was observed for the ET/US pretreatment. Ultrasound alone (US30) and in combination with ethanol (ET/US) significantly improved rehydration ability and essential oil yield (up to 1.31%, p < 0.05). Furthermore, the ET/US treatment preserved more antioxidant activity, total phenolic content, and flavonoid content compared to other pretreatments and control (p < 0.05). The results of this study can show new perspectives for using the potential of ethanol- ultrasound as a cost-effective and energy-efficient method for industrial drying sensitive medicinal plants. Future studies could explore its scalability and applicability to other aromatic or perishable botanical species.