Comparative Assessment of Conventional and Sustainable Extraction Methods for Essential Oils and Phenolic Compounds...

The aim of this study was to identify the most suitable extraction methods for isolating essential oils and polyphenols from Ammodaucus leucotrichus. Essential oils were extracted using hydrodistillation (HD), microwave-assisted HD (MW-HD) and microwave-assisted steam distillation (MW-SD), while polyphenols were obtained via maceration (MAC), Soxhlet (SOX), ultrasonic extraction (ULTR), and microwave-assisted extraction (MW). HD yielded the highest amount of essential oil (1.95%), and GC/MS analysis revealed that perillaldehyde (56.80%-62.67%) and limonene (22.04%-62.50%) are the most abundant compounds in the essential oils obtained through all techniques. Although the microwave-assisted methods (MW-HD and MW-SD) resulted slightly lower yields, but they offer substantial advantages in terms of reduced extraction time, lower energy consumption, and preservation of essential oil quality. For polyphenol extraction, MW and ULTR techniques produced the richest extracts, with a concentration of 624.11 mg EAG/g at 917.73 mg EAG/g. LC/MS analysis of the polyphenol extracts revealed several bioactive compounds identified for the first time, including taxifolin (2.24-12.90 mg/g), rutin (10.25 mg/g), isorhamnetin (12.82-43.33 mg/g), and 3-hydroxyflavone (0.85-5.21 mg/g). DPPH radical scavenging assays revealed the high potent radical-scavenging activity of extracts, highlighting the potential of A. leucotrichus as a promising natural source of bioantioxidant.