Maceration of Extra Virgin Olive Oil with Common Aromatic Plants Using Ultrasound-Assisted Extraction: An UV-Vis Spectroscopic Investigation

Rosemary (Rosmarinus officinalis), garden sage (Salvia officinalis), summer savory (Satureja hortensis), laurel (Laurus nobilis), and other aromatic plants were put in olive oil and exposed to ultrasounds for different duration. Filtrated oils were dissolved in cyclohexane, and UV-Vis measurements were carried out. Absorbance values corresponding to chlorophylls, carotenoids, flavonoids (370 nm), and polyphenols (around 300 nm) were measured. In addition, for some samples, total phenols were determined using Folin-Denis reagent and compared with the similar maceration procedure in water solvent (instead of olive oil). Maceration without ultrasound in olive oil for each plant was also compared with ultrasound-assisted extraction. The results show that significant amount of aromatic content can be extracted in olive oil by applying ultrasounds for only few minutes, especially for Salvia officinalis powder. The use of UV-Vis measurements is simple but enough to examine the extent of phenol content extraction through such maceration procedure.