Sage, Rosemary, and Bay Laurel Hydrodistillation By-Products as a Source of Bioactive Compounds

Abstract

Essential oils from Mediterranean wild plants are widely used, but the hydrodistillation residues produced in parallel with these essential oils are significantly understudied and underexploited. Since there are only fragmentary data in the literature, we have, for the first time, systematically analyzed the chemical composition of the by-products obtained after hydrodistillation of sage, bay laurel, and rosemary leaves, i.e., hydrolates, water residues, and solid residues. The chemical composition of the hydrolates changed compared to their respective essential oils towards the dominance of more hydrophilic, oxygenated compounds, such as camphor in sage, 1,8-cineole in bay laurel, and berbenone in rosemary. However, some compounds, mostly sesquiterpenes, which were present in considerable amounts in essential oils, were absent or only present in very small amounts in the hydrolates. Furthermore, both the water and the solid residues were rich in polyphenols, such as procyanidins in bay laurel and rosmarinic acid in rosemary and sage. In conclusion, we demonstrate the valuable chemical composition of sage, rosemary, and bay laurel hydrodistillation by-products and discuss a wide range of their possible applications.

Exploring the Volatile Composition and Antibacterial Activity of Edible Flower Hydrosols with Insights into Their Spontaneous Emissions and Essential Oil Chemistry

“…EO evidenced a lesser number of constituents (13) in comparison with spontaneous emission (18) and VOC-Hyd (21). Sixty-eight percent of the identified portion was represented by apocarotenoids uniquely constituted by hexahydrofarnesylacetone (40).…”

“…During this process, three main by-products are created: solid residue (plant debris), water residue (non-distilled aqueous phase), and hydrosols (also known as hydrosols or aromatic water). The latter are aqueous aromatic solutions saturated with water-soluble volatile compounds [ 13 ]. Hydrosols distillate together with the EOs, retaining a good quantity of dissolved compounds that are, however, in lesser amounts than EOs, both in terms of number and concentration.…”

“…Hydrosols distillate together with the EOs, retaining a good quantity of dissolved compounds that are, however, in lesser amounts than EOs, both in terms of number and concentration. Despite this, oxygenated components (e.g., oxygenated monoterpenes (OM)) are higher in hydrosols, while EOs are richer in highly hydrophobic compounds such as monoterpene and sesquiterpene hydrocarbons [ 13 ]. Currently, aromatic waters have several applications in the food sector, as well as in the aromatherapy, cosmetics, and perfume industries, representing the most commonly used by-product of EO production [ 14 ].…”

Sustainable Recovery of Phenolic Compounds from Distilled Rosemary By-Product Using Green Extraction Methods: Optimization, Comparison, and Antioxidant Activity

“…SWR remained after distillation of the essential oil, which is a rich source of phenolics with strong redox properties, which are responsible for a wide range of health-related biological activities, including antibacterial, antifungal, and antioxidant functions [ 15 , 28 ]. This work investigated the efficacy of UAE, MAE, and ASE techniques with varying ratios of ethanol/water solvents for the rapid and selective recovery of phenolic compounds present in SWR.…”

“…To date, there are only a few studies focusing on the bioactive composition of SWR extracts, mainly applying UAE [ 16 , 18 , 28 ]. At the same time, there are no reports demonstrating the influences of other “green” extraction methods like MAE and ASE on the yield, phenolic composition, and antioxidant activity of SWR extracts.…”