Deodorization by Solar Steam Distillation of Rosemary Leaves Prior to Solvent Extraction of Rosmarinic, Carnosic, and Ursolic Acids

Abstract

This study aims total valorization of rosemary for food applications, moving toward developing an original biorefinery concept using solar steam distillation (SSD) to extract essential oil while preserving active compounds in the raw material, mainly antioxidants, for a further extraction. The deodorization process is important to avoid the extraction of antioxidants with strong aromas which limit their utilization for food preservation. The SSD process was compared with conventional steam distillation (CSD) for essential oil extraction as well as deodorization of dried rosemary leaves. The treated leaves were recovered afterward for the extraction of antioxidants by solvent extraction to recover rosmarinic, carnosic, and ursolic acids. With standard protocol extraction and analysis, the antioxidants seem to be mostly preserved by SSD rather than by CSD. The Folin–Ciocalteu reagent was used to determine the polyphenol content, whereas diphenylpicrylhydrazyl (DPPH) was used to analyze the antiradical properties. It was found that both the polyphenol content and antioxidant activity were preserved after SSD. Scanning electron microscopy (SEM) and fluorescence microscopy showed complete destruction of glandular trichomes for both processes, which indicates that the extraction of essential oil was complete. Overall, the results specify clearly that solar steam distillation (SSD) is a green alternative, an efficient and economical process for essential oil extraction and leaf deodorization.

Green Extraction of Essential Oils, Polyphenols, and Pectins from Orange Peel Employing Solar Energy: Toward a Zero-Waste Biorefinery

“…Similar results were reported in numerous studies ,, for melissa, peppermint, rosemary, cumin, and cloves where it was found that solar and conventional extractions provide similar essential oil yields with a negligible deviation. It was established in previous work that the solar extraction efficiency is affected by both the daily solar radiation and the cloud cover density since the solar reflector only uses direct radiation.…”

“…The solar apparatus for the hydro-distillation extraction of orange peels is placed in the National Centre for Studies and Research on Water and Energy at Cadi Ayyad University (Marrakech, Morocco) Figure shows the solar system mainly composed of a 10 m 2 solar reflector coupled to a hydro-distillation unit; each component has numerous specific characteristics.…”

Study of the Energetic, Exergetic, and Thermal Balances of a Solar System in comparison with a Conventional System during the Distillation of Rosemary Leaves

“…While the mass yield in EO is 0.83%, slightly higher than 0.82% that found by Hilali with the same solar system (Hilali et al 2018).…”

“…As shown in Table 3, the quantities of EOs recovered are 17, 35, and 50 mL, and essential oil extraction yields are 0.85%, 0.88%, and 0.83%, respectively, for 2, 4, and 6 Kg of AMPs, slightly higher than 0.82% that found by Hilali with the same solar system (Hilali et al 2018).…”

Optimization of aqueous enzyme‐assisted extraction of rosmarinic acid from rosemary ( Rosmarinus officinalis L.) leaves and the antioxidant activity of the extract

“…However, these techniques are unsuitable for RA extraction because RA is unstable and sensitive to heat, which degrades RA and lowers its biological activity (Barbieri et al, 2020). Furthermore, the Soxhlet extraction needs a long time (>10 hr) and consumes high energy (Hilali et al, 2018). Consequently, microwave-and ultrasound-assisted extraction methods have been developed for RA extraction (Bellumori et al, 2016;Jacotet-Navarro et al, 2015).…”