Transforming essential oil extraction Wastes: Sustainable valorization approaches for agricultural, industrial, and cosmetic applications

Abstract

The solid and liquid residues generated from essential oil extraction are often regarded as waste; however, they present significant untapped potential for sustainable applications. This review critically examines recent research and industrial practices focused on the valorization of these residues, with a focus on their environmental impact, chemical composition, functional properties, and potential applications across various sectors. The study underscores the importance of advanced extraction techniques and biorefinery concepts in unlocking the full value of these by-products, contributing to a circular and resource-efficient bioeconomy. Essential oil extraction residues are rich in bioactive compounds, including phenols, flavonoids, essential nutrients, polysaccharides, and volatile compounds (e.g., phenolic monoterpenoids, monoterpenoid alcohols, terpene oxides, and monoterpenic aldehydes), making them valuable resources for agriculture, cosmetics, pharmaceuticals, food, and biorefinery industries. Agricultural applications include composting and organic fertilizers, while industrial uses involve bioenergy production (bioethanol, biogas) through pyrolysis and anaerobic digestion. In cosmetics and pharmaceuticals, their antioxidant properties make them suitable for skincare formulations. The food industry benefits from the antioxidant-rich residues by enhancing shelf life and nutritional value. Valorizing these residues aligns with sustainable development goals, mitigating environmental issues such as soil, air, and water contamination, and by reducing greenhouse gas emissions. © 2025 Elsevier Ltd