A step closer to circular bioeconomy for citrus peel waste: A review of yields and technologies for sustainable management of essential oils

This study presents a critical overview of reported essential oil (EO) extractions from citrus peel wastes (CPW), including harmonized data on the various species and cultivars. Harmonization is vital to enable sustainable management practices. The review only includes eco-efficient extraction techniques. In total, contains 66 quantified examples using i) mechanical cold press ii) thermal with water or steam media iii) microwave-assisted iv) other innovative methods (such as ultrasound). technologies were assessed for their potential use in cascading production achieve economies scope, particularly considering residues subsequent fermentation produce products energy carriers enzymes. Two techniques found insufficient direct fermentation. Cold extracts an inadequate amount EO (average yield 2.85% DW) ensure suitable fermentation, while solvent contaminates its use. Extractions media, such hydrodistillation 2.87% DW), are feasible liquid-based processes, submerged Steam any type Our highlighted solvent-free microwave 5.29% most effective method, which provides high short time. We also uncovered discussed several inconsistencies existing yields consumption published data.