Residual biomass from major aromatic and medicinal flora of the Mediterranean: challenges towards sustainable integration into food systems within the circular bioeconomy

Waste biomass from aromatic and medicinal plants (AMPs) encloses multifunctional compounds that could offer a poly-diverse pool of applications in sectors of food/feed, cosmetics, pharmaceuticals and agriculture. The production of essential oils (EOs) constitutes the main process that generates huge amounts of waste and/or by-product streams, since >95% of the AMPs is left as residual biomass after distillation. This review presents the current situation of AMPs’ waste production within the Mediterranean basin and their potential valorization. A thorough mapping of the enclosed bioactive compounds is performed, focusing on sustainable and high-performing methods for their recovery. The integration of bioactives into novel-food-related systems via emerging techniques is highlighted. An insight to a holistic approach of these residues in the framework of advanced biorefineries is proposed, including biomass fractionation and bioconversion into value-added compounds. AMPs constitute a new avenue of value-added components with multi-faceted applications. Following the extraction of EOs, the residues are rich in natural antioxidants which can be recovered employing novel and “green” methods. Innovative encapsulation techniques have been developed, enabling the incorporation of these compounds into food-related systems. Besides phenolic compounds, plant biomass could be further fractionated and bioconverted into chemicals, biofuels and polymers, encompassing the principles of bioeconomy and sustainability. Such integrated approaches comprising the complete exploitation of waste biomass pave the way towards modern and sustainable food systems.