From Flavedo to Flavors and Fragrance: Botanical Foundations of Citrus Peel Essential Oils in Bio-Based Value Chains

Citrus is a genus of great economic importance and a complex history of hybridization. The aim of this work is to present the trajectory of essential oil (EO) from the citrus fruit peel to their main uses. The flavedo is a morpho-functional region of the citrus fruit peel where EO-producing cavity glands are located. The EO produced is the source of the characteristic citrus aroma relevant for flavor (food and beverage industry) and fragrance applications (perfumery). The citrus EO is dominated by monoterpene hydrocarbons. Out of these, D-limonene is the major compound in the peel EO of commercial citrus types, accounting for 30% and over 90% of its composition. Minor oxygenated components are important contributors to the distinct sensory characteristics. Selected studies on various citrus types indicate that EOs exhibit a strain-dependent antimicrobial activity as well as certain antioxidant activity relevant in particular for food preservation and active packaging. The most dynamic area of research is the optimization of delivery systems that seek to improve the stability and functionality across applications. The citrus value chain is integrated vertically, generating value for the customer and is linked horizontally to other value chains. Its main vulnerability resides in upstream production constraints from the agronomic segment that can potentially impact sustainability and supply. For the next decade, growth is projected for citrus flavor and fragrance markets.