Study on green extraction of limonene from orange peel and cascade catalysis to produce carvol and carvone in deep eutectic solvents

Carvol and carvone are oxidation products from the natural product limonene. They important raw materials for flavours fragrances industry also act as pharmaceutical active ingredients. Orange waste peels possibly represent an attractive source limonene, but studies on valorizing orange peel wastes rare. In this study, we report a new enzymatic cascade system in-situ conversion of limonene into valued-added carvol carvone. The use deep eutectic solvents (DES) allows efficient extraction peels. We propose dual function DES solvent biocatalytic well cosubstrate to promote reaction. Using ChCl-Pro-H2O peels, approximately 17 milligrams per gram was achieved at 40°C 24 h. Then, with extractant reaction medium, choline oxidase (ChOx) unspecific peroxygenase (UPO) established catalyse concentration final up about 1.6 mmol L−1. This study showed transformation pathway provides technical support high-value utilization in peel.