Supercritical fluid extraction of coumarins and flavonoids from citrus peel

The production manufacture of juices generates a large amount of waste consisting mainly of fruit peels. The peels are source of molecules such as coumarins and flavonoids. In this study, the peels of Citrus limonia, Citrus deliciosa, Citrus latifolia and Citrus sinensis were the raw material for supercritical fluid extraction. The BoxBehnken design was used to optimize the global yield in function of process variables. The chemical analysis of the extract was carried out by LC-MS and GC-MS. CFD was applied to the mass and momentum conservation equations in the study of supercritical extraction using citrus peels, which allowed the determination of unknown parameters of the bidimensional mathematical model. The flavonoids, nobiletin, sinensetin and tangeretin, as well as the coumarin, citropten, were identified in all species investigated. The maximum global yield obtained were 3.93% for Citrus limonia, 4.18% for Citrus deliciosa, 3.48% for Citrus latifolia and 5.32% for Citrus sinensis.