Transforming waste into resources: extracting and characterizing volatiles and bioactive compounds, maximizing the value of <i>Citrus</i> industry biomass within a circular economy framework

The agro-food industry is responsible for the generation of a consistent amount of waste, the correct disposal of which is of paramount importance to mitigate its environmental impact. The objective of this project was to re-evaluate sweet orange biomass by extracting the residual aroma and bioactive molecules (phenols). The essential oil was obtained using hydrodistillation and microwave-assisted distillation, and then analysed by means of gas chromatography coupled with a flame ionization detector and a single quadrupole mass spectrometer to characterize the volatile fraction. To assess the composition of the non-volatile fraction, the samples underwent solid–liquid extraction, and the extracts obtained were analysed by liquid chromatography coupled with photodiode array detector. The workflow developed in this study enables the recovery of both the residual aroma and bioactive molecules still present in Citrus biomass, which can be used to fortify the final products destined for consumers, thereby enhancing the flavour and nutraceutical properties.