CHARACTERIZATION OF (BIO)ACTIVE COMPOUNDS IN VEGETABLE MATRICES SUPPORTED BY LC-HRMS/MS

Agri-food wastes and by-products are complex mixtures containing precious (bio)actives, the recovery of which represents an important and continuously growing economic and environmental challenge. In this framework, chromatographic techniques are the elective choice for the determination of ingredients from food waste in line with the new trends in the food, cosmetic and pharmaceutical fields. The high structural variability of naturally occurring food compounds, such as polyphenols and carotenoids, together with the limited availability of commercial standards, complicates their identification. In addition, the chemical transformation they may undergo during food processing requires continuous monitoring to ascertain their integrity or identify potential side-products that could deeply affect the biological properties. For this reason, the hyphenation of LC to MS offers several benefits, allowing unique identification of (bio)active compounds in complex matrices (e.g. when peak overlap is a pitfall) or transformation products. Moreover, LC-MS systems represent an unavoidable final analytical step to confirm the identity of molecules previously analysed through most widely used UV or DAD detectors. This is the leitmotif of the case studies presented in this work (Fig. 1), where LC-HRMS/MS investigations were carried out in support of HPLC-DAD analyses to allow the characterization of carotenoids in pumpkin extracts and of the phenolic profile in potato, grape- and apple-pomace by-products [1,2]. Additionally, thorough HPLC-HRMS/MS investigations were performed to confirm the identity of chlorogenic acid isomers and enable the structural elucidation of their transformation products after microwave-assisted extraction [3].