Valorisation, Green Extraction Development, and Metabolomic Analysis of Wild Artichoke By-Product Using Pressurised Liquid Extraction UPLC-HRMS and Multivariate Data Analysis.

Valorisation of food by-products has recently attracted considerable attention due to the opportunities to improve the economic and environmental sustainability of the food production chain. Large quantities of non-edible parts of the artichoke plant (Cynara cardunculus L.) comprising leaves, stems, roots, bracts, and seeds are discarded annually during industrial processing. These by-products contain many phytochemicals such as dietary fibres, phenolic acids, and flavonoids, whereby the most challenging issue concerns about the recovery of high-added value components from these by-products. The aim of this work is to develop a novel valorisation strategy for the sustainable utilisation of artichoke leaves' waste, combining green pressurised-liquid extraction (PLE), spectrophotometric assays and UPLC-HRMS phytochemical characterization, to obtain bioactive-rich extract with high antioxidant capacity. Multivariate analysis of the major selected metabolites was used to compare different solvent extraction used in PLE.

Characterisation of nutraceutical compounds from different parts of particular species of Citrus sinensis 'Ovale Calabrese' by UHPLC-UV-ESI-HRMS.

Consumers are aware of diet causing health problems and therefore there is an increased demand for natural ingredients that are expected to be safe and health-promoting. Many of these compounds belong to the class of flavonoids and can be divided into these five groups: flavanones, flavones, flavonols, flavanols, isoflavones and anthocyanidins. Extracts from citrus fruits are usually used as functional ingredients for several products. The aim of this paper was to develop an UHPLC-UV-ESI-HRMS method to define the metabolite profile of different parts of citrus fruit, of a particular cultivar called 'Ovale Calabrese', and in its main by-products. The high resolution mass spectrometry analysis allowed the identification of 27 compounds belonging to the classes of flavonoids and terpenoids. The high contents of phytochemical compounds, reveal the potential use of the 'Ovale Calabrese' as a rich source of nutraceutical compounds.

Response surface methodology to optimize supercritical carbon dioxide/co-solvent extraction of brown onion skin by-product as source of nutraceutical compounds.

Food industry produces a large amount of onion wastes. Due to the high amount of bioactive compounds in onion by-products an idea for their reuse, could be use them as source of high-value functional and health ingredients. In this study, outer dry layers of coppery onion "Ramata di Montoro" were used as source of bioactive compounds. Firstly, the chemical profile of secondary metabolites of exhaustive extract, obtained by ultrasound assisted extraction was established by UHPLC-UV-HRMS/MS analysis. Subsequently, the supercritical fluid extraction was used as alternative and green method to recover flavonoids from onion skin. Main parameters such as pressure, temperature and composition of solvent modifier were optimized in order to improve the extraction efficiency of SFE technique, by using a response surface Box-Behnken design.

Non-destructive flavour evaluation of red onion (Allium cepa L.) ecotypes: an electronic-nose-based approach.

This work reports preliminary results on the potential of a metal oxide sensor (MOS)-based electronic nose, as a non-destructive method to discriminate three "Tropea Red Onion" PGI ecotypes (TrT, TrMC and TrA) from each other and the common red onion (RO), which is usually used to counterfeit. The signals from the sensor array were processed using a canonical discriminant function analysis (DFA) pattern recognition technique. The DFA on onion samples showed a clear separation among the four onion groups with an overall correct classification rate (CR) of 97.5%. Onion flavour is closely linked to pungency and thus to the pyruvic acid content. The e-nose analysis results are in good agreement with pyruvic acid analysis. This work demonstrated that artificial olfactory systems have potential for use as an innovative, rapid and specific non-destructive technique, and may provide a method to protect food products against counterfeiting.