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The valorization of biomass residuals constitutes a key aspect of circular economy and thus a major challenge for the scientific community. Among industrial wastes, plant residuals could represent an attractive source of bioactive compounds. In this context, a residue from the industrial extraction of Cucurbita pepo L. seeds, whose oil is commercialized for the treatment of genito-urinary tract pathologies, has been selected. Supercritical CO2 technology has been employed as a highly selective "green" methodology allowing the recovery of compounds without chemical degradation and limited operational costs. Free fatty acids have been collected in mild conditions while an enrichment in sterols has been selectively obtained from sc-CO2 extracts by appropriate modulation of process parameters (supercritical fluid pressure and temperature), hence demonstrating the feasibility of the technique to target added-value compounds in a selective way. Obtained fatty acids were thus converted into the corresponding ethanol carboxamide derivatives by lipase-mediated biocatalyzed reactions, while the hydroxylated derivatives of unsaturated fatty acids were obtained by stereoselective hydration reaction under reductive conditions in the presence of a selected FADH2-dependent oleate hydratase. [ABSTRACT FROM AUTHOR]

Protein additives have a dramatic effect on the H2O2 oxidation of hyperforin by either protecting the enolized phloroglucinol core from oxidation or promoting the reaction pathways derived from the intermediacy of the enollactone. The use of protein additives allows a straightforward and multigram preparation of the enollactone, an interesting multifunctionalized scaffold for bioactivity induction and/or modulation.

Among the waste valorisation strategies, particular attention is given to plant and agri-food biomasses. They are particularly valuable since they are produced in large amounts worldwide and have been widely studied since ancient times for the richness in secondary metabolites, displaying strong bioactive properties. Within this context, the following biomasses have been selected and processed for the present study: • Residues from medicinal plants (Cucurbits pepo L. seeds and Serenos repens L. fruits). Given the selectivity of the method employed from the company processing the commercial oils, the residual biomasses are expected to still contain a significant amount of valuable natural products. • Coffee silverskin, the only by-product of coffee roasting process. Silverskin has already been investigated as combustible, fertilizer and animal feed, but our work points out the relevance of its phytochemical profile in terms of polar compounds dealing with its antioxidant properties. The aim of the study was to set up a green methodology minimizing the use of organic solvents, employing a green extraction technique, supercritical CO2, selectively enriching the extracts of target high value compounds. Plant biomasses were chosen in order to assess different methodologies, based on the same supercritical fluid technique, able to demonstrate the feasibility to target separately narrow windows of compounds, differentiated by their polarities. [ABSTRACT FROM AUTHOR]

Recovery of agro and food-industrial waste and their valorisation via green technologies can help to outline new concepts of industrial strategies. In this contest, a fat enriched of added-value components was extracted from coffee silverskin by applying a supercritical fluid extraction technique (sc-CO2). An appropriate modulation of process parameters like temperature (T = 35, 50, 60 °C) and pressure (p = 200–300 bar) influences the fat yield and the chemical composition, opening the way for targeted extraction. The extraction time, the organic solvent use and the energy consume were reduced compared to Soxhlet. Moreover, a mathematical model was constructed based on the experimental data collected, employed apparatus, and physico-chemical characteristics of biomass, pointing to a possible industrial scale-up. The experimental results are accompanied by a preliminary cost of manufacturing (COM), highlighting how the high investment for the apparatus is compensated by several benefits. [ABSTRACT FROM AUTHOR]

The electronic nose contributes, together with other chemical analyses, to identify botanical and geographical origin of honey. Two different honey samples were analysed: Italian Sainfoin (Sulla coronaria (L.) Medik.) and Eucalyptus (Eucalyptus camaldulensis Dehnh.). Aromatic profiles were evaluated using an electronic nose with a sensor array made up of 10 metal oxide semiconductor sensors (MOS). The maximum value for each sensor was used to plot data on a radar graph and for Principal Component Analysis (PCA). The PCA plot revealed a clear separation of samples. A complementary analysis of the volatile species in honeys was carried out using the head space solid phase microextraction coupled to gas chromatography and mass spectroscopy (HS-SPME-GC-MS) and the chemical profile of each sample was derived. Chemical data were compared to the results obtained with the electronic nose and confirmed the assignment of the different unifloral samples. The results showed that the electronic nose, combined with chemical identification of the volatile species, allows to classify and discriminate the different types of honey and to assign them to groups that have similar taste and aroma characteristics. [ABSTRACT FROM AUTHOR]

In the last decade, the cyanobacterium Spirulina has gained a high commercial interest as a food supplement, mainly due to its high protein content as well as high amounts of pigments, such as carotenoids, chlorophylls and phycocyanins. In particular, phycocyanin has been widely considered as a precious food-dye because of its protein-based structure and the rare intense-blue color. Different strategies were developed for the isolation and purification of phycocyanin. The main drawback of such processes is that carotenoids and chlorophylls are generally wasted together with the residual biomass. In this study, a different approach is proposed, suggesting an integrated pigment extraction chain. The body of the strategy involves two consecutive steps of the supercritical-CO2 extraction of carotenoids and chlorophylls, before phycocianin extraction. The total carotenoid, chlorophyll a and chlorophyll b contents in the extracts were equal to 3.5 ± 0.2 mg g−1, 5.7 ± 0.2 mg g−1 and 3.4 ± 0.3 mg g−1, respectively (by dry Spirulina weight). The biomass residue, exhausted in terms of carotenoids and chlorophylls, was then extracted in water to yield phycocyanin. Consecutive steps were developed in order to ehance the phycocyanin purity, including electrocoagulation, dialysis and protein salting-out. These processes yielded 250 mg g−1 of phycocyanin (by dry Spirulina weight). A potentially scalable strategy to obtain the blue pigment with high purity (A620/A280 = 2.2) was developed. The practical application of the extracted blue phycocyanin pigment as a cotton-based tissue colorant was also experimented. [ABSTRACT FROM AUTHOR]

The article explains the nitration, as well as the nitrosation chemistry of menthofuran, a toxic furan obtained from various mint oils. It also demonstrates the synthetic and biomedical significance of menthofuran-derived scaffolds.