Ricerc@Sapienza

Selenium is an essential micronutrient for humans. In food, selenium can be present in both inorganic and organic forms, the latter mainly being selenomethionine, Se-methyl-selenocysteine, and selenocystine. Selenoamino acid speciation rarely involves the chirality of selenoamino acids.

Interest in research into bioactive peptides (BPs) is growing because of their health-promoting ability. Several bioactivities have been ascribed to peptides, including antioxidant, antihypertensive and antimicrobial properties. As they can be produced from precursor proteins, the investigation of BPs in foods is becoming increasingly popular. For the same reason, production of BPs from by-products has also emerged as a possible means of reducing waste and recovering value-added compounds suitable for functional food production and supplements.

The work describes the development of an enrichment method for the analysis of endogenous phosphopeptides in serum. Endogenous peptides can play significant biological roles, and some of them could be exploited as future biomarkers. In this context, blood is one of the most useful biofluids for screening, but a systematic investigation of the endogenous peptides, especially phosphorylated ones, is still lacking, mainly due to the lack of suitable analytical methods.

Sea bass represents one of the main fish products in the market. Most of it comes from farming and is bred in different conditons with respect to the wild fish. Differences may thus be expected. In this study, a proteomic profile of farmed and wild sea bass samples was performed, employing a fractionation strategy where peptide samples were first separated by 2D chromatography. The peptides were finally analyzed by shotgun proteomics workflow combined to tandem MS.

The combination of an efficient chromatographic separation with post-column addition of a supercharging agent was evaluated for the determination of small peptides. The procedure takes advantage of porous graphitic carbon (PGC) ability in retaining very polar and ionic molecules to overstep the poor retention of small peptides on conventional reversed phase (RP) columns. The method was developed specifically for the most hydrophilic di-, tri- and tetrapeptides, which are not identified in ordinary peptidomics experiments.

The connection between chocolate and cocoa is studied. As cocoa is produced in different countries, samples coming from the same geographical region are analysed. The analyses focus on the characterisation of the considered samples for different aspects of quality and to individuate the original locations of production, also connecting this with the nutritional aspects. For this purpose, qualitative and quantitative traditional analysis and determination of fatty acid content are performed. The obtained experimental data show interesting correlations.

A microwave-assisted extraction method was optimised for the recovery of bioactive compounds from Crocus sativus L. stigmas with the use of water/ethanol mixture. HPLC-DAD was employed to evaluate the extraction parameters, in particular, solvent type and volume, and the duration of the procedure. Microwave-assisted extraction enhanced the recovery of the active principles, limiting extraction time and solvent waste.

Magnetic solid-phase extraction is one of the most promising new extraction methods for liquid samples before ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC–MS/MS) analysis. Several types of materials, including carbonaceous ones, have been prepared for this purpose. In this paper, for the first time, the preparation, characterization, and sorption capability of Fe3O4-graphitized carbon black (mGCB) composite toward some compounds of environmental interest were investigated.

The aim of metabolic untargeted profiling is to detect and identify unknown compounds in a biological matrix to achieve the most comprehensive metabolic coverage. In phytochemical mixtures, however, the complexity of the sample could present significant difficulties in compound identification. In this case, the optimization of both the chromatographic and the mass-spectrometric conditions is supposed to be crucial for the detection and identification of the largest number of compounds.

A novel type of graphene-like quantum dots, synthesized by oxidation and cage-opening of C60 buckminsterfullerene, has been studied as a ?uorescent and absorptive probe for heavy-metal ions. The lattice structure of such unfolded fullerene quantum dots (UFQDs) is distinct from that of graphene since it includes both carbon hexagons and pentagons. The basic optical properties, however, are similar to those of regular graphene oxide quantum dots.