Lignins are phenolic polymers endowed with potent antioxidant properties that are finding increasing applications in a variety of fields. Consequently, there is a growing need for easily available and sustainable sources, as well as for green extraction methodologies of these compounds. Herein, a ball milling/deep eutectic solvent (DES)-based treatment is reported as an efficient strategy for the recovery of antioxidant lignins from the shells of edible nuts, namely chestnuts, hazelnuts, peanuts, pecan nuts, and pistachios. In particular, preliminarily ball-milled shells were treated with 1:2 mol/mol choline chloride:lactic acid at 120 °C for 24 h, and the extracted material was recovered in 19–27% w/w yields after precipitation by the addition of 0.01 M HCl. Extensive spectroscopic and chromatographic analysis allowed for confirmation that the main phenolic constituents present in the shell extracts were lignins, accompanied by small amounts (0.9% w/w) of ellagic acid, in the case of chestnut shells. The recovered samples exhibited very promising antioxidant properties, particularly in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay (EC50 values ranging from 0.03 to 0.19 mg/mL). These results open new perspectives for the valorization of nut shells as green sources of lignins for applications as antioxidants, e.g., in the biomedical, food, and/or cosmetic sector.

Identification of strategies to prolong emulsion kinetic stability is a fundamental challenge for many scientists and technologists. We investigated the relationship between the emulsion stability and the surfactant supramolecular organization at the oil–water interface. The pseudo-phase diagrams of emulsions formed by water and, alternatively, a linear or a branched oil, stabilized by mixtures of two sugar-based surfactants, Span80 and Tween80, are presented. The surfactant ordering and dynamics were analyzed by electron paramagnetic resonance (EPR) spectroscopy. In Oil-in-Water (O/W) emulsions, which are stable for more than four days, disordered surfactant tails formed a compact and viscous layer. In Water-in-Oil (W/O) emulsions, whose stability is much lower, surfactants formed an ordered layer of extended tails pointing toward the continuous apolar medium. If linear oil was used, a narrow range of surfactant mixture composition existed, in which emulsions did not demix in the whole range of water/oil ratio, thus making it possible to study the phase inversion from O/W to W/O structures. While conductometry showed an abrupt inversion occurring at a well-defined water/oil ratio, the surfactant layer microstructure changed gradually between the two limiting situations. Overall, our results demonstrate the interconnection between the emulsion stability and the surfactant layer microstructuring, thus indicating directions for their rational design.

The ion content of drinking water might be associated with urinary stone formation, representing a keystone of conservative nephrolithiasis management. However, the effects of specific ions on calcium oxalate crystal formation and their mechanism of action are still highly controversial. We report an investigation of the effects of oligomineral waters with similar total salt amount but different ion composition on calcium oxalate (CaOx) precipitation in vitro, combining gravimetric and microscopic assays. The results suggest that the “collective” physicochemical properties of the aqueous medium, deriving from the ion combination rather than from a single ionic species, are of importance. Particularly, the ability of ions to strengthen/weaken the aqueous medium structure determines an increase/decrease in the interfacial energy, modulating the formation and growth of CaOx crystals.

The research aimed to generate an early warning system highlighting in real-time bacterial contamination of meat matrices and providing information which could support companies in accepting or rejecting batches. Current microorganisms' detection methods rely on techniques (plate counting), which provide retrospective values for microbial contamination. The purpose of this research was to evaluate the ability of the headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC/MS) methodologies to detect volatile organic carbons (VOCs), which may be associated to a peculiar microbiological contamination of food. The disposal of fast headspace gas chromatography-mass spectrometry (HS-SPME-GC/MS) able to accurately and rapidly (30 min per sample) detect pathogens in raw meat could replace the traditional and time-consuming (3 to 4 days) standardized microbiological analysis required by regulations. Experiments focused on qualitative and quantitative evaluations of VOCs produced by Salmonella Typhimurium, Campylobacter jejuni, and Staphylococcus aureus in different types of raw meat (beef, pork, chicken). HS-SPME-GC/MS allowed to use smaller sample volumes compared to traditional methods with no sample processing and the potentiality for its application on various food matrices for the detection of a wide variety of pathogens. Data analysis showed the identification of unique VOCs' profiles being possible markers of meat contamination due to their association to specific pathogens. The identification of VOCs markers in association to selected bacterial pathogens and their metabolites could support the rapid determination of specific meat samples contamination. Further research is required to outline-specific metabolic profiles for each microorganism responsible of meat contamination and prevent false positives.

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