Sourdough fermentation for the valorization of sorghum flour: Microbiota characterization and metabolome profiling.

Due to a large adaptability to different cultivation conditions and limited input compared to other cereals, sorghum is considered an emerging crop. Its antioxidant properties, high fiber content and low glycemic index also make it a valuable addition to a healthy diet, nevertheless, the presence of antinutritional factors and the lack of gluten, hamper its use as food ingredient. This study investigated the impact of sourdough fermentation on sorghum nutritional quality. Lactic acid bacteria dominating sorghum flour and sourdough were identified by culture-dependent analysis revealing Lactiplantibacillus plantarum as the dominant species found in the mature sourdough, whereas Weissella cibaria and Weissella paramesenteroides were the species isolated the most after the first refreshment. Among yeasts, Saccharomyces cerevisiae was the most prevalent. Lactic acid bacteria pro-technological and functional performances as starter were evaluated in sorghum type-II sourdoughs through an integrated characterization combining chromatographic and NMR spectroscopic techniques. The metabolic profile of the strains mainly grouped together W. cibaria strains and W. paramesenteroides AI7 which distinguished for the intense proteolysis but also for the presence of compounds particularly interesting from a physiological perspective (allantoin, glutathione, γ-aminobutyric acid and 2-hydroxy-3-methylbutyric acid), whose concentration increased during fermentation in a species or strain specific matter.

NMR Untargeted and HPLC-MS/MS Targeted Metabolomic Approaches for Evaluating Styrene Exposure in the Urine of Shipyard Workers.

Due to its chemical properties, styrene is largely employed in the manufacturing of several products including rubber, polymers and resins, and it is particularly suitable for shipbuilding industry purposes. In this context, the main exposure to styrene occurs in occupational settings. Despite its widespread use, its long-term effects on human health at the occupational level are still unclear. The aim of this pilot study was to evaluate changes in styrene exposure biomarkers related to the metabolic and oxidative stress profiles in the urine of seventeen shipyard workers and seventeen non-exposed subjects. Urinary metabolites were assessed by means of NMR spectroscopy, including mandelic and phenylglyoxylic acids; four oxidative stress biomarkers, namely 8-oxo-7,8-dihydroguanine, 8-oxo-7,8-dihydroguanosine, and 8-oxo-7,8-dihydro-2'-deoxyguanosine and 3-nitrotyrosine, were evaluated via HPLC-MS/MS. The metabolic profiles of exposed workers showed both long- and short-term metabolic responses to styrene exposure compared to non-exposed subjects. From the comparison between non-exposed and before-shift workers, only 8-oxo-7,8-dihydroguanine and 8-oxo-7,8-dihydro-2'-deoxyguanosine levels were significantly different (long term exposure response). At the same time, comparing the non-exposed group with after-shift workers, we observed lower levels of pseudouridine and 1-methylnicotinamide and higher glutamine levels in after-shift workers. The comparison between before-shift and after-shift workers showed that 8-oxo-7,8-dihydroguanine significantly increased after the shift, suggesting its involvement in the exposure to styrene (short-term exposure response). The obtained results, although preliminary, allow us to lay the basis for further human studies aimed at establishing a global understanding of styrene metabolism.

Comparison of the metabolic profile of pecan nuts cultivars [Carya illinoinensis (Wangenh.) K. Koch] by NMR spectroscopy.

Pecan nuts (Carya illinoinensis (Wangenh.) K. Koch) contain the highest number of phytochemicals of all nuts, are a natural source of unsaturated fatty acids and other nutrients and can be considered an important addition to the Mediterranean diet al.though several studies have been carried out on pecans, employing several analytical techniques, no systematic study of the metabolic profile is available in literature. In this study, the metabolic profile of pecan nuts of three different cultivars was analysed by Nuclear Magnetic Resonance Spectroscopy. The cultivars compared were Wichita, Stuart, and Sioux, all grown in Italy in the same pedoclimatic conditions. 31 metabolites were identified and 28 were quantified and the three species were differentiated based on multivariate PCA analysis. The differences among them, and the levels of scutellarein and GABA, in particular, were attributed to the adaptation of the plants to the climate in their original areas.