Cristina Manis

Background/Objectives: High dietary fructose consumption has been linked to impaired intestinal barrier function and several metabolic disorders. Although oxidative stress has been proposed as a mediator of fructose-related epithelial injury, the involvement of tight-junction (TJ) proteins and sphingolipid metabolism is still not fully defined. Here, differentiated Caco-2 monolayers were exposed to fructose (1–50 mM) to examine changes in epithelial barrier integrity and associated molecular responses. Methods: Cell viability, transepithelial electrical resistance (TEER), reactive oxygen species (ROS), intracellular reduced and oxidized glutathione (GSH/GSSG) ratio, nitrites as an indirect assessment of nitric oxide (NO) production, TJ protein level (ZO-1, JAM-A and occludin), sphingolipid profile by UHPLC-QTOF-MS, and expression of the ceramide synthases CERS2 and CERS6 were evaluated. Results: Fructose did not affect cell viability but induced a rapid, concentration-dependent increase in ROS generation, an early reduction in the GSH/GSSG ratio, and increased nitrites production. The observed alterations were concurrent with a temporary reduction in TEER, which returned to control levels at subsequent time points. Fructose selectively reduced JAM-A and ZO-1 protein expression, whereas occludin remained unaffected. Lipidomic analysis revealed sphingolipid remodelling, characterised by increased ceramide species and reduced sphingomyelins, while gene expression analysis showed downregulation of CERS2, with CERS6 remaining unchanged. The altered sphingolipid profile mainly involved long- and very-long-chain ceramides, suggesting a possible link between altered membrane lipid homeostasis and barrier dysfunction. Conclusions: Fructose exposure transiently compromises intestinal epithelial barrier function and is associated with oxidative stress, changes in TJ proteins, and sphingolipid remodelling. These preliminary findings identify sphingolipid remodelling as a candidate contributor to fructose-induced intestinal barrier dysfunction, warranting confirmation through dedicated mechanistic follow-up studies.

Human milk is the gold standard for infant nutrition; however, infant formulas (IFs) remain the main alternative when breastfeeding is not possible. Cow and goat milk-based IFs are well established, whereas sheep milk IFs have attracted increasing interest. IFs are among the most studied food products; nevertheless, little is known about the evolution of small molecules during digestion. This study monitored the metabolomic changes in sheep and goat IFs during simulated digestion using the dynamic in vitro gastrointestinal digestion system (DIDGI^®). Using an untargeted GC–MS approach, a total of 51 metabolites were identified in samples collected throughout the digestion process. The results of multivariate statistics indicated that the gastric and the intestinal digestion stages, rather than milk origin, were the primary sources of metabolic variation. However, different sheep and goat IF metabolite fingerprints were detected and persisted throughout digestion. Temporal profile analysis showed limited amino acid release during gastric digestion followed by a rapid increase during intestinal transition, reflecting extensive proteolysis. Similarly, massive lipolysis led to the accumulation in the intestine of free fatty acids, including medium-chain fatty acids derived from milk fat. These findings provide the first untargeted GC–MS characterization of the metabolomic evolution of sheep and goat milk IFs during dynamic in vitro gastrointestinal digestion.

Broccoli processing generates large quantities of leaves that remain underutilized despite being rich in bioactive compounds. Their valorization as a functional ingredient aligns with sustainable food production and offers an opportunity to enhance the nutritional quality of cereal-based foods. This study evaluated the impact of broccoli leaf powder (BLP) fortification (2.5 and 5%) on the phytochemical composition and functional properties of durum pasta under three drying regimes. BLP introduced glucosinolates, flavonols, carotenoids, and chlorophylls that were absent in the control samples, and their contents increased proportionally with the fortification level. The drying regime modulated compound stability, with low-temperature drying generally favoring retention, whereas cooking caused up to a 50% loss of glucosinolate, depending on the processing conditions. Functional properties were markedly enhanced by BLP addition. The 5% fortification level showed the greatest improvement, resulting in the highest antioxidant activity, antiglycation potential, and angiotensin-converting enzyme (ACE)-inhibitory activity compared to the control pasta. Antioxidant, antiglycation, and ACE-inhibitory activities increased proportionally with the fortification level, and although drying reduced some activities, the fortified pasta consistently outperformed the control. Among the tested formulations, pasta enriched with 5% BLP showed the most favorable overall functional and bioactive compound profiles. Overall, broccoli leaves represent a valuable by-product for developing nutritionally enriched pasta, and the processing conditions play a key role in shaping the stability and bioactivity of the incorporated compounds.

To protect wine authenticity and quality, two Sardinian red wines, Carignano del Sulcis and Cannonau di Sardegna, were characterized using an FT-IR and untargeted GC–MS integrated approach. FT-IR-derived oenological parameters, together with GC–MS profiles of polar low-molecular-weight metabolites, were subjected to multivariate statistical analysis. Compared with Cannonau, Carignano exhibited higher color intensity, greater density, and higher contents of glucose, lactic acid, and malic acid. Discriminant analysis of GC-MS data revealed that Carignano was characterized by uronic acids and arabitol, suggesting possible exposure to Botrytis. In contrast, Cannonau was characterized by 2,3 butanediol and ethyl-tartrate, indicating more pronounced yeast fermentative activity, consistent with the lower residual glucose content measured by FT-IR. Classification analysis demonstrated that the different wineries exert significant influence on the final characteristics of the wine. Overall, the findings demonstrated the effectiveness of this integrated analytical approach as a promising tool for wine authentication.

The valorization of agri-food by-products aligns with circular economy principles and offers sustainable sources of bioactive compounds. This study investigated the peels of the purple-fleshed Solanum tuberosum L. cv. Vitelotte Noire (VN), cultivated in Sardinia, as a potential resource for nutraceutical antioxidants. Extracts were obtained using solvents of different polarities (water, 80% and 96% ethanol) and characterized. Phytochemical screening revealed high concentrations of total phenolics, flavonoids, and anthocyanins, with the 96% ethanolic extract showing superior anthocyanin content. Antioxidant capacity, assessed via ORAC-PYR, TEAC-ABTS, and DPPH assays, was highest in the alcoholic extracts. Furthermore, all extracts showed protective effects in an in vitro model of AAPH-induced oxidative DNA damage, as indicated by the preservation of plasmid supercoiling. Untargeted LC-QTOF-MS analysis detailed a rich metabolomic profile, including organic acids, amino acids, and vitamins. The findings confirm VN peel as a potent, sustainable source of antioxidants, supporting its valorization for developing high-added-value nutraceutical and functional food ingredients, while reducing waste disposal costs and environmental impact.

Fermented dairy products such as yogurt, kefir, and traditional cheeses are increasingly consumed worldwide for their nutritional and probiotic properties. Lipidomic profiling provides valuable insights into microbial-driven biochemical changes during fermentation. In this study, we performed a comprehensive untargeted lipidomic analysis of sheep milk and Gioddu, a traditional Sardinian fermented dairy product. Using UHPLC-QTOF-MS platform, we observed that fermentation significantly reshaped the lipidome. Gioddu samples showed higher levels of phosphatidylethanolamines (PE) and lysophosphatidylethanolamines (LPE), together with a pronounced reduction in sphingolipids (glucosylceramides, ceramides, sphingomyelins) and glycerophospholipids (phosphatidylinositols, phosphatidylserines, phosphatidylcholines) compared to sheep milk. These findings align with known enzymatic activities of lactic acid bacteria (LAB), including phospholipases A1 and A2, phosphatidylinositol-specific phospholipase C (PI-PLC), and sphingomyelinase. Fermentation also affected triglycerides, with reduced levels of FA 18:1-containing species, suggesting the selective lipolysis of monounsaturated fatty acids by microbial lipases. Complementary metabolomic profiling revealed reduced levels of simple sugars such as galactose and inositol in Gioddu samples, consistent with their use as primary carbon sources during early fermentation. Conversely, a marked accumulation of carboxylic acids (succinic, malic, hydroxyisovaleric, hydroxyglutaric, glyceric) was revealed, reflecting enhanced microbial fermentative activity. Increased levels of amino acids, including alanine, serine, proline, and ethanolamine, further highlighted active proteolysis and membrane remodeling driven by LAB metabolism. These findings show that LAB enzymes play a key role in modifying the lipidome of fermented dairy products, highlighting their metabolic flexibility and potential impact on nutritional and health properties. This integrated approach sheds new light on the metabolic plasticity of fermentative processes and underscores the value of omics-based tools in understanding traditional food systems.