Two wild-type Saccharomyces cerevisiae yeast strains (Sa and Sb) were tested for white wine production using Assyrtiko grape of Santorini. A third commercial Saccharomyces strain was also studied for comparison reasons. Two concentrations of yeast extract and diammonium phosphate (DAP) were added to the must (150 and 250 mg/L) in order to evaluate the effect of nitrogen content on the final wine quality. Analytical methods (HPLC, GC-MS) and sensory analysis were employed to assess the quality of the wines. Fermentation kinetics were monitored throughout the experiment. By the second day of fermentation, all strains showed an approximate consumption of 70% of amino acids. Differences among strains were observed regarding inorganic nitrogen requirements. Sb strain resulted in higher concentrations of higher alcohols (1.9-fold) and ketones (5.6-fold) and lower concentrations of esters (1.2-fold) compared to the control, while Sa strain resulted in higher content of fatty acids (2.1-fold). Both indigenous strains scored better results in aroma quality, body and acidity compared to control. The overall evaluation of the data highlights the great potential of the indigenous S. cerevisiae strains as fermentation starters providing promising results in the sector of terroir wines.

Wine’s chemical structure is affected by many biochemical transformations during the winemaking process, which are catalysed by specific enzymes. These compounds participate in the formation of amino acids, which also have fundamental functions in the sensory quality of wine. Therefore, this research focuses on monitoring the effect of enzymes on amino acid concentration during the fermentation of Fetească regală and Sauvignon blanc wines. A total of 22 amino acids were quantified using an ultra-high liquid chromatography system coupled with mass spectrometry detection. Data indicated a major impact of the analysed variables (enzyme type and grape variety) on wine’s characteristics. Considerable amounts of some essential amino acids, such as histidine, isoleucine, phenylalanine, and tryptophan, were found in samples treated with pectinases preparations. The administration of pectinases was more effective in the Fetească regală wines in the applied work conditions, although the β-glycosides generated the highest values for most amino acids in the Sauvignon blanc. Pectinases can provide more acceptable sensory characteristics of wine compared to β-glycosides in the applied work conditions (when they are applied in the pre-fermentation stage), while these samples generally showed the lowest intensity for some negative descriptors, such as phenolic, mineral or a bitter taste.

Oxidative stress is induced by tobacco smoking and is also associated with exposure to air pollution, which are two of the most important risk factors for chronic obstructive pulmonary disease (COPD). The aim of this study was to correlate tobacco use and exposure to air pollution with oxidative stress markers useful in clinical practice in patients with COPD. A total of 102 patients were included and the levels of polycyclic aromatic hydrocarbons (PAHs), malondialdehyde, uric acid and number of packs-years (PY) were determined. Also, six different ratios were used to assess the source of exposure. The results obtained in this study show an admission of pollutants according to smoking status (former smokers/smoker/non-smokers) quantified in average total concentrations for the group of patients with COPD of 4.12 ng/mL, 6.76 ng/mL, 6.04 ng/mL. The six ratios used show that in COPD, the content of PAHs in the blood could be a result of diesel emissions and fuel combustion. Uric acid levels were lower in the smoker group of COPD patients (mean = 5.21 mg/dL), which indicates that oxidative stress is intensified with each cigarette smoked. Additionally, high concentrations of malondialdehyde were quantified for smoking patients diagnosed with COPD (mean = 2.72 µmol/L) compared to former smokers (mean = 2.43 µmol/L) and non-smoking (mean = 2.32 µmol/L) patients, which is another indicator of the implication of smoking in oxidative stress in COPD patients.

In classical methods of wine production, amino acids play a critical role, as they are fundamental to all types of fermentation. Beyond their consumption in fermentative processes, amino acids undergo several transformations, such as decarboxylation, which produces biogenic amines. These biogenic amines can increase under certain conditions, such as the presence of spoilage bacteria or during malolactic fermentation. Alternative methods of vinification were applied, using sulfur dioxide as a preservative (+SO₂) and methods without added sulfites. Alternative methods of vinification were applied using sulfur dioxide as a preservative (+SO₂) and methods without added sulfite (−SO₂). Monitoring was conducted for Cabernet Sauvignon red (CS), Cabernet Sauvignon rosé (CSR), Fetească regală still (FR), and Fetească regală frizzante (FRF). Alternative procedures employed the use of Pichia kluyveri for its ability to block the oxidation reactions of grapes, malolactic fermentation for all wines without sulfur dioxide (−SO₂) to ensure superior stability, and the use of several tannin mixtures to avoid oxidation reactions. Correlations were considered between the amino acids and biogenic amines that have a direct relation through decarboxylation or deamination. The pH of the wines, total acidity, and volatile acidity as principal factors of microbiological wine evolution remained constant. The highest mean concentrations of the detected biogenic amines were putrescine at 23.71 ± 4.82 mg/L (CSRSO₂), tyramine at 14.62 ± 1.50 mg/L (FR-SO₂), cadaverine at 4.36 ± 1.19 mg/L (CS-SO₂), histamine at 2.66 ± 2.19 mg/L (FR + SO₂), and spermidine at 9.78 ± 7.19 mg/L (FR + SO₂). The wine conditions ensured the inhibition of decarboxylases, but some correlations were found with the corresponding amino acids such as glutamine (r = −0.885, p < 0.05) (CSR-SO₂), tyrosine (r = −0,858, p < 0.05) (FR-SO₂), lysine (r = −0.906, p < 0.05) (FR-SO₂), and histamine (r = −0.987, p < 0.05) (CSR-SO₂). Multivariate analysis was performed, and no statistical differences were found between samples with (+SO₂) and without added sulfur dioxide (−SO₂). The vinification conditions ensured the wines’ stability and preservation and the conditions of producing biogenic amines at the lowest levels in order to not interfere with the olfactive and gustative characteristics.