Search results for " wine"
showing 10 items of 335 documents
Basal catalase activity and high glutathione levels influence the performance of non-Saccharomyces active dry wine yeasts.
2020
Non-Saccharomyces wine yeasts are useful tools for producing wines with complex aromas or low ethanol content. Their use in wine would benefit from their production as active dry yeast (ADY) starters to be used as co-inocula alongside S. cerevisiae. Oxidative stress during biomass propagation and dehydration is a key factor in determining ADY performance, as it affects yeast vitality and viability. Several studies have analysed the response of S. cerevisiae to oxidative stress under dehydration conditions, but not so many deal with non-conventional yeasts. In this work, we analysed eight non-Saccharomyces wine yeasts under biomass production conditions and studied oxidative stress parameter…
NMR spectroscopy evaluation of direct relationship between soils and molecular composition of red wines from Aglanico grapes
2010
1H NMR spectroscopy was employed to investigate the molecular quality of Aglianico red wines from the Campania region of Italy. The wines were obtained from three different Aglianico vineyards characterized by different microclimatic and pedological properties. In order to reach an objective evaluation of “terroir” influence on wine quality, grapes were subjected to the same winemaking procedures. The careful subtraction of water and ethanol signals from NMR spectra allowed to statistically recognize the metabolites to be employed in multivariate statistical methods: Principal Component Analysis (PCA), Discriminant Analysis (DA) and Hierarchical Clustering Analysis (HCA). The three wines we…
Natural hybrids fromSaccharomyces cerevisiae,Saccharomyces bayanusandSaccharomyces kudriavzeviiin wine fermentations
2006
Several wine isolates of Saccharomyces were analysed for six molecular markers, five nuclear and one mitochondrial, and new natural interspecific hybrids were identified. The molecular characterization of these Saccharomyces hybrids was performed based on the restriction analysis of five nuclear genes ( CAT8 , CYR1 , GSY1 , MET6 and OPY1 , located in different chromosomes), the ribosomal region encompassing the 5.8S rRNA gene and the two internal transcribed spacers, and sequence analysis of the mitochondrial gene COX2 . This method allowed us to identify and characterize new hybrids between Saccharomyces cerevisiae and Saccharomyces kudriavzevii , between S. cerevisiae and Saccharomyces ba…
Natural co-occurrence of ochratoxin A, ochratoxin B and aflatoxins in Sicilian red wines
2015
The natural occurrence of ochratoxin A, ochratoxin B, aflatoxin B1, aflatoxin B2, aflatoxin G1 and aflatoxin G2 (OTA, OTB, AFB1, AFB2, AFG1, AFG2) in red wines was investigated by HPLC/FLD after immunoaffinity column clean-up in 57 market samples produced in Sicily (Italy). The results showed a very low incidence of these mycotoxins in analysed samples, confirming the high degree of quality and safety of Sicilian red wines. The results indicated 71.9% and 64.9% positive samples for OTA and OTB respectively, with an average level of 0.13 μg l(-1), well below the European maximum permitted levels (MLs). The aflatoxin most frequently detected in the samples was AFG1, present in 57.9% of sample…
Determination of Aflatoxins and Ochratoxins in Sicilian Sweet Wines by High-Performance Liquid Chromatography with Fluorometric Detection and Immunoa…
2015
Ochratoxin A is the only mycotoxins with legal limits in the European Union for wine, by contrast, there is no EU legislation imposed for Aflatoxins and Ochratoxin B. A reproducible and sensitive analytical method for six mycotoxins: Ochratoxin A, Ochratoxin B, Aflatoxins B1, Aflatoxin B2, Aflatoxin G1 and Aflatoxin G2 was developed by using immunoaffinity column cleanup and HPLC-FLD method in 30 sweet wines produced in Sicily. This typical type of wine is manufactured from grapes grown in warmer climates, which have a higher sugar content; also, the over-ripening and the drying process of the grapes before fermentation conditions are responsible for the particular susceptibility of these b…
An overview of ochratoxin A in beer and wine.
2007
Ochratoxin A (OTA) is a mycotoxin produced mainly by several fungal species of the genera Aspergillus and Penicillium. This mycotoxin has been shown to be nephrotoxic, hepatotoxic, teratogenic and carcinogenic to animals and has been classified as a possible carcinogen to humans. OTA occurs in a variety of foods, including beer and wine. Reports on OTA occurrence in beer indicate that this is a worldwide problem due to the widespread consumption of this beverage. At present, the European Union (EU) has not set a maximum allowable limit (MAL) for this mycotoxin in beer, although there is a limit in barley and malt. Studies carried out in different countries agree in the high proportion of sa…
Comparison of stir bar sorptive extraction in the liquid and vapour phases, solvent-assisted flavour evaporation and headspace solid-phase microextra…
2017
The volatile fraction plays an important role on the organoleptic properties and overall acceptability of fruit juices. This work reports for first time a non-targeted approach for the analysis of the volatile fraction of fruit juice by stir bar sorptive extraction (SBSE[1]) in liquid and vapour phase (HSSE[2]) at three extraction times (30, 60, and 120 min), two temperatures (room temperature and 40 °C), and two sample volumes (5 and 10 mL). The resultant volatile profiles were compared with solvent-assisted flavour evaporation (SAFE[3]) and headspace solid-phase microextraction (HS-SPME[4]). SBSE and HSSE enabled the detection and identification of more compounds than HS-SPME and less tha…
Technological properties of Oenococcus oeni strains isolated from typical southern Italian wines.
2010
Aims: To isolate indigenous Oenococcus oeni strains suitable as starters for malolactic fermentation (MLF), using a reliable polyphasic approach. Methods and Results: Oenococcus oeni strains were isolated from Nero di Troia wines undergoing spontaneous MLF. Samples were taken at the end of alcoholic fermentation and during MLF. Wine samples were diluted in a sterile physiological solution and plated on MRS and on modified FT80. Identification of O. oeni strains was performed by a polymerase chain reaction (PCR) experiment using strain-specific primers. Strains were further grouped using a multiplex RAPD-PCR analysis. Then, six strains were inoculated in two wine-like media with two differe…
PLASMA ANTIOXIDANT CAPACITY STATUS AFTER RED WINE CONSUMPTION
2013
Several studies report that the plasma antioxidant capacity (PAC) increases after a single ingestion of red wine. However, data on the different behaviour of PAC after food intake in subjects of the same sex are still lacking. On the basis of these observations some investigations were undertaken in order to evaluate the effects of red wine intake on PAC in a homogeneous groups of healthy female volunteers (n=18). Additionally, the possible correlation between increase of PAC values and increase in uric acid levels was also assessed. PAC and uric acid concentrations were determined before wine intake and 50, 120 and 240 minutes thereafter. The results obtained following these studied highli…