[Show abstract][Hide abstract] ABSTRACT: PHOSPHITE CONTENT CHANGES CAUSED BY THE WINEMAKING TECHNIQUE AND THE YEAST STRAIN
From a normative viewpoint, the main reason to analyse phosphites in grape and wine lies in the phosetyl-Al residues and in their legal definition and chemical determination since phosphites are the main degradation product of that chemical. The current differences among EU, USA, Chine and India rules and relative interpretations recently caused some concern to wine exporters. So, we decided to go deeper into the matter with this winemaking experiment.
10 grape batches were processed using 2 yeast strains to produce 20 white and 20 red wines. Each batch was spiked with varied doses (max 100 mg/L) of H3PO3.
The white wines, processed according to a protective protocol against oxygen, had phosphite contents non significantly different from the juices, while phosphites were halved in the corresponding red wines, processed with lower protection and higher temperature. No differences were found between yeast strains.
[Show abstract][Hide abstract] ABSTRACT: The recent finding that grape tannin may contain significant amount of S-glutathionylated (GSH-3MH) and S-cysteinylated (Cys-3MH) precursors of the varietal thiols 3-mercapto-1-hexanol and 3-mercaptohexyl acetate, characteristic of Sauvignon blanc wines, offers new opportunities for enhancing the tropical aroma in fermented beverages. In this study this new hypothesis was investigated: Müller Thurgau (17 samples) and Sauvignon blanc (15 samples) grapes were fermented with and without addition of a selected grape tannin. As expected, the tannin-added juices were higher in precursors, and they produced wines with increased free thiols. Preliminary informal sensory tests confirmed that in particular the Sauvignon wines produced with the tannin addition were often richer with increased "fruity/green" notes than the corresponding reference wines. This outcome confirms that grape tannin addition prior to fermentation can fortify the level of these compounds.
[Show abstract][Hide abstract] ABSTRACT: Grape flavonols are involved in the phenomenon of copigmentation in red wines. These compounds are characterised by nutraceutical properties, have antioxidant activity and are studied for chemotaxonomy of grapes. In general, hybrid grapes are characterised by presence of polyphenols often qualitatively and quantitatively different from Vitis vinifera varieties. In this work, flavonols of 34 hybrid grape varieties (22 red and 12 white) produced by crossing of V. vinifera, Vitis riparia, Vitis labrusca, Vitis lincecumii and Vitis rupestris species, were studied. Compounds were characterised by combining different liquid chromatography/mass spectrometry (LC/MS) methods: precursor-ion and neutral-loss multiple-reaction-monitoring (MRM), and high-resolution mass spectrometry. Twenty-four glycoside flavonols were identified, including 4 quercetin, 5 myricetin, 4 kaempferol, 3 isorhamnetin, 2 laricitrin, 3 syringetin and 3 dihydroflavonol derivatives; myricetin hexoside-glucuronide, myricetin O-di-hexoside, syringetin O-di-hexoside, isorhamnetin rutinoside and kaempferol rutinoside were found in grape for the first time. Statistical analysis (PCA and cluster analysis) divided the samples in four groups on the basis of their flavonol profiles.
[Show abstract][Hide abstract] ABSTRACT: Currently, hybrid vine cultivars are not significantly used for wine making in Europe due to technological and legal reasons, nor as table grapes. VITENERGY1 is a project finalized to the evaluation and selection of grapevine hybrid cultivars suitable for production of biomasses destined to the production of bioenergies (e.g., bioethanol, cellulose). Anthocyanins, flavonoids, flavonols and seed oil triglyceride composition of 34 grape cultivars collected from the CRA-VIT vine germplasm collection were characterized to evaluate their production of by-products useful for the food, nutraceutical and pharmaceutical industry. 'Seibel 8357', 'Burdin 4077' and 'Bacò 30-12' grape had very high total anthocyanins content (between 3-5 g/kg) and total flavonoids (5-6 g/kg grape). 'Seibel 19881', 'Siebel 8745' and 'Seyve Villard 12-347' had total flavonol contents between 100-200 mg/kg; 'Bacò 1' showed high percentage of unsaturated triacylglycerols, and 'Seibel 10878' high seed oil production. The considerable commercial value of these bioactive compounds can play an important role in the economic sustainability of a vineyard dedicated also to production of biomass for energy uses.
No preview · Article · Apr 2014 · Acta horticulturae
[Show abstract][Hide abstract] ABSTRACT: Tannins are widely used in winemaking and food and beverage preparation for the many different contributions they can give to the overall characteristics of the product (e.g., colour stability, mouthfeel and aromatic composition). Varietal thiols and their precursors are one of the most interesting research areas in food science and a lot of effort has been put to further the current understanding on their formation and on the impact of different production strategies on their concentration in the final product. This paper reports the identification of two important thiol precursors (Cys-3MH and GSH-3MH) in commercial grape oenological tannins and, to the best of our knowledge, this information is reported here for the first time. This finding allows potential new perspectives in the winemaking and the food industry, offering the possibility of controlled additions of thiol precursors in pre-fermentative stages in order to tune the aroma profile of fermented products.
[Show abstract][Hide abstract] ABSTRACT: Background and AimsGrape maceration plays an important role in the formation of precursors of 3-mercaptohexan-1-ol (3MH), 3-S-glutathionyl mercaptohexan-1-ol (GSH-3MH) and 3-S-cysteinyl mercaptohexan-1-ol (Cys-3MH), but its contribution is still not well understood. The aim of this paper was to study the effect of oxygen deprivation on the concentration of these 3MH precursors during skin-contact maceration in two grape cultivars. Methods and ResultsMüller-Thurgau (n = 19) and Sauvignon Blanc (32) grapes from Trentino (Italy) were hand harvested and processed under the following conditions: reductive (air protected; 80 mg/kg sulfur dioxide, 80 mg/kg L-ascorbic acid, and 200 mg/kg dimethyl dicarbonate) and oxidative (no addition of adjuvants and air contact). After maceration, GSH-3MH and Cys-3MH were analysed by liquid chromatography-mass spectrometry and isotopic dilution. Conclusions
Both GSH-3MH and Cys-3MH were identified for the first time in Müller-Thurgau juices. Oxidative maceration increased the GSH-3MH concentration in 16 out of 19 Müller-Thurgau and in 23 out of 32 Sauvignon Blanc juices, while Cys-3MH was higher in 13 and 20 juices, respectively, of the two cultivars. Parametrical and non-parametrical statistical tests confirmed that oxidative maceration of Müller-Thurgau increased GSH-3MH concentration significantly (P < 0.01). Significance of the StudyThis work highlights the complexity of the mechanisms involved in the potential de novo formation of thiol precursors.
No preview · Article · Oct 2013 · Australian Journal of Grape and Wine Research
[Show abstract][Hide abstract] ABSTRACT: Aim : To evaluate the potential risk of ethyl carbamate (EC) formation in wine by studying its production kinetics at sub-optimal storage temperatures. Methods and results : The kinetics of EC formation was investigated in 60 white wines obtained from 6 varietal juices fermented with 10 yeast strains. The wines were analysed for their urea content at bottling, then EC formation was monitored during in-bottle storage at < 12 degrees C for 150 days followed by 152 days at 40 degrees C. Storage at < 12 degrees C had no effect on EC formation, regardless of initial urea content; however, at 40 degrees C we found a positive correlation between initial urea content and final EC content. Conclusion : Urea content higher than 20 mg/L in wine kept at 40 degrees C can produce from 15 up to 30 mu g/L EC in less than 5 days. Two yeast strains, La Claire SP665 and Maurivin Platinum, minimised the urea in wine, reducing the risk of EC formation. Significance and impact of the study: The temperatures used in this study can be accidentally - but easily - reached during sub-optimal wine storage and shipping, and in the presence of substantial amounts of urea, the EC level can exceed the warning levels established by some countries in just a few days. The paper confirms the importance of minimising urea production in wine and controlling temperature during storage and shipping.
No preview · Article · Jan 2013 · Journal International des Sciences de la Vigne et du Vin
[Show abstract][Hide abstract] ABSTRACT: The extraction of varietal terpene, sesquiterpene, norisoprenoid and benzenoid aroma compounds in free and bound form as well as of C6 aroma compounds was monitored by GC-MSMS during the membrane pressing of 3 Gewúrztraminer grapes after a skin-contact phase. The content of most compounds is higher in the fractions obtained at higher pressure and the levels reached by geraniol, linalool, citronellol, damascenone, beta-ionone and farnesol could contribute to the floral aroma of juice. About 66 % of free and bound rose oxide is extracted with the last third of juice.
[Show abstract][Hide abstract] ABSTRACT: The anthocyanins of 21 hybrid red varieties produced by crossing V. vinifera, V. riparia, V. labrusca, V. lincecumii and V. rupestris species, the profiles for which have not yet been reported, were studied. Profiles were determined by LC/DAD, and identification of single anthocyanins was confirmed by LC/MS precursor-ion analysis. Anthocyanidin precursors (pelargonidin at m/z 271, dephinidin at m/z 303, cyanidin at m/z 287, petunidin at m/z 317, peonidin at m/z 301, and malvidin at m/z 331) and precursors of monoglucoside compounds allowed 24 different compounds to be identified. Analysis of precursor ions of monoglucoside anthocyanins at low capillary voltage revealed the signals of diglucosides only, providing a very selective method for analysis of diglucoside anthocyanins in grape. According to anthocyanin profile, the samples were subdivided into two groups: one characterized by the substantial presence of diglucoside compounds (particularly Seyve Villard 23-399 and Seyve Villard 23-369) and one by the scarce presence or practical absence of diglucosides (Seibel 10878, Burdin 4077, and Galibert 238-35). Particularly interesting for producing anthocyanin for the natural colorant industry were the varieties Siebel 8357, Bacò 30-12 and Terzi 100-31.
No preview · Article · Jun 2012 · Analytica chimica acta
[Show abstract][Hide abstract] ABSTRACT: Surface-enhanced laser desorption and ionization time-of-flight mass spectrometry (SELDI-TOF/MS), a laboratory-friendly technique, is used to identify biomarkers for cancer. The aim of the present study was to explore the application of SELDI proteomic patterns in serum for distinguishing between cases of pancreatic cancer, chronic pancreatitis, type 2 diabetes mellitus and healthy controls.
Sera from 12 healthy controls, 24 patients with type 2 diabetes mellitus, 126 with pancreatic cancer, including 84 with diabetes, and 61 with chronic pancreatitis, 32 of which were diabetics, were analyzed using SELDI-TOF/MS. Spectra (IMAC-30) were clustered and classified using Biomarker Wizard and Biomarker Pattern software.
Two decision tree classification algorithms, one with and one without CA 19-9, were constructed. In the absence of CA 19-9, the splitting protein peaks were: m/z 1526, 1211, and 3519; when CA 19-9 was used in the analysis, it replaced the m/z 3519 splitter. The two algorithms performed equally for classifying patients. A classification tree that considered diabetic patients only was constructed; the main splitters were: 1211, CA 19-9, 7903, 3359, 1802. With this algorithm, 100% of patients with type 2 diabetes mellitus, 97% with chronic pancreatitis and 77% of patients with pancreatic cancer were correctly classified. SELDI-TOF/MS features improved the diagnostic accuracy of CA 19-9 (AUC = 0.883 for CA 19-9; AUC = 0.935 for CA 19-9 and SELDI-TOF/MS features combined).
SELDI-TOF/MS allows identification of new peptides which, in addition to CA 19-9, enable the correct classification of the vast majority of patients with pancreatic cancer, which can be distinguished from patients with chronic pancreatitis or type 2 diabetes mellitus.
Full-text · Article · Jun 2009 · Clinical Chemistry and Laboratory Medicine
[Show abstract][Hide abstract] ABSTRACT: Baltic amber contains high levels of succinic acid, most of which is part of the polymer framework, and only recently has the presence of microcrystals of free succinic acid been documented by scanning electron microscopy and X-ray diffraction analysis. The determination of succinic acid can be used for an easy identification of Baltic amber among other fossil resins and to distinguish it from imitations, widely diffused on the market, produced with natural or modified recent or sub-fossil resins, such as copals. We report here a simple method, based on negative ion electrospray ionization mass spectrometry, for evaluating the free succinic acid content in water/methanol extracts of ambers from different origin, using a sample of about 20 mg. The limit of quantification is better than 1 ppm and, when applied to a set of amber samples of different origin, it was able to distinguish those of Baltic origin (showing free succinic acid levels in the range 50-400 ppm) from the others (for which succinic acid was undetectable, i.e. at levels lower than 1 ppm).
No preview · Article · Feb 2009 · Rapid Communications in Mass Spectrometry
[Show abstract][Hide abstract] ABSTRACT: The paper presents the application of a method based on coupled gas chromatography-mass spectrometry, using an isotopically labelled internal standard for the quantitative analysis of benzene (B), toluene (T), ethyl benzene (E), and o-, m-, p-xylenes (X). Their atmospheric concentrations were determined based on short-term sampling, in different sites of Cluj-Napoca, a highly populated urban centre in N-W Romania, with numerous and diversified road vehicles with internal combustion engines. The method is relatively inexpensive and simple and shows good precision and linearity in the ranges of 7–60 μg/m3
(B), 13–90 μg/m3
(T), 7–50 μg/m3
(E), 10–70 μg/m3
(X-m,p), and 20–130 μg/m3
(X-o). The limits of quantitation/detection of the method LOQ/LOD are of 10/5 μg/m3
(Xo), 5/3 μg/m3
(B, E, X-m,p), and of 3/1 μg/m3 (T), respectively.
Full-text · Article · Jan 2009 · Journal of Environmental and Public Health
[Show abstract][Hide abstract] ABSTRACT: Amber is a fossil resin constituted of organic polymers derived through complex maturation processes of the original plant resin. A classification of eight samples of amber of different geological age (Miocene to Triassic) and geographical origin is here proposed using direct mass spectrometric techniques, i.e. laser desorption ionization (LDI), atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization (APPI), in order to obtain a fingerprint related to the amber origin. Differences and similarities were detected among the spectra with the four methods, showing quite complex spectra, full of ionic species in the mass range investigated (up to m/z 2000). The evaluation required statistical analysis involving multivariate techniques. Cluster analysis or principal component analysis (PCA) generally did not show a clear clustering with respect to the age of samples, except for the APPI method, which allowed a satisfying clustering. Using the total ion current (TIC) obtained by the different analytical approaches on equal quantities of the different amber samples and plotted against the age, the only significant correlation appeared to be that involving APPI. To validate the method, four amber samples from Cretaceous of Spain were analyzed. Also in this case a significant correlation with age was found only with APPI data. PCA obtained with TIC values from all the MS methods showed a fair grouping of samples, according to their age. Three main clusters could be detected, belonging to younger, intermediate and older fossil resins, respectively. This MS analysis on crude amber, either solid or extract, followed by appropriate multivariate statistical evaluation, can provide useful information on amber age. The best results are those obtained by APPI, indicating that the quantity of amber soluble components that can be photoionized decreases with increasing age, in agreement with the formation of highly stable, insoluble polymers.
Full-text · Article · Mar 2008 · Rapid Communications in Mass Spectrometry
[Show abstract][Hide abstract] ABSTRACT: In an investigation devoted to the search for plasma markers for colorectal cancer (CRC), carried out by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry, a series of overexpressed peptides were identified in the plasma of patients. Among them the peptide with molecular weight 903 Da was the most abundant one, with a mean +/- (SD) relative abundance of 37 +/- 17% and a frequency over 60%. Interestingly, also in plasma samples of ten subjects affected by familial adenomatous polyposis (FAP), the peptide with molecular weight 903 was overexpressed. In this investigation, MALDI/MS/MS experiments were carried out on the ion at m/z 904 detected in the MALDI mass spectra of CRC and FAP patients. The data analysis by SwissProt.2007.01.09 indicates that this peptide is due to the sequence RPPGFSPF, found in the kininogen-1 precursor, which is an alpha-2-thiol proteinase inhibitor. In the case of subjects affected by a particular FAP syndrome, the MALDI/MS/MS spectra were quite different from those obtained from CRC and FAP patients. In fact, two sequences have been evidenced: RPPGFSPF belonging to kininogen-1 precursor, and PRKSSSSR belonging to Forkhead box protein 01A.
Full-text · Article · Dec 2007 · Journal of Mass Spectrometry
[Show abstract][Hide abstract] ABSTRACT: The behaviour of some N,N'-disubstituted hexahydropyrimidines, a class of naturally occurring compounds of biological and biomedical interest, has been studied in both electron ionization (EI) and electrospray ionization (ESI) modes coupled with collisional experiments (ESI-MSn). In both techniques, the [M-H]+ ions are highly abundant, even if their formation is generated by two different mechanisms, i.e. H. loss from the M+. species in the case of EI and hydride (H-) abstraction from the molecules in the case of ESI. Furthermore, due to the low, step-by-step internal energy deposition typical of collisional experiments performed in an ion trap mass spectrometer, different fragment ions were observed in EI and ESI-MSn collisions. In both cases, the ions can be related to the original structure and allow us to identify the positions in which the different substituents are present.
Full-text · Article · Mar 2006 · Rapid Communications in Mass Spectrometry