Arsenic content in some Spanish wines Influence of the wine-making technique on arsenic content in musts and wines

Summary All of the essential technological means of treating grapes, must and wine were examined systematically. The main reasons for the differences in the arsenic (As) content of rosé and red wines are explained. In this study a relationship has been found between the As level and the wine-making technique. Rosé wines contain more As than red wines because they require a shorter period of contact with the skins. In order to prove this, the average values for the rosé and red wine samples from the same winery were compared.

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Arsen-Gehalt in einigen spanischen Weinen. Beeinflussung des Arsengehaltes von Most und Weinen durch kellertechnische Maßnahmen

Zusammenfassung Durch systematische Überprüfung aller wesentlichen kellertechnischen Schritte der Most- und Weinbehandlung wurden die Hauptursachen der großen Unterschiede im Arsengehalt von Weinen aufgeklärt. Dieser vermindert sich schon beim ersten Abstich nach der Gärung und weiterhin durch die Entfernung der Trübstoffe. Bei starkstreuenden Gehalten zeigte sich, daß die Rotweine geringere Werte als die Roséweine aufwiesen. Außerdem unterschieden sich vergleichbare Weine aus verschiedenen Betrieben deutlich im Arsengehalt.

     

Resveratrol content in wines and musts from the south of Spain

Trans- and cis-resveratrol and their glycosides have been determined in eighty-one samples including musts, substrate wines and commercial wines (red, white and Sherry-type wines) from the south of Spain. Sample analysis was performed using a direct injection technique by HPLC with photodiode array detector. Prior to the injection, the sample was filtered using a filter selected through a complete filtration study. Climatological data can affect total resveratrol levels. Values obtained for total resveratrol content in red wines ranged from 0.038 mg/l in a dry year to 1.164 mg/l for a normal year. The pressure applied to the berries to obtain must, has been object of study in order to ascertain its influence in final resveratrol content. For the same vintage, the total resveratrol content ranged from 0.032 mg/l in a wine, obtained from the lighest pressure musts, to 0.873 mg/l for those obtained from the highest pressure musts. No resveratrol has been found in Sherry wines, being present in the substrate wines in all cases.     

Influence of co-winemaking technique in sensory characteristics of new Spanish red wines

The influence of co-winemaking technique on the sensory profile of wines made from minority red grape varieties cultivated in La Mancha region (Spain) was researched by sensory characterization. Sensory analysis was carried out by a panel of 15 experienced wine-testers, all with a previous training. The sensory profiles of monovarietal red wines—Cencibel, Bobal and Moravia Agria—were studied and also the effects of co-winemaking technique on sensory characteristics were evaluated. Co-winemaking red wines were obtained by blending (a) Cencibel (50%) + Bobal (50%); (b) Cencibel (50%) + Moravía Agria (50%) and (c) the three grape varieties Cencibel (33%) + Bobal (33%) + Moravía Agria (33%). The co-winemaking technique intensified the principal sensory properties of monovarietal wines and the wines proved to be more complex than the monovarietal wines.     

Influence of wine-making protocol and fining agents on the evolution of the anthocyanin content,colour and general organoleptic quality of Vinhão wines

This paper reports the evolution, over two years, of the anthocyanin content, colour and organoleptic quality of red wines prepared from a single batch of Vinhão grapes by means of three different protocols (maceration/fermentation with conventional pumping-over or in rotary vats, and fermentation after initial carbonic maceration), with and without the use of four different fining agents (polyvinylpolypyrrolidine, gelatin, egg albumin, and casein). Carbonic maceration led to lower anthocyanin levels and less intense coloration than the other two methods immediately following vinification, but during storage the carbonic maceration wines underwent less colour degradation than the others, so that after two years the colour density differences among the three were negligible. Wines treated with fining agents tended to have somewhat lower anthocyanin levels and, especially in the case of PVPP, less intense colouration than untreated wines, and their colour was at best only marginally more stable during storage, but they nevertheless generally achieved higher panel ratings for organoleptic quality than untreated wines, especially as regards taste.     

Metal ion content of some Greek wines

The concentrations of fourteen metal ions were determined in 113 commercial Greek wines by atomic absorption or emission spectroscopy. The ions of K (1440 mg l⁻¹), Na (27.7 mg l⁻¹), Mg (101 mg l⁻¹) and Ca (31.9 mg l⁻¹) were found in greatest concentration. Among the others, mean Fe and Al concentrations were 3.51 and 2.35 mg l⁻¹, respectively; Cu, Zn and Pb were between 0.20 and 0.41 mg l⁻¹; and Li, Ni, Cr, Co and Cd were < 0.10 mg l⁻¹. These results are compared critically with published data on wines of widely differing origins.     

Influence of atmospheric pollution on the lead content of wines

Over the last century, the atmospheric fallout of anthropogenic lead has evolved with time, as a function of the chronological variability of transient lead inputs from both industrial and gasoline origins. This variability has been mostly documented over North America and northern Europe. In this study we used ICP-MS for the determination of lead isotope ratios and showed that a series of French wines followed the evolution of the environmental lead record over the last century. We observe the same three-step chronological evolution of the lead isotopic composition, which reflects a western European signal. In the post 1950 vintages, the lead isotope composition reflects a dominant atmospheric fallout. Since ~1950, Pb concentrations have been much lower than before, decreasing consistently from ~0.25mg l^-1 around the early 1950s, down to less than ~0.1mg l^-1 nowadays. Reflecting the airborne pollution, the lead isotopic signature is also specific of the continental origin of the wines and lead isotope ratios determination in wines appears to be a promising tool for certifying wine authenticity.     

Arsenic content of some edible mushroom species

The arsenic contents of 162 fruit body samples of 37 common edible mushroom taxa were analyzed. The samples were gathered from different habitats of Hungary (mainly from mountains) between 1984 and 1999. The arsenic content of the samples was measured by the inductively coupled plasma spectrometry method. Very low [lower than 0.05 mg/kg dry matter (DM)] concentrations were found in the samples of 13 taxa, while higher (or very high) contents were quantified in other common taxa (the highest arsenic content was recorded in the fruit body of Laccaria amethysthea at 146.9 mg/kg DM). The species of eight genera (Agaricus, Calvatia, Collybia, Laccaria, Langermannia, Lepista, Lycoperdon, Macrolepiota) belong to the so-called accumulating taxa, and this tendency is evident on all habitats. This arsenic accumulation capability is found in two orders of Basidiomycetes (Agaricales and Gasteromycetales), which is to say this phenomenon occurs in the families Agaricaceae, Tricholomataceae and Gasteromycetaceae. The accumulating taxa found all have a saprotrophic type of nutrition; arsenic accumulation is not detectable in xilophagous or in mycorrhizal species. The consumption of the accumulating species found has only a low toxicological risk for three reasons: the consumed fresh fruit bodies contain about a tenfold lower arsenic level than the dried ones, the majority of arsenic occurs not in poisonous inorganic, but in less dangerous (or not poisonous) organic forms, and the frequency of consumption is low.     

Quantitative determination of Botrytis laccase in musts and wines by the syringaldazine test

The syringaldazine assay was adapted for quantitative determination of laccase (EC 1.10.3.2) activity from Botrytis cinerea Pers in musts and new wines. This colorimetric method is fast, specific and sensitive. It makes it possible to assess the level of contamination of crops by Botrytis cinerea. The assay can be performed in the presence of tyrosinase but the phenolic compounds of the grape must first be eliminated because of their inhibition of syringaldazine oxidation by laccase. When measured in botrytised grape, laccase activity is related to the stages of development of the fungus.     

Ochratoxin A in wines,musts and grape juices from Spain

A survey on the occurrence of ochratoxin A (OTA) in 240 grape‐based beverages was carried out. Red and white wines from four different Spanish Designations of Origin (n = 160), musts (n = 20), grape juices (n = 10), ordinary wines (n = 20), special wines (Malaga, muscatel, sherry, vermouth, etc) (n = 20) and sparkling wines (n = 10) were assayed for OTA content using immunoaffinity column clean‐up and high‐performance liquid chromatography with fluorimetric detection (detection limit 0.05 µg l^?1). Forty‐three (17.9%) of the samples tested contained detectable levels of OTA. The overall mean OTA concentration in red and white wines of Designations of Origin was 0.30 and 0.18 µg l^?1 respectively (ranges 0.05–3.19 and 0.05–1.13 µg l^?1 respectively). The percentage of wine samples with detectable amounts of OTA was higher for red (18.3%) than for white (10%) wines. OTA was also found in two of 10 red ordinary wines (0.68 and 4.24 µg l^?1), whereas none of 10 white ordinary wines contained OTA. The mean OTA amount detected in sparkling wines was 0.44 µg l^?1 (range 0.14–0.71 µg l^?1). Two of 20 must samples contained OTA at low levels (0.08 and 0.18 µg l^?1), while none of 10 grape juice samples contained OTA. Highest amounts of OTA were found in special wines (45%), with a maximum of 15.25 µg l^?1 in a muscatel sample. Copyright © 2004 Society of Chemical Industry     

Differentiation of some Spanish wines according to variety and region based on their anthocyanin composition

On the basis of anthocyanin composition, and using the multivariate statistical methods of principal component and stepwise discriminant analyses, differentiation of 23 Spanish wines according to grape variety and wine-growing region was procured. Acylated derivatives, particularly of malvidin-3-glucoside, appeared as key factors in this characterisation. Thus, malvidin 3-acetyl-glucoside was the variable with the largest discriminating power in the differentiation of varieties. Larger relative concentrations in this compound were found in the wines of Merlot and Cabernet Sauvignon. In addition, a neat separation of wines according to production area is obtained in terms of their relative contents of the P-coumaric acid ester of malvidin 3-glucoside.     

Phenolic compounds and colour stability of Vinhão wines: Influence of wine-making protocol and fining agents

The purpose of this work is to study the evolution, over three selected harvests, of phenolic compounds and colour stability of red wines produced in the north of Portugal by means of two wine-making processes (conventional maceration/fermentation and fermentation after initial carbonic maceration), with and without the use of four different fining agents (polyvinylpolypyrrolidine, gelatine, egg albumin, and casein). In general, it was observed that wines obtained by conventional maceration/fermentation (PO) present the highest colour intensity and polyphenolic content (total and monomeric anthocyanins, flavan-3-ol monomers and polymers), and the lowest orange–red hue, immediately following vinification. Nevertheless, carbonic maceration (CM) afforded wines with most stability in colour density, for 26 months’ storage. Different evolutions of anthocyanins and of flavan-3-ol monomers (catechins) and polymers (procyanidins) in PO and CM protocols during storage were observed. Decrease of anthocyanins and flavan-3-ol dimmers were, in general, more remarkable in PO wines. Monomers and trimers underwent a rise, especially in CM wines. Wines treated with fining agents tended to have somewhat lower anthocyanins levels, and especially in the case of PVPP, less intense colouration than untreated wines. Principal component analysis (PCA) revealed that catechins and some procyanidins are mainly responsible for the separation and evolution of wines during storage according polyphenolic composition. Partial least squares (PLS) regression models confirm that colour density in wines from PO and CM protocols explains a high proportion of the variance in hue, chemical age, IFC and anthocyanins and a prediction model has been built.     

Influence of skin maceration time on the proanthocyanidin content of red wines

This paper studies the influence of different maceration times (5, 10 and 20?days) during the elaboration of Monastrell, Syrah and Cabernet Sauvignon wines on the proanthocyanidin composition and sensory characteristics of the resulting wines. Significant differences were found between wines elaborated with different maceration times. The different maceration times affected the qualitative and quantitative proanthocyanidin composition of the resulting wines, the total proanthocyanidin content increasing with the maceration time. The percentage of skin-derived proanthocyanidins was always higher than that of seed-derived proanthocyanidins for all the maceration time assayed, although the contribution of seed proanthocyanidins to wine composition increased for the longest maceration time. However, the study also shows that differences exist between wines elaborated with the same maceration time but with different varieties, indicating the importance of two factors, the initial concentration of grape phenolic compounds and their extractability, on the final concentration of wine proanthocyanidins. In this way, the wines obtained from Syrah had the highest proanthocyanidin content compared with the corresponding wines from Cabernet Sauvignon or Monastrell, even though Syrah grapes presented the lowest proanthocyanidin content in skins and similar seed proanthocyanidin content to Cabernet and Monastrell grapes.     

Contribution to the study of ochratoxin A in Spanish wines.

With the aim of assessing ochratoxin A (OTA) contamination in wines from a Spanish northern region and the influence of harvest conditions, the following samples were analysed: 40 wines (28 red and 12 white) obtained from grapes cultivated in three different places of the northern Spanish region of Navarra, but in different years, 20 samples in 1997 and 20 in 1998. Wine samples were provided by a viticultural experimental station with very consistent and controlled cultural and enological practices. A high-performance liquid chromatography (HPLC) method with fluorescence detection and immunoaffinity columns was employed (LOD = 0.05 ng ml(-1); method recovery = 101%). Eighty five per cent of the samples from 1997 showed OTA levels >0.05 ng ml(-1) (range 0.056-0.316 ng ml(-1)) and 15% of the samples from 1998 showed OTA levels above the LOD (range 0.074-0.193 ng ml(-1)). Averages detected in 1997 positive samples were 0.185 ng OTA ml(-1) wine (SD = 0.023) in white wine samples (n = 6) and 0.160 ng ml(-1) (SD = 0.119) in the red wine samples (n = 11). These differences between contamination by OTA in the samples from the two different years were attributed to the different quality of the grapes, due to the bad climate in 1997. The possibility of the loss of the mycotoxin was excluded by the analysis of OTA in contaminated wine during 12 months. This study showed that OTA is stable in wine for at least 1 year.     

Comparison of the total antioxidant status of Bohemian wines during the wine-making process

The total antioxidant status (TAS) of two white and two blue wine varieties from the ?ernoseky wine region (North Bohemia, Czech Republic) during the wine-making process was assessed by measurement with different radical scavenging assays: ABTS, DPPH and DMPD. Significant differences in the antioxidant activity between white and red wines were confirmed and changes of TAS during the wine production process were demonstrated. Moreover, differences were ascertained between individual varieties of red wine. No statistically significant relationship between the results provided by the ABTS and DPPH assays was found, obviously due to the fact that each phenolic substance in wine gives a different response to each specific radical used in the assay. The results obtained supported the assumption that variety plays a considerable role in TAS; the blue wine varieties showed a much higher TAS than did the white wines. The ABTS assay showed higher EQA (equivalents of ascorbic acid, mg/ml) values than the DPPH assay.     

Influence of yeast strain and pH on pyruvic acid content of wines

Pyruvic acid content of wines was investigated on laboratory and pilot-plant scale and found to be strongly influenced by the strain of yeast used to conduct the fermentation, and pH of the medium, with high pH correlating with high pyruvic acid content. Results obtained with artificial medium confirmed those obtained with grape juice. Yeast strain and pH appear to be the two most important factors influencing pyruvic acid content of wines, and their biochemical and oenological significance is discussed.     

Effect of grape pectic enzyme treatment on foaming properties of white musts and wines

White grapes of three different varieties (Macabeo, Xarel.lo and Parellada), which are used in Spanish sparkling wines production (O.A.C. Cava), were treated with a pectic-enzyme preparation on an industrial scale. Foam capacity (foamability (HM), Bickerman coefficient (Σ), foam stability time (TS) and surface tension (ST)) of nine musts from pectic enzyme treated grapes and their corresponding wines were compared to their respective control samples. The HM, Σ, and TS values decreased and ST increased in most of the treated samples. This could be the case, because samples from enzyme-treated grapes had lower protein and polysaccharide contents and higher values of polyphenols than untreated samples: HM and Σ were positively correlated with proteins and polysaccharides and negatively with ST; polyphenol contents had a negative relationship with TS values.     

Biogenic amine content of red Spanish wines: comparison of a direct ELISA and an HPLC method for the determination of histamine in wines

Biogenic amines were determined in 61 commercial red Spanish wines from various winemaking areas and elaborated with different vinification/ageing procedures. Biogenic amines (histamine, methylamine, ethylamine, tyramine, phenylethylamine, putrescine and cadaverine) analysis was carried out by RP-HPLC with o-phthaldialdehyde precolumn derivatization and fluorescence detection. Overall, histamine and putrescine were the most prevalent amines, being present in 75% and 71%, respectively, of the wines, followed by tyramine (56% of the wines). There were no significant differences between biogenic amine levels and ageing characteristics of the wines tested. Moreover, it was found that amines suspected to cause toxicological effects (histamine, tyramine and phenylethylamine) are no cause for concern in these Spanish wines as they are present in amounts well below the limit considered as physiological. A commercial competitive direct ELISA immunoassay method specific for the detection of histamine has also tested on these wines and the results were compared with the RP-HPLC method. Both methods showed a good agreement for histamine analysis of wines.     

不同方法对大米中无机砷含量测定结果的影响

目的 建立不同方法测定大米和以大米为原料的食品中无机砷的含量,并对结果进行比较.方法 用0.15 mol/L硝酸或0.3 mol/L三氟乙酸作为提取液,95℃下热辅助提取2h、75℃下超声提取2h或90℃下微波辅助提取lh,提取物经阴离子交换柱X-100(250 mm×4.1 mm,10 μm)分离,电感耦合等离子体-质谱(ICP-MS)和氢化物发生-原子荧光光谱(HG-AFS)分别测定.结果 两种方法测定无机砷含量,加标回收率分别在94.8％～111.7％、91.9％～ 96.0％之间,相对标准偏差均小于5.8％,应用这两种方法对质控样品米粉SRM 1568a和大米样品进行测定,结果协同性良好.结论 两种方法均可简单、准确、快速的测定大米中的无机砷,结果比较差异无统计学意义.     

Inducing malolactic fermentation in Chardonnay musts and wines using different strains of Oenococcus oeni

Malolactic fermentations (MLF) were induced in a commercially prepared Washington State Chardonnay must to evaluate the influence of timing of inoculation and pre-culture conditions of Oenococcus oeni strains MCW, EQ-54, and WS-8. The must (pH 3.62, 21.5°Brix) was divided into lots and inoculated with Saccharomyces cerevisiae strain CY3079. Strains of O. oeni were pre-cultured by growing in diluted juice or by re-hydration of freeze-dried strains. Bacteria were inoculated into the musts before (Day 0) or after completion of the alcoholic fermentation (Day 22). Yeast populations exceeded 10⁷cfu/mL in all fermentations that proceeded to dryness. However, the viability of most strains of O. oeni quickly declined after inoculation regardless of the timing of inoculation or the strain used. MLF was induced in the wines inoculated with strains EQ-54 and WS-8 but not with MCW, and the rate depended on the time of inoculation. The method used to prepare bacterial starter cultures had no apparent influence on the completion of MLF. Values for volatile acidity were slightly higher (P< 0.05) in wines inoculated with O. oeni before alcoholic fermentation compared with those inoculated after alcoholic fermentation.