Purification and characterization of a cysteine protease in Vitis vinifera L. grapes (Macabeo variety)

Protease from Vitis vinifera L. (Macabeo variety) was partially purified (15-fold) by PVPP and Sephadex gel G-100 filtration and characterized afterwards by gel electrophoresis. The enzyme had an optimum pH of 2.50 and a Km value of 0.32 mM for haemoglobin. The results of applying diagnostic inhibitors indicated that the enzyme studied was a cysteine-protease.     

Effect of chemical treatments on ochratoxigenic fungi and common mycobiota of grapes (Vitis vinifera)

The effect of the application of two fungicides (cyprodinil alone and a mixture of cyprodinil and fludioxonil) on the mycoflora of grapes, especially ochratoxigenic fungi, was studied. Different doses and application times were analyzed. Grape mycobiota was isolated and identified, and the classification of black aspergilli was carried out. We found that 81.7% of the isolates belonged to Aspergillus niger aggregate and 18.3% to Aspergillus carbonarius. The ability to produce ochratoxin A (OTA) was studied on Czapek yeast extract agar (CYA) medium in 238 isolates. Most A. carbonarius (97.2%) produced detectable amounts of OTA, while only 2.9% of the A. niger aggregate were OTA producers. Most of the isolates (58%) produced less than 2.5 microg OTA per g of CYA. That, together with the highest levels of black aspergilli detected near harvest, proved the reported theory that they are primarily responsible for OTA in grapes. The fungicides studied had a significant effect on black aspergilli in three of the four vineyards sampled, as the natural increase of black aspergilli when approaching harvest was in general lower in all the fields treated with fungicides as compared to the control treatment. A mixture of cyprodinil (37.5%) and fludioxonil (25%) applied at veraison and 21 days before harvest was the most effective treatment to prevent black aspergilli in grapes, together with a single application of this mixture at veraison followed by an application of cyprodinil (50%) 21 days before harvest. No OTA was detected in musts (n=112) produced from either the control treatment or the treated grapes.     

Rate of degradation of λ-cyhalothrin and methomyl in grapes (Vitis vinifera L.)

Rates of degradation of λ-cyhalothrin and methomyl residues in grape are reported. The dissipation behavior of both insecticides followed first-order rate kinetics with similar patterns at standard and double-dose applications. Residues of λ-cyhalothrin were lost with pre-harvest intervals (PHI) of 12.0-12.5 and 15.0-15.5 days, corresponding to the applications at 25 and 50 g a.i. ha^-1, respectively. In the case of methomyl, residues were lost with PHI of 55.0 and 61.0 days, following applications at 1 and 2 kg a.i. ha^-1, respectively. The PHI, recommended on the basis of the experimental results, was shown to be effective in minimizing residue load of these insecticides below their maximum residue limits (MRLs) in vineyard samples.     

Factors influencing sensory quality in red wines of the variety Aghiorghitiko (Vitis vinifera L.) from Nemea

Sensory quality in wines from the indigenous Greek cultivar Aghiorghitiko of Nemea, in 2 years, was studied with multivariate modelling. The appearance, aroma and oral attributes were assessed separately using rank-rating in 13 red Nemea wines, dominated (10 of 13) by Aghiorghitiko, and headspace congeners (51) quantified by solid phase microextraction with gas chromatography. Partial least squares regression (PLS) and discriminant PLS studied relationships between sensory data and congeners, viticultural and oenological data, producers and influence of wood maturations, respectively. Principal component analysis (PCA) spaces for aroma (11 attributes; 64% variance, 3 PCs), congeners (51; 72%, 7 PCs) and oral characters (13 attributes; 77%, 3 PCs) showed similarities in product clustering. Modelling showed clear relationships between sensory character and plant density, wood maturation and producer, respectively. Sensory characters in Aghiorghitiko wines were primarily differentiated by oak maturation and producer influences. A part of the results of this work was presented at the Second International Symposium on the Evaluation and Exploitation of Grapes of Corresponding Terroir through Winemaking and Commercialisation of Wines, 1–3 June 2006, Santorini.     

Cell wall anthocyanin adsorption by different Saccharomyces strains during the fermentation of Vitis vinifera L. cv Graciano grapes

This work reports the adsorption of anthocyanins by the cell walls of different strains of Saccharomyces during the production of red wine from Vitis vinifera L. cv Graciano grapes. The anthocyanin derivative contents of the yeast cell walls were substantially different to those of their corresponding wines. Cinnamoyl derivatives (6-p-coumaroyl and 6-caffeoyl) were strongly adsorbed while vitisins (adducts of pyruvic acid and acetaldehyde) were weakly adsorbed. The mean total anthocyanin concentration of the wines was 507.64 mg L^?1 with the following distribution: 3-glucosides (3G), 82.2%; vitisins, 0.97%; 6-acetyl derivatives, 7.44%; 6-caffeoyl derivatives, 1.81%; and 6-p-coumaroyl derivatives, 7.54%. A mean of 18.57 mg of anthocyanins were adsorbed by the lees corresponding to 1 L of wine; this quantity was distributed: 3G, 52.60%; vitisins, 0.15%; 6-acetyl derivatives, 4.06%; 6-caffeoyl derivatives, 6.61%; and 6-p-coumaroyl derivatives, 36.58%. Large differences were seen between the different yeast strains examined with respect to the quantities of anthocyanins adsorbed. The mean adsorption percentage was 3.67%, but this varied between 1.60% (strain 3VA) and 5.85% (strain 9CV). The adsorption percentage of 6-p-coumaroyl derivates for strain 3VA (7.61%) was fourfold less than that of 9CV (28.37%). Strains 2EV and 3VA showed no vitisin adsorption.     

Capsaicin,an inhibitor of Ochratoxin A production by Aspergillus section Nigri strains in grapes (Vitis vinifera L.)

ABSTRACT

Food decay by spoilage fungi leads to significant economic losses and hazards to consumers’ health due to the potential of mycotoxin occurrence. Ochratoxin A (OTA) is a mycotoxin known as nephrotoxic and carcinogenic to humans. Natural capsaicin was evaluated for its effectiveness against the growth of five Aspergillus section Nigri strains and accumulation of OTA in inoculated black grapes. Results showed that capsaicin was effective in inhibiting fungal growth and OTA production by new four Aspergillus section Nigri strains (ATHUM 6997, 6998, 6999, 7000) and by Aspergillus carbonarius as well. Moreover, capsaicin addition exhibited maximum inhibition of OTA produced by ATHUM 6997, 6998, 6999, and 7000 in black grapes at 28.9%, 8.6%, 68.4%, and 78.1%, respectively. Inhibition percentage of OTA production by A. carbonarius in grapes treated with capsaicin was estimated at 61.5%. These results suggest that capsaicin influences the OTA biosynthesis pathway of all Aspergillus section Nigri strains and therefore could be used as an effective natural preservative against OTA contamination of vineyards. Risk assessment revealed that when grapes are treated with capsaicin, consumers are less exposed to OTA.     

Comparison of major volatile compounds from Riesling and Cabernet Sauvignon grapes (Vitis vinifera L.) from fruitset to harvest

Background and Aims: Research on concentration changes of volatile compounds during grape physiological development has focused on the period from veraison to harvest. This study compared the developmental changes in the major volatile compounds released after the crushing of Riesling and Cabernet Sauvignon grapes sampled from fruitset to harvest during the 2007–2008 season. Methods and Results: Volatile compounds were extracted from the headspace of crushed Riesling and Cabernet Sauvignon grapes sampled throughout berry development using solid-phase microextraction and analysed by gas chromatography–mass spectrometry. A multivariate statistical approach coupled with analysis of variance was applied to compare the developmental changes in volatile compounds for the two cultivars. In both cultivars, E-2-hexenal was the most abundant volatile compound, and it showed a significant increase in concentration after veraison. Benzene derivatives discriminated ripe Cabernet Sauvignon grapes, whereas monoterpenes and sesquiterpenes discriminated both cultivars pre-veraison with a broader range of terpenes observed in the Cabernet Sauvignon samples compared with the Riesling samples. At veraison, terpene production in both varieties was low, but Riesling grapes produced some terpenes (geraniol and α-muurolene) post-veraison. Generally, esters and aldehydes were the major class of compounds from Riesling grapes, while Cabernet Sauvignon showed a greater tendency to form alcohols. Conclusions: Both Riesling and Cabernet Sauvignon grapes had a more complex volatile compound composition pre-veraison than post-veraison. This study suggests that some compounds that contribute to grape aroma may be produced pre-veraison, and not simply accumulate after veraison. Significance of the Study: Understanding the timing of volatile compound production and cultivar differences will guide viticulture researchers and growers in the optimisation of vineyard strategies to enhance grape aroma attributes that may, in turn, contribute to wine aroma.     

Quality response of table grapes (Vitis vinifera L.) during cold storage to postharvest cap stem excision and hot water treatments

Berry quality, total phenol, sensory characteristics and decay incidence of grapes (V. vinifera cvs. Mü?küle and Red Globe) as affected by prestorage hot water immersion with or without cap stem excision treatments were investigated with 7‐day interval during storage at 1 °C for 21 days. Weight loss occurred mainly up to the second week and was more pronounced for the untreated control samples subjected to the stem excision. In Mü?küle, the least weight loss value was obtained from hot water–treated grapes (0.62%), while the highest loss occurred in control grapes of stem‐excised berries (0.96%). Immersion of stem‐retained grapes in hot water was the best applications for maintenance of overall storage quality for both cultivars. According to panellist scores, it is evident that hot water has positive effect on maintaining the minimally processed table grapes without altering the flavour and taste of the commodity. Stem‐retained berries of hot water treatment had the highest score for both Mü?küle and Red Globe, with their values 3.8 and 4.2, respectively, while the least values were obtained from stem‐excised berries of untreated control group of both the cultivars (1.9 and 3.0, respectively). At the end of three‐week storage, the least decay rates were determined in stem‐retained berries that received hot water treatment (5.3% for Mü?küle and 1.1% for Red Globe). Attenuate influence of brief high temperature exposure on ripening parameters (SSC, TA, MI, pH) was also observed. Postharvest hot water treatment may be used as a nonchemical means to extent storage life of minimally processed grapes with its alleviating effect on physiological disorders. Cap stem retaining in minimal processing can be recommended to maintain the quality of grapes.     

Combining microsatellite markers and capillary gel electrophoresis with laser-induced fluorescence to identify the grape (Vitis vinifera) variety of musts

In this work, a new method that combines the use of microsatellite markers (VVMD5 and ZAG79) together with capillary gel electrophoresis with laser-induced fluorescence (CGE–LIF) is developed and applied to the identification of Albariño and Moscatel Grano Menudo musts. The GCE-LIF method uses commercially available products including polymers, DNA-intercalating dyes and bare fused silica capillaries to provide reproducible and sensitive separations of DNA fragments for grapevine characterization. The CGE–LIF procedure offers highly resolved separations of DNA fragments from 48 to 1031 bp in ca. 30 min with efficiencies up to 1.8×10⁶ plates/m allowing the separation of fragments that differ in 4 bp. The use of different DNA standards (i.e., 100 bp ladder, Ф×174 and pBR322) and their effect on size assignment of the amplified DNA is also investigated. It is demonstrated that the microsatellite markers (VVMD5 and ZAG79) provide DNA amplification patterns specific for Albariño and Moscatel Grano Menudo grapes that can be adequately differentiated by using CGE–LIF. Moreover, the DNA sizes determined by this CGE–LIF method are corroborated using a more standard procedure (i.e., an automatic genetic analyzer with a commercial kit) demonstrating the usefulness of this new methodology.     

Relationships between different berry components in Tempranillo (Vitis vinifera L) grapes from irrigated and non‐irrigated vines during ripening

The impact of water availability on Vitis vinifera L cv Tempranillo grape yields and juice composition over a 3 year period was studied. Grape juice composition during the different stages of berry growth was compared. The analytical data collected were used to investigate the relationships between some of the different components studied in these berries during the ripening period. The object was to determine whether the relationships could be used to derive mathematical equations for use as indicators of the changes taking place in the different parameters considered and thus of the optimum time for harvesting the grapes for a given wine‐making process. Very similar equations were derived for this grape variety irrespective of the culture conditions (use or non‐use of irrigation) or the different ripening conditions employed. A high degree of correlation between some of the components considered was observed. In any case, cause‐and‐effect relationships could only be established for certain of the parameter pairs considered (total acidity/pH, pH/potassium, °Brix/glucose + fructose, total acidity/tartaric acid and malic acid). For other parameter pairs (berry weight/°Brix, °Brix/pH, °Brix/total acidity) the relationship found was attributable to accumulation and breakdown processes which took place concurrently or overlapped in time. In two cases only there was uncertainty as to whether the relationship observed between the parameters was a cause‐and‐effect relationship or whether the parameters were so closely related that they acted as mutually limiting factors (°Brix/proline, °Brix/total anthocyanins). © 2002 Society of Chemical Industry     

Characterisation of calamansi (Citrus microcarpa). Part I: Volatiles,aromatic profiles and phenolic acids in the peel

Volatile compounds in the peel of calamansi (Citrus microcarpa) from Malaysia, the Philippines and Vietnam were extracted with dichloromethane and hexane, and then analysed by gas chromatography–mass spectroscopy/flame ionisation detector. Seventy-nine compounds representing >98% of the volatiles were identified. Across the three geographical sources, a relatively small proportion of potent oxygenated compounds was significantly different, exemplified by the highest amount of methyl N-methylanthranilate in Malaysian calamansi peel. Principal component analysis and canonical discriminant analysis were applied to interpret the complex volatile compounds in the calamansi peel extracts, and to verify the discrimination among the different origins. In addition, four common hydroxycinnamic acids (caffeic, p-coumaric, ferulic and sinapic acids) were determined in the methanolic extracts of calamansi peel using ultra-fast liquid chromatography coupled to photodiode array detector. The Philippines calamansi peel contained the highest amount of total phenolic acids. In addition, p-Coumaric acid was the dominant free phenolic acids, whereas ferulic acid was the main bound phenolic acid.     

First study of determination of aromatic compounds of red wine from Vitis vinifera cv. Castañal grown in Galicia (NW Spain)

Wines produced from Vitis vinifera cv. Castañal from Galicia (NW Spain), harvest 2002 and 2003, were submitted to gas chromatography (GC/FID). A total of 36 varietal and fermentative aroma compounds were identified and quantified. The total concentration of aroma compounds in 2002 and 2003 vintage was 872.06 and 520.70 mg/L, respectively, which include free and bound terpenes and C₁₃-norisoprenoids, alcohols, acetates and ethyl esters. To estimate the contribution of specific compound to the aroma, the odour activity value (OAV) was calculated using the concentration of each component and the corresponding odour threshold reported in the literature. From 36 compounds identified, 10 were determined as the most powerful odorants: β-ionone, 3-methyl-1-butanol, benzyl alcohol, 2-phenylethanol, ethyl acetate, isoamyl acetate, ethyl lactate, ethyl butyrate, ethyl hexanoate and ethyl octanoate. These data suggested Castañal wines as a fruity (blackberry) and floral (rose) product.     

Effects of the maceration enzymes on evolution of pyranoanthocyanins and cinnamic acids during the cabernet gernischet (Vitis vinifera L. cv.) red wine making

The effects of the maceration enzymes on the evolution of 4-vinylphenols pyranoanthocyanins and cinnamic acids were investigated during the Cabernet Gernischet red wine making. The results showed that the contents of p-coumaric acid and caffeic acid in the maceration enzyme-treated wine (the treated wine) were higher than those in the maceration enzyme-untreated wine (the control wine) at the alcoholic fermentation (AF), maceration (M), and malolactic fermention (MLF) stages. Malvidin-3-O-glucoside-4-vinylphenol (Mv-glu-vp) and malvidin-3-O-(6-O-acetyl)-glucoside-4-vinylphenol (Mvacet-glu-vp) were formed at the AF and M stages in the treated wine, while they were formed at the end of MLF stage in the control wine. However, the contents of these 2 kinds of 4-vinylphenol pyranoanthocyanins in the control wine were higher than those in the treated wine during aging. These results showed that the use of maceration enzymes in winemaking can promote p-coumaric acid and p-caffeic acid transformed to vinylphenols and accelerate the formation of pyranoanthocyanins.     

Effects of some technologies of curing uncomminuted meat products on their flavour Part 1. Changes in the contents of fatty acids as meat flavour precursors

A study was made of the fatty-acid composition of phospholipids and the fraction of free fatty acids in two uncomminuted pork products, loin and neck, manufactured by three technologies: I, brine curing; 11, dry curing; 111, dry curing using%.6% honey. A higher phospholipid content was found in the loin products. Brine curing caused a more intensive lipid hydrolysis in both types of meat products. The free fatty-acid fraction in the meat products manufactured by technologies II and III was richer in unsaturated fatty acids, which are some of the most important meatflavour precursors.     

避雨栽培条件下红宝石无核葡萄光合特性初探

以欧亚种葡萄红宝石无核为试材,使用LI-6400光合作用测定系统,对其在避雨栽培条件下果实膨大期的光合特性进行了研究.结果表明:葡萄叶片的净光合速率(Pn)日变化呈双峰曲线,具有明显的光合午休现象.光饱和点(LSP)为1500цmol/(m2·s),光补偿点(LCP)为55.48 u mol(m2·s); C02饱和点(CSP)为1200 u mol/mol,CO2补偿点(CCP)为45.04 u mol/mol;表观量子效率(AQY)为0.0436,羧化效率(CE)为0.0461.     

Phenolic Compounds from the Leaves of Vitis labrusca and Vitis vinifera L. as a Source of Waste Byproducts: Development and Validation of LC Method and Antichemotactic Activity

The cultivation of Vitis (Vitaceae) grape varieties is one of the most important economic activities in agribusiness in southern Brazil. Vitis varieties are rich in polyphenolic compounds with several pharmacological and biological activities, such as antioxidant action. In this context, this study analyzed qualitatively and quantitatively the anthocyans and flavonoids found in the leaves of grape varieties Vitis vinifera and Vitis labrusca. For this purpose, vine leaf extracts were prepared and the chemical profile of each was characterized by LC/MS-MS. Two high performance liquid chromatography-validated methods were performed using UV/VIS-LC-DAD detector to quantify phenolic compounds. The main anthocyanins isolated from vine leaves were cyanidin-3-O-glucoside and peonidin-3-O-glucoside. The flavonoids identified were rutin, quercetin-3-O-galactoside, quercetin-3-O-glucoside, and quercetin-3-O-glucuronide, which was the predominant compound. The Waters X-Terra® RP18 column allowed the effective separation of quercetin-3-O-glucuronide from the other flavonoids for the first time, besides the partial separation of quercetin-3-O-galactoside from quercetin-3-O-glucoside. Furthermore, another phenolic compound was confirmed by MS spectrometry, using direct infusion, as being trans-caftaric acid. The present study also investigates the antichemotactic activity in vitro of grape crude extracts, fractions, and isolated compounds. It was demonstrated that almost all fractions and isolated compounds showed increased antichemotactic effect in response to LPS with a more pronounced values of IC₅₀ for anthocyanins fraction, rutin, quercetin-3-O-galactoside, and trans-caftaric acid (0.9, 1.6, 3.7, and 5.1 ng/mL, respectively).     

Evolution of polyphenols in red wines from Vitis vinifera L. during aging in the bottle

The evolution of non-anthocyanin phenolic compounds (as measured by high-performance liquid chromatography) in young red wines from Vitis vinifera L. cv Tempranillo, Graciano and Cabernet Sauvignon (vintage 2000) from Navarra (Spain) was studied during 26 months of aging in the bottle. Hydroxybenzoic acids and derivatives (gallic, protocatechuic, vanillic and syringic acids, and methyl and ethyl gallates), hydroxycinnamic acids and derivatives (trans-caftaric, cutaric, caffeic and p-coumaric acids, and hexose esters of trans-p-coumaric acid), stilbenes (trans- and cis-resveratrol-3-O-glucosides, and trans- and cis-resveratrol), phenolic alcohols and other related compounds (tyrosol and tryptophol), flavanols [procyanidins B1 and B2, (+)-catechin and (–)-epicatechin] and flavonols (myricetin-3-O-glucoside, quercetin-3-O-galactoside and quercetin-3-O-glucuronide, kaempherol-3-O-glucoside, myricetin and quercetin) presented different evolution patterns during aging, in some cases also being different depending on the grape variety studied. The changes that occurred during aging in the bottle were the decrease of the concentration of trans-caftaric and cutaric acids accompanied by an increase of trans-caffeic acid and, especially of trans-p-coumaric acid. The greater increase of trans-p-coumaric acid was also associated with the disappearance of p-coumaroyl-acylated anthocyanins that occurs during aging in the bottle. Flavanols registered a major decrease, with the disappearance rate being greater for the dimeric procyanidins than for the monomeric flavanols, and the order of the disappearance rate by variety was as follows: Tempranillo相似文献