Influence of grapevine leafroll associated viruses (GLRaV-2 and -3) on the fruit composition of Oregon Vitis vinifera L. cv. Pinot noir: Free amino acids,sugars, and organic acids

Individual free amino acids, yeast assimilable amino acid (YAN) content, ammonia, organic acids, and simple sugars of berries from vines infected with GLRaV-2 or -3 were compared with paired vines free of these viruses. Samples were taken from two commercial vineyards during two growing seasons (2005 and 2006), with three different rootstock/scion combinations. Vines infected with GLRaV-2 did not differ significantly from their healthy counterparts in individual free amino acids, ammonia, or YAN content. Vines infected with GLRaV-3 were significantly lower in valine and methionine from Vitis riparia rootstock/‘Pinot noir’ clone 114 (VY2a) samples, and lower in glutamic acid from self-rooted/‘Pinot noir’ clone Pommard (VY2b) samples, compared to samples from their healthy counterparts. Samples from VY2b (self-rooted/‘Pinot noir’ clone Pommard) infected vines had significantly lower levels of malic acid and total organic acids compared to samples from their healthy counterparts. There were no significant differences between healthy and infected vines from all three rootstock/scion pairs in ammonia or free amino acids in samples taken during the weeks before ripening and at commercial harvest. This is the first study to report the influence of GLRaV-2 and -3 on ‘Pinot noir’ berries nitrogen (N) compounds significant to fermentation. Individual free amino acids may be inferior to phenolic compounds as indicators of GLRaV infection status.     

Influence of extraction methodology on grape composition values

This work demonstrated similarities and differences in quantifying many grape quality components (>45 compounds) that were extracted from berries by three distinct preparations, before being analysed by eight spectrophotometric and HPLC methods. All sample extraction methods were appropriate for qualitative results only. Different extraction procedures showed altered component composition in ‘Pinot noir’ berries, possibly due to the localisation of the compounds of interest within the grape and how those compounds were extracted from the berry. Sample extraction is an often-overlooked part of berry evaluations, but this study illustrates that it should be carefully considered prior to berry component analysis for its influence upon measurements.     

Analysis of grape polyamines from Grapevine leafroll associated viruses (GLRaV-2 and -3) infected vines

This is the first report comparing the free polyamine content of ‘Pinot noir’ grapes from vines infected with Grapevine leafroll associated viruses (GLRaV)-2 or -3, with samples taken from healthy vines. Berries were collected from three different rootstock/scion combinations, and all samples were from commercial vineyards in Oregon. Three free polyamines (putrescine, cadaverine, and spermidine) were found in all ‘Pinot noir’ grapes analysed in this study. Berries from healthy Vitis riparia rootstock/‘Pinot noir’ clone 114 were significantly higher in putrescine (28.6 μmol/l) and total polyamines (41.9 μmol/l), compared to their GLRaV-3 infected samples (20.7 and 33.0 μmol/l, respectively). Vine virus status did not alter total or individual polyamines in berries from the other two rootstock/scion combinations (unknown rootstock/‘Chardonnay’ interstock/‘Pinot noir’ scion [clone unknown] and self-rooted/‘Pinot noir’ clone Pommard). Levels of putrescine, spermidine, and total polyamines varied between berries taken from the healthy vines of the three different rootstock/scion combinations.     

Berry nitrogen status altered by cover cropping: Effects on berry hormone dynamics,growth and amino acid composition of Pinot Noir

The influence of altered nitrogen (N) content, caused by cover crop, on Pinot Noir berry quality was studied. Treatments included two levels of cover cropping and clean-cultivation. Berry N-content was reduced by grass cover crop competition, with the highest reductions of N at the early stage of berry formation and at the commercial harvest stage. Growth regulators, trans-zeatin and indole-3-acetic acid, and berry growth were influenced by the changes in N-status at different stages of berry formation. The total amino acid content of berries at harvest decreased with cover cropping, while the proline to arginine ratio and assimilable amino acids content improved compared to the berries from clean-cultivated vines. Our data indicate that early stage berry development is influenced by N-status but finally it results in an improved amino acid composition for yeast fermentation in mature berries. At the same time, sugar and pigment contents were not negatively influenced by cover crop-induced changes in berry N-status.     

Influence of grapevine leafroll associated viruses (GLRaV-2 and -3) on the fruit composition of Oregon Vitis vinifera L. cv. Pinot noir: Phenolics

Some of the 10 known grapevine leafroll associated viruses (GLRaVs) have negative impacts upon vine productivity and grape quality, though these negative influences are dependent on factors such as GLRaV strain, cultivar, clone, rootstock, and vine age. This is the first study to report on GLRaV-2 and GLRaV-3 infected vines, with regard to phenolic compounds, and other fruit maturity indices, of ‘Pinot noir’ grapes, compared to berries from adjacent vines free of GLRaVs (same vineyards). Three different rootstock/scion combinations were included in this study. Clusters were collected for two growing seasons from commercial vineyards in the Willamette Valley of Oregon, and each vine sampled was tested for GLRaV-1, -2, -3 and Rupestris stem pitting-associated virus (RSPaV). All sampled vines were infected with RSPaV. Grapevine leafroll associated virus-infected vines tested positive for GLRaV-2 or GLRaV-3. Overall, fruit infected with GLRaV-2 and -3 had reduced percent soluble solids, decreased individual and total anthocyanins, and increased skin and pulp weight for all three ‘Pinot noir’ rootstock/scion combinations examined. Vitis riparia rootstock/‘Pinot noir’ clone 114 scion combination appeared to be the most sensitive to GLRaV-3 infection, having significant reduction of all five anthocyanins, total phenolics, and total tannins, with an increased cluster weight and 100-berry weight. No clear trends were observed in the polyphenolics analysed.     

Rootstock and vineyard floor management influence on ‘Cabernet Sauvignon’ grape yeast assimilable nitrogen (YAN)

This is a study on the influence that two rootstocks (110R, high vigour; 420A, low vigour) and three vineyard floor management regimes (tilled resident vegetation – usual practise in California, and barley cover crops that were either mowed or tilled) had upon grape nitrogen-containing compounds (mainly ammonia and free amino acids recalculated as YAN), sugars, and organic acids in ‘Cabernet Sauvignon’ clone 8. A significant difference was observed for some of the free amino acids between rootstocks. In both sample preparation methods (juiced or chemically extracted), 110R rootstock grapes were significantly higher in SER, GLN, THR, ARG, VAL, ILE, LEU, and YAN than were 420A rootstock grapes. Differences in individual free amino acid profiles and concentrations were observed between the two sample preparations, which indicate that care should be taken when comparing values from dissimilar methods. No significant differences among vineyard floor treatments were detected, which suggests that mowing offers vineyard managers a sustainable practise, alternative to tilling, without negatively affecting grape nitrogen compounds, sugars, or organic acids.     

Effects of timing and rate of N supply on leaf nitrogen status, grape yield and juice composition from Shiraz grapevines grafted to one of three different rootstocks

Yeast cells have a minimum N requirement to ferment a must through to dryness, so that grape N content (hence must N) becomes critical in meeting that prerequisite. Viticultural practices aimed at meeting that N requirement are of special relevance because interactions between rootstock and vineyard nitrogen supply strongly influence scion mineral nutrient status as well as shoot vigour, and via those processes, fruit composition. Such outcomes were investigated in a field trial involving Shiraz on three rootstocks viz. Teleki 5C, Schwarzmann and Ramsey. Five N supply regimes, varying from 0 to 80 kg/(haseason), were imposed through a drip-irrigation system during two periods (either flowering to veraison, or post-harvest to leaf-fall, or both) over three successive growing seasons. Post-harvest N supply increased scion leaf N and nitrate N concentrations at flowering for vines on Teleki 5C and Schwarzmann. By veraison, N recently applied in the flowering to veraison period elevated these indicators of N status in all vines on all rootstocks. Grape yields from vines on Teleki 5C and Schwarzmann were elevated by N supply after harvest, whereas juice soluble solids levels were lowered. Free amino acids in Shiraz juice were dominated by non-assimilable N, amounting to about 50% or more of the total free amino-N in the juice. Increasing N supply increased free amino acid concentrations in the juice of berries from vines on all rootstocks, but only vines on Schwarzmann derived any benefit from N supplied after harvest. The highest concentrations of free amino acids were measured in the berries from vines on Schwarzmann receiving 80 kg N/(ha.season). Of immediate practical relevance for N management of Shiraz grapevines on either Teleki 5C or Ramsey rootstocks, the minimum value for assimilable free amino-N concentration required to ferment a must through to dryness was not achieved if vineyard N application was limited to the post-harvest period.     

Proline and arginine accumulation in developing berries of Vitis vinifera L. in Australian vineyards: Influence of vine cultivar, berry maturity and tissue type

Using HPLC analysis, free amino acid profiles were obtained for ripe berries of six grapevine cultivars (Cabernet Sauvignon, Grenache, Muscat Gordo, Pinot Noir, Riesling and Sangiovese) grown under comparable conditions and harvested at similar maturities. Compositional differences were observed between cultivars, however proline and arginine were always the major amino acids. Mature berries of Cabernet Sauvignon contained a very high concentration of proline, but a much lower concentration of arginine. Those of other cultivars contained moderate levels of both arginine and proline.
Changes in free amino acid profiles during grape berry development were further investigated in four cultivars (Cabernet Sauvignon, Chardonnay, Gewurztraminer and Muscat Gordo). In all cases, most of the proline accumulation occurred late in ripening, around four weeks post-veraison. In contrast, arginine accumulation began before veraison and continued to full maturity, except for those cultivars in which a high concentration of proline accumulated, in which case the concentration of arginine reached a plateau relatively early in development. Accumulation of both proline and arginine appears to be develop-mentally regulated. These observations are discussed with reference to proline and arginine metabolism and possible links between them.
The distribution of free proline, arginine and other amino acids amongst pulp, skin and seed was examined using mature fruit of Cabernet Sauvignon and Riesling. Amino acid profiles were found to vary considerably between the berry components. The skin contained a greater ratio of arginine:proline compared with the pulp. This suggests that the yeast-assimilable nitrogen content of juices, and therefore their fermentability, could be enhanced in the presence of skins.     

Shiraz berry size in relation to seed number and implications for juice and wine composition

This study was conducted over three seasons on irrigated Shiraz grapevines growing in a warm climate. We addressed the question of whether differences in berry size (within a population of berries from minimally pruned, own‐rooted or Ramsey‐grafted vines), would lead to differences in juice composition, wine composition or wine sensory score. Predictably, berry mass was found to increase with seed number, but berries in the smallest mass categories (0.3–0.7 g) still had similar juice soluble solids and pH; and similar concentrations of K+, tartaric acid and malic acid, compared with larger berries (1.4–2.0 g). Only for the very smallest mass category (0.3–0.55 g) was there any indication of better colour density (both for own‐rooted and Ramsey‐grafted vines) or higher anthocyanin concentration (for own‐rooted vines) compared with larger berries (1.4–2.0 g). Concentrations of tartaric acid and K+ in berry skins were highest in the smallest berry mass categories (0.3–0.7 g) and decreased with increasing berry mass (up to 1.4–2.0 g). A strong correlation (R²= 0.85) between skin tartaric acid and K+ concentrations was observed across that range. Small‐scale wine lots based on small berries (0.8–0.9 g) versus large berries (1.2–1.3 g) showed no differences in measures such as soluble solids, total acids or pH of juice; nor any differences in pH, total acids, K+, tartrate, malate, spectral characteristics or sensory score of corresponding wines. Moreover, small berries had a similar skin to fruit ratio, and a similar juice yield, compared to large berries. However, when measured post‐fermentation, the ratio of seed weight to skin weight was higher for small berries. The mass range of berries used here for small‐scale winemaking (i.e. from 0.8–0.9 g up to 1.2–1.3 g), covered the range of Shiraz berry mass typically found in irrigated vineyards (from 0.8 to 1.5 g), and thus confirms the relevance of present outcomes to practical winemaking. Finally, our data for variation in juice and wine composition as a function of berry size, showed consistent trends for all seasons, and thus implies that reported instances of improved wine quality from small berries (often associated with certain pruning treatments or deficit irrigation strategies), are more likely due to treatment effects that lead to small fruit, rather than to intrinsic developmental differences between large and small berries.     

Changes in Free Amino Acid and Total Nitrogen Concentrations During Maturation of Muscadine Grapes (V. rotundifolia)

Free amino acids, ammonia and total nitrogen were followed during maturation of berries of Carlos and Noble muscadine grapes (V. rotundifolia). Chemical analysis was done on deseeded berries. Ammonia decreased in the berries of both cultivars during maturation. Total nitrogen content fluctuated and was not significantly correlated with maturity in either cultivar. Threonine (THR) and histidine + gamma aminobutyric acid (HIS + GABA) were the predominant free amino acids in both cultivars at an immature berry stage. At full berry maturity, arginine (ARG) was the predominant amino acid in Carlos, having increased over 100-fold during the sampling period while ARG, alanine (ALA), THR, and HIS + GABA accounted for 72.3% of the total free amino acids. ALA was the predominant free amino acid in mature berries of Noble and accounted for 30.4% of the total free amino acids. Of the additional cultivars sampled only at their normal harvest date, berries of Pride, Magnolia and Regale contained nearly equal amounts of ARG and ALA as the predominant amino acids. Mature Dixie berries had twice as much ALA (29.8%) as ARG (12.8%). In general, the free amino acids in berries of muscadine grapes were found in concentrations similar to those reported in the literature for V. vinifera and V. labrusca cultivars. However, the large increase in proline concentration reported to occur during maturation of berries of V. vinifera cultivars was not found in any of the muscadine cultivars examined.     

The effect of mechanical harvesting and long-distance transport on the concentration of haze-forming proteins in grape juice

The concentration and composition of soluble, haze-forming protein in juice of hand-harvested (HH) and mechanically harvested (MH) Pinot Noir and Sauvignon Blanc grapes was determined. The major soluble proteins in both varieties were pathogenesis-related (PR) proteins, specifically thaumatin-like proteins and chitinases. Comparison among HH berries, MH intact berries and the mixture of broken fruit and juice, the predominant form of MH fruit, indicated that little if any protein was produced as a result of stress caused by MH. Nevertheless, MH coupled with long-distance transport which caused a delay in pressing the mechanically damaged fruit, resulted in juice with a higher concentration of PR proteins compared to juice obtained from pressing HH fruit. Soluble PR proteins were detected in the berry skin of both varieties. Increases in protein content of juice from MH fruit are predominantly caused by extraction of protein from skins and solids of broken grapes during transport to the winery.     

Inhibitory Effects of ‘Enokitake’ Mushroom Extracts on Polyphenol Oxidase and Prevention of Apple Browning

‘Enokitake’ mushroom (Flammulina velutipes) extracts were prepared by three different solvents: 70 mL/100 mL acetone, 70 mL/100 mL ethanol as well as hot water. Effects of the extracts on mushroom tyrosinase activity and browning of apple were investigated. Mushroom tyrosinase activities assayed spectrophotometrically and by oxygen uptake were found to be inhibited significantly by all three extracts. Lyophilized ‘enokitake’ fruit body powder inhibited the browning of fresh apple. Immersing sliced apple into the acetone extract was found to prevent effectively the browning development. Freshly squeezed apple juice with added hot-water extract showed the concentration-dependent inhibition of browning. No browning was observed on the apple juice when mixed with the extract containing 1.0 g wet ‘enokitake’/mL in a mixture. Under the same conditions, no significant changes in color in terms of a* and b* values of the mixture were observed for up to 6 h. These observations suggested that ‘enokitake’ mushroom contained certain compounds which inhibited mushroom tyrosinase activity and the development of browning induced by the catalytic oxidation due to polyphenol oxidase.     

Myrtle hydroalcoholic extracts obtained from different selections of Myrtus communis L.

Hydroalcoholic extracts obtained from myrtle berries of five different selections were studied to obtain unique clones. During the typical 40 day maceration period, dry matter, pH, colour, and anthocyanins, were analyzed. Variability among myrtle selections was observed both in fresh berries (yield berries/plant, weight of the berries, number and weight of seeds per berry) and in the hydroalcoholic extract physical–chemical characteristics (dry matter, colour intensity, tint and anthocyanins). Reversed-phase high performance liquid chromatography (RP-HPLC) analysis with photodiode array detection (PDA) was used for anthocyanins characterization in myrtle hydroalcoholic extracts. Anthocyanin qualitative composition was the same in all selections, but varied strongly in its total amount. D was the selection with the characteristics most suitable for industrial use.     

European elderberry (Sambucus nigra L.) rich in sugars,organic acids,anthocyanins and selected polyphenols

Sugars and organic acids in the fruit of two cultivars and three selections of black elderberry (Sambucus nigra L.): ‘Haschberg’, ‘Rubini’, ‘Selection 13’, ‘Selection 14’ and ‘Selection 25’ were quantified. The anthocyanin as well as quercetin profiles of this plant material were also established by the use of HPLC/MS. Significant differences in the concentration of sugars and organic acids were detected between the widely spread cultivar ‘Haschberg’ and all other cultivars/selections; ‘Haschberg’ was the richest in organic acids (6.38 g kg⁻¹ FW), and it contained the least sugar (68.5 g kg⁻¹ FW). The following major cyanidin based anthocyanins were identified in the fruit of black elderberry: cyanidin 3-sambubioside-5-glucoside, cyanidin 3,5-diglucoside, cyanidin 3-sambubioside, cyanidin 3-glucoside and cyanidin 3-rutinoside. The most abundant anthocyanin in elderberry fruit was cyanidin 3-sambubioside, which accounted for more than half of all anthocyanins identified in the berries. The ‘Rubini’ cultivar had the highest amount of the anthocyanins identified (1265 mg/100 g FW) and the lowest amount was measured in berries of the ‘Selection 14’ (603 mg/100 g FW). The ‘Haschberg’ cultivar contained a relatively low amount of anthocyanins in ripe berries (737 mg/100 g FW). From the quercetin group, quercetin, quercetin 3-rutinoside and quercetin 3-glucoside were identified; the latter prevailing in black elderberry fruit. The cultivar with the highest amount of total quercetins was ‘Selection 25’ (73.4 mg/100 g FW), while the ‘Haschberg’ cultivar contained average amounts of quercetins (61.3 mg/100 g FW). The chemical composition of the ‘Haschberg’ cultivar, the most commonly planted, conforms to the standards for sugars, anthocyanins and quercetins and exceeds them in the content levels of organic acids, the most important parameter in fruit processing.     

Effect of foliar nitrogen and sulfur on petit manseng (Vitis vinifera L.) grape composition

Vineyard applications of foliar nitrogen (N) and sulfur were evaluated in the Yadkin Valley of North Carolina in 2011 and 2012 as a means to modify grape composition of Vitis vinifera cv. petit manseng. Four treatments were applied each year in a randomized complete block design with six replicates of six vines each: untreated control, soil N at 30?kg/ha, foliar N at 15?kg/ha and foliar N at 15?kg/ha plus sulfur at 5?kg/ha. Fruit ammonia and yeast assimilable nitrogen (YAN) concentrations increased in foliar-treated vines both seasons compared to control vines. Total glycosides (TGGs) increased ～80% in foliar N/sulfur-treated vines compared to control vines in 2011, and TGGs increased ～157% in foliar N/sulfur-treated vines relative to glycoside level in foliar N alone in 2012. Foliar N and foliar N/sulfur applications increased the majority of amino acid concentrations analyzed in 2011. Measured concentrations of various amino acids, partly responsible for aroma and flavor of petit manseng wines, were differentially dependent on the method of N application. Foliar applied nitrogen may be an effective technique to contribute to berry composition optimization of petit manseng grown in a warm, humid climate.     

The influence of seed weight on the development and growth of berries and live green ovaries in Vitis vinifera L. cvs. Pinot Noir and Cabernet Sauvignon

Background and Aims:  Variation in berry size is observed at harvest. Although the growth of seeded berries has been described, no such data are reported for seedless berries or live green ovaries that occur in wine cultivars. This study describes the growth of individual berries in relation to seed development.
Methods and Results:  Regular measurements of berry diameter described the growth of Pinot Noir and Cabernet Sauvignon. Seeded berries had typical double sigmoid growth curves, whereas seedless berries, which developed more slowly from midway through Phase I, continued to grow in Phase III if a seed trace was present. Berries without a seed trace did not enlarge after Phase II. Live green ovaries failed to grow after a small initial expansion post-cap fall.
Conclusion:  Seeded berries had double sigmoid growth as a result of cell division and expansion, whereas the growth of seedless berries and live green ovaries was the result of cell expansion alone. Seed development is necessary for cell division within the mesocarp.
Significance of the Study:  Seed development is essential for the full development of Pinot Noir and Cabernet Sauvignon berries. The data suggest that divergence of berry development from a characteristic growth curve may be linked to the extent of seed development.     

Effects of manipulated grape berry transpiration on post-veraison sugar accumulation

A series of experiments were conducted on container-grown Pinot Noir and Sangiovese grapevines ( Vitis vinifera L.) to investigate whether changes in berry water loss at veraison influence the pattern of sugar accumulation. Berry transpiration was induced to vary either by changing the vapour pressure deficit (VPD) around bunches through temperature or relative humidity (RH) manipulations, or by applying drying-accelerating emulsion or a hydrophobic coating (vaseline) over the berry skin. In all the experiments, every berry of every bunch was rated prior to treatment as to softness and colour intensity. Transpiration rates were derived either from measurements of attached bunches using a custom-built open gas-exchange system or from weight loss calculated for single excised berries. Berry development and ripening were monitored throughout each experiment as deformability, fresh weight, and sugar concentration and content. Berries either did not respond to VPD-enhancement or showed reduced water loss when bunches were subjected to high temperature. Low berry transpiration in the latter treatment led to lower sugar content per berry up to harvest, and berry transpiration and net sugar intake were linearly correlated up to 0.20–0.25 mmol/m².s. A similar correlation was found also in the coating experiment within the first five days after treatments. When berry transpiration was restricted by applying vaseline, sugar accumulation was retarded. Low values of VPD, induced by raising the RH around the bunches, lowered sugar concentration but not sugar content per berry. The present study provides preliminary evidence that sugar accumulation in grapevine berries responds to changes in the evaporative demand around the bunch at veraison.     

Comparative study of primary and secondary metabolites in 11 cultivars of persimmon fruit (Diospyros kaki L.)

Primary metabolites (sugars, organic acids) and secondary metabolites (phenolics and carotenoids) were quantified by HPLC in fully ripe fruit of 11 kaki cultivars: ‘Amankaki’, ‘Cal Fuyu’, ‘Fuji’, ‘Hana Fuyu’, ‘Jiro’, ‘O’Gosho’, ‘Tenjin O’Gosho’, ‘Thiene’, ‘Tipo’, ‘Tone Wase’ and ‘Triumph’. Amongst the analysed cultivars, ‘Tone Wase’ stands out as the richest in sugars, particularly glucose, and cultivars ‘Tipo’ and ‘Triumph’ contained the highest amounts of organic acids. Cultivars ‘O’Gosho’, ‘Cal Fuyu’ and ‘Hana Fuyu’ contained the least sugars and cultivar ‘Jiro’ the least organic acids. Amongst the individual phenolic compounds catechin and gallic acid were present in highest concentrations. The predominant carotenoid in both skin and pulp of ripe persimmon fruit was β-carotene, the highest content was measured in skin of cultivar ‘Hana Fuyu’, which also contained the highest level of total carotenoids. In persimmon pulp, much lower values for carotenoids were obtained, particularly in fruit of cultivar ‘Cal Fuyu’.     

Chemical composition and antioxidant activities of Myrtus communis L. berries extracts

Myrtle (Myrtus communis L.) berries extracts were prepared with solvents at different polarity (water, ethanol, and ethyl acetate) and analysed using different in vitro tests in order to evaluate their antioxidant properties. Antiradical and total antioxidant activities were measured with DPPH and FRAP tests, respectively. Their ability to protect biological molecules was assessed using the cholesterol and LDL oxidation assays. In addition, phenolic compounds and unsaturated fatty acids composition was analysed by HPLC–DAD and HPLC–MS/MS. Ethanol and water extracts showed the highest amount of extracted compounds, but the highest antiradical and antioxidant activities were found in ethanol and ethyl acetate extracts. These extracts were also the ones with the highest content of phenolic compounds. In addition, our results showed a highly significant correlation between the amount of total phenols and antiradical (R² = 0.9993) or antioxidant activities (R² = 0.9985) in these extracts. HPLC–DAD and HPLC–MS analyses showed significant quantitative and qualitative differences among these three extracts. The ethyl acetate extract had the highest protective effect in assays of thermal (140 °C) cholesterol degradation and Cu²⁺-mediated LDL oxidation, inhibiting the reduction of polyunsaturated fatty acids and cholesterol, and the increase of their oxidative products. These results suggest that because of these properties, myrtle berries could be used in dietary supplements preparations or as food additives.