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Aroma is an identifying characteristic of wines and is of crucial importance for the consumer appreciation. Among all odour-active compounds, some key molecules appear only after ageing and give a strong contribution to both identity and added value of the wine bottle. Methyl salicylate (MeSA) is an odorant which usually appears after ageing and could provide an increase in fruity aromas and freshness. This odour-active ester can be found mainly bound to one or more carbohydrates, forming a glycoside. In wines, the hydrolysis of glycosides contributes to the aroma evolution of wine. In our previous works, MeSA was found in relevant content, both in bound and free form, in some genetically related Italian varieties such as Trebbiano di Lugana, Trebbiano di Soave (both employed in the production of Lugana wines), and Verdicchio. In this research, a straightforward filter-and-shot LC-MS/MS method was used for the determination of 7 different MeSA glycosides in 246 samples representative of 18 different monovarietal Italian white wines. MeSA glycosides were found in relevant concentrations in Verdicchio and Lugana wines, whereas they were determined for the first time in all others. Results were in accordance with the literature since Lugana and Verdicchio emerged for the total amount of glycosides, together with Erbaluce, whose richness was not known to date. This trend was observed for all analytes, with stronger intensity, especially in MeSA–glucoside, MeSA–gentiobioside and MeSA–violutoside. The triglycosylated form was not detected in any case. The same trend was also observed for the free form, whose value was not above the olfactory threshold for any sample. MeSA in all its forms also showed a qualitative trend, with MeSA - glucoside and MeSA–primeveroside emphasised in richer cultivars with also a characteristic pattern. The knowledge of the concentration of MeSA glycosides could be considered a potential predictor of the potential evolution of white wines towards balsamic-like nuances.

In a growing context of green and circular economy, gaining knowledge of the composition of every crop is crucial, as this will allow for their full exploitation. Cherry (Prunus avium L.) is a widespread tree of particular interest for its fruits and its valuable timber. Its wood is rich in extractives and its characterization will allow to consider other applications for this feedstock. In this study, chipped cherry wood was extracted and chemically analysed to determine its total phenolic content, total condensed tannin, antioxidant capacity, and polysaccharide content through wet chemistry analysis. These investigations were coupled with 13C-NMR and FTIR spectrometry, with HPLC as well as elemental analysis to conduct a comprehensive chemical characterization. Thermogravimetric measurements were also taken to understand the behaviour of the extract when exposed to high temperature. The registered findings were benchmarked against commercial mimosa (Acacia mearnsii De Wild.) and chestnut (Castanea sativa Mill.) tannins which were selected as template for condensed and hydrolysable tannins, respectively. Cherry extract was found to be the poorest in phenolics which are mainly constituted of pyrogallic flavonoids strongly interconnected with significant amounts of polysaccharides.

This work aimed to investigate the occurrence of different monoterpenoids and norisoprenoids in 10 monovarietal Italian red wines (Aglianico, Cannonau, Corvina, Montepulciano, Nebbiolo, Nerello, Primitivo, Raboso, Sangiovese and Teroldego) from 12 regions across Italy. The wines were produced in their terroirs following the oenological practices and legislation of the respective appellation. Data showed that different wine varietals were characterised by peculiar profiles of monoterpenoids and norisoprenoids.Montepulciano and Cannonau wines showed highest levels of nerol, terpinolene, α-terpineol, limonene and of the norisoprenoids β-damascenone, α-ionone, TPB, TDN and vitispirane.Aglianico, Corvina, Nebbiolo and Primitivo were characterised by relatively high levels of linear monoterpene alcohols such as linalool and geraniol. Sangiovese samples from Tuscany could be differentiated from those of Romagna, with the former characterised by a higher content of α-terpinene and the latter of γ-terpinene. The monoterpene 1,4-cineole was present in Montepulciano, Raboso and Sangiovese at potentially relevant olfactory levels, its occurrence associated with higher content of terpinen-1-ol acting as a potential precursor under wine acid conditions.

Greening is a major problem for garlic’s quality. This phenomenon leads to discoloration of the product and is directly related to the alliinase-catalyzed conversion of isoalliin into 1-propenyl-containing thiosulfates. Garlic crushing, refrigeration, and storage in normal atmosphere, as well as in the presence of monocarboxylic acids, are established the main factors that promote its greening. In last decades, the study of biochemical pathway of this phenomenon has allowed to effectively understand the main steps and key enzymes involved, and to identify optimum conditions for chemical and enzymatic reactions leading to discoloration. These findings have, in some cases, determined the development of new tools for the control of garlic greening on large scale. After providing an updated description of the biochemistry of green pigments produced in garlic, this review reports an overview on the strategies for controlling discoloration of garlic at industrial level.

In this opinion article we explore the link between regular wine consumption and human health, starting from the teachings that Alvise Cornaro, a Scholar at the University of Padova, left us, especially on his “La Vita Sobria”, a treatise published in Padova in 1558. A key role in his suggested diet is reserved for wine, an alcoholic beverage that, he advocated, should be consumed regularly, a concept that fits well with the central role that wine played in the Middle age society. Indeed, at that time, wine was consumed in large quantities, and it was generally mixed with water to make the latter safer for consumption. Monks and doctors also used wine as a medicine, as this was regularly administered to sick people of all ages to cure their illnesses. Wine maintained a similar role until the middle of the 20th Century, shifting from a source of energy to a pleasure, even if moderate wine consumption has been reported by epidemiological studies as having health benefits, particularly in relation to cardiovascular diseases. Conversely, any level of alcohol intake has recently been recognized as harmful, an occurrence that the modern wine industry is tackling by increasing the production of wines with reduced alcohol content. Nevertheless, nowadays, wine continues to be consumed for the pleasure it can provide and for its role as a social catalyzer.

Der Rauchgeschmack ist zu einem wichtigen Thema fur die globale Weinindustrie geworden. Grund dafur ist der Klimawandel, der sich zunehmend auf die Dauer und Intensitat von Waldbranden auf der ganzen Welt auswirkt. Im Rauch befindliche, fluchtige Verbindungen (z. B. fluchtige Phenole wie Guajakol, 4-Methylguajakol, o-, m- und p-Kresol und Syringol) konnen von den Weinreben uber die Blatter und die Fruchte aufgenommen werden. Diese Verbindungen sind anfangs noch in freier Form (Aglykon) nachweisbar, werden allerdings relativ schnell glykosyliert und in Glykokonjugatverbindungen umgewandelt. Wahrend des Garungsprozesses konnen diese Glykokonjugate abgebaut werden. Dies kann zur Freisetzung fluchtiger Phenole fuhren, die dem daraus resultierenden Wein unerwunschte sensorische Eigenschaften verleihen (d. h. rauchige und aschige Noten). Verschiedene Methoden des Weinanbaus und der Weinherstellung wurden evaluiert, mit dem Ziel, die negativen Auswirkungen auf die Reben nach Kontakt mit Rauch zu mildern bzw. zu beheben. Zurzeit gibt es allerdings keine universelle Losung, die das Problem des Rauchgeschmacks im Wein beseitigt. In diesem Artikel diskutieren wir deshalb mogliche Strategien, mit deren Hilfe die negativen Auswirkungen des Rauchgeschmacks minimiert werden konnen (Abbildung 1).

Verjuice is an acidic unfermented unripe grape juice that has recently been proposed as an alternative to vinegar in different food preparations. In this study, pickled cucumber preserves were industrially prepared using two dilutions of verjuice as acidifying agent and compared with the traditional vinegar-pickled samples. Samples were chemically characterized and subjected to sensory analyses using a trained panel and consumers. The different acidifying agents resulted in pickled cucumbers giving different olfactory and gustatory evaluations. No differences in appearance and texture were found. Despite showing chemical and sensory differences, pickles preserved with verjuice and vinegar had similar overall liking scores for visual, olfactory and gustatory aspects. A key feature of pickles prepared with verjuice is their lack of acetic acid potentially conferring them an additional value, suggesting that verjuice represents a viable alternative to vinegar for the production of pickles with distinctive sensorial properties.

Haze can appear in white wines as a result of the denaturation and subsequent aggregation of grape pathogenesis-related (PR) proteins. Yeast cell-wall polysaccharides, particularly mannoproteins, represent a promising strategy to reduce the incidence of this phenomenon. The aim of this study was to evaluate the effects of 13 Starmerella bacillaris strains, in sequential fermentation with Saccharomyces cerevisiae, on wine protein stability of three white wines (Sauvignon blanc, Pinot grigio, and Manzoni bianco). The resulting wines were characterized in terms of their chemical composition, content of PR proteins and polysaccharides, and heat stability. In addition, the mannoprotein fraction was purified from six wines, five produced with S. bacillaris and one with S. cerevisiae EC1118 used as control. Generally, wines produced with S. bacillaris strains were more heat-stable, despite generally containing higher amounts of PR proteins. The increased heat stability of Starmerella wines was attributed to the stabilizing effect resulting from their higher concentrations of both total polysaccharides and mannoprotein fractions. In particular, for the most heat unstable wine (Manzoni bianco), the low MW mannoprotein fraction resulted to be the most involved in wine stability. The ability to produce wines with different heat stability was demonstrated to be strain-dependent and was more evident in the most unstable wines. By reducing fining waste, the use of S. bacillaris as an enological starter can be proposed as a new tool to manage wine protein stability for a more sustainable winemaking.

A current research interest of the wine industry is the improvement of wine quality by producing wines to meet the consumers’ demands and desires. However, this requires an understanding of the complex chemical matrix and the nature of interactions between molecular components of the wine. Wine polysaccharides are macromolecules whose presence and interactions with other wine components can lead to the modulation of technological and organoleptic wine quality attributes. Indeed, grape and yeast derived polysaccharides play a major role in modulating wine astringency through interactions with exogenous salivary protein-tannin complexes formed within the oral cavity. Polysaccharides participate in the formation of colloidal particles through their interactions with wine tannins and proteins, with crucial implications on the clarity and stability of finished wines. Additionally, polysaccharides modulate wine aroma volatility and foaming. The extent to which they influence these attributes is dependent on the concentration and physico-chemical properties of all the species involved in these interactions. Overall, the structure, size and type of the polysaccharides are key components governing the success and intensity of their interactions with other species. Therefore, to better understand the relevance of polysaccharides in wine, this review discusses the molecular interactions facilitated by these species and details their potential roles within the wine matrix.

Verjuice is the unfermented juice obtained from unripe grape berries, typically thinned fruit that is normally discarded. Despite a long history of use as a food ingredient, verjuice does not have a recognized standard of identity nor is made by standardized methods. To assess the potential for production in the Veneto region of Italy, verjuice produced from six different winegrape varieties harvested at three different dates from bunch closure through early veraison, and stabilized using either sulphite or sorbate, was subjected to compositional and sensory analyses. pH was found to range from 2.6 to 2.9 while soluble solids (°Brix) ranged from 3.8 to 9.9. Acidity (g/L) ranged from 17.4 to 40.5 while color (A420) varied from 0.04 to 0.50. With respect to sensory character, harvest date had no influence on aroma, but affected taste, whereas the type of preservative used had no effect on taste, but did affect aroma. Industrial relevance Unripe grape juice can be used as a food ingredient to provide acidity and flavor and may be suitable as an alternative to vinegar in salad dressings and other applications where the sensory character of acetic acid is unacceptable. Because it can be produced from thinned grapes, a currently unused by-product of winegrape growing, it represents a product of great interest to grape growers and to the food industry.

Background: Approximately two-thirds of wine produced in the UK is bottle-fermented sparkling wine. Effervescence and foamability are key features used to assess English sparkling wine (ESW) quality. A critical, yet understudied, area of research is the potential for dosage to influence foam behaviour via associated changes in wine viscosity.; Results: In this study, dosage treatments of five increasing levels of sucrose (from 0 to 31 g L-1 ) were added to an ESW. After storage, the foamability attributes of the wines were analysed via an adapted Mosalux method and a novel image analysis method combined with free pour of the wine. Results indicate that increasing sucrose concentration improved foam formation, but reduced foam stability, likely due to the sucrose added causing a modification in wine viscosity.; Conclusions: These results highlight the impact that dosage treatments can have on the quality of foam produced upon pouring, and therefore have the potential to inform future sparkling winemaking practices. © 2017 Society of Chemical Industry.; © 2017 Society of Chemical Industry.

In this work, we compare the effect of the addition during fermentation of both sodium bentonite and sodium-activated bentonite on the protein content, protein stability, lees volume, and aroma compounds of a Sauvignon blanc wine. Protein unstable Sauvignon blanc juices were vinified with or without bentonite added at three different stages: before fermentation, early during fermentation, and towards the end of fermentation. Different addition doses of bentonite were used (X, X − 0.1, X − 0.2 g/L) according to protein instability of the grape juice (X = 1.7 and 2.7 g/L to sodium bentonite and sodium-activated bentonite, respectively). The wines stabilized with sodium-activated bentonite presented a higher content of volatile compounds and a lower volume of lees were produced than those treated with sodium bentonite, an effect that was greater when the fining treatment was done before the start of the fermentation.

Background and Aims There is a growing interest in finding alternative wine fining agents to replace potentially allergenic animal-derived and plant-derived proteins. In this context, the potential use of grape-derived fining agents would be beneficial as they would not introduce additional, potentially allergenic products to the finished wine. In this project, grape seed flour, a by-product of the grape oil seed industry, has been used to prepare a grape seed extract (GSE) for testing as a novel wine fining agent. Methods and Results The fining performance of GSE was compared with that of patatin, pea proteins, polyvinylpolypyrrolidone and potassium caseinate in a white and in a rose wine, and of ovalbumin and gelatin in a red wine. Reduction of turbidity, effect on wine colour, the concentration of phenolic substances, browning potential and wine sensory attributes were determined. Grape seed extract was effective in decreasing white wine turbidity when compared to potassium caseinate. In red wine, GSE removed some anthocyanin and proanthocyanins, while wine colour was only slightly affected. The greatest GSE effect was observed on the sensory properties of the treated wines, as it strongly reduced the vegetal notes in the rose wine and improved the overall taste of the red wine as a result of the reduction in both acidity and astringency. Conclusions Grape seed extract can be considered a valid allergen-free alternative to the most common wine fining agents. Significance of the Study Grape seed extract is the first effective fining agent endogenous to grapes, thus not attracting the legal restrictions concerning the presence of foreign substances.

Background Since the second half of the 20th century, the cultivation of ancient and local apple cultivars has almost disappeared from orchards in Italy. Some of these ancient apple cultivars often possess high nutraceutical values and display lower allergenicity than the modern ones, supporting the so-called 'green revolution' theory. Results In this study, the phenolic composition and the antioxidant activity of five ancient apple cultivars ('Belfiore', 'Pomella Genovese', 'Gravenstein', 'Bella del Bosco', and 'Piatlin') were compared with a 'Golden Delicious' commercial cultivar. Additionally, apples were tested for their potential allergenicity by detecting the presence of Mal d 3, a non-specific lipid transfer protein that represents the main apples' allergen. All apples came from northern Italy (Trentino Region) and were organically produced. Results showed that, for all cultivars, the skins contained more polyphenols than the pulps. 'Bella del Bosco' had the highest amount of polyphenols and antioxidant activity, whereas 'Piatlin' had the lowest phenolic content. All ancient cultivars presented a higher amount of pulp phenolic compounds than 'Golden Delicious'. Immunoblotting techniques showed that 'Bella del Bosco' and 'Piatlin' had very low quantities of Mal d 3 allergen; hence, they can be considered hypoallergenic cultivars. Conclusions The preservation of ancient apple cultivars would be of great importance, not only to maintain the biodiversity but also for their nutritional properties. The hypoallergenic activity of some of these cultivars could be of interest also for the preparation of different apple-based products. © 2020 Society of Chemical Industry.

While proteins are present in wine at low concentration, and are largely associated with undesirable haze formation in white wines, certain types or fractions make direct and indirect contributions to sensory quality and physical stability. The proteins found in wine represent a small subclass of the total pool of grape proteins that remain soluble in the non-physiological conditions of the wine matrix which is characterised by the presence of alcohol, high acidity, and relatively high levels of phenolic compounds. Although initially stable in these conditions, during storage of white and rose wines proteins undergo changes leading to haze formation which is considered one of the most relevant non-microbiological defects, and which makes the wine commercially unacceptable. This phenomenon involves the two most abundant proteins present in wines: thaumatin-like proteins and chitinases, both belonging to pathogenesis-related proteins of the grape berry. Haze formation is often triggered by thermal fluctuations occurring during storage of white wines, although the presence of other non-protein-related factors seems to be necessary. Here, we review the characteristics of these two protein families and the factors that influence their solubility with a focus on the disulfide bonds reduction as a possible trigger for the onset of their aggregation.

An extensive survey was conducted on 110 Italian monovarietal red wines from a single vintage to determine their standard compositional, color, and phenolic characteristics, analysing more than 35 parameters evaluated through methods commonly used in the wine industry. ‘Primitivo’ achieved the highest average alcohol strength (15.4% v/v) and dry extract values, while ‘Cannonau’ showed the lowest total acidity. ‘Corvina’ had the lowest phenolic content (1065 mg/L by Folin-Ciocalteu assay), remarkably different from the highest found in ‘Sagrantino’ (3578 mg/L), the latter being also the richest variety in both proanthocyanidins and vanillin-reactive flavanols. ‘Teroldego’ wines were the richest in both total and monomeric anthocyanins (702 and 315 mg/L, respectively), followed by ‘Aglianico’ and ‘Raboso Piave’, while ‘Corvina’, ‘Nebbiolo’, and ‘Nerello Mascalese’ were the poorest. ‘Montepulciano’ and ‘Sangiovese’ showed intermediate values for the majority of the parameters analyzed. A multivariate PCA-DA approach allowed achieving both a classification of the different wines as well as the discrimination of ‘Sangiovese’ wines produced in two regions (Emilia Romagna and Toscana) that returned a 42–66% success rate depending on the zone considered. Taking into account the number and diversity of the wines analyzed, a correlation study helped in better understanding the underlying relations between the most common and widespread analytical techniques for phenolic and color determinations.

Approximately two-thirds of wine produced in the UK is bottle-fermented sparkling wine. Effervescence and foamability are key features used to assess English sparkling wine (ESW) quality. A critical, yet understudied, area of research is the potential for dosage to influence foam behaviour via associated changes in wine viscosity.In this study, dosage treatments of five increasing levels of sucrose (from 0 to 31 g LThese results highlight the impact that dosage treatments can have on the quality of foam produced upon pouring, and therefore have the potential to inform future sparkling winemaking practices. © 2017 Society of Chemical Industry.

Zirconia pellets (25 g/L) enclosed in a metallic cage were added on the second day to fermenting Riesling, Sauvignon blanc, and Semillon juices. After 48 hours, the zirconia-treated juices showed a large decrease in protein content and the resulting wines were heat stable. Compared to control juices, the fermentation rate was significantly increased for two juices and unchanged in the other juice. There were reductions in concentration of some mineral elements and tartaric acid and increases in pH in the resulting wines from the zirconia-treated juices.

Climate change presents risks and opportunities for the wine industry. Little has been written about possible impacts on wine safety. This chapter draws on the latest scientific consensus regarding climate change to examine how changing production environments could be realised in the vineyard and winery. The impacts of climate change are likely to vary between viticultural regions, so this chapter looks at a range of conditions: temperature, precipitation, humidity, variability and extreme weather events which could impact viticulture and wine to differing degrees in different locations. It identifies wine safety risks resulting from climatic conditions directly, and indirect risks from practices employed to manage climatic conditions and weather events. Whilst climatic trends and changes to average conditions can often be managed in the vineyard, the frequency and nature of extreme events may prevent appropriate management strategies being implemented. In the winery a combination of oenological capability and due diligence is required to ensure product quality and safety. These will function best when supported by appropriate legal or regulatory control.

Backgrounds and Aims: Bentonite is commonly added to white wines to remove the grape proteins responsible for haze formation. Despite being effective, this technique has drawbacks; thus, new solutions are desirable. The ability of carrageenan and pectin to remove heat-unstable grape proteins, and the impact that such addition has on the physicochemical and sensorial profile of a wine were assessed. Methods and Results: Carrageenan and pectin were added separately or in combination to a Chardonnay juice prior to fermentation. Both adsorbents removed proteins (up to 75%), thus increasing wine protein stability. Carrageenan was more effective than pectin at increasing wine protein stability. Conclusions: Pectin and carrageenan removed protein and partially stabilized the samples of the wine. Significance of the Study: Pre-fermentation addition of pectin or carrageenan may provide the wine industry with an alternative protein stabilization procedure.

Background and Aims: Grape proteins are responsible for the appearance of haziness in white wines during storage after bottling. However, only a few studies have approached the analysis of the fate of must proteins throughout the alcoholic fermentation. This study aimed to systematically investigate the daily variations in protein type and content during the fermentation in order to understand its influence on hazing potential and to attain some basic information to improve the practical management of grape proteins involved in the hazing of white wines. Methods and Results: The evolution of total soluble protein and individual protein fractions was studied in samples taken before, during and after alcoholic fermentation of a white grape must. The results were then related to variations in protein instability as measured by the heat test. Both the quantity of soluble protein and the protein instability increased during fermentation and then decreased after 1-month storage of the wine. Protein composition did not vary during fermentation as assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and anion exchange chromatography (AEC). However, variations in the relative proportions of the six protein fractions obtainable by AEC were noted in the different samples. The contribution of each AEC protein fraction to wine instability was determined by considering both the intrinsic instability and the relative quantity of each of the individual protein fractions in the wine. It was demonstrated that the grape thaumatin-like protein VVTL1, as identified by mass spectrometry, showed the largest increase during fermentation and accounted for almost 40% of the heat-induced haze of the final wine. Moreover, the decreased protein instability noted after one month storage of the wine could be attributed to the stabilizing effect of polysaccharides released by the yeast cells. Conclusions: The quantity and relative proportion of soluble proteins vary during and after the alcoholic fermentation, as does their heat instability in wine. Grape VVTL1, constituting a large proportion of the total proteins in wine, seems to play a major role in protein haze formation. The release of yeast polysaccharides is related to an increased heat stability of total wine protein, despite the increase in the relative proportion of their most unstable component VVTL1. Therefore, the hazing potential of a white wine seems to be affected by variations in the relative proportions of its macromolecular components occurring in the early stages of winemaking. Significance of the Study: This study addressed for the first time the issue of the protein changing during the fermentation of white wine. The results obtained here offer useful information to aid understanding of the contribution of individual proteins to white wine instability, which can be applied for the improvement of the winemaking process. Abbreviations AEC anion-exchange chromatography; KDS potassium dodecyl sulfate; MS mass spectrometry; MW molecular weight, PAS periodic acid-Schiff stain, PR-proteins pathogenesis-related proteins, RT retention time, SDS-PAGE sodium dodecyl sulfate-polyacrylamide gel electrophoresis, TL thaumatin-like, VVTL1 Vitis vinifera thaumatin-like protein

Backgrounds and Aims: White wines are stabilised by removing the heat unstable proteins through adsorption by bentonite. Bentonite fining is not an efficient wine processing step and can also remove other wine components. Alternative absorbents are thus sought; zirconium dioxide (zirconia) is recognised as a promising candidate. The aim of this work was to assess the viability of zirconia treatments to stabilise white wines, with particular attention on process development. Methods and Results: Effective treatment was achieved by enclosing zirconia pellets into a metallic cage submerged in the wine. With this method, the wine could be treated with the adsorbent for the time required for protein stabilisation, and then removed without further manipulation. Zirconia treatments of three unstable wines partially or fully stabilised them without detectable modifications of their physicochemical parameters and colours, apart from the removal of metals and some acids, particularly when wines were treated for long times and with high dosages of the adsorbent. A simple and inexpensive zirconia regeneration method was also developed. Conclusions: The zirconia application to wine was very effective in removing proteins, and the proposed regeneration procedure could facilitate the uptake and development of zirconia-based solutions for the wine industry. Significance of the Study: This study confirmed the effectiveness of zirconia in removing wine proteins and demonstrated that the proposed method of application has the potential to become a viable alternative to bentonite.

During the storage, bottled white wines can manifest haziness due to the insolubilisation of the grape proteins that may 'survive' in the fermentation process. Although the exact mechanism of this occurrence is not fully understood, proteins and tannins are considered two of the key factors involved in wine hazing, since their aggregation leads to the formation of insoluble particles. To better understand this complex interaction, proteins and tannins from the same unfined Pinot grigio wine were separated. Wine proteins were then fractionated by hydrophobic interaction chromatography (HIC). A significant correlation between hydrophobicity of the wine protein fractions and the haze formed after reacting with wine tannins was found, with the most reactive fractions revealing (by SDS-PAGE and RP-HPLC analyses) the predominant presence of thaumatin-like proteins. Moreover, the effects of both protein heating and disulfide bonds reduction (with dithiotreithol) on haze formation in the presence of tannins were assessed. These treatments generally resulted in an improved reactivity with tannins, and this phenomenon was related to both the surface hydrophobicity and composition of the protein fractions. Therefore, haze formation in wines seems to be related to hydrophobic interactions occurring among proteins and tannins. These interactions should occur on hydrophobic tannin-binding sites, whose exposition on the proteins can depend on both protein heating and reduction.

Three-dimensional data acquisition systems are becoming progressively more affordable, especially those that rely on photographic cameras and motion sensing input devices such as the Microsoft Kinect and PlayStation Eye. At the same time, mobile devices capable of rendering complex 3D graphics and with always-on broadband connectivity are becoming increasingly wide-spread. As a result, there is a potential opportunity for the development of novel mobile-oriented streaming mechanisms that can support the visualisation of large and rapid changing spatial-temporal datasets. In this work, we introduce a framework for the visualisation of spatial-temporal point cloud models on mobile devices. One advantage of our framework is that it eliminates the need to pre-downloading spatial-temporal models prior to their visualisation, hence avoiding the need of large storage requirements. Additionally, it streams spatial-temporal geometry using progressive levels of detail that are optimised to the mobile’s rendering capabilities and network bandwidth. The representation of different levels of detail is not bounded to a particular geometry reduction algorithm and the streaming process is totally transparent to the user, who perceives remote 3D models as local ones. To evaluate the relevance and impact of this study, a use case is also presented.

Residual proteins in finished wines can aggregate to form haze. To obtain insights into the mechanism of protein haze formation, a reconstitution approach was used to study the heat-induced aggregation behavior of purified wine proteins. A chitinase, four thaumatin-like protein (TLP) isoforms, phenolics, and polysaccharides were isolated from a Chardonnay wine. The same wine was stripped of these compounds and used as a base to reconstitute each of the proteins alone or in combination with the isolated phenolics and/or polysaccharides. After a heating and cooling cycle (70 °C for 1 h and 25 °C for 15 h), the size and concentration of the aggregates formed were measured by scanning ion occlusion sensing (SIOS), a technique to detect and quantify nanoparticles. The chitinase was the protein most prone to aggregate and the one that formed the largest particles; phenolics and polysaccharides did not have a significant impact on its aggregation behavior. TLP isoforms varied in susceptibility to haze formation and in interactions with polysaccharides and phenolics. The work establishes SIOS as a useful method for studying wine haze.

Grape chitinase was found to be the primary cause of heat-induced haze formation in white wines. Chitinase was the dominant protein in a haze induced by treating Sauvignon blanc wine at 30 °C for 22 h. In artificial wines and real wines, chitinase concentration was directly correlated to the turbidity of heat-induced haze formation (50 °C for 3 h). Sulfate was confirmed to have a role in haze formation, likely by converting soluble aggregates into larger visible haze particles. Thaumatin-like protein was detected in the insoluble fraction by SDS-PAGE analysis but had no measurable impact on turbidity. Differential scanning calorimetry demonstrated that the complex mixture of molecules in wine plays a role in thermal instability of wine proteins and contributes additional complexity to the wine haze phenomenon.

A method to fractionate grape and wine proteins by hydrophobic interaction chromatography (HIC) was developed. This method allowed the isolation of a thaumatin-like protein in a single step with high yield and >90% purity and has potential to purify several other proteins. In addition, by separating HIC fractions by reverse phase HPLC and by collecting the obtained peaks, the grape juice proteins were further separated, by SDS-PAGE, into 24 bands. The bands were subjected to nanoLC-MS/MS analysis, and the results were matched against a database and characterized as various Vitis vinifera proteins. Moreover, either directly or by homology searching, identity or function was attributed to all of the gel bands identified, which mainly consisted of grape chitinases and thaumatin-like proteins but also included vacuolar invertase, PR-4 type proteins, and a lipid transfer protein from grapes.