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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.

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.

With increasing concerns about the production of sustainable materials, the field of wood-based materials still offers a critical challenge. Indeed, a close dependence on petroleum derivatives is still required, involving high consumption of non-renewable and toxic chemicals in the assembly of wooden parts. Herein, the aim of this research was to evaluate the potentiality of an entirely renewable tannin-based adhesive for particleboard production. Industrial quebracho (Schinopsis balansae) tannin powder was selected as a raw material and analyzed in terms of polyphenols, polysaccharides, and the total condensed amount. Furfural was proposed as a bio-sourced hardener to establish crosslinking between the flavonoid units and hence produce a resin. This formulation was analyzed in terms of viscosity and curing time and then applied to laboratory-scale single-layer particleboard production. The density, mechanical properties, and thickness swelling of the panels were investigated at different glue ratios and pressing conditions. It was observed that time has a higher impact than temperature on the internal bond, and panels pressed at 160 °C for a longer pressing time (>7 min) performed better than the boards obtained at a higher temperature. The registered values at 160 °C for 11 min of pressing of internal bond (0.37 MPa) and modulus of elasticity (1417 MPa) met the required standards for P1 panels according to European norms EN 312 (2010). Conversely, the modulus of rupture (4.9 MPa) did not satisfy the requirements suggesting the need for the use of additive or post-treatments. Considering the results achieved, quebracho–furfural adhesives are an interesting base for bio-based adhesive formulations.

Thanks to their low odor detection thresholds, free varietal thiols (VTs) play a key role in the primary aroma of wines, to which they confer an intense scent reminiscent of box tree, grapefruit, citrus fruits, passionfruit and cat urine odor. Excluding wines from a few VT-rich grapevine cultivars, VTs appear to be present in most cultivars at trace levels, although a comprehensive dataset is still missing. The low concentration of VTs combined with their high reactivity and matrix complexity make their determination in wines a challenging task. In this research an optimized liquid chromatography – tandem mass spectrometry (LC-MS/MS) method was validated and used for the quantification of 4-methyl-4-sulfanylpentan-2-one (4-MSP), 3-sulfanylhexan-1-ol (3-SH), 3-sulfanylhexyl acetate (3-SHA) and ethyl 3-sulfanylpropionate (E3SP) in 246 samples (vintage 2019) representative of 18 monovarietal Italian white wines. VTs were detected in all cultivars even though higher values of 3-SH were found in Lugana, Müller-Thurgau and Verdicchio cultivars. Müller-Thurgau wines showed the highest level of 4- MSP, that was mainly correlated to the odor descriptors of passionfruit and box tree/cat urine. The VTs composition of Müller-Thurgau was confirmed on a second set of 50 wines from different vintages. From a sensory perspective, the samples of Müller-Thurgau showed the best positive correlations between chemical variables and the odor descriptors thiol note, passion fruit and box tree/cat urine. These notes are significantly related to 4-MSP, suggesting that it could play a relevant olfactory role for the aroma of Müller-Thurgau wines. Sorting analysis allowed to group these wines according to their thiolic characteristics. The chemical variables and the odor descriptors attributable to the thiol notes are important for Müller-Thurgau and Lugana wines, while the contribution of thiol notes was sensorially negligible for the other wines.

Colloids are an important component of wines, but their study is challenging due to their instability. Asymmetrical Flow-Field Flow Fractionation (AF4)-multidetection is here proposed as a suitable approach to isolate and characterize red wine colloids in native state. AF4 provided size-separation and enabled quantification of the colloidal content of two wines. The gyration radius of colloids was determined by multi-angle light scattering, and ranged between 25 and 50 nm. Analysis of the collected AF4-fractions showed that proteins, polysaccharides and phenolics were present in different proportions among fractions. The composition of AF4-fractions differed between wines. SDS-PAGE analysis of AF4-fractions indicated the presence of protein-phenolics sub-aggregates only in the fractions containing colloids with small radius. The results allowed proposing a model for red wine colloids structure, which comprises two coexisting entities, one made of covalently linked proteins-phenolics sub-aggregates interacting by non-covalent forces with polysaccharides, and a second in which only polysaccharides and phenolics are present. The proposed model is consistent with the reported relative stability of red wine proteins, a fact that can be due to the stabilizing activity of polysaccharides. Given that enological practices affect the extraction of proteins, polysaccharides and phenolics, AF4-technique represents a very promising tool to investigate the effects of these practices on wine colloidal aggregation and behavior.

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.

The exogenous application of yeast-derived mannoproteins presents many opportunities for the improvement of wine technological and oenological properties. Their isolation from the cell wall of Saccharomycescerevisiae has been well studied. However, investigations into the efficiency of extraction methods from non-Saccharomyces yeasts are necessary to explore the heterogeneity in structure and composition that varies between yeast species, which may influence wine properties such as clarity and mouthfeel. In this study, nine yeast strains were screened for cell wall mannoprotein content using fluorescence microscopy techniques. Four species were subsequently exposed to a combination of mechanical and enzymatic extraction methods to optimize mannoprotein yield. Yeast cells subjected to 4 min of ultrasound treatment applied at 80% of the maximum possible amplitude with a 50% duty cycle, followed by an enzymatic treatment of 4000 U lyticase per g dry cells weight, showed the highest mannoprotein-rich yield from all species. Furthermore, preliminary evaluation of the obtained extracts revealed differences in carbohydrate/protein ratios between species and with increased enzyme incubation time. The results obtained in this study form an important step towards further characterization of extraction treatment impact and yeast species effect on the isolated mannoproteins, and their subsequent influence on wine properties.

Smoke taint has become a prominent issue for the global wine industry as climate change continues to impact the length and extremity of fire seasons around the world. Although the issue has prompted a surge in research on the subject in recent years, no singular solution has yet been identified that is capable of maintaining the quality of wine made from smoke-affected grapes. In this review, we summarize the main research on smoke taint, the key discoveries, as well as the prevailing uncertainties. We also examine methods for mitigating smoke taint in the vineyard, in the winery, and post production. We assess the effectiveness of remediation methods (proposed and actual) based on available research. Our findings are in agreement with previous studies, suggesting that the most viable remedies for smoke taint are still the commercially available activated carbon fining and reverse osmosis treatments, but that the quality of the final treated wines is fundamentally dependent on the initial severity of the taint. In this review, suggestions for future studies are introduced for improving our understanding of methods that have thus far only been preliminarily investigated. We select regions that have already been subjected to severe wildfires, and therefore subjected to smoke taint (particularly Australia and California) as a case study to inform other wine-producing countries that will likely be impacted in the future and suggest specific data collection and policy implementation actions that should be taken, even in countries that have not yet been impacted by smoke taint. Ultimately, we streamline the available information on the topic of smoke taint, apply it to a global perspective that considers the various stakeholders involved, and provide a launching point for further research on the topic.

Due to their natural origin and broad availability, industrial tannin extracts are extending their application field from the classical, and still principal, application in tannery, to oenology, pharmacy, adhesives and material science. Despite the growing interest, not much is known about the thermal valorization of these biomolecules. In this article we present the thermal properties of the eight most common commercial tannin extracts and their elemental chemical composition to shed light on the end-life of the bio-materials based on these polyphenols. Results have shown that hydrolysable tannins can be managed similarly to wood, while condensed tannins have higher heating values but also generally higher chlorine content. Sumac and gambier leaf extracts registered contained heating values and significant amounts of ashes rich in calcium and sulfur. The high chlorine content observed for the extracts of mimosa (Acacia Mearnsii) does not hinder the combustion of its derived products which can still be thermally valorized. Mimosa tannin-based materials can also be added up to 2% to wood pellets and briquettes without significantly affecting the overall quality of the biofuels according to the in-force standards.

Wine lees are an under-exploited sludge-like material mainly consisting of yeast cells that, upon fermentation, settle at the bottom of wine tanks. Lees from commercial red and white winemaking were processed to yield mannoprotein-rich extracts. An established autoclave-based extraction protocol, as well as a simplified version of it, were applied. The composition of the obtained wine lees extracts was determined. Extracts were tested as emulsifying and foaming agents in model food systems and benchmarked against analogues extracts derived from laboratory-grown yeast cultures of the same two strains used for red and white wines production. All extracts showed good functionalities as emulsifying and foaming agents. However, some differences were noted in both composition and functionality, and these were related to the purification process used, yeast strain, and to the extract's origin (red lees, white lees, lab-grown yeasts). Extracts from real wine lees, which contained also grape-derived polyphenols, performed equally or better than the corresponding extracts derived from laboratory-grown yeast cultures of the same strains. Both red and white wine lees can be a novel and effective source of emulsifiers and foaming agents representing a valid alternative to the yeast biomass produced in bioreactors to be potentially used in the food industry.

Wine lees, a sludge-like material mainly consisting of yeast cells, are rich in mannoproteins. However, no reports on the extraction of mannoproteins from wine lees to be used as winemaking additives are available. This study aimed at developing efficient methods for yeast glycocompounds extraction from wine lees, and to assess their impacts when added back to wine. White wine lees were extracted using physical (autoclave and ultrasonication) and enzymatic (a β-glucanases) approaches. The autoclave extract was the richest in glycocompounds and showed the highest impact on wine tartrate stability and foaming properties. Conversely, the extracts containing less glycocompounds (ultrasonication and enzymatic) both improved wine protein stability upon heat test and had a low effect on wine foaming. In general, wine lees can be considered as a valuable source of substances to be used as winemaking additives thus opening the way to a new type of exploitation of these by-products.

Background Polysaccharides are a major class of complex macromolecules present in the wine matrix. These polysaccharides can be classified as being either grape or yeast derived. The key polysaccharides identified within the wine matrix are the pectic polysaccharides: polysaccharides rich in arabinose and galactose (PRAG), rhamnogalactouronans (RG-I and RG-II) and yeast mannoproteins (MP). The transformation of grapes into wine induces significant changes in the chemical composition and profile of these polysaccharides. Scope and approach This review aims to summarise and discuss the prevalence of polysaccharides in wine, with a focus on their profile during the transformation from grape to wine. This study emphasises the chemical complexity of the wine matrix, highlighting the many factors influencing the profile and abundance of polysaccharides which could in turn assist winemakers in making informed decisions. Key findings and conclusions Many factors during grape maturation and throughout the winemaking process have been shown to influence the profile and chemical composition of polysaccharides. Environmental factors can significantly influence the polysaccharide profile of grape berries prior to harvest. Fermentation is responsible for the largest modification in the polysaccharide profile throughout vinification. Overall, the transition of must to wine is characterised by an increase in grape derived AGPs and RG-II, as well as a dramatic and progressive increase in yeast MP, especially true for wines aged on yeast lees.

Polyphenols are an important constituent of wines and they are largely studied due to their antioxidant properties and for their effects on wine quality and stability, which is also related to their capacity to bind to proteins. The effects of some selected polyphenols, including procyanidins B1 and B2, tannic acid, quercetin, and rutin, as well as those of a total white wine procyanidin extract on the conformational properties of the major wine protein VVTL1 (Vitis vinifera Thaumatin-Like-1) were investigated by Synchrotron Radiation Circular Dichroism (SRCD). Results showed that VVTL1 interacts with polyphenols as demonstrated by the changes in the secondary (far-UV) and tertiary (near-UV) structures, which were differently affected by different polyphenols. Additionally, polyphenols modified the two melting temperatures (TM) that were found for VVTL1 (32.2 °C and 53.9 °C for the protein alone). The circular dichroism (CD) spectra in the near-UV region revealed an involvement of the aromatic side-chains of the protein in the interaction with phenolics. The data demonstrate the existence of an interaction between polyphenols and VVTL1, which results in modification of its thermal and UV denaturation pattern. This information can be useful in understanding the behavior of wine proteins in presence of polyphenols, thus giving new insights on the phenomena that are involved in wine stability.

Wine lees is a sludge material mainly composed of dead yeast precipitated at the bottom of wine tanks. Along with grape pomace and grape stalks, it is one of the main by-products of the winemaking industry. Given that wine lees are considered a soil pollutant, their disposal represents a cost for wineries. Numerous wine lees recovery and valorization strategies have been proposed, with a particularly steep increase in published research in recent years. This attention is strictly linked to the concepts of circular economy and environmental sustainability that are attracting the interest of the scientific community. In this review, an overview on the available wine lees recovery and valorization strategies is reported. Additionally, the methods for the extraction and valorization of yeast's cell wall polysaccharides (β-glucans and mannoproteins) are discussed. Finally, current and future innovative applications in different sectors of yeast β-glucans and mannoproteins are described and critically discussed.

The aim of this project was to register, in a liquid chromatography–mass spectrometry-based untargeted single-batch analysis, the metabolome of 11 single-cultivar, single-vintage Italian red wines (Aglianico, Cannonau, Corvina, Montepulciano, Nebbiolo, Nerello, Primitivo, Raboso, Sagrantino, Sangiovese, and Teroldego) from 12 regions across Italy, each one produced in their terroirs under ad hoc legal frameworks to guarantee their quality and origin. The data provided indications regarding the similarity between the cultivars and highlighted a rich list of putative biomarkers of origin wines (pBOWs) characterizing each individual cultivar–terroir combination, where Primitivo, Teroldego, and Nebbiolo had the maximum number of unique pBOWs. The pBOWs included anthocyanins (Teroldego), flavanols (Aglianico, Sangiovese, Nerello, and Nebbiolo), amino acids and N-containing metabolites (Primitivo), hydroxycinnamates (Cannonau), and flavonols (Sangiovese). The raw data generated in this study are publicly available and, therefore, accessible and reusable as a baseline data set for future investigations.

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.