scholarly journals Effect of Pre-Fermentative Maceration and Fining Agents on Protein Stability, Macromolecular, and Phenolic Composition of Albariño White Wines: Comparative Efficiency of Chitosan, k-Carrageenan and Bentonite as Heat Stabilisers

Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 608
Author(s):  
Inma Arenas ◽  
Miguel Ribeiro ◽  
Luís Filipe-Ribeiro ◽  
Rafael Vilamarim ◽  
Elisa Costa ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Protein Stability ◽  
White Wine ◽  
The Other ◽  
White Wines ◽  
Comparative Efficiency ◽  
Fining Agents ◽  
Protein Instability ◽  
Related Proteins ◽  
Protein Stabilisation

In this work, the effect of pre-fermentative skin maceration (PFSM) on the chemical composition of the macromolecular fraction, polysaccharides and proteins, phenolic compounds, chromatic characteristics, and protein stability of Albariño monovarietal white wines was studied. PFSM increased the extraction of phenolic compounds and polysaccharides and reduced the extraction of pathogenesis-related proteins (PRPs). PFSM wine showed significantly higher protein instability. Sodium and calcium bentonites were used for protein stabilisation of wines obtained with PFSM (+PFSM) and without PFSM (−PFSM), and their efficiencies compared to fungal chitosan (FCH) and k-carrageenan. k-Carrageenan reduced the content of PRPs and the protein instability in both wines, and it was more efficient than sodium and calcium bentonites. FCH was unable to heat stabilise both wines, and PRPs levels remained unaltered. On the other hand, FCH decreased the levels of wine polysaccharides by 60%. Sodium and calcium bentonite also decreased the levels of wine polysaccharides although to a lower extent (16% to 59%). k-Carrageenan did not affect the wine polysaccharide levels. Overall, k-carrageenan is suitable for white wine protein stabilisation, having a more desirable impact on the wine macromolecular fraction than the other fining agents, reducing the levels of the wine PRPs without impacting polysaccharide composition.

scholarly journals White Wine Protein Instability: Mechanism, Quality Control and Technological Alternatives for Wine Stabilisation—An Overview

Beverages ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 19 ◽  
Author(s):  
Fernanda Cosme ◽  
Conceição Fernandes ◽  
Tânia Ribeiro ◽  
Luís Filipe-Ribeiro ◽  
Fernando M. Nunes
Keyword(s):  
Protein Stability ◽  
White Wine ◽  
Instability Mechanism ◽  
Stability Tests ◽  
Pathogenesis Related ◽  
Instability Factor ◽  
Main Protein ◽  
Protein Instability ◽  
Related Proteins ◽  
Grape Proteins

Wine protein instability depends on several factors, but wine grape proteins are the main haze factors, being mainly caused by pathogenesis-related proteins (thaumatin-like proteins and chitinases) with a molecular weight between 10~40 kDa and an isoelectric point below six. Wine protein stability tests are needed for the routine control of this wine instability, and to select the best technological approach to remove the unstable proteins. The heat test is the most used, with good correlation with the natural proteins’ precipitations and because high temperatures are the main protein instability factor after wine bottling. Many products and technological solutions have been studied in recent years; however, sodium bentonite is still the most efficient and used treatment to remove unstable proteins from white wines. This overview resumes and discusses the different aspects involved in wine protein instability, from the wine protein instability mechanisms, the protein stability tests used, and technological alternatives available to stabilise wines with protein instability problems.

scholarly journals Gelatine, casein and potassium caseinate as distinct wine fining agents: different effects on colour, phenolic compounds and sensory characteristics

OENO One ◽  
2007 ◽  
Vol 41 (4) ◽  
pp. 203 ◽  
Author(s):  
Asençao Braga ◽  
Fernanda Cosme ◽  
Jorge Manuel Ricardo-da-Silva ◽  
Olga Laureano
Keyword(s):  
Phenolic Compounds ◽  
Charge Density ◽  
Surface Charge ◽  
Surface Charge Density ◽  
White Wine ◽  
Sensory Characteristics ◽  
Wine Quality ◽  
Physico Chemical ◽  
Fining Agents ◽  
Monomeric Anthocyanins

<p style="text-align: justify;"><strong>Aims</strong>: Describe and compare some characteristics, such as molecular weight (MW) distribution and surface charge density of commercial protein fining agents and to enhance the understanding of their effect on wine chemical and sensory characteristics.</p><p style="text-align: justify;"><strong>Methods and results</strong>: Protein (casein, potassium caseinate and gelatine) MW distribution was characterised by electrophoresis. These proteins were added to a red and a white wine, in order to evaluate its effect on colour, phenolic compounds and sensory attributes.</p><p style="text-align: justify;"><strong>Conclusion</strong>: A band at 30.0 kDa characterised casein and potassium caseinate. Gelatines showed polydispersion on the MW distribution, gelatine GSQ on the higher MW (&gt; 43.0 kDa) and gelatine GL on the lower MW (&lt; 43.0 kDa). Despite the fact that casein and potassium caseinate had similar MW distribution, casein decreased essentially the monomeric ((+) - catechin and (-) - epicatechin) while the potassium caseinate showed a lower influence on these compounds. Also, among the two gelatines used, a different behaviour was observed. The gelatine characterised by a polydispersion below 43.0 kDa depleted more the polymeric tannin fractions than the gelatine characterised by a polydispersion above 43.0 kDa. That gelatine has also decreased colour intensity and coloured anthocyanins of red wine but the hue remains unchanged. Addition of fining agents did not affect greatly the concentration of monomeric anthocyanins. Sensory analysis showed that wines fined with the different proteins presented distinct characteristics.</p><p style="text-align: justify;"><strong>Significance and impact of study</strong>: The knowledge of the physico-chemical characteristics, such as MW distribution and surface charge density, is important for wine fining optimisation and consequently for the wine quality.</p>

scholarly journals Regeneration of Magnetic Nanoparticles Used in the Removal of Pathogenesis-Related Proteins from White Wines

Foods ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 1 ◽  
Author(s):  
Agnieszka Mierczynska-Vasilev ◽  
Geridi Qi ◽  
Paul Smith ◽  
Keren Bindon ◽  
Krasimir Vasilev
Keyword(s):  
Magnetic Nanoparticles ◽  
Acrylic Acid ◽  
Water Solution ◽  
White Wine ◽  
Wine Industry ◽  
White Wines ◽  
Pathogenesis Related Proteins ◽  
Removal Capacity ◽  
Pathogenesis Related ◽  
Related Proteins

Protein haze remains a serious problem for the wine industry and requires costly bentonite treatment, leading to significant wine volume loss. Recently developed magnetic separation technology that allows a fast and efficient separation of haze proteins from wine shows promise for the development of an alternative method for white wine fining. The key purpose of this study was to understand the potential of the nanoparticles to be reused in multiple fining and regeneration cycles. Bare and acrylic-acid-based plasma polymer coated magnetic nanoparticles were cleaned with water, 10% SDS/water and acetone/water solution after each adsorption cycle to investigate their restored efficiency in removing pathogenesis-related proteins from three unfined white wines. The concentrations of metals, acids and phenolics were monitored to determine changes in the concentration of these essential wine constituents. The regeneration study verified that the acrylic acid plasma-coated magnetic nanoparticles, which underwent ten successive adsorption-desorption processes, still retained close to the original removal capacity for haze proteins from wines when 10% SDS solution and water were used for surface regeneration. In addition, the concentrations of organic acids and wine phenolic content remained almost unchanged, which are important indicators for the retention of the original wine composition.

scholarly journals Effect of Pre-fermentation Maceration on the Content of Antioxidant Compounds in Grapevine Juice

2017 ◽  
Vol 45 (1) ◽  
pp. 105-111 ◽  
Author(s):  
Mojmir BARON ◽  
Michal KUMSTA ◽  
Bozena PRUSOVA ◽  
Lenka TOMASKOVA ◽  
Jiri SOCHOR
Keyword(s):  
Phenolic Compounds ◽  
Red Wine ◽  
White Wine ◽  
Hydroxycinnamic Acids ◽  
Antioxidant Compounds ◽  
Main Role ◽  
Lower Content ◽  
White Wines ◽  
Anti Oxidant

Lower antioxidant capacity of white wines is caused by a lower content of phenolic compounds. In red wine, a higher content of phenolic compounds is the result of maceration. This study deals with effects of pre-fermentation maceration on contents of some selected compounds (above all antioxidants) in juices made of grapes of white varieties 'Welschriesling', 'Green Veltliner' and 'Neuburger'. The grapevine mush was macerated for 0; 2; 4; 8; 12; 24 and 48 hours. The spectrophotometry methods was used to estimate juice antioxidant activity and content of flavanols, anthocyans, catechins, hydroxycinnamic acids and flavonols. Contents of total titratable acids and pH were estimated as well. Results of this study show increasing tendency of all parameters with length of maceration. The highest content of antioxidants were found out in the variety 'Welschriesling'. Important are increasing values of hydroxycinnamic acids. However, the main role of the phenolics acids is to contribute to the anti-oxidant capacity, the tartaric esters of hydroxycinnamic acids (particularly caftaric acid) are centrally involved in oxidation and browning reactions in white wine. Their levels increased during the whole period of maceration. In 'Welschriesling', their content increased by 74 mg·L-1. Decreasing tendency show results of titratable acids. Their contents decreased within the first 12 hours of maceration and thereafter they do not change. Longer must maceration could contribute to a decrease in contents of total titratable acids and, thus, to a better harmony of produced wine.

scholarly journals Impact of Hanseniaspora Vineae in Alcoholic Fermentation and Ageing on Lees of High-Quality White Wine

Fermentation ◽  
2020 ◽  
Vol 6 (3) ◽  
pp. 66 ◽  
Author(s):  
Juan Manuel Del Fresno ◽  
Carlos Escott ◽  
Iris Loira ◽  
José Enrique Herbert-Pucheta ◽  
Rémi Schneider ◽  
...  
Keyword(s):  
Alcoholic Fermentation ◽  
Yeast Species ◽  
White Wine ◽  
The Other ◽  
High Quality ◽  
White Wines ◽  
Viable Method ◽  
Ageing On Lees ◽  
Saccharomyces Yeasts

Hanseniaspora vineae is an apiculate yeast that plays a significant role at the beginning of fermentation, and it has been studied for its application in the improvement of the aromatic profile of commercial wines. This work evaluates the use of H. vineae in alcoholic fermentation compared to Saccharomyces cerevisiae and in ageing on the lees process (AOL) compared to Saccharomyces and non-Saccharomyces yeasts. The results indicated that there were not significant differences in basic oenological parameters. H. vineae completed the fermentation until 11.9% v/v of ethanol and with a residual sugars content of less than 2 g/L. Different aroma profiles were obtained in the wines, with esters concentration around 90 mg/L in H. vineae wines. Regarding the AOL assay, the hydroalcoholic solutions aged with H. vineae lees showed significantly higher absorbance values at 260 (nucleic acids) and 280 nm (proteins) compared to the other strains. However, non-significant differences were found in the polysaccharide content at the end of the ageing process were found compared to the other yeast species, with the exception of Schizosaccharomyces pombe that released around 23.5 mg/L of polysaccharides in hydroalcoholic solution. The use of H. vineae by the wineries may be a viable method in fermentation and AOL to improve the quality of white wines.

scholarly journals Clarification des vins par filtration en flux tangentiel (ultrafiltration). Incidence sur la composition chimique et les qualités organoleptiques. Evolution des produits au cours du vieillissement

OENO One ◽  
1988 ◽  
Vol 22 (1) ◽  
pp. 49
Author(s):  
Michel Serrano ◽  
Anne-Claire Vannier ◽  
Pascal Ribéreau-Gayon
Keyword(s):  
Phenolic Compounds ◽  
Chemical Analysis ◽  
Protein Stability ◽  
Breaking Point ◽  
Red Wines ◽  
Colour Intensity ◽  
Composition Chimique ◽  
White Wines ◽  
Two Samples ◽  
Composés Phénoliques

<p style="text-align: justify;">Les auteurs étudient la clarification des vins en flux tangentiel avec un ultrafiltre pilote muni de membranes organiques. Les débits de perméat sont faibles (30 l x h<sup>-1</sup> x m<sup>-2</sup>) mais le colmatage peu important. Les pourcentages de retentat sont peu élevés (0,3 à 0,7 %). Les produits ainsi clarifiés présentent de faibles turbidités et des indices de colmatage très bas. Cette technique entraîne une rétention importante des polysaccharides et des composés phénoliques des vins rouges. Les qualités organoleptiques sont légèrement affectées dans les premiers mois qui suivent l'opération, mais les différences entre les vins témoins et ultrafiltrés sont difficiles à détecter après douze mois de conservation des échantillons.</p><p style="text-align: justify;">+++</p><p style="text-align: justify;">Wine clarification with a tangentiel flux through a pilot ultrafilter with organic pads (breaking point 50,000 Daltons.) has been studied. Porosity is low (30 l x h<sup>-1</sup> x m<sup>-2</sup>), but the blockage of the filter is hardly possible as the percentage of retentiveness is limited (0.3 % to 0.7 %). The finished wines thus clarified have a perfect sparkling clarity and a low blockage potential. The type of sterilization, however, used with this type of filter-pads made it impossible to obtain a complete erradication of all microorganisms in the filtrate. Close filtration has little influence on the aromatic flavours and aromas of white wines although macromolecules are highly affected. A 76 % to 88 % fall in the amount of polysaccharides may be observed. In the same way the phenolic compounds in red wines are affected. The more mature, the richer in alcohol and colour the wine is, the greater the effect of close filtration upon the wine; this may provoke a visible fall in the colour intensity. Close filtration improves tartric stability but has hardly any effect at all on protein stability in white wines. When applied to young wines, close filtration does not show a significant change in the organoleptic analysis compared to more traditional filtration processes, particularly when tasted after a six months period of ageing. When close filtration is applied to more mature wines, the organoleptic analysis may detect it during the first months after the filtration, but it tends to disappear and it is hardly traceable after a year or two. It is surprising to note that on such red wines the organoleptic analysis cannot detect the differences between two samples, one which had undergone close filtration and one which had not, despite a major changes in the chemical analysis particulary concerning the colour and the amount of polysaccharides.</p>

scholarly journals A comprehensive analysis of novel disulfide bond introduction site into the constant domain of human Fab

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hitomi Nakamura ◽  
Moeka Yoshikawa ◽  
Naoko Oda-Ueda ◽  
Tadashi Ueda ◽  
Takatoshi Ohkuri
Keyword(s):  
Thermal Stability ◽  
Pichia Pastoris ◽  
Protein Stability ◽  
Disulfide Bond ◽  
Binding Activity ◽  
Comprehensive Analysis ◽  
The Other ◽  
Constant Domain ◽  
Intermolecular Disulfide Bond ◽  
Sds Page

AbstractGenerally, intermolecular disulfide bond contribute to the conformational protein stability. To identify sites where intermolecular disulfide bond can be introduced into the Fab’s constant domain of the therapeutic IgG, Fab mutants were predicted using the MOE software, a molecular simulator, and expressed in Pichia pastoris. SDS-PAGE analysis of the prepared Fab mutants from P. pastoris indicated that among the nine analyzed Fab mutants, the F130C(H):Q124C(L), F174C(H):S176C(L), V177C(H):Q160C(L), F174C(H):S162C(L), F130C(H):S121C(L), and A145C(H):F116C(L) mutants mostly formed intermolecular disulfide bond. All these mutants showed increased thermal stability compared to that of Fab without intermolecular disulfide bond. In the other mutants, the intermolecular disulfide bond could not be completely formed, and the L132C(H):F118C(L) mutant showed only a slight decrease in binding activity and β-helix content, owing to the exertion of adverse intermolecular disulfide bond effects. Thus, our comprehensive analysis reveals that the introduction of intermolecular disulfide bond in the Fab’s constant domain is possible at various locations. These findings provide important insights for accomplishing human Fab stabilization.

scholarly journals Characterisation of Extracts Obtained from Unripe Grapes and Evaluation of Their Potential Protective Effects against Oxidation of Wine Colour in Comparison with Different Oenological Products

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1499
Author(s):  
Giovanna Fia ◽  
Ginevra Bucalossi ◽  
Bruno Zanoni
Keyword(s):  
Antioxidant Activity ◽  
Red Wine ◽  
Waste Product ◽  
Natural Antioxidants ◽  
White Wine ◽  
Small Scale ◽  
Protective Effects ◽  
White Wines ◽  
Accelerated Oxidation ◽  
Wine Colour

Unripe grapes (UGs) are a waste product of vine cultivation rich in natural antioxidants. These antioxidants could be used in winemaking as alternatives to SO2. Three extracts were obtained by maceration from Viognier, Merlot and Sangiovese UGs. The composition and antioxidant activity of the UG extracts were studied in model solutions at different pH levels. The capacity of the UG extracts to protect wine colour was evaluated in accelerated oxidation tests and small-scale trials on both red and white wines during ageing in comparison with sulphur dioxide, ascorbic acid and commercial tannins. The Viognier and Merlot extracts were rich in phenolic acids while the Sangiovese extract was rich in flavonoids. The antioxidant activity of the extracts and commercial tannins was influenced by the pH. In the oxidation tests, the extracts and commercial products showed different wine colour protection capacities in function of the type of wine. During ageing, the white wine with the added Viognier UG extract showed the lowest level of colour oxidation. The colour of the red wine with the UG extract evolved similarly to wine with SO2 and commercial tannins. The obtained results indicated that natural and healthy UG extracts could be an interesting substitute for SO2 during wine ageing.

scholarly journals Impact of Specialty Malts on Wort and Beer Characteristics

Fermentation ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 137
Author(s):  
Luis F. Castro ◽  
Abigail D. Affonso ◽  
Renata M. Lehman
Keyword(s):  
Phenolic Compounds ◽  
Free Amino ◽  
Amino Nitrogen ◽  
The Other ◽  
Fermentable Sugars ◽  
Total Phenolic ◽  
Total Phenolic Compounds ◽  
Polyphenol Content ◽  
The Impact

Specialty malts are commonly used in brewing to provide flavor, aroma, and color to wort and beer. The use of specialty malts contributes to the variety of beer products; therefore, it is important to understand their effect on the characteristics of wort and beer. This study investigates the impact of various specialty malts on wort and beer properties. A control beer was prepared with 100% base malt, and four beer treatments were prepared with the addition of kilned, roasted, and caramel specialty malts. For each treatment, 20% of the base malt was substituted with the various specialty malts when preparing the wort. The fermentable sugars and free amino nitrogen (FAN) content for each wort were analyzed. Alcohol by volume (ABV), international bitterness units (IBU), diacetyl, and polyphenol content of each prepared beers were subsequently analyzed. Results showed that wort prepared with the addition of roasted and caramel malts contained a lower concentration of fermentable sugars and FAN than wort prepared with the base and kilned malts. Beers prepared with the addition of roasted and caramel malts exhibited the lowest levels of ABV, as well as the lowest levels of diacetyl. These beers also exhibited higher levels of total phenolic compounds compared to the other beer samples. No change was observed in IBU levels as a result of brewing with the different specialty malts. This study illustrates how the use of specialty malts impacts wort and beer properties, providing useful information to aid in the production of quality beer products.

Sign in / Sign up

Export Citation Format

Share Document