Different physicochemical interactions between varietal wines and human saliva: Correspondence with astringency.

Astringency corresponds to the sensation of dryness and roughness that is experienced in the oral cavity in association with the interaction between salivary proteins and food polyphenols. In this study, the phenolic composition of seven varietal wines, the intensity of astringency they evoke and the physicochemical reactivity of these wines with whole human saliva were evaluated. Phenolic composition of wines was characterized by spectrophotometry and HPLC chromatography. Intensity of astringency was evaluated by trained sensory panels. Saliva from a single volunteer subject was used to assess wine-saliva interactions. To this end, binary mixtures were produced at different v/v wine/saliva ratios and each of them assayed for the ability of the salivary protein to diffuse on a cellulose membrane (diffusion test) and to remain in solution (precipitation test). Physicochemical reactivities between wine components and the protein fraction of saliva were contrasted against the astringency and the phenolic profile of each varietal wine. The study supports the view that astringency depends on physicochemical interactions between two complex matrices -wine and saliva- and not between some of their particular components.

Paper chromatography approach for the assessment of interaction between red wine and whole saliva.

In-mouth interaction of red wine compounds with salivary proteins is a primary event allegedly responsible for eliciting the mouth-feel sensation of astringency. Those interactions have been currently associated with precipitation of salivary protein/polyphenol complexes. However, such single physicochemical evidence for interaction does not account for the complexity of astringency. This study aimed to develop a paper chromatography method to assess interactions between red wine and the salivary protein fraction using stepwise series of red wine/saliva binary mixtures from 100% wine to 100% saliva ("Alpha and Omega series"). Aliquots of each one of the mixtures were spotted on a cellulose membrane to scrutinize independently the distribution areas of wine components (naturally pink-colored) and salivary protein (stained blue in Coomassie Brilliant R-250). This double target detection revealed interactions between saliva and red wine components along most of the quantitative Alpha and Omega series, a point of equivalence corresponding to maximum interactivity for both complex reactants and a non-diffusible sub-fraction of saliva displaying the highest interactivity. The results indicate a novel way to assess quantitatively physicochemical interactions between red wines and human saliva but also provide new lights to approach the identification of molecular salivary structures involved in triggering astringency.

Perception of quality and complexity in wine and their links to varietal typicality: An investigation involving Pinot noir wine and professional tasters.

Quality and complexity are abstract terms employed frequently to describe a wine's overall attributes. In the present study, we investigated: (i) attributes driving wine professionals' judgments of quality and complexity in Pinot noir wines; (ii) the relation between these two abstract concepts; and (iii) association of each concept with varietal typicality. Twenty-two wine professionals evaluated 18 New Zealand Pinot noir wines in both clear and opaque glassware via two sensory tasks, a descriptive rating task and an 8-attribute, perceived complexity questionnaire. Sensory data were associated with wine UV-spectrophotometry colour measures to aid interpretation of the influence of tasting-glass colour. Results demonstrated the key drivers of perceived quality were descriptors varietal typicality, expressiveness, overall structure, and attractive fruit aromatics, along with complexity questionnaire attributes of harmony, balance and number of identifiable flavours. Reductive notes drove low-quality judgments. Data show that quality and complexity were positively associated concepts and that both were linked positively with varietal typicality. Visual influence was not a major driver of wine professionals' judgments but being able to see a wine's colour influenced tasters' judgments to wines at each end of the price/quality spectrum. We discuss the results in terms of cognitive phenomena associated with judgments by those with domain-specific expertise.

Correction: Del Barrio-Galán, R., et al. Evaluation of Yeast Derivative Products Developed as an Alternative to Lees: The Effect on the Polysaccharide, Phenolic and Volatile Content, and Colour and Astringency of Red Wines. Molecules 2019, 24, 1478.

The authors wish to make the following corrections to this paper [...].

Evaluation of Yeast Derivative Products Developed as an Alternative to Lees: The Effect on the Polysaccharide, Phenolic and Volatile Content, and Colour and Astringency of Red Wines.

Due to the increase of the use of yeast derivatives (YDs) in winemaking to improve the technological and sensory properties in wines, in this work we evaluated the effect of the post-fermentation application of different yeast derivative products on the physical and chemical properties and astringency of red wines during two consecutive harvests. A commercial and two experimental new yeast derivatives were applied at a medium‒high dosage (30 g/hL). The addition of different yeast derivatives in red wine increased the concentration of different polysaccharide fractions and, therefore, the total polysaccharide content, producing a decrease in the duration of the wine astringency perception over time. The use of yeast derivatives could produce an adsorption/clarification and/or protective effect on the phenolic compounds. However, it did not produce an important modification of the colour parameters. An intensification or a lower decrease of the most volatile compound groups was produced, but it depended on the YDs and yeast strain used in fermentation and post-fermentation processes.

Study of the changes in volatile compounds, aroma and sensory attributes during the production process of sparkling wine by traditional method.

One of the strongest factors that affects the volatile profile of sparkling wine is the winemaking process. Here we focus on determining the effects of the second fermentation and aging on lees of sparkling wine from País grape variety combining different analysis techniques for the first time in sparkling wine: gas chromatography/mass spectrometry/olfactometry and sensorial analysis. During the second fermentation and aging, there was a significant loss of esters that might be related to the adsorption on lees and ester volatility and chemical hydrolysis. The concentration of several compounds such as some esters (diethyl succinate, ethyl lactate, and ethyl isovalerate) increased during aging and could be used as aging markers. Vitispiranes were identified as the best norisoprenoids aging markers for young sparkling wines (12 months of aging). Also, PCA showed that time of aging on lees affected mostly esters and terpenes. On the other hand, the diminution of fruity/floral impact odorants during aging was not perceived in sensorial trials. Our results suggest that the responsibility for fruity/floral nuances in sparkling wine might reside in a few high-impact aromatic compounds, such as ethyl isobutyrate, isoamyl acetate, ethyl hexanoate, ß-phenylethanol and diethyl succinate.

Wines in contact with oak wood: the impact of the variety (Carménère and Cabernet Sauvignon), format (barrels, chips and staves), and aging time on the phenolic composition.

BACKGROUND: This study characterized the flavonoid and nonflavonoid phenolic composition of Carménère and Cabernet Sauvignon wines that were in contact with barrels, chips, and staves during a 12 month aging period. The wines were evaluated by spectrophotometric (for total phenols, anthocyanins and tannins, colorant intensity, hue, CIELab parameters, and fractionation into mono-, oligo-, and polymers of proanthocyanidins) and high-performance liquid chromatography diode array detection analyses (for ellagitannins, gallotannins, anthocyanins, and low molecular weight phenols). RESULTS: Wines in contact with oak wood presented a strong enrichment with nonflavonoid compounds, such as caffeic, gallic, and ellagic acids and ellagitannins. Wines in contact with staves stood out for the increased presence of total phenols, vanillic acid, and higher color intensity, whereas wines aged in contact with chips showed large contents of proanthocyanidin gallates. Wines aged in barrels exhibited high contents of ellagitannins and ethyl gallates. The effect of wood on the phenolic composition was mostly associated with the original and intrinsic characteristics of each grape variety. CONCLUSION: Extraction of phenolic compounds from oak wood during wine aging is closely related to the wood format, grape variety (Carménère or Cabernet Sauvignon), and aging time. The final effect of wood on wine would be related not just to the transference of polyphenols from wood, but also to structural modifications of grape polyphenols. © 2018 Society of Chemical Industry.

Location effects on the polyphenolic and polysaccharidic profiles and colour of Carignan grape variety wines from the Chilean Maule region.

This paper reports on a study of chemical characterization and colour parameters of cv. Carignan red wines from six locations and two production years of the Chilean Maule valley. The chemical study was performed on polyphenolic composition (benzoic acids, hydroxycinnamic acid derivatives, stilbenes, flavan-3-ols, flavonols and anthocyanins) and several fractions of proanthocyanidins and polysaccharides. Results revealed that although significantly (p < 0.05) different content of anthocyanins were observed according to the production year, it could be possible to establish fingerprints of the different locations of the Maule valley wines. Thus, wines from zones closer to the Andes Mountains had higher content of procyanidin B3 (Caliboro), polysaccharides and cis-resveratrol-glucoside (Loncomilla and Melozal), whereas the proximity to the Pacific Ocean provoked a unifying effect in chemical and colorimetric terms (Cauquenes, Sauzal and Huerta del Maule).

Great diversity among commercial inactive dry-yeast based products.

Commercial inactive dry-yeast based (IDYB) products have been shown to impact positively in different ways on the winemaking process, including sensory enhancement. Despite their relevance little information about physicochemical characteristics of individual IDYB products is available. This study aimed to physicochemically characterize a group of ten commercial IDYB products. Organic, protein and carbohydrate contents by spectrophotometric methods, protein diffusion on cellulose membranes and electrophoretic protein profiles were assessed. Interaction of a IDYB product (CP10) with either salivary protein or a proanthocyanidin-rich extract (binary mixtures) or with both of them (ternary mixtures) was also assessed. Marked physicochemical differences were observed among all ten products. CP10 was found to interact with seed extract and salivary protein. Also, as part of CP10-SE complexes, CP10 interacted with the salivary protein to form ternary complexes. Due to their huge diversity, physicochemical characterization of IDYB products before use in winemaking is recommended.

Effect of different aging techniques on the polysaccharide and phenolic composition and sensory characteristics of Syrah red wines fermented using different yeast strains.

The effect of high levels of the polysaccharide Saccharomyces cerevisiae yeast strain (HPS) and another conventional yeast strain (FERM) on the polysaccharide and phenolic composition of Syrah red wines during alcoholic fermentation and subsequent aging on lees, with or without oak wood chips, and on inactive dry yeast was investigated. The HPS yeast released higher amounts of polysaccharides during alcoholic fermentation than FERM yeast (485 g L(-1) and 403 g L(-1), respectively) and after the aging period (516 g L(-1) and 500 g L(-1), respectively). The different aging techniques increased the polysaccharide concentration; the concentration was dependent on the aging technique applied. The interaction of the polysaccharides with the phenolic compounds depended on the yeast strain, aging technique, aging period and compound analysed. The HPS wines exhibited better sensory characteristics than the FERM wines after alcoholic fermentation; however, during the aging period, it was difficult to determine which technique produced the best wine due to the interactions of aging technique, aging period and sensory attribute evaluated.

Effect of selected Saccharomyces cerevisiae yeast strains and different aging techniques on the polysaccharide and polyphenolic composition and sensorial characteristics of Cabernet Sauvignon red wines.

BACKGROUND: The objective of this work was to study the effect of two Saccharomyces cerevisiae yeast strains with different capabilities of polysaccharide liberation during alcoholic fermentation in addition to subsequent aging on lees with or without oak wood chips as well as aging with commercial inactive dry yeast on the physical, chemical and sensorial characteristics of Cabernet Sauvignon red wines. RESULTS: The HPS (high levels of polysaccharides) yeast strain released higher amounts of polysaccharides (429 g L(-1)) than EC1118 (390 g L(-1)) during alcoholic fermentation, but the concentration equalized during the aging period (424 and 417 g L(-1) respectively). All aging techniques increased the polysaccharide concentration, but the increase was dependent on the technique applied. A higher liberation of polysaccharides reduced the concentration of most of the phenolic families analyzed. Moreover, no clear effect of the different aging techniques used in this study on color stabilization was found. The HPS wines were better valued than the EC1118 wines by the panel of tasters after alcoholic fermentation. CONCLUSION: In general, the HPS wines showed better physicochemical and sensorial characteristics than the EC1118 wines. According to the results obtained during the aging period, all aging techniques contributed to improve wine quality, but it was difficult to establish the technique that allowed the best wine to be obtained, because it depended on the aging technique used and the period of aging.

Phenolic composition and mouthfeel characteristics resulting from blending Chilean red wines.

BACKGROUND: The blending of wine is a common practice in winemaking to improve certain characteristics that are appreciated by consumers. The use of some cultivars may contribute phenolic compounds that modify certain characteristics in blended wines, particularly those related to mouthfeel. The aim of this work was to study the effect of Carménère, Merlot and Cabernet Franc on the phenolic composition, proanthocyanidin profile and mouthfeel characteristics of Cabernet Sauvignon blends. RESULTS: Significant differences in chemical composition were observed among the monovarietal wines. Separation using Sep-Pak C18 cartridges revealed differences in the concentration but not in the proportion of various proanthocyanidins. Blending reduced polyphenol concentration differences among the various monovarietal wines. Although no major overall differences were observed after blending the monovarietal wines, this oenological practice produced clear differences in mouthfeel characteristics in such a way that the quality of the perceived astringency was different. CONCLUSION: This study showed that the use of a particular wine variety (Cabernet Sauvignon) in a higher proportion in wine blending produced blends that were less differentiable from the monovarietal wine, owing to a suppression effect, producing an apparent standardization of the wines regarding chemical composition.