The value of quality clues in the wine market: evidences from Lazio,Italy

The purpose of the paper is to contribute to understanding the role and effectiveness of different quality clues in the creation of value for the main wines of the Lazio region. The study presents a hedonic price model. An ordinary least squares and a quantile regression models were estimated. The latter is able to detect additional patterns related to the effects of the covariates. Prices are regressed on wine color, sub-regional area of origin, the type of certification of origin, and on experts' evaluation. The analysis is based on data released by three major Italian wine guides: Gambero Rosso, l'Espresso, and AIS (Italian Sommelier Association). Results show that: (i) white and red wines follow two different price patterns; (ii) prices are correlated with experts' evaluation; (iii) the impact of the latter is higher when other quality clues, such as geographical indications, are less effective; (iv) the role of different quality clues varies at different price levels and it is different for red and white wines; overall, wines from the Lazio region are associated with poor to mediocre quality levels. This may explain the decline in reputation and in market share that these wines are experiencing after centuries of popularity.     

Comparative study of the antioxidant capacity and polyphenol content of Douro wines by chemical and electrochemical methods

A comparative study of the antioxidant capacity and polyphenols content of Douro wines by chemical (ABTS and Folin–Ciocalteau) and electrochemical methods (cyclic voltammetry and differential pulse voltammetry) was performed. A non-linear correlation between cyclic voltammetric results and ABTS or Folin–Ciocalteau data was obtained if all types of wines (white, muscatel, ruby, tawny and red wines) are grouped together in the same correlation plot. In contrast, a very good linear correlation was observed between the electrochemical antioxidant capacity determined by differential pulse voltammetry and the radical scavenging activity of ABTS. It was also found that the antioxidant capacity of wines evaluated by the electrochemical methods (expressed as gallic acid equivalents) depend on background electrolyte of the gallic acid standards, type of electrochemical signal (current or charge) and electrochemical technique.     

Influence of training system on chromatic characteristics and phenolic composition in red wines

Chromatic characteristics and phenolic composition of red wines elaborated from Sousón and Brancellao grapes (Vitis vinifera L.), whose vines were trained in cordon and Guyot systems, were determined. This comparison was possible because there were no significant differences between yields for each one. Hue was the only significantly different chromatic parameter for both training systems and cultivars. In Sousón cultivar, saturation, colour intensity and red percentage were greater for Guyot system. Sousón cultivar trained in Guyot system and Brancellao cultivar trained in cordon system were characterized by higher total anthocyanin concentration. However, greater ionization index and flavanols reagent with dimethyl aminocinemaldehyde were associated with Guyot and cordon systems, respectively, independently on cultivar. Furthermore, gentisic acid, as well as malvidin-3-glucoside, petunidin-3-acetylglucoside and malvidin-3-caffeoylglucoside in less extension, permitted to differentiate training systems in both Sousón and Brancellao cultivars. Principal component analysis was also performed for a better understanding of the differences found.     

Influence of the elaboration process on the peptide fraction with angiotensin I-converting enzyme inhibitor activity in sparkling wines and red wines aged on lees

The influence of some variables on the manufacturing process for sparkling and red wines on the angiotensin I-converting enzyme inhibitory (ACEI) activity has been studied. Ageing on lees significantly influenced the angiotensin I-converting enzyme inhibitor activity in sparkling wines. It reached maximum values at 9 months, decreasing afterwards. In red wines, the ACEI activity also increased in the wines aged on lees. In both wines, hydrophobic peptides were responsible for the ACEI activity. These peptides would make a much greater contribution to the total activity if present in higher proportions. It would therefore be advantageous to increase their concentrations in wines, either by using starting materials with high initial peptide contents or by using a highly autolytic yeast, giving a greater degree of hydrolysis of wine proteins, and higher concentrations of peptides with ACEI activity.     

Formation of the highly stable pyranoanthocyanins (vitisins A and B) in red wines by the addition of pyruvic acid and acetaldehyde

Pyruvic acid (500 mg/l) and acetaldehyde (200 mg/l) were added, either as a large single dose or as smaller weekly doses over a 10 week period, to a young red wine (Vitis vinifera L. cv Tempranillo) in order to study the formation of vitisin A and B, and p-coumaroylvitisin A and B. In a further trial, pyruvic acid and acetaldehyde were added simultaneously as a single administration to test for any synergistic effect on vitisin formation. The addition of pyruvic acid led to the production of higher concentrations of vitisin A (4.08 ± 0.86 mg/l; 2.03% of the total anthocyanin content), while additions of acetaldehyde increased the concentration of vitisin B (2.47 ± 0.09 mg/l; 1.35%). The single, large dose administrations led to greater vitisin formation than did the smaller, weekly doses. Different patterns of formation were seen for vitisin A and B: the highest vitisin A content was achieved during the latter half of the 10 week study period while the highest vitisin B concentration was achieved early. The addition of acetaldehyde produced a greater reduction in monomeric anthocyanins than did the addition of pyruvic acid (loss of total anthocyanins 81.5%). The simultaneous addition of pyruvic acid and acetaldehyde led to less vitisin formation than did the addition of the reagents separately. p-Coumaroylvitisin A reached a maximum concentration of 0.86 ± 0.15 mg/l when the single dose of pyruvic acid was added, while the maximum recorded for p-coumaroylvitisin B was 0.66 ± 0.05 mg/l when the single dose of acetaldehyde was added. All anthocyanins were identified using HPLC/DAD and HPLC/ESI–MS.     

Study of major aromatic compounds in port wines from carotenoid degradation

The carotenoids degradation and the formation of volatiles were examined by simulating Port wine aging. A two year old red Port wine was saturated with oxygen, supplemented with lutein and β-carotene and kept at 60 °C during 87 h. A similar study was performed in a model wine solution. Results showed that the percentage decrease in lutein levels was, respectively, 79% and 95%, in the wine model solution and in the Port wine, and 55% and 10% for β-carotene, indicating that lutein was more sensitive to degradation than β-carotene. Two other unknown degradation carotenoid compounds were identified by HPLC/DAD (reverse phase λ_max: 422; 445; 475 and 422; 445; 472) in the lutein supplemented wine. Levels of β-ionone and β-cyclocitral increased (2.5 times) in both, wine and wine model solution, supplemented with β-carotene. Along with these compounds, the same behaviour was observed in β-damascenone in the supplemented lutein wine and wine model solution. New insights were provided into the understanding of aroma modifications occurring during Port wine aging. The relationship between carotenoid molecules (β-carotene and lutein) and some volatiles has also been provided.     

The profile of volatile compounds and polyphenols in wines produced from dessert varieties of apples

The aim of this study was to determine the influence of apple variety (Šampion, Idared and Gloster) on the polyphenol profile, volatile composition and sensory characteristics of apple wines. Apples were harvested from the orchard in Garlica Murowana (Poland) and the experiments were conducted on a laboratory scale. Statistically significant differences were detected in the chemical composition of the analyzed wines. The highest antioxidant activity was found in Šampion wines, which was associated with a relatively high concentration of chlorogenic acid and procyanidins. These samples also contained high amounts of acetaldehyde, ethyl acetate and methanol. Idared wines showed a similar polyphenol profile, but they had lower antioxidant capacity and were characterized by a high level of butanol and acetic acid. Gloster wines were distinguished from other samples by a lower concentration of polyphenols and higher concentration of fusel alcohols. During sensory evaluation, wines produced from Idared apples scored the highest value for overall quality.