Evolution of anthocyanins during maturation of tempranillo grape variety (Vitis vinifera) using polynomial regression models

In general, the anthocyanin content of grapes increases during ripening but presents a concentration minimum a few days before physiological maturity. This minimum is sharper for the acyl derivatives. Significant behavioural differences were found between monoglucosides and their acyl derivatives. A polynomial model was used to describe the evolution of anthocyanins in the maturation of Tempranillo grapes (Vitis vinifera L).     

The influence of skin contact during alcoholic fermentation on the aroma composition of Ribolla Gialla and Malvasia Istriana Vitis vinifera (L.) grape wines

Grapes from the Vitis vinifera (L.) varieties Ribolla Gialla and Malvasia Istriana were subjected to two skin contact procedures: pomace maceration and whole berry maceration during alcoholic fermentation. Wine free volatile compounds were determined using two extraction techniques coupled to GC; odour activity values were calculated and compared to control wines without skin contact. The highest concentrations of esters and relative fruity impacts were determined in the control wines for both varieties. Pomace maceration was found to be an effective procedure for the extraction of varietal aroma compounds like terpenes, but only in the Malvasia Istriana was their higher impact on floral odour determined. Pomace maceration resulted in higher total phenol and methanol content. Whole berry maceration was less efficient in terpene extraction, and its impact on general wine composition was not so radical. Control wines were chosen as preferred wines for odour and overall impression.     

Evolution of polyphenols in red wines from Vitis vinifera L. during aging in the bottle

The evolution of non-anthocyanin phenolic compounds (as measured by high-performance liquid chromatography) in young red wines from Vitis vinifera L. cv Tempranillo, Graciano and Cabernet Sauvignon (vintage 2000) from Navarra (Spain) was studied during 26 months of aging in the bottle. Hydroxybenzoic acids and derivatives (gallic, protocatechuic, vanillic and syringic acids, and methyl and ethyl gallates), hydroxycinnamic acids and derivatives (trans-caftaric, cutaric, caffeic and p-coumaric acids, and hexose esters of trans-p-coumaric acid), stilbenes (trans- and cis-resveratrol-3-O-glucosides, and trans- and cis-resveratrol), phenolic alcohols and other related compounds (tyrosol and tryptophol), flavanols [procyanidins B1 and B2, (+)-catechin and (–)-epicatechin] and flavonols (myricetin-3-O-glucoside, quercetin-3-O-galactoside and quercetin-3-O-glucuronide, kaempherol-3-O-glucoside, myricetin and quercetin) presented different evolution patterns during aging, in some cases also being different depending on the grape variety studied. The changes that occurred during aging in the bottle were the decrease of the concentration of trans-caftaric and cutaric acids accompanied by an increase of trans-caffeic acid and, especially of trans-p-coumaric acid. The greater increase of trans-p-coumaric acid was also associated with the disappearance of p-coumaroyl-acylated anthocyanins that occurs during aging in the bottle. Flavanols registered a major decrease, with the disappearance rate being greater for the dimeric procyanidins than for the monomeric flavanols, and the order of the disappearance rate by variety was as follows: Tempranillo相似文献   

Evolution of polyphenols in red wines from Vitis vinifera L. during aging in the bottle

The evolution of anthocyanins and pyranoanthocyanins (as measured by high-performance liquid chromatography) in young red wines from Vitis vinifera L. cv Tempranillo, Graciano and Cabernet Sauvignon (vintage 2000) from Navarra (Spain) was studied during 26 months of aging in the bottle. For the anthocyanin pigments of grape origin, a progressive decrease in their concentration, corresponding to first-order kinetics, was observed during this period. Independently of the anthocyanin structure studied, grape anthocyanins in Tempranillo wine presented twofold slower kinetics than those in Graciano and Cabernet Sauvignon wines, which exhibited a very similar disappearance rate. Acylated anthocyanins presented a slightly higher disappearance rate than the nonacylated ones, indicating the possible hydrolysis of the former into the latter forms. However, no distinction was observed in the kinetics of the different anthocyanidin forms (delphinidins, petunidins, peonidins and malvidins). These results indicate that during aging under nonoxidative conditions (bottle), the chemical reactivity of grape anthocyanins in wine is influenced by the grape variety, a factor that imposes over the stability associated with the chemical structure of each anthocyanin form. In relation to the evolution of pyranoanthocyanins, anthocyanin–pyruvic acid adducts presented a similar or lower disappearance rate than their corresponding anthocyanin precursors during the first months of aging in the bottle, while anthocyanin–vinylphenol and anthocyanin–vinylflavanol adducts did not exhibit significant variations during the whole period studied.     

Antioxidant activity in relation to the phenolic profile during the winemaking of sweet wines Vitis vinifera cv. Cabernet Sauvignon

The phenolic profile during the winemaking of Cabernet Sauvignon sweet wines has been studied, including the stages of controlled grape drying and the posterior maceration of the fortified musts with their skins. Each phenolic family has been correlated individually with the antioxidant activity measured by the 2,2,‐diphenylpicrylhydrazyl assay. Linear regressions with a confidence level superior to 99% have been found with hydroxybenzoic acids, esters of hydroxycinnamic acids, flavan‐3‐ol derivatives, tannins, anthocyanin adducts, polymers and polymeric pigments. With a multiple correlation, the antioxidant properties of musts and sweet wines were explained jointly by the families of polymeric pigments and flavan‐3‐ol derivatives. The musts during the drying process and the wines during the maceration presented a different phenolic composition and were distinguished using a cluster analysis and a principal component analysis.     

Time course of the colour of young red wines from Vitis vinifera L. during ageing in bottle

The colour characteristics of red wines from Vitis vinifera L. cv Tempranillo, Graciano and Cabernet Sauvignon (vintage 2000) from Navarra (Spain), was studied during 26 months of ageing in bottle through the evaluation of the wine visible spectrum and of several colorimetric indices (colour intensity, %red, %yellow, %blue, %dA and tint) and CIELAB variables (L*, C*, h, a* and b*). During ageing in bottle, the spectrum of Tempranillo wine (pH 4.3) mainly changed in the absorbance range between 420 and 500 nm, whereas Graciano (pH 3.5) and Cabernet Sauvignon (pH 3.6) wines registered a decrease in absorbance in the interval between 500 and 560 nm. The time course of the different wine colour parameters was found to fit either a second‐order polynomium or a linear model, depending on the grape variety employed. CIELAB variables could be described in terms of their colorimetric index counterparts, showing b* and h relative greater errors. Although the wine total chromatic changes in CIELAB units registered after 26 months of ageing in bottle indicated changes perceivable by the human eye (ΔE* ≥ 2.7) for the three varieties studied, Graciano and Cabernet Sauvignon wines showed a more balanced colour evolution than Tempranillo wine.     

Polyphenolic composition of Spanish red wines made from Spanish Vitis vinifera L. red grape varieties in danger of extinction

Phenolic composition, chromatic characteristics, and antioxidant activity of young wines made from three minority red grape varieties (Moravia Dulce, Rojal and Tortosí) cultivated in the Spanish region of Castilla-La Mancha were studied over two vintages. Phenolic contents were affected by both grape variety and vintage, whereas phenolic profiles were mainly affected by grape cultivar, thus allowing their differentiation The anthocyanin profiles of Moravia Dulce and Tortosí wines were dominated by malvidin 3-glucoside, whereas peonidin 3-glucoside was in Rojal wines. The flavonol profile of Rojal and, in a lesser extent, Tortosí wines were dominated by B-ring di-substituted flavonols (mainly quercetin-type flavonols). In contrast, B-ring tri-substituted flavonols (mainly myricetin-type) predominated in Moravia Dulce wines. All studied wines had high quantities of total resveratrol, especially Rojal and Moravia Dulce wines, although they mainly occurred as cis-isomers. Rojal wines always appeared as the most different single-cultivar wines in all parameters in this study, being characterized by the lowest content of almost all families of phenolic compounds. With regard to the colour characteristics, all the studied wines had normal values to be considered young red wines except for Rojal wines, which should be considered as rosé wines. Finally, all wines showed remarkable antioxidant activity, closely connected with their phenolic content. The results suggest that Moravia Dulce and Tortosí grape cultivars could be appropriate raw materials for the elaboration of quality young red wines, whereas Rojal grapes could be for rosé wines.     

Physico-chemical and sensory quality of extruded light red kidney bean (Phaseolus vulgaris L.) porridge

A laboratory co-rotating twin-screw extruder was used to study the effect of extrusion conditions on physical, chemical, and sensory characteristics of extruded light red kidney beans (Phaseolus vulgaris L). Raw bean flour was extruded at 25 g/100g and 36 g/100g moisture content. Other extrusion parameters were: barrel temperatures, 120 °C/105 °C (BT-1) and 130/115 °C (BT-2); screw speeds, 118 rpm (SS-1), 194 rpm (SS-2), and 253 rpm (SS-3); and feed rates of 80 and 120 g/min (FR-1 and FR-2, respectively). Extrudates were analyzed for expansion ratio (ER), bulk density (BD), water absorption index (WAI), water solubility index (WSI), and lectins, as phytohemagglutinin (PHA) activity. Sensory evaluation of bean porridge, obtained after coarsely grinding extrudates, was done to compare it to Sosuma, a traditional Rwandan porridge. Feed rate significantly influenced average ER, which was determined to be 1.22 and 1.30 for FR-1 and FR-2, respectively. Increasing moisture content from 25 g/100g to 36 g/100g significantly increased average BD. The WAI and WSI values did not show a clear trend under extrusion conditions used in this study. For all extruded samples, lectin was reduced to less than one-tenth of that in the raw beans. Sensory evaluation of bean porridge, on a 1-9 hedonic scale (1 = dislike extremely and 9 = like extremely), exhibited scores of 7.65, 7.69, 6.25, and 6.94 for color, texture, flavor, and overall acceptability, respectively.     

Differences in the phenolic composition and sensory profile between red wines aged in oak barrels and wines aged with oak chips

The aim of this study was to evaluate the similarities or differences in the phenolic composition and the sensory characteristics between wines traditionally aged in new French and American barrels for different periods of time, and wines aged for 30 days with different kinds (different geographical origin al toasting degree) of oak chips. This study was carried out with two grape varieties, Mencía and Tinta del País, and in two consecutive vintages. The results obtained indicated that it was not possible to obtain wines aged with chips with sensory characteristics similar to those aged for a long time in new barrels, independently. However, the results showed that the use of oak chips could be a good alternative for elaborating young wines with slight olfactory and gustative wood notes quite similar to wines aged in new barrels for short periods of time (about three months).     

The relationship between sensory quality and volatile compounds in raw juice processed from elderberries (Sambucus nigra L.)

Elderberry juice was processed by pressing of 101 samples of elderberries (Sambucus nigra L.) picked in Austria, England and Denmark at optimum maturity. Taste panels trained in determination of elderberry flavour evaluated the juices and the results from the sensory evaluation were correlated to the content of volatile compounds. The volatile compounds were isolated from elderberry juices by dynamic headspace technique and analysed by GC-FID and GC-MS. A total of 59 volatile compounds were identified, 9 of which have not previously been detected in elderberry products. A total of 53 compounds occurred in quantifiable amounts and significant differences among the investigated elderberry samples were observed for 50 compounds. The importance of the isolated volatile compounds to elderberry flavour was determined by classical factor analysis using the results from the sensory evaluation and information on the odour of the individual volatile compounds. Classical factor analysis were used including determination of eigenvalues, factor loadings and factor scores by varimax rotation of standardised variables for extraction of four non correlated factors (principal components) explaining approximately 73% of the variation in elderberry flavour. Twenty-eight volatile compounds and sensory quality were included in the four factors. Using the compounds with highest numerical values (loadings) the four factors were named: fresh-elderberry-elder flower (35.2%), fresh-fruity-sweet (17.3%), fresh-fruity (13.7%) and green-floral-fruity (6.7%). Three compounds with characteristic elderberry odour (-damascenone, nonanal, dihydroedulan) were closely correlated with the sensory quality of elderberry together with compounds with fruity, floral, green and/or miscellaneous odours.     

Relationship between sensory quality and volatile compounds of elderflower (Sambucus nigra L.) extracts

Elderflower samples (Sambucus nigra L.) of 89 different genotypes were picked at optimum flowering time in Austria, England and Denmark and extracted with an aqueous solution containing sucrose, citric acid, ascorbic acid, and sodium benzoate, and investigated for the emission of volatile compounds. Volatile compounds emitted from elderflower extracts were collected by dynamic headspace technique (purge and trap) and analysed by GC–FID and GC–MS. A total of 59 volatile compounds were identified and quantified, and significant differences among the investigated elderflower extracts were observed for 58 compounds. Diluted elderflower extracts was evaluated by sensory panels trained in determination of elderflower flavour and the results from the sensory evaluation was correlated to the content of volatile compounds in the extracts using classical factor analysis including determination of eigenvalues, factor loadings and factor scores. Four principal components (PC1–PC4), which included 28 volatile compounds and sensory quality, were extracted from the factor analysis. The four PCs explained, altogether 73.7% of the data variation [PC1 (38.5%), PC2 (19.7%), PC3 (8.1%) and PC4 (7.4%)]. Important contributors to the floral and elderflower flavour of the extracts were rose oxides, hotrienol, linalool, linalool derivatives and α-terpineol, whereas the fruitiness and freshness of the extracts were mainly due to non-oxidized monoterpenes, aliphatic aldehydes and alcohols. Possibilities for selection of cultivars with specific flavours are discussed.     

A Novel Process for the Recovery of Polyphenols from Grape (Vitis vinifera L.) Pomace

ABSTRACT: A novel process for enzyme-assisted extraction of polyphenols from winery by-products was established on a pilot-plant scale. Optimization of enzymatic hydrolysis of grape skins, that is, selection of pectinolytic and cellulolytic enzymes, enzyme-substrate ratio, and time-temperature regime of enzymatic treatment, was conducted on a laboratory scale. Enzyme activities were monitored by viscosity measurement of resuspended grape pomace and by quantification of oligomeric pectin and cellulose degradation products released from cell wall material. Optimal conditions were obtained with 5000 ppm (based on dry matter) of a pectinolytic and 2500 ppm of a cellulolytic enzyme preparation, respectively, at 50°C, which were also applied in pilot-plant scale experiments. Concomitant determination of individual polyphenolics demonstrated a significantly improved yield for most compounds when compared with experiments without enzyme addition. Recovery rates were comparable to those obtained when grape pomace was extracted using sulfite. Pre-extraction of the pomace with hot water followed by treatment with cell wall degrading enzymes even increased yields of phenolic compounds. Only some quercetin glycosides and malvidin coumaroylglucoside were partly hydrolyzed due to enzyme side activities. This new process may provide a valuable alternative to the application of sulfite, which is considered crucial in food processing.     

Comparing the effects of exogenous abscisic acid on the phenolic composition of Yan 73 and Cabernet Sauvignon (Vitis vinifera L.) wines

Phenolic compounds from red wines exert a strong influence on wine quality. Abscisic acid (ABA) is essential for the physiological and biochemical function of plants, but few investigators have thoroughly researched its effects on phenolic compounds in dyer grape varieties. The effects of exogenous ABA treatment on the phenolic composition and individual anthocyanin and non-anthocyanin phenolic contents of Yan 73 and Cabernet Sauvignon wines from the ABA-treated grapes, including anthocyanins, flavan-3-ols, flavonols, phenolic acids, and stilbenes were compared. The phenolic compounds in the Yan 73 wine were different from those in the Cabernet Sauvignon wine. The phenolic content (anthocyanins and non-anthocyanins) of the Yan 73 wine was significantly higher than that of the Cabernet Sauvignon wine. The concentrations of the individual phenolic compounds were enhanced by the ABA treatment for the two different wine varieties. The effects on the compositions varied, a similar trend was observed for the ratios of Cy-derivative and Dp-derivative pigments from the two wine varieties, and all non-acylated pigments were enhanced. The stilbene content was enhanced, the ratios of flavan-3-ol dimers and dimer-glucosides were reduced, and the effects on the composition of other compounds varied between the two grape varieties.     

Effect of micro-oxygenation on the evolution of aromatic compounds in wines: Malolactic fermentation and ageing in wood

The effect of micro-oxygenation on the aromas of two varietal wines (Tempranillo and Cabernet Sauvignon) when alcoholic fermentation is complete was examined. Several factors, such as whether malolactic fermentation (MLF) took place in barrels or stainless steel vats and ageing time in oak barrels, were taken into account. Major aroma components were studied using GC-FID and minor compounds were studied by GC-MS analysis before and after MLF and after 4 and 8 months of maturation in oak barrels. Sensorial analysis was performed to describe and quantify the different wine notes. Micro-oxygenation affects different compounds but the effect depends to a great extent on the grape varietal used; the effect of micro-oxygenation was more marked on the aroma of Cabernet Sauvignon wine than Tempranillo wines. The concentration of extractable compounds of wood was higher in wines after MLF in barrels than in wines after MLF in steel vats; wines with steel vat MLF had fewer toast and wood notes. The compounds that showed significant differences in concentration after 8 months of maturation were present in higher concentrations in wines fermented in barrels than in stainless steel vats. Barrel-fermented wines were sweeter, with wood and toast notes, fewer alcohol notes and fewer reductive notes.     

Physicochemical and sensory quality of wines from red sorrel/roselle (Hibiscus sabdariffa L.) calyces: effects of pretreatments of pectolase and temperature/time

The effects of pretreating red sorrel (Hibiscus sabdariffa L.) calyces on the physicochemical and sensory quality of wines were investigated. Sorrel calyces were processed at 60 °C for 3.5 h or 90 °C for 30 min at 0%, 0.5% and 1.0% w/w pectolase addition in fermentation of wines. Significant changes (P < 0.01) in all physicochemical parameters of sorrel wines were found during fermentation, but not (P > 0.05) because of temperature/time effects. Colour (P < 0.01) became redder with pectolase and on storage at 23 °C for 2 months. Significant differences (P < 0.01) were noted in sensory quality for taste and flavour, balance, duration and overall quality. Higher (P < 0.01) overall sensory quality scores were obtained for wines by pretreatment at 90 °C for 30 min (10.44–11.06/20) when compared with wines at 60 °C for 3.5 h (6.88–9.06/20). Colour of wines from 90 °C/30 min was most saturated and red than all wines and had pH 2.57 ± 0.01, 0.43 ± 0.07% citric acid, 10.53 ± 0.53 °Bx and 15.29 ± 0.71% alcohol.     

Anthocyanin profiles of major red grape (Vitis vinifera L.) varieties cultivated in Greece and their relationship with in vitro antioxidant characteristics

A range of fourty‐six red grape (Vitis vinifera spp.) samples, originating from six widely cultivated varieties and covering major parts of the Hellenic vineyard, were assayed for their content in six principal anthocyanin pigments. Representative in vitro antioxidant parameters were also determined, including antiradical activity (A_AR), reducing power (P_R) and hydroxyl free radical scavenging activity (SA_HFR). Quantitative determination using high performance liquid chromatography showed that the prevalent pigment was malvidin 3‐O‐glucoside (average content 82.53 mg per 100 g fresh berry weight), followed by its coumarate derivative (29.26 mg per 100 g), paeonidin 3‐O‐glucoside (10.84 mg per 100 g), petunidin 3‐O‐glucoside (7.80 mg per 100 g) cyanidin 3‐O‐glucoside (5.67 mg per 100 g) and delphinidin 3‐O‐glucoside (1.28 mg per 100 g). The richest variety was Syrah, with total average anthocyanin content of 186.02 mg per 100 g, whereas the Hellenic native variety Xinomavro had the lowest average anthocyanin level (38.70 mg per 100 g). The establishment of correlations of individual and total anthocyanin contents with the values from the antioxidant test was accomplished with linear regression. The links of total anthocyanins were significant with all antioxidant parameters (P < 0.001), but more importantly with SA_HFR (R² = 0.740). Malvidin 3‐O‐glucoside content had the higher correlation with SA_HFR compared with all other anthocyanins (R² = 0.698, P < 0.001).     

Effect of smoking on quality parameters of farmed gilthead sea bream (Sparus aurata L.) and sensory attributes of the smoked product

The effect of smoking on the proximate composition, chemical parameters and microbial loads of farmed gilthead sea bream (Sparus aurata L.), as well as the sensory attributes of the smoked product were investigated. The process reduced the moisture content and the total aerobic count and increased the protein, lipids and total volatile basic nitrogen content and the thiobarbituric acid number . The values of the last two parameters were much lower than acceptable limits reported in the literature references for smoked fish products. No effect was noted on the fatty acid composition of total lipids. The new product was highly acceptable to laboratory and consumer panels.Kyriakos Vareltzis deceased