Sensory and analytical study of rose sparkling wines manufactured by second fermentation in the bottle

The sensory and analytical characteristics of five rose sparkling wines manufactured by the traditional method have been determined. Moreover, the changes that take place in the nitrogen and volatile fraction of the wines during the second fermentation and the aging with the yeasts have been studied. Each of these wines was made from a single industrial rose base wine of the Garnacha Tinta variety, with five selected yeasts strains. The base wine had a low content in free amino acids, 16 mg/L, and the yeast consumed more peptides than free amino acids during second fermentation. From the application of the two-way analysis of variance, yeast strain, and aging time factors to the data of volatile compounds, it has been found that most of the differences between these sparkling wines are due to the aging time. It has been verified that these rose sparkling wines have foam of good quality and that the grape variety Garnacha Tinta is suitable for the production of rose sparkling wines.     

Sensory and foaming properties of sparkling cider

The effect of yeast strain and aging time on the chemical composition, analytical, and sensory foam properties of sparkling ciders has been studied. The analytical foam parameters (foamability, HM; Bikerman coefficient, sigma; and foam stability time, T(s)) were significantly influenced by aging and yeast strain. The sensory attributes (initial foam, foam area persistence, bubble size, foam collar, and overall foam quality) improved with aging time. Likewise, the yeast strain positively influenced the assessment of initial foam, foam area persistence, number of bubble chains, and overall foam quality. Significant and positive correlations were found between alcoholic proof, dry extract, total and volatile acidities, total phenols and total proteins, and sigma, whereas HM was negatively correlated with specific gravity, alcoholic proof, dry extract, and total proteins.     

Effect of accelerated autolysis of yeast on the composition and foaming properties of sparkling wines elaborated by a champenoise method

Five mutants (obtained by UV mutagenesis) and the parent strain were selected to produce sparkling wines following the traditional or champenoise method. The wines were aged with the yeast for 9 months, with samples being taken each month for analytical and sensory determinations. The wines elaborated with mutant strain IFI473I demonstrated an accelerated release of protein, amino acids, and polysaccharides. An analysis of the secreted polysaccharides revealed that mannose was the major sugar present. The effects of the products released by yeasts on the foaming properties of the wines were determined by both sensory and instrumental analysis. In all cases, the wines elaborated with mutant strain IFI473I showed improved foaming properties as compared to wines fermented without this strain. Similar results were obtained at a decreased aging time of 6 months, thereby confirming the capacity of IFI473I strain to carry out an accelerated autolysis. These results demonstrate that mutant strain IFI473I can significantly reduce production times of high-quality sparkling wines.     

Characterization of the nitrogen compounds released during yeast autolysis in a model wine system

The nitrogen composition of wines aged with yeast for a long period of time, as in the case of sparkling wines, depends on the composition of the base wine and on the compounds released by the yeast. In this paper, the release of the different classes of nitrogen compounds during autolysis of one of the strains of yeast used in the manufacture of sparkling wines has been studied. The yeast, Saccharomyces bayanus, was suspended in a model wine buffer, pH 3.0 and 10% ethanol, and incubated at 30 degrees C. Samples of the autolysate were taken after 4, 24, 48, 72, 168, and 360 h of autolysis. An electrophoretic and chromatographic study was conducted of the proteins, peptides with molecular weights higher and lower than 700 Da, and amino acids released during the autolysis. Using SDS-PAGE, it was observed that it was predominantly polypeptides with molecular weights lower than 10 000 that were released. Through HPLC of the fraction lower than 10 000 Da, it was observed that it is polypeptides with molecular weights of between 10 000 and 700 Da that are released first and that these later break up to give rise to peptides with molecular weights lower than 700 Da, which in turn break down into amino acids. This indicates that the nature of the nitrogen compounds present in wines aged with yeast depends on the aging time, being less polymerized as the aging time increases.     

Biological aging of sherry wines using pure cultures of two flor yeast strains under controlled microaeration

Sherry wines obtained after biological aging for an average of 0, 2, and 4 years were inoculated separately with the flor yeast strains Saccharomyces cerevisiae var. capensis and Saccharomyces bayanus and subjected to short, periodic microaeration to a dissolved oxygen concentration of 4 mg L(-1) after formation of the yeast film. A principal component analysis with the acetaldehyde, ethanol, volatile acidity, and glycerol concentrations obtained was performed. The first principal component was found to account for 49.5% of the overall variance and to be defined mainly by glycerol and ethanol. The second component accounted for 38.8% of the variance and was defined by volatile acidity and acetaldehyde. The conditions used in the tests allowed the biological aging of the wines to be substantially shortened. Thus, 42 days after flor-film formation by S. cerevisiae var. capensis, 0- and 2-year-old wines exhibited parameter values similar to those obtained for the wine aged for 4 years. The wines inoculated with S. bayanus exhibited high acetaldehyde concentrations and ethanol levels above 15% (v/v)-sherry wines with alcohol concentrations below 14.5% are undesirable-, so one need not exclude the sequential or simultaneous inoculation of S. bayanus together with S. cerevisiae var. capensis in order to improve the biological aging process.     

Response of the aroma fraction in sherry wines subjected to accelerated biological aging.

The effect of an acceleration assay, carried out with a periodic aeration and an increased surface/volume ratio, on various aroma compounds of "fino" Sherry wines aging under a veil of a pure culture of Saccharomyces cerevisiae race capensis G1 flor film yeast was studied. The results were subjected to multifactor analysis of variance, and the compounds simultaneously depending on acceleration conditions and aging time at p < 0.01 were subjected to principal component analysis. The first component, accounting for 86.14% of the overall variance, was mainly defined by acetaldehyde and its derivatives 1,1-diethoxyethane and acetoin. These compounds reached higher concentrations in accelerated aging wines in a shorter time than they did in control wines, and no browning problems were detected. Taking into account that these compounds can be used as indicators for biological aging of "fino" Sherry wines, the acceleration condition assayed can be applied to shorten the time of this process.     

Occurrence of pyranoanthocyanins in sparkling wines manufactured with red grape varieties

The anthocyanin pigments in rosé (Vitis vinifera cv. Garnacha) and blanc de noir (V. vinifera cv. Monastrell) base and sparkling wines were studied by LC-DAD/ESI-MS. Anthocyanins of grape origin and pyranoanthocyanins resulting from C-4/C-5 cycloaddition of the former ones with pyruvic acid, acetaldehyde, 4-vinylphenol, 4-vinylguaiacol, and 4-vinylcatechol were identified in the different wines. Rosé wines presented a higher total pigment content than blanc de noir wines. Pyranoanthocyanins represented 68.9-76.0% of total pigment content in rosé wines and 49.4-60.7% in blanc de noir wines. Malvidin 3-glucoside-pyruvate was the most abundant pigment in both rosé and blanc de noir base wines. Important qualitative and quantitative changes were observed in terms of the anthocyanin and pyranoanthocyanin pigments after the second (bottle) fermentation and 9 months of aging on yeast lees, but not after a further time (3-9 additional months) of aging on lees. Evaluation of the wine color characteristics was consistent with a greater color stability for the rosé sparkling wines that could be associated with the high content, structural diversity, and spectroscopic features of the pyranoanthocyanins present in these wines.     

Study of low molecular weight phenolic compounds during the aging of sparkling wines manufactured with red and white grape varieties

Thirty-two phenolic compounds of low molecular weight were identified in 36 white, blanc de noir, and rosé sparkling wines by using HPLC with photodiode array and mass spectrometry detection. Some of the identified compounds, such as cis- and trans-ethylcaftaric, cis- and trans-ethylcaffeic, and cis- or trans-ethyl-p-coumaric acids, 2R,3R-dihydroquercetin, 2R,3R-dihydrokaempferol 3-O-beta-d-glucoside, and a lignan derivative are described for the first time in sparkling wines manufactured with grapes of red varieties. This is also the first time that cis- or trans-diethylfertaric acids have been identified in wines. When cluster analysis was applied to the data of 19 of the 32 identified compounds, the greatest differences found in the low molecular weight phenolic compounds in sparkling wines were due to the grape variety from which they were manufactured, whereas aging time did not significantly influence phenolic composition. Nine phenolic compounds, that is, trans-p-coumaric and trans-caftaric acids, trans-resveratrol glucoside, cis-coutaric, trans-coutaric, cis-p-coumaric, and cis-caftaric acids, tryptophol, and syringic acid, permit the wines to be classified correctly in accordance with the grape variety from which they were manufactured.     

Multivariate modeling of aging in bottled lager beer by principal component analysis and multiple regression methods

Data collected from the sensory test score evaluation of bottled lager beer, together with the chemical components related to aging, including carbonyl compounds, higher alcohols, unsaturated fatty acid, organic acids, alpha-amino acids, dissolved oxygen, and staling evaluation indices, including lag time of electron spin resonance (ESR) curve, 1,1'-diphenyl-2-picrylhydrazyl (DPPH) scavenged amounts, and thiobarbituric acid (TBA) values, were used to predict the extent of aging in bottled lager beer, using both multiple linear regression and principal component analysis methods. Carbonyl compounds, higher alcohols, and TBA value were significantly and positively correlated with sensory evaluation of staling flavor. While lag time and DPPH scavenging amount were negatively correlated with taste test score. Multiple regression analysis was used to fit the sensory test data using the above chemical compound aging related parameters and evaluation indices as predictors. A variable selection method based on high loadings of varimax rotated principal components was used to obtain subsets of the predominant predictor variables to be included in the regression model of beer aging, so as to eliminate the multicollinearity of the original nine variables. It was found that staling extent was influenced significantly by higher alcohols, TBA value, and DPPH scavenging amount, and the multicollinearity of the regression model was found to be weak by examining the variance inflation factors of the new predictor variables. A mathematic model of the organoleptic test score for beer aging using these three predictors was obtained by multiple linear regression, showing that the major contributors to the sensory taste of beer aging were higher alcohols, TBA index, and DPPH scavenging amount, with the adjusted R(2) of the model being 0.62.     

Influence of fatty acids on wine foaming

The influence of fatty acids (free and bound as ethyl esters) on wine foaming was studied in different white wines and the corresponding sparkling wines. Moreover, from three of these wines the foam formed by CO(2) injection was separated, and two fractions were then obtained: foam wine (FW) and remainder wine (RW). In these fractions and the sparkling wines produced from them, foam properties and fatty acids were also determined. The free fatty acids C8, C10, and C12 were negatively correlated with foamability (HM), whereas the ethyl esters of hexanoic, octanoic, and decanoic acids were positively related to HM. The value of HM was directly proportional to the ratio of esterified to unesterified fatty acids. This was confirmed by the changes that occur in the esterification ratio during the second fermentation and aging. No influence was observed on either the Bikerman coefficient or the stability time of foam.     

酵母硒和枣粉饲粮对鸡肉宰后氧化及氨基酸的影响研究

为研究酵母硒和枣粉饲粮对白羽肉鸡鸡胸肉成熟过程中蛋白质氧化及氨基酸含量变化的影响,本试验采用不同浓度酵母硒和枣粉饲喂白羽肉鸡42 d,根据酵母硒和枣粉添加量分为6个处理组,分别为CK(基础日粮)、J组(基础日粮+8％枣粉替换8％玉米)、0.3S(基础日粮+0.3 mg·kg-1酵母硒)、0.6S(基础日粮+0.6 mg...     

Cider proteins and foam characteristics: a contribution to their characterization

A capillary sieving electrophoretic method for protein analysis and molecular weight determination was used to characterize ciders from Asturias, northern Spain. The total protein content (Bradford method) and the foam parameters (Bikerman method) were also analyzed to complete this characterization. The polypeptide profile, based on the molecular weight, together with exploratory and classification techniques, that is, principal component analysis (PCA) or linear discriminant analysis (LDA), allowed ciders to be differentiated on the basis of their foam assessment and the apple juice extraction technology used in the cidermaking process. In addition, the application of correlation analysis, that is, canonical correlations (CCA) or partial least-squares (PLS), revealed that the proteins with higher molecular weight were more relevant with respect to cider foamability. PLS analysis also provided a mathematical equation that is able to predict the stabilization time of foam from the polypeptide profile of the cider, because this is the foam parameter most influenced by these compounds.     

酵母发酵法改善沙丁鱼蛋白酶解液风味与品质的研究

为研究长孢洛德酵母对鱼蛋白酶解液风味与品质的改善作用,本试验以远东拟沙丁鱼酶解液为原料进行发酵,采用电子鼻主成分分析(PCA)法判断不同发酵条件下产物风味物质的差异,以感官评价及氨基酸态氮含量为指标,通过正交试验优化其发酵条件,对发酵产物进行游离氨基酸组成分析和必需氨基酸营养评价,并利用气相色谱-离子迁移谱(GC-IM...     

Nitrate/Gly ratios in nutrition influenced the growth and amino acid composition in Spinach (Spinacia oleracea L.)

A hydroponic experiment was conducted to study the effects of fertilization with different nitrate/glycine (Gly) ratios on spinach growth and composition of amino acids. Results showed partly replacing nitrate (NO₃^?) by Gly supplied both nitrogen and carbon nutrition for spinach. Spinach accumulated the equal biomass. Total nitrogen (N) in plant had a positive relationship with nitrate/Gly ratios in nutrition. There was more than 2-fold increase in N uptake from all glycine to nitrate, and plant nitrate contents increased from 0.97 to 3.13 mg g^?1. All of 17 proteogenic amino acids in mature leaves exhibited a similar trend, the content in leaf tissue increased with an increasing ratio of nitrate/Gly, whereas relative change rate differed for each individual amino acid. In principal component analysis (PCA), the first component accounted for 80.5% of the total variance, and the N treatment appeared to be separated by this factor. In self-organizing map (SOM), 17 amino acids were divided into three clusters according to responds to nitrate/Gly ratios.     

Principal component and linear discriminant analyses of free amino acids and biogenic amines in hungarian wines

Principal component analysis (PCA) and linear discriminant analysis (LDA) were used to classify 187 Hungarian white and red wines according to wine-making technology, geographic origin (wine-making region), grape variety, and year of vintage based on free amino acid and biogenic amine contents. Determination of free amino acids and biogenic amines was accomplished by ion-exchange chromatography. Six principal components accounted for >77% of the total variance in the data. The plots of component loadings showed significant groupings of free amino acids and biogenic amines. The component scores grouped according to wines made by different wine-making technologies. Using LDA the variables with a major discriminant capacity were determined. Almost complete classification (94.7%) was achieved concerning both white and red wines and wines made by different wine-making technologies. The results of differentiation between white wines according to geographic origin, grape variety, and year of vintage were 70.8, 62.4, and 73.5%, respectively. The same numbers for red wines according to geographic origin, grape variety, and year of vintage were 64.9, 71.6, and 82.4%, respectively.     

Influence of aeration on the physiological activity of flor yeasts.

The effect of periodic aeration on the physiological activity of a strain of Saccharomyces cerevisiae yeast during development of velum (flor) and biological aging of Sherry wine of the Fino type was investigated. L-Proline amino acid was the main nitrogen source for yeasts cells during the biological aging, and its exhaustion may be the cause of the production and consumption of other compounds that are involved in the aroma of wines. Aeration was found to increase adenylate energy charge, growth, and viability of the yeast cells. Also, it affected the intracellular redox equilibrium and the consumption and production of compounds including acetoin, acetaldehyde, higher alcohols, ethanol, glycerol, and acetic acid. Acetaldehyde reached its highest level after the second aeration, which coincided with the exhaustion of the nitrogen source in the medium. The enzyme activity of alcohol dehydrogenases I and II decreased immediately after each aeration, subsequently increasing once all of the dissolved oxygen in the wine had been consumed by yeast cells. Aldehyde dehydrogenase activity was detected only after the first aeration, and it may be related to the production and consumption of acetic acid in the wine.     

Gas chromatographic analysis of total fatty acids in cider

This paper reports the composition of total fatty acids in an apple beverage, cider. Fatty acids are present in the free or esterified form and contribute to both the flavor and foam properties of cider. Fatty acids were separated and identified as methyl esters by GC-MS, and 12 of these were subsequently determined by GC-FID. The major fatty acids found in cider were caproic, caprylic, capric, and palmitic acid, the saturated acids predominating over the unsaturated ones. The proposed method was applied to 59 ciders from three consecutive harvests (1996, 1997, and 1998), which were made by 19 cider-makers from the region of Asturias (Spain). Linear discriminant analysis of fatty acids in these samples allowed selection of palmitoleic, pentadecanoic, linoleic, myristic, and linolenic acid as the most predictive variables to differentiate ciders made from apples grown in the Asturias region (1997 harvest) and ciders made from apples grown outside this region (1996 and 1998 harvests).     

Release of lipids during yeast autolysis in a model wine system

The release of lipids during the aging of sparkling wines in contact with yeast can influence wine sensory attributes and, especially, foam characteristics. Model systems allow study of the autolysis process in a reasonable period of time compared to natural conditions, at which it can last several months. In this paper, the release of the different classes of lipids during the autolysis of three commercial yeast strains in a model wine medium has been monitored. Due to the absence of accurate quantitative methods, an HPLC method for separating and quantifying the different neutral and polar yeast lipid classes was developed. Lipids were eluted through a YMC PVA-Sil column with a complex solvent mixture. Detection was carried out with a light-scattering detector. The yeasts were suspended in the model wine buffer and incubated at 30 degrees C for up to 12 days. A release of triacylglycerols, 1,3-diacylglycerols, 2-monoacylglycerols, free fatty acids, sterol esters, and sterols was observed over the first 2 days, a period that corresponded to the maximum loss of yeast viability. A decrease in most of these lipids was observed from day 2, possibly indicative of the release of yeast hydrolytic enzymes due to the breakdown of the cell wall. Phospholipids were not detected in any of the autolysates. The mean lipid content in the autolysates as a percentage of the total lipid content in the yeasts was 8.6% for sterol esters, 3.8% for sterols, 2% for triacylglycerols, and <2% for 1,3-diacylglycerols and free fatty acids.     

Soil extracts and co-culture assist biodegradation of 2,4,6-tribromophenol in culture and soil by an auxotrophic Achromobacter piechaudii strain TBPZ

Achromobacter piechaudii strain TBPZ is a 2,4,6-tribromophenol (TBP) degrader that was isolated from contaminated desert soil. In the current study we have found that yeast extract has a substantial impact on the debromination activity of non-dividing cells of TBPZ harvested during the stationary phase. The results suggest that yeast extract provides a factor that is necessary for activity and that is missing in stationary cells. Nevertheless, strain TBPZ from the stationary phase did survive and degrade TBP in soils with different degrees of contamination without yeast extract supplements. Experiments with soil extracts showed that a soluble factors is responsible for this phenomenon in a similar way to yeast extract. To test whether other soil bacteria provide these factors, co-culture experiments with strain TBPZ and a bisphenol A (BPA) degrader, Sphingomonas strain WH1, that was isolated from the same contaminated desert soil, were carried out. These experiments clearly demonstrated that growth of strain WH1 on BPA enables strain TBPZ to degrade TBP rapidly, suggesting that a metabolic product from WH1 is involved. In experiments with mixed amino acid blend (casamino acid), slower growth was observed when compared to growth with yeast extract. Providing vitamins and a defined mixture of two amino acids, tryptophan and phenylalanie, caused rapid degradation of TBP without the rapid growth seen in yeast extract treatment, indicating that the amino acids are needed to sustain biodegradation activity. The results of this study highlight that degradation of TBP by strain TBPZ is possibly controlled by micronutrients. In addition, the results suggest that an auxotrophic bacterium able to degrade halo-organic pollutants can survive in a natural environment due to its interaction with natural organic matter or other microorganisms.     

Formation pathways of ethyl esters of branched short-chain fatty acids during wine aging

The particular behavior during wine aging of fermentative branched fatty acid ethyl esters, related to yeast nitrogen metabolism, compared that of their straight-chain analogues, related to yeast lipid metabolism, was first checked in 1-5 year aged Muscadet wines. Quantitative SIDA measurements showed that the levels of the former increased, whereas those of the latter decreased. Then, three hypothetical pathways suggested in the literature to explain these variations of branched esters were investigated. Two Muscadet and Sylvaner wines were spiked with levels of deuterated isobutanoic acid and its ethyl ester, similar to those of their natural analogues, then they were submitted to model aging. Quantitative SIDA measurements on the formation of these natural and labeled ethyl esters from the corresponding acids revealed that the behavior of the natural and labeled compounds were similar. The acid levels were much higher than the ester levels in the initial young wine, and a significant upward trend of their esterification ratios to those of the acid-ester equilibrium was observed with aging. Thus, this equilibrium proved to be the most effective in generating the branched fatty acid ethyl esters during wine aging. In contrast, the formation of these acids by Strecker-type degradation of wine amino acids in the conditions of the model aging or by hydrolysis of their glycoconjugates proved to be ineffective.