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.     

Simultaneous Quantification of Primary, Secondary Amino Acids, and Biogenic Amines in Musts and Wines Using OPA/3-MPA/FMOC-CI Fluorescent Derivatives

ABSTRACT: Free amino acids and biogenic amines occur in musts and wines and affect the course of fermentation in musts and the quality of wines. Each sample was analyzed in 138 min and each analysis involved quantification of 23 amino acids and 10 amines. The detection limit for proline was 27.3 mg/L. The mean detection limit for amino acids was 0.58 mg/L and for amines 0.28 mg/L. Precision was 0.5 to 19.2% for wine samples and accuracy by the standard addition method was 99.8% (recovery value). In all, 33 wines and 39 must samples were analyzed. In wines, ethanolamine, histamine, ethylamine, and putrescine amounted to 93% of the amine content.     

Thiol precursors in Catarratto Bianco Comune and Grillo grapes and effect of clarification conditions on the release of varietal thiols in wine

Background and Aims

Varietal thiols characterise the typical aroma of several white wines, such as Sauvignon Blanc. Their presence and sensory perception were suggested in two Sicilian grape cultivars, Catarratto Bianco Comune (CBC) and Grillo, though it has not been analytically proven.

Methods and Results

Varietal thiol precursors and free varietal thiols were assessed in CBC and Grillo grapes, musts and wines by ultra‐performance liquid chromatography/electrospray ionisation high‐resolution MS. The isobaric compounds including S‐3‐(hexanal)‐glutathione and S‐3‐(4‐mercapto‐4‐methylpentan‐2‐one)‐glutathione (GSH‐4MMP) were distinguished by comparing their accurate masses and high‐resolution‐MS/MS spectra with those of their synthetic standards. S‐3‐(Hexanal)‐glutathione, S‐3‐(hexan‐1‐ol)‐glutathione and S‐3‐(hexan‐1‐ol)‐cysteine were found in grape, must and wine, whereas GSH‐4MMP and its hydrolysed forms were not found. Their concentration decreased during winemaking, mostly after grape pressing. We compared the effect of clarification conditions based on the exposure of must to either air or CO₂ on the concentration of thiol precursors and free thiols in wine; however, negligible differences were observed. The concentration of free thiols in the wines was found to be in the range 400–1100 ng/L and they were unaffected by the two clarification conditions tested.

Conclusions

The isobaric S‐3‐(hexanal)‐glutathione and GSH‐4MMP were clearly distinguished for the first time by ultra‐performance liquid chromatography/high‐resolution MS through their retention times and MS spectra. These varietal thiols were revealed in CBC and Grillo wines for the first time. The air‐free and air‐exposed clarification treatments had little effect on the concentration of the varietal thiols.

Significance of the Study

This study highlights the major impact of the varietal thiols (mainly 3‐mercapto‐hexan‐1‐ol and its acetate form) on the sensory properties of CBC and Grillo wines.     

Monitoring of chemical parameters of oxygen-treated musts during alcoholic fermentation and subsequent bottle storage of the resulting wines

The effect of hyper-oxygenation of Airén white wines on color characteristics, phenolic composition, and volatile profile has been evaluated in different processing steps, not previously reported in conjunction: musts, musts during the alcoholic fermentation, resulting young wines and after 1 year of bottle storage. Hyper-oxygenation treatment achieved a positive effect on color stabilization by means of significantly lower contents of most important phenolic compound families (hydroxycinnamic acid derivatives, benzoic acids, flavonols, and flavan-3-ols) in oxygen-treated musts in fermentation, young wines, and one-year-stored white wines. Therefore, browning was avoided in wines elaborated from hyper-oxygenated musts and their values of a* (green–red component of color) were maintained, in contrast to what occurred in control wines. With regard to volatile profile, the concentration of the majority of individual volatile compounds was significantly higher in wines derived from hyper-oxygenated musts, even after 1 year of bottle storage, especially those derived from alcoholic fermentation (alcohols: 2-methyl-1-butanol and 3-methyl-1-butanol, polar esters: ethyl lactate and ethyl glutarate, C₆ alcohols: 3-methyl-1-pentanol, and acetates: 2-phenylethyl acetate). This study enhances knowledge regarding the effects of hyper-oxygenation process during and after alcoholic fermentation and 1 year of bottle aging, especially as there is scarce literature available on the subject.     

A rapid method for quantifying aroma precursors: Application to grape extract,musts and wines made from several varieties

This paper reports on a quick and simple method for reliably quantifying aroma precursors in grape extract, musts and wines of different grape varieties. The method, which is intended mainly for use by wineries and analytical laboratories, is based on isolation of terpenyl-β-d-glycosides through selective retention on a C₁₈ reversed-phase column, followed by hydrolysis to liberate terpenes, yielding an equimolar proportion of free aglycons and glucose. Sugar was measured using an enzyme analysis kit. Aroma precursors were quantified using this method, in a range of crushed grapes, musts and wines produced in the Castilla La Mancha region. The method was also applied on a larger scale in a wine analytical laboratory, to chart the behavior of terpenyl glycosides during the final stages of ripening of grapes from different viticulture Spanish regions.     

Free amino acids and biogenic amines in Alicante Monastrell wines

The simultaneous determination of 17 free amino acids and 8 biogenic amines in Alicante Monastrell wines was investigated for the first time. The quantification was carried out by using a RP-HPLC method, based on a pre-column derivatization with o-phthaldialdehyde (OPA) and fluorescence detection. From the results obtained it may be concluded that the most abundant free amino acids were Glu, Arg, Ala Asp, and Lys. None of the wine samples analysed had histamine (HIM) or Tyramine (TYM) levels above the limits considered as a possible toxic risk for healthy individuals. No measurable amounts of cadaverine (CAD) or methylamine (MEA) were found, showing no spoilage symptoms of sensory properties of the wines. Tryptamine (TRM) content was significantly higher in aged wines compared to young wines. However ethanolamine (ETA) content was lower. These data were used to make a preliminary classification of the samples using cluster analysis.     

Changes to polyphenols in the process of production of must and wines from blackcurrants and cherries. Part I. Total polyphenols and phenolic acids

The effect of pulp treatment on the qualitative and quantitative changes to polyphenol compounds exhibiting antioxidant properties, in musts and wines from blackcurrants and cherries was investigated. The following variants of pulp treatment were used: hot maceration, hot maceration and pulp pectinolysis with Rohapect MA Plus and Pektopol PM preparations, and also pulp pectinolysis with Rohapect and Pektopol preparations. Blackcurrant musts contained from 4800 to 6600 mg l^-1 of total polyphenols and cherry musts from 3060 to 3920 mg l^-1. The fermentation process caused a decrease in polyphenols content of approximately 25%. In production of fruit wines, the pulp treatment method had a considerable effect on the total content of polyphenols. In blackcurrant wines the highest extraction of polyphenols was obtained after pectinolysis with a Rohapect preparation. In the case of cherry wines the highest content of these compounds was extracted during pectinolysis with a Pektopol preparation. In musts and wines the presence of the following compounds, derivatives of hydroxycinnamic acid, was determined: neochlorogenic, chlorogenic, caffeic, p-coumaric and ferulic acids. The content of neochlorogenic acid was the highest both in musts and wines from blackcurrants and cherries and amounted to 41.7-126.3 mg l^-1, and 24.7-35.3 mg l^-1 respectively for blackcurrants and 74.3-87.7 mg l^-1and 44.5-71.4 mg l^-1 respectively for cherries. The enzymatic preparation Pektopol PM contained an enzyme acting as depsidase. It broke down chlorogenic acid and other compounds to simple phenolic acids (caffeic acid, p-coumaric acid).     

采用氨基酸自动分析仪测定黄酒中的游离氨基酸

<正> 前言 黄酒是中国的一种传统的饮料酒,已有数千年历史,它的酿造用料及发酵工艺与国外酒类不同。众所周知,发酵制品含有多种营养成份,黄酒也不例外,它含有人体必需的氨基酸,具有很高的营养价值。然而,有关黄酒中各种氨基酸含量与酒质优劣和营养价值高低之间的关系等,国内尚未见到系统报道。为配合工艺试验,我们开展了这项方法研究。     

Comparative study of the volatile composition in wines obtained from traditional vinification and from the Ganimede method

BACKGROUND: This study compares the volatile composition between wines obtained from vinification carried out by the traditional method or using a new method of vinification (so‐called Ganimede). For this, Shiraz, Merlot and Cabernet Sauvignon musts were fermented by both vinification methods. RESULTS: The volatile compounds that were above their threshold of perception in the wines were practically the same, irrespective of the vinification method used. Most of the compounds studied did not present significant differences in their concentrations between the wines obtained from the traditional and the new vinification methods. When there were significant differences, the concentration of alcohols and acids was higher in the wines vinificated by the traditional method rather than in the wines vinificated by the Ganimede method, whereas for esters, the concentration in the wines depended on the grape variety. CONCLUSION: The Ganimede method favoured polyphenol extraction without greatly affecting the studied volatile composition of the wines. Copyright © 2008 Society of Chemical Industry     

Nutritive assessment of amino acids for three Chinese Zajius produced from hull‐less barley

In this study, the free amino acid content of traditional Zajiu , ‘small‐scale trial’ Zajiu and commercial Zajiu , produced from hull‐less barley, was determined using an automatic amino acid analyser. The amino acid nutritive value of the tested wines were measured using the ratio coefficient of amino acid and linear‐regression analysis. A Chinese yellow wine was used as a reference. At least 17 types of free amino acids were found in all four of the tested wines. Chinese yellow wine exhibited the highest total amino acid content (3094 mg/L), followed by traditional Zajiu (2875 mg/L) and commercial Zajiu (2042 mg/L). However, Zajiu s had a higher essential amino acids/total amino acid ratio than Chinese yellow wine, and their composition of essencial amino acid more closely matched the recommendations of the World Health Organization/UN Food and Agriculture Organization. Analysis based on linear regression showed that the amino acid nutritive value of the wines was ranked from high to low as follows: commercial Zajiu , traditional Zajiu , Chinese yellow wine and ‘small‐scale trial’ Zajiu . These results provide some information on the amino acid nutritional quality of Chinese Zajiu , and a new method for the amino acid nutritive value assessment of foods and beverages. Copyright © 2017 The Institute of Brewing & Distilling     

Influence of yeast strain,immobilisation and ageing time on the changes of free amino acids and amino acids in peptides in bottle‐fermented sparkling wines obtained from Vitis vinifera cv. Emir

This paper reports the influence of yeast strain, immobilisation and ageing time on the free amino acids and amino acids in peptides of sparkling wine made by the traditional method from the Emir grape variety over a period of 365 days in vintages 2004 and 2005. Four sparkling wines were obtained from the same base wine using yeast strains (both immobilised and free Saccharomyces bayanus and Saccharomyces oviformis). The analysis of variance and cluster revealed that there were significant differences between free amino acids and amino acids in peptides due to ageing time. However, the yeast strain affected most of the free amino acids and amino acids in peptides in only the 2004 vintage. The total amount of free amino acids was higher in the wine made with the S. oviformis compared to S. bayanus. Furthermore, there were no significant differences between the use of immobilised and free yeast in cases of free amino acids and amino acids in peptides.     

Selection of Volatile Aroma Compounds by Statistical and Enological Criteria for Analytical Differentiation of Musts and Wines of Two Grape Varieties

ABSTRACT: Aroma compounds in Airen and Macabeo musts and wines were submitted to multivariate analysis of variance and only those significantly depending (p < 0.05) on grape variety, prefermentative treatment, and exhibiting no significant interaction were selected for discriminant analysis. Benzyl alcohol, Z‐3‐hexen‐1‐ol, hexanoic acid, benzaldehyde, β‐ionone, and E‐nerolidol contents in musts were used to calculate 2 discriminating functions, which allow classifying 100% of all must by variety and treatment. Discriminant analysis carried out with 1‐propanol, isoamyl alcohol, 2‐phenylethanol, ethyl acetate, ethyl propanoate, ethyl lactate, isobutyl acetate, and 7‐butyrolactone contents in wines, allows to establish 2 other functions, which led to accurate classification of 100% of the wine samples.     

Phenolic Content and Antioxidant Activity of Primitivo Wine: Comparison among Winemaking Technologies

ABSTRACT: The aim of this study was to assess the influence of 9 winemaking technologies (traditional, delestage, saignée, delayed punching‐down, addition of grape seed tannins, addition of ellagic‐skin‐seed tannins, heating of must‐wine, cryo‐maceration, and prolonged maceration) on the phenolic content and antioxidant activity of Primitivo musts and wines. Three methods for the determination of the antioxidant activity were compared: DPPH, β‐carotene bleaching assay, and ABTS. Oenological parameters and composition of the phenolic fraction of 1‐y‐aged wines was also determined. The addition of tannins allowed the increase of the phenolic content of musts and wines in a greater amount than the other technologies. The results concerning the antioxidant activity depended on the method applied. Concerning musts, the DPPH assay did not highlight great differences among technologies, whereas the addition of tannins allowed the obtainment of the highest antioxidant activity according to β‐carotene and ABTS assays. The wine aging determined an increase of the antioxidant activity, independently on the method applied. Wine obtained through traditional technology, saignée, and addition of tannins showed the highest antioxidant activities according to DPPH and β‐carotene. The highest correlation coefficients (0.961 and 0.932) were calculated between phenolic content and ABTS values of musts whereas the lowest values (0.413 and 0.517) were calculated between phenolic content and ABTS values of wines. Wines produced through traditional technology were the richest in anthocyanins. The addition of tannins allowed to obtain high content in monomeric anthocyanins, flavonoids, flavans reactive to vanillin, and coumaroylated malvidin and a low content in acetylated malvidin. Practical Applications: It is well known that a moderate consumption (equivalent to 2 glasses per day) of red wine is actually recommended since it appears associated with a decreased incidence of cardiovascular diseases. The mechanisms involved in this protective effect are not completely understood although they appear related to the presence of phenolic compounds. To increase the intake of these compounds without increase of the wine consumption, it is necessary to improve their extraction during maceration. This study could represent a helpful tool for wineries aimed to know the way to increase the antioxidant content of their wines, thus changing them in functional beverages and prolonging their shelf life.     

Sweet Wine Production by Two Osmotolerant Saccharomyces cerevisiae Strains

The use of Saccharomyces cerevisiae to produce sweet wine is difficult because yeast is affected by a hyperosmotic stress due to the high sugar concentrations in the fermenting must. One possible alternative could be the coimmobilization of the osmotolerant yeast strains S. cerevisiae X4 and X5 on Penicillium chrysogenum strain H3 (GRAS) for the partial fermentation of raisin musts. This immobilized has been, namely, as yeast biocapsules. Traditional sweet wine (that is, without fermentation of the must) and must partially fermented by free yeast cells were also used for comparison. Partially fermented sweet wines showed higher concentration of the volatile compounds than traditionally produced wines. The wines obtained by immobilized yeast cells reached minor concentrations of major alcohols than wines by free cells. The consumption of specific nitrogen compounds was dependent on yeast strain and the cellular immobilization. A principal component analysis shows that the compounds related to the response to osmotic stress (glycerol, acetaldehyde, acetoin, and butanediol) clearly differentiate the wines obtained with free yeasts but not the wines obtained with immobilized yeasts.     

HPLC Determination of Amino Acids in Musts and Port Wine Using OPA/FMOC Derivatives

ABSTRACT: Musts and port wines pose specific problems for amino acid analysis because of high sugar content. An HPLC technique was applied to the simultaneous quantification of primary and secondary amino acids in these matrices as their OPA-FMOC derivatives. This method enabled the fully automated analysis of 21 amino acids in 20 minutes. The average detection limit was 1.3 mmole/L, precision was 5%-12% for wine samples and accuracy by the standard addition method was 108.3 % (recovery value). Ten port wine and 43 must samples were analyzed for free amino acid contents. Proline represented 73% of the total for wine samples.     

A method for the detection of carbonyl compounds in wine: Glyoxal and methylglyoxal

Wine aldehydes were identified as O-(2,3,4,5,6-pentafluorobenzyl)-hydroxylamine derivatives by GC-MS or with a GC-electron-capture detector. This method has been used to evaluate levels of glyoxal and methylglyoxal in wine. Reproducibility and linearity studies gave satisfying results. Glyoxal and methylglyoxal are formed during fermentation. Among the factors affecting their production, high musts pH increased the levels found in the corresponding wines. Various microorganisms of the wine such as Saccharomyces cerevisiae and Leuconostoc ænos can produce glyoxal and methylglyoxal. The concentrations in Sherry wines were particularly high. Because of the toxicological properties of these substances, their determination and the knowledge of their metabolism by wine microorganisms are very important.     

Effects of hyper-oxygenation and storage of Macabeo and Airén white wines on their phenolic and volatile composition

The effects of hyper-oxygenation and storage period of Macabeo and Airén white wines on color characteristics, phenolic, and volatile composition have been evaluated. Hyper-oxygenation treatment provoked a significant decrease in virtually all individual phenolic compounds in must, young wine, and one-year-aged wines, above all hydroxycinnamic acid derivatives, flavonols, and the new GRP derivatives compounds (derived from 2-S-glutathionyl-caftaric acid or grape reaction product). Despite this fact, the contribution of the yellow color component (b*) of white wines derived from hyper-oxygenated musts was significantly higher in comparison with untreated ones, even after 1 year of bottle storage. On the other hand, the concentration of major volatile compounds and some alcohols (namely, C₆ alcohols, terpenes, and lactones) was higher in wines derived from hyper-oxygenated musts, but the hyper-oxygenation effect on volatile profile deeply depended on the grape variety. After 1 year of bottle storage, the significant differences were maintained and the content of some long-chain esters increased as a consequence of oxygen addition.     

Effect of the duration of feeding of a protein‐free diet on endogenous ileal nitrogen and amino acid loss in the growing pig

The aim of the study was to determine whether endogenous nitrogen and amino acid excretions at the terminal ileum change over time in the growing pig fed a protein‐free diet for 8 days. Seven entire male pigs with an overall mean live weight of 81.6 kg (SEM 3.3 kg) and surgically implanted post‐valve T caecum cannulas were fed a semi‐synthetic casein‐based diet for 8 days. Food was withheld from the pigs for 24 h, after which they were fed a protein‐free diet for a further 8 days at a rate of 10% of metabolic body weight per day. Chromic oxide was included in the protein‐free diet as an indigestible marker. Ileal digesta were collected continuously from 13:00 to 18:00 h on each day of the experimental period. Endogenous ileal nitrogen flows were determined for each pig each day the protein‐free diet was given, and endogenous ileal amino acid flows for the first and eighth days. There were no significant (P > 0.05) effects of the duration of feeding of the protein‐free diet on endogenous ileal total nitrogen or amino acid flows, except for the amino acids glycine and cysteine, the flows of which significantly decreased over the 8 day period (P < 0.01 and P < 0.05 for glycine and cysteine respectively), from (mean ± SEM) 1639 ± 217 to 892 ± 212 µg g⁻¹ dry matter intake (DMI) for glycine and from 173 ± 13 to 127 ± 19 µg g⁻¹ DMI for cysteine. The relative contributions (moles of each amino acid as a proportion of total moles of amino acids) of threonine, glycine and cysteine decreased significantly (P < 0.05) and that of proline increased significantly (P < 0.05) during the 8 days that the protein‐free diet was fed to the pigs. © 2000 Society of Chemical Industry     

Clarifying agents effect on the nitrogen composition in must and wine during fermentation

The effect of static sedimentation with and without clarifying agents (silica sol and gelatine) upon the nitrogenous fraction of musts and wines was studied. Four vinifications were carried out using a Vitis vinifera cv. Cayetana white grape must. Static sedimentation reduced less than other techniques the assimilable nitrogen (FAN), however the employment of fining agents promoted a net decrease. The changes in the amino acids during fermentation were similar in all the experiments carried out. In general, during the first days there was a fast decrease followed by a slight increment and then stabilisation. This decrease fitted, in most of the cases, with first order kinetics. For most of the amino acids, the percent consumption was higher in the must settled with clarifying agents. The clarifying agent’s addition did not have the same effect on the amino acid concentration in the final wines.