Sugar-free Extract Research Articles

Inspired by nature: Fiber networks functionalized with tannic acid and condensed tannin-rich extracts of Norway spruce bark show antimicrobial efficacy.

This study demonstrated the antibacterial and antiviral potential of condensed tannins and tannic acid when incorporated into fiber networks tested for functional material purposes. Condensed tannins were extracted from industrial bark of Norway spruce by using pressurized hot water extraction (PHWE), followed by purification of extracts by using XADHP7 treatment to obtain sugar-free extract. The chemical composition of the extracts was analyzed by using HPLC, GC‒MS and UHPLC after thiolytic degradation. The test matrices, i.e., lignocellulosic handsheets, were produced and impregnated with tannin-rich extracts, and tannic acid was used as a commercial reference. The antibacterial and antiviral efficacy of the handsheets were analyzed by using bioluminescent bacterial strains (Staphylococcus aureus RN4220+pAT19 and Escherichia coli K12+pCGLS11) and Enterovirus coxsackievirus B3. Potential bonding of the tannin-rich extract and tannic acid within the fiber matrices was studied by using FTIR-ATR spectroscopy. The deposition characteristics (distribution and accumulation patterns) of tannin compounds and extracts within fiber networks were measured and visualized by direct chemical mapping using time-of-flight secondary ion mass spectrometry (ToF-SIMS) and digital microscopy. Our results demonstrated for the first time, how tannin-rich extracts obtained from spruce bark side streams with green chemistry possess antiviral and antibacterial properties when immobilized into fiber matrices to create substitutes for plastic hygienic products, personal protection materials such as surgical face masks, or food packaging materials to prolong the shelf life of foodstuffs and prevent the spread of infections. However, more research is needed to further develop this proof-of-concept to ensure stable chemical bonding in product prototypes with specific chemistry.

The influence of the vine rootstock on the agrobiological and technological characteristics of the Kaylashki Rubin variety

The rootstock had a significant impact on the quantity and quality of grapes of the varieties grafted on it. That had been determined by the different growth strength of the rootstocks, their different absorption capacity and compatibility with the cultivated vine. During the period 2017-2020, a study was carried out on the agrobiological and technological properties of grapes and wine of the Kaylashki Rubin variety, grafted on vine rootstocks SО4, 110 Rihter, 44-53 Malegue and Fercal. Differences in the investigated indicators were found as a result of the influence of the used rootstocks. A mechanical analysis was made to determine the composition and structure of the clusters and berries. For the period, the highest average yield per vine was reported for Fercal rootstock, while the best theoretical yield had the variant on 44-53 Malegue rootstock. The chemical composition of grapes and experimental wines had been determined. On the average for the period the highest sugar accumulation and respectively the lowest titratable acids in grapes were reported in the variant of 44-53 Malegue rootstock. The opposite relationship was observed for 110 Richter. Differences in the chemical composition of the wines depending on the used rootstocks were found. The wines from 44-53 Malegue variant had the highest average alcohol content and sugar-free extract, but the lowest rates of titratable acids. The average amounts of the total phenolic compounds and anthocyanins in the wines from the variants of the different rootstocks were close. Their values were the lowest in the samples 2017 vintage. The rootstock type also affected the organoleptic properties of the Kaylashki Rubin wines; however, there was no common trend for the studied period. In 2018 and 2020, the samples from the 110 Rihter variant showed the best tasting qualities.

Characteristic parameters of honey wines and dessert meads

The aim of this study was to evaluate the chemical composition of 17 samples of mead originating from the Czech Republic. The samples included honey wines (made only from water and honey) and dessert meads which were treated mainly by the addition of sugar or alcohol. The following chemical parameters were analysed: ethanol, sugar-free extract, hydroxymethylfurfural (HMF), sugars (monosaccharides, disaccharides), organic acids, assimilable nitrogen, and polyphenols. Substantial differences were found between samples: i) the content of glucose and fructose was 2.5–113.1 g L<sup>–1</sup> and 17.3–136.3 g L<sup>–1</sup>, respectively; ii) the HMF content ranged from 1.0 mg L<sup>–1</sup> to 87.7 mg L<sup>–1</sup>. The most abundant organic acids were lactic acid (average 1.0 g L<sup>–1</sup>), gluconic acid (0.6 g L<sup>–1</sup>), and acetic acid (0.4 g L<sup>–1</sup>); the amount of phenolic compounds was 151.9–385.3 mg gallic acid equivalent (GAE) L<sup>–1</sup>. Honey wines typically contained turanose (2.0–7.6 g L<sup>–1</sup>) and trehalose (1.1–10.1 g L<sup>–1</sup>), while dessert mead was characterised by an increased sucrose content (up to 76.5 g L<sup>–1</sup>).

Comparative Technological Characteristic of the Aligote 61-6 and Aligote N 10 Clones, Cultivated in the Soil and Climatic Conditions of the Region of Pleven

Abstract In the period 2011–2013 a technological characteristic of the Ukrainian clone Aligote 61-6 was made at the Institute of Viticulture and Enology – Pleven. The Bulgarian candidate-clone Aligote N 10 was used for control. During the grapes ripening, the dynamics of sugar accumulation was monitored. Upon technological maturity the indicators of the yields were accounted and mechanical analysis was performed. The chemical composition of the must, the obtained wines and their organoleptic qualities were analyzed. In its mechanical composition, Aligote 61-6 was typically wine one and it did not differ significantly in the texture and structure of the cluster and berry from the control. The theoretical yield of both clones was high. They exhibited good sugar accumulation and similar acid content. Grapes from the control had better technological indicators for obtaining wines of optimal chemical composition and quality. In the 2011 and 2013 vintages, the control wines exceeded those of the Ukrainian clone in terms of sugar-free extract content. The experimental wines Aligote N 10 had higher titratable acidity compared to the Ukrainian clone. The difference in the phenolic substances ratio and the colour intensity in the samples from both clones were insignificant. The control wines were superior in their organoleptic qualities to those of the Ukrainian clone.

Effects of different pretreatments on physicochemical properties and phenolic compounds of hawthorn wine

ABSTRACT The physicochemical properties, organic acid, and phenolic profiles of hawthorn wines prepared by different pretreatments were analyzed. It was found that fermentation together with smashed seeds was favorable for ethanol production, while thermal maceration, addition of pectinase and amyloglucosidase significantly increased the levels of sugar-free extract, residual sugar, total phenolics, flavonoids, and most individual phenolic comounds, showing beneficial effects on improving nutritive value of hawthorn wine. Addition of pectinase and amyloglucosidase caused an increase of methanol content by 34.88% and 26.97%, respectively, while thermal maceration decrease the methanol content by 36.20%. Addition of amyloglucosidase yielded the highest contents of procyanidins as well as flavanols, while thermal maceration and addition of pectinase were favorable for improving phenolic acid level. All the pretreatments significantly increased the contents of succinic acid and malic acid in the final wines, among which thermal maceration and addition of pectinase yielded the highest content of succinic acid and malic acid respectively.

Chemical, sensory and antioxidant characteristics of Bulgarian wines from native cultivars

A study of the chemical composition, the antioxidant capacity and the sensory characteristics of three Bulgarian wines (vintage 2015) from the native cultivars Misket Vrachanski (white), Pamid (red) and Gamza (red), grown in the region of Pleven, Central Northern Bulgaria was carried out. The results showed that the wine composition was mainly determined by the cultivar and its peculiarities. Misket Vrachanski white wine had the lowest rate of sugar-free extract, glycerol, total phenolic compounds and the highest acid content. From the red wine samples, Pamid had lower rates for the above parameters compared to Gamza. The experimental wines were analyzed for total content of esters, aldehydes and higher alcohols. A correlation was found between the rates of the studied volatile components in the wines and their aromatic sensory characteristics. At the wine tasting, Misket Vrachanski that contained the most of esters and aldehydes, was the best evaluated, followed by Gamza and Pamid. There was no correlation between the amount of total phenolic compounds in the experimental samples and their antioxidant capacity, which according to ABTS and MRAP methods increased in the order of Pamid < Misket Vrachanski < Gamza.

Проучване на химичния състав, антиоксидантната активност и органолептичния профил на български вина от хибридни сортове

The chemical composition, the antioxidant activity and the organoleptic profile of Bulgarian wines from the hybrid varieties Misket Kaylashki, Rubin, Kaylashki Rubin and Trapezitsa was studied. The properties of the red wines were compared to those of Cabernet Sauvignon wine. The varieties were grown in the region of Pleven, Central Northern Bulgaria. The results had shown that the wine composition was mainly determined by the variety and its peculiarities. Misket Kaylashki white wine had the lowest rate of sugar-free extract and total acidity. From the red wines, Rubin contained the highest sugar-free extract and glycerol, Kaylashki Rubin had the lowest concentration of glycerol and the highest total acidity, Trapezitsa had the lowest sugar-free extract. In the red wines, the rate of total phenolic compounds and anthocyanins was highest in Rubin and the lowest in Trapezitsa. Misket Kaylashki, as a typical muscat wine, had the highest rates of esters. From the red wines Rubin contained the highest rate of total esters and aldehydes and the lowest higher alcohols. According to the ABTS and MRAP methods, Misket Kaylashki had the lowest antioxidant capacity, while from the red samples Rubin was reported to have the highest and Kaylashki Rubin the lowest.

The profile of organic acids and polyphenols in apple wines fermented with different yeast strains.

Influence of two apple cultivars (cvs. Cripps Pink and Idared) and two commercial strains of Saccharomyces bayanus (Lalvin EC1118, Fermol Blanc) on the chemical composition and sensory characteristics of apple wines was tested. Chemical parameters (alcohol, sugar-free extract, reducing sugars, titratable and volatile acidity) of the analyzed wines were strongly affected by apple variety. Ash and sugar-free extracts in Cripps Pink wines were significantly higher than Idared wines. Polyphenols and main organic acids were determined in apple juice and wines. Chlorogenic acid was the most abundant polyphenolic compound with the significantly higher concentrations detected for Idared wines. Total phenolic acids, as well as total flavan-3-ols content, were also higher for wines made from Idared variety where fermentation was conducted with Fermol blanc yeast. Among organic acids significantly higher succinic acid content was determined in wines where Fermol Blanc yeast was used while Lalvine EC1118, irrespective of apple variety, significantly influenced the concentration of lactic acid. Sensory evaluation showed the pronounced influence of variety but also the yeast used, singling out Idared cultivar and Fermol Blanc yeast achieving the best overall quality results.

Comparative Study of the Phenolic Complex, the Resveratrol Content and the Organoleptic Profile of Bulgarian Wines

Abstract A comparative study of the phenolic complex, the resveratrol content, the antioxidant activity and the organoleptic profile of Bulgarian wines from the local vine varieties Dimyat, Pamid, Gamza and from the hybrid varieties Plevenska rosa, Storgozia, Kaylashki rubin was carried out. Differences in the chemical composition and tasting characteristics of the experimental wines were identified. As for the white wines, Dimyat had higher sugar-free extract and titratable acidity, while concerning the red ones, Storgozia and Kaylashki rubin showed higher rates. The trans-resveratrol amount in the red wines was significantly higher compared to the white ones, as the samples from the red local varieties had a higher content than the hybrid varieties. Difference in the phenolic composition of the wines was also found. Gamza wine had the highest concentration of total phenolic compounds, total flavonoids and catechin. Storgozia sample contained the highest rates of monomeric anthocyanins and epicatechin. Pamid revealed the lowest concentrations of all analyzed phenolic components except catechin. The red wines had better antioxidant features than the white ones. From the red wines, the highest and the lowest activity were reported in the local varieties – Gamza and Pamid, respectively. There was no strict correlation between the effects of the studied phenolic components on the wine organoleptic profile.

Changes in Non-Volatile Compounds and Extracts of Wines Due to Yeast Species and Fermentation Temperature

The real reducing sugar-free extracts and the calculated extracts of wines vary significantly with fermentation temperature within the range of l2°-2l°C. Relevant compositional changes are shown and discussed. The three yeasts used did not cause any significant difference in the calculated extracts. The conclusions were that any critical assessment of wine or juice amelioration based only on these forumulas would be subject to criticism.

How intrinsic values influence wines prices

The use of hedonic price indices is quite common in the wine economics literature, yet they mainly include scores of organoleptic tests and some dummy variables representing varieties and quality signs as geographical indications. This study focuses on the relation between the composition and the price of wines on the example of Hungarian wines. In Hungary, the wine law renders chemical analysis compulsory for all wines released to the market. The study includes five main compounds: actual alcoholic strength, total sugars, total acidity, sugar free extract and pH value and is based on hedonic price indices calculated on a sample of 2,453 wines. Results of several regressions – using different model specifications – consistently show that actual alcoholic strength, sugar content, sugar free extract and pH value are related with the price. Some characteristics have an optimal level, while in other cases the relation is linear.

The effect of inactivated yeast-based products on the process of wine aging, phenolic compounds and sensory characteristics of red wine Prokupac

Keeping of red wine in bottles is very important for its maturation and quality. However, there are numerous changes that happen during that period, usually caused by oxidative processes and changes in structure and content of polyphenolic compounds. The goal of this study was to determine the effects of Inactivated dry yeast (IDY) products on aging, phenolics content, colour stability and sensory characteristics of red wine Prokupac (Serbian autochthonous variety). The treatment of wine was done by 3 different IDYP (Lallemand, Canada): Optimum White, Opti Less and Noblesse, applied as 0.2 g/L and 0.4 g /L during 15 days. Subsequently, wine clarification was done, followed by filtration and bottling. Untreated wines were used for comparison. Wine was subjected to accelerated aging (10 days at 55 ° C) and also to normal aging conditions during one year. To determine the influence of IDYP following parameters were monitored: dissolved O2 , free and total SO2 , sugar free extract, content of total phenolics, flavonoids, flavan-3-ols and anthocyanins, percent of polymeric color, color tint, color intensity and sensory characteristics (Panel method). The obtained results clearly show that IDY products are good scavengers of oxygen and have a positive impact on wine quality preservation and its organoleptic characteristics. However, a slight decrease of polyphenols content was detected.

Effect of Some Oenological Practices Applied Before the Alcoholic Fermentation on the Chemical Composition and Sensory Characteristics of White Wines

Abstract The effect of the oenological practices, maceration and maceration with the addition of aromatic enzyme before the alcoholic fermentation on the composition, aromatic components and organoleptic profile of experimental wines from the local varieties Dimyat, Muscat Vrachanski and the newly-selected variety Plevenska Rosa was studied. The investigation was carried out during the period 2013–2014, with grapes and wine from the studied varieties grown in the soil and climatic conditions of the town of Pleven (Central Northern Bulgaria). The applied technological practices had increased the sugar-free extract and the total phenolic compounds content in the experimental samples. The highest rates for these indicators revealed the variants of Plevenska Rosa variety. The amount of esters and higher alcohols was greater in the wines obtained after maceration and maceration with the addition of aromatic enzyme in the grape must. The total esters concentration was the highest in the samples of the aromatic varieties Muscat Vrachanski and Plevenska Rosa. There was not observed a direct correlation between the applied oenological practices, enhancing the extraction and the aromatic components content in the experimental variants and their organoleptic profile.

Zuckeralkohole und myo-Inosit in Weinen und Sherries

Alditols and myo-inositol in wines and sherries The alditols - erythritol, xylitol, arabitol, mannitol, sorbitol and myo-inositol - occur in increasing amounts in German wines as the quality of these wines rises. Especially in Auslese, Beerenauslese and Trockenbeerenauslese wines alditols can constitute as much as 17.5 % of the sugar-free extract and therefore are a significant part of it. These sugar alcohols surely are involved in the full-bodyness of wines just as glycerol is. The presence of sorbitol - even if higher than the tolerated amount of 70 mg/l - does not indicate a falsification with pomefruit juice. In Q.b.A. wines 5 of 12, in Kabinett wines 17 of 42 and in Spatlese wines 14 of 23 have higher amounts. Not one of the Auslese wines showed less than 84 mg/l sorbitol. Beerenauslese and Trockenbeerenauslese wines contained up to 989 mg/l of sorbitol. Mannitol, myo-inositol and arabitol were also detected in unexpected high quantities. The maximum amount of mannitol was nearly 13 g/l in a Trockenbeerenauslese wine : Nearly 2.5 g/l of myo-inositol and 2.3 g/l of arabitol were found in these high quality wines. All alditols are natural in wines. The high concentrations found presumably stem from their synthes is by Botrytis cinerea and by associated yeasts on grapes infected by this mould.

Measuring Routine Parameters of Wine by ATR-MIR Spectroscopy

In this paper, common parameters of wine are measured using attenuated total reflectance Fourier transform infrared spectrometer (ATR-FTIR). ATR cell is used which have the advantage of easy filling and cleaning. The parameters include sugar, alcohol, acid,, sugar-free extract, which is routinely measured in the wine quality determination. Commercial wines (n=125) both red and white were analyzed using the ATR-FTIR spectrometer. Reference data were measured based on standard procedure (GB150382006) and performed by technical analyst. Using PLS calibration method samples concentration can be predicted. The accuracy of quantification of main component such as total acidity, sugar, alcohol was excellent, with the measure error low than 1g/L. Some subdivision components are well, that concentration can be predicted in a lower accuracy. Based on the accuracy we obtained, the presented method can be used in winery widely as a fast method for measuring wines content.

Antioxidant Activity of Mulberry Fruit Extracts

Phenolic compounds were extracted from the fruits of Morus nigra and Morus alba using methanol and acetone. The sugar-free extracts (SFEs) were prepared using Amberlite XAD-16 column chromatography. All of the SFEs exhibited antioxidant potential as determined by ABTS (0.75–1.25 mmol Trolox/g), DPPH (2,2-diphenyl-1-picrylhydrazyl) (EC50 from 48 μg/mL to 79 μg/mL), and reducing power assays. However, a stronger activity was noted for the SFEs obtained from Morus nigra fruits. These extracts also possessed the highest contents of total phenolics: 164 mg/g (methanolic SFE) and 173 mg/g (acetonic SFE). The presence of phenolic acids and flavonoids in the extracts was confirmed using HPLC method and chlorogenic acid and rutin were found as the dominant phenolic constituents in the SFEs.

Dietary fibre content and cell wall polysaccharides in prunes

Dietary fibre content and cell wall polysaccharides in prunes

Analytical characterization and the impact of ageing on anthocyanin composition and degradation in juices from five sour cherry cultivars

Five different sour cherry cultivars were processed to sour cherry juices in order to analyze their composition and the impact of storage on anthocyanin composition. Regarding primary juice parameters all cultivars showed high dry masses (13.8–17.2° Brix) and sugar free extracts (59.4–74.3 g/L). Anthocyanins were identified as cyanidin-3-(2G-glucosylrutinoside), cyanidin-3-(2G-xylosylrutinoside), cyanidin-3-sophoroside, cyanidin-3-glucoside, cyanidin-3-rutinoside, and peonidin-3-rutinoside. Besides the original anthocyanins, 5-carboxypyrano-anthocyanins occurred as new reaction products during storage. HPLC-MSn experiments revealed, that a further ageing pigment was probably resulting from the reaction of an original anthocyanin with acetaldehyde. A significant decline of the original anthocyanin concentrations could be observed (70–75%) during 6 months of storage at 20 °C. Degradation kinetics of anthocyanins were calculated taking the reaction rate as first order. Colourless polyphenol concentrations and antioxidant capacities (TEAC) of the juices were not affected during storage.

Optimised processing technique for colour- and cloud-stable plum juices and stability of bioactive substances

Plum (Prunus domestica) juices were produced from different cultivars with optimised processing technology. High results for dry mass (19–21 °Brix), sugar-free extract (75–105 g/L), total acidity (6–11 g/L), sorbitol (27–52 g/L) and minerals were found. Secondary plant metabolites were present in high amounts as well. By means of HPLC/PDA 1465–2590 mg/L of colourless polyphenols were found. Neochlorogenic acid, chlorogenic acid, (+)-catechin and (−)-epicatechin were the predominant polyphenols. Total anthocyanins were found in amounts of 43–168 mg/L in the fresh juices. They were identified as cyanidin-3-glucoside, cyanidin-3-rutinoside, peonidin-3-glucoside and peonidin-3-rutinoside. A fast decline of the anthocyanin concentrations could be observed during a 6 months storage at 20 °C, which changed the red colour of the juices drastically. Beside high polyphenol concentrations, high antioxidant capacities of the juices were determined as well. The applied processing technology allowed the production of cloud-stable plum nectars.

Application of FT-MIR spectrometry in wine analysis

By means of liquid Fourier transform-middle infrared spectrometry, it is possible to analyse wine and must within 90 s simultaneously on a significant number of important parameters like alcohol, relative density, extract, sugar-free extract, refraction, conductivity, glycerol, total phenols, reducing sugar, fructose, glucose, sucrose, total acid, pH value, volatile acid, total SO 2 and tartaric acid, malic acid, lactic acid and citric acid. Within a short time, it is possible to obtain information on the chemical composition of the product and it is useful to monitor the changes in chemical composition from beginning of grape ripening, must and fermentation to finished wines. Additionally, it is possible to obtain a fingerprint of the products which can serve as an identity check for quality management and production control. In the first part, a sample set with 327 typical German wines from 1989 to 2001 were analysed using Fourier transform-middle infrared spectrometry (FT-MIR) and also with different reference methods. In the second part, the results of a Ring test with 52 typical wines from each of 13 German wine regions are discussed. The results from this study demonstrated that a calibration model could be transferred between FT-MIR machines with the same hardware. The inter-laboratory reproducibility proved to be satisfactory and the instrument results were comparable with those obtained by the “classical reference methods”.