scholarly journals Chemical Composition of White Wines Produced from Different Grape Varieties and Wine Regions in Slovakia

2021 ◽  
Vol 11 (22) ◽  
pp. 11059
Author(s):  
Silvia Jakabová ◽  
Martina Fikselová ◽  
Andrea Mendelová ◽  
Michal Ševčík ◽  
Imrich Jakab ◽  
...  

In this work, chemical parameters such as sugar (glucose and fructose) content, organic acid (total acids, malic and tartaric acids), total phenolic content and the antioxidant activity of 12 white wines (chardonnay, pinot blanc and pinot gris) from various wine regions in Slovakia were studied in order to identify differences among the varieties and wine-growing regions. The wine samples were examined by Fourier-transform infrared spectroscopy (FTIR) and UV-VIS spectrophotometry (for determination of total polyphenolic content (TPC) and total antioxidant activity (TAA)) methods. Content of alcohol ranged between 11.50% and 13.80% with the mean value 12.52%. Mean content of total acids varied between 4.63 ± 0.09 and 6.63 ± 0.05 g.L−1, tartaric acid varied between 1.62 ± 0.09 and 2.93 ± 0.03 g L−1, malic acid was found in the concentrations ranged from 0.07 ± 0.05 and 2.50 ± 0.08 g L−1 and lactic acid was present between 1.53 and 0.01 g L−1. The content of fructose was, in general, higher in the samples from the Južnoslovenská and Nitrianska wine regions and glucose was higher in the Malokarpatská wine region. Chardonnay wines showed the highest content of total polyphenols and the antioxidant activity in the samples ranged from 51.06 ± 027 to 72.53 ± 0.35% inhibition of DPPH. The PCA analysis based on chemical descriptors distinguished the Nitrianska and Stredoslovenská wine regions. According to similarities among the wine samples, four main classes were formed by cluster analysis.

Agriculture ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 233 ◽  
Author(s):  
Georgiana-Diana Dumitriu (Gabur) ◽  
Carmen Teodosiu ◽  
Iulian Gabur ◽  
Valeriu V. Cotea ◽  
Rafael A. Peinado ◽  
...  

In this study, a complete physical–chemical analysis was performed for Fetească neagră wine, aged with oak staves. Red wine samples were taken from grape varieties grown in Northeast Romania and produced during 2013 vintage. At the end of the fermentation process, four oak mini staves (1 cm width × 10 cm length × 1 cm thickness) from heavy toasted French oak were added to 5 L of red wine. Samples were aged using two time periods, respectively at 1.5 and 3 months, in a room at 14–16 °C. Results showed that the initial content of total phenolic decreased during ageing, from 931.1 mg catechin/L at 1.5 months to 775.4 mg catechin/L at 3 months. In contrast, the initial content of total antioxidant activity increased after the same period of ageing to 13.3 mM Trolox as compared to the aged wines for 1.5 months, at 12.8 mM Trolox. The corregram representing the relationship between the total phenols, total antioxidant activity (TAA) and their fractions and CieLab parameters was performed. Thirty-seven minor volatile compounds were quantified by stir bars sorptive extraction and gas chromatography coupled with mass spectrometry (SBSE-GC-MS). An increase in odor activity value (OAV) with ageing time was observed, especially for fruity, fatty and woody series. The oak staves used in ageing processes can contribute positively to the aromatic profile of wines and could be considered a good choice for producing short-aged wines.


2019 ◽  
pp. 49-59
Author(s):  
Nu Linh Giang Ton ◽  
Thi Hoai Nguyen ◽  
Quoc Hung Vo

Avocado peel has been considered as a potential source of natural antioxidants in which phenolics are among the most important compounds. Therefore, this study aims to optimize the extraction process of phenolics using response surface methodology and evaluate the corresponding antioxidant activity. From the quadratic model, the optimal condition was determined including the ethanol concentration 54.55% (v/v), the solvent/solute ratio 71.82/1 (mL/g), temperature 53.03 oC and extraction time 99.09 min. The total phenolic content and the total antioxidant capacity at this condition with minor modifications were 26,74 ± 0,04 (mg GAE/g DW) and 188.06 ± 1.41 (mg AAE/g DW), respectively. The significant correlation between total phenolic content and total antioxidant capacity was also confirmed. Key words: response surface methodology, central composite rotatable design, total phenolic content, total antioxidant capacity, avocado peel


Author(s):  
Hattem Mekky ◽  
Samah El Sohafy ◽  
Rasha Abu El-khair ◽  
Amr El Hawiet

Objective: The present study was designed to study the effect of supplementing Silybum marianum cultures with different combinations and concentrations of growth regulators on the total phenolic content and the antioxidant activity of the produced cultures.Methods: The total polyphenolic content of 23 extracts of calli was calculated as µg of gallic acid/mg of dry weight extract (DWE) using Folin–Ciocalteu reagent. The antioxidant activity was calculated as trolox equivalent antioxidant capacity using 1,1-Diphenyl-2-picryl-hydrazyl (DPPH) assay for extracts containing more than 10 µg gallic acid/mg DWE.Results: Most of the combinations showed an increase in the total polyphenolic concentration compared to the wild plant. However, cultures grown on media supplemented with combinations of benzyl aminopurine (BAP) and gebberellic acid (Gb), adenine (Ad) and kinetin (Kin), BAP and indole acetic acid (IAA) possessed the highest total polyphenolic contents 20.5, 13.09 and 12.15 µg gallic acid/mg DWE, respectively. However, only (BAP+Gb), (BAP+1-Naphthaleneacetic acid (NAA), IAA, kin and (BAP+Ad) showed a significant increase in the antioxidant activity calculated as trolox equivalent with 2.65, 1.56, 1.56, 1.35 and 1.22 folds increase over the wild plant, respectively.Conclusion: The results obtained clearly indicated that changing the growth regulator system of Silybum marianum cultures serves as an easy and reliable method for increasing the total phenolic content and the antioxidant activity of cultures.


2019 ◽  
Vol 79 (3) ◽  
pp. 452-459 ◽  
Author(s):  
F. R. G. Silva ◽  
T. M. S. Matias ◽  
L. I. O. Souza ◽  
T. J. Matos-Rocha ◽  
S. A. Fonseca ◽  
...  

Abstract The study aimed to evaluate the antimicrobial activity, antioxidant, toxicity and phytochemical screening of the Red Propolis Alagoas. Antimicrobial activity was evaluated by disk diffusion method. Determination of antioxidant activity was performed using the DPPH assay (1.1-diphenyl-2-picrylhydrazyl), FTC (ferric thiocyanate) and determination of phenolic compounds by Follin method. Toxicity was performed by the method of Artemia salina and cytotoxicity by MTT method. The phytochemical screening for the detection of allelochemicals was performed. The ethanol extract of propolis of Alagoas showed significant results for antimicrobial activity, and inhibitory activity for Staphylococcus aureus and Candida krusei. The antioxidant activity of the FTC method was 80% to 108.3% hydrogen peroxide kidnapping, the DPPH method showed an EC50 3.97 mg/mL, the content of total phenolic compounds was determined by calibration curve gallic acid, resulting from 0.0005 mg/100 g of gallic acid equivalent. The extract was non-toxic by A. salina method. The propolis extract showed high activity with a higher percentage than 75% inhibition of tumor cells OVCAR-8, SF-295 and HCT116. Chemical constituents were observed as flavonones, xanthones, flavonols, and Chalcones Auronas, Catechins and leucoanthocyanidins. It is concluded that the extract can be tested is considered a potential source of bioactive metabolites.


Genetika ◽  
2020 ◽  
Vol 52 (3) ◽  
pp. 825-834
Author(s):  
Emre Sevindik ◽  
Sinem Aydin ◽  
Mehmet Paksoy ◽  
Bahar Sokmen

The genus Inula belongs to family Asteraceae and it is medicinally important because it possesses cytotoxic, anticancer, hepatoprotective, antibacterial and anti-inflammatory properties. The aim of this research was to explore antioxidant and anti-urease activities of fifteen Inula taxa in Turkey. Ethanol extracts of Inula taxa were obtained by Soxhlet extraction. Antioxidant activity was determined through total antioxidant activity, total phenolic content and copper reducing antioxidant capacity (CUPRAC) analyses. The highest total phenolic content and total antioxidant capacity were found in I. orientalis (158.54?0.002 ?g GAE/mL) and I. macrocephala (189.16?0.002 ?g AAE/mL). CUPRAC activity increases with the increasing concentration of the extracts and the standard. Moreover, all the tested plants exhibited better anti-urease activity than standard thiourea except for I. anatolica and I. thapsoides subsp. thapsoides. Results obtained from this study demonstrate that Inula species might be utilized as a probable natural source in the pharmaceutical and food industries but further and more specific studies are needed to determine active antioxidative and anti-urease compounds in the extracts.


2017 ◽  
Vol 15 (2) ◽  
pp. 79-95 ◽  
Author(s):  
ODHIAMBO PETER OKELLO ◽  
JOSEPH P. ONYANGO GWEYI ◽  
MILDRED PAULINE NAWIRI ◽  
WINFRED MUSILA

Okello OP, Gweyi JPO, Nawiri Mp, Musila W. 2017. Effects of water stress on phenolic contents and antioxidant activity of African nightshades. Biofarmasi J Nat Prod Biochem 15: 79-95. This study aimed at mapping out the distribution of different African Nightshade species in Siaya and Kisii Counties of Kenya and to determine water stress effect on total antioxidant capacity and total phenolic content of two selected African nightshade namely, giant nightshade (Solanum scabrum) and black nightshade (Solanum villosum). Before selection of the two varieties, the study involved farmer field visits, mapping of nightshades present and administration of semi-structured questionnaires to farmers to determine the indigenous vegetables being grown, the nightshade species grown and factors affecting their production. The experiments were conducted both in the field and greenhouse conditions. Watering intervals were at 15 cbars, 50 cbars, and 85 cbars. Data on the number of secondary buds, leaf area, shoot height, shoot and root dry weights were gathered. The total antioxidant capacity and the total phenolic content were recorded using DPPH radical scavenging method and Folin-Ciolcalteu method, respectively. The data collected were subjected to ANOVA. In both counties where production was 100% under small scale, Solanum scabrum was the main variety grown is Siaya County (36%) while in Kisii the main variety was Solanum villosum (32%). There were significant differences (P≤0.05) among treatments in leaf area, plant height, shoot biomass, number of secondary buds, leaf and root total phenolic content and leaf and root antioxidant activity. At all stress levels, Solanum scabrum exhibited the tallest plants with a maximum height of 45.17cm at 15cbars, while Solanum villosum had the shortest plants at all stress levels, with the shortest one being recorded at 16.65 cm at 85 cbars. S. scabrum also had the highest root dry weight (7.78g), shoot dry weight (50.78g) and highest leaf area of (304.45cm2). However, Solanum villosum had the highest number of secondary buds at all stress levels with the highest being 24 at 15 cbars. Concerning phytochemicals, Solanum villosum had a higher concentration of both the total phenolics and antioxidant activity in the shoots (46.41g GAE/Kg DM total phenolic content and 52.68% total antioxidant activity). Meanwhile, Solanum scabrum had a higher concentration in the roots (25.06gGAE/Kg DM total phenolic content and 27.18% total antioxidant activity). Water stress cause a decline in all growth parameters but increased phytochemical accumulation in nightshade accessions grown. It is therefore suggested that for better yields, irrigation should be performed at every 15 cbars, however for adequate phytochemical accumulation, the irrigation should be carried out at 50 cbars. Further research to explore and quantify other phytochemical components as affected by different watering regimes need to be undertaken.


2020 ◽  
Vol 7 (4) ◽  
Author(s):  
Bince Mani ◽  
Sinjumol Thomas

Antioxidant compounds play a significant role in preventing and scavenging free-radicals by reducing oxidative stress and providing protection to humans against degenerative diseases and infections. Obviously, antioxidant molecules of plant origin are pivotal to combat the oxidative harm in cells. Present work intended to evaluate the antioxidant capacity of the fruits of Spondias pinnata. Methanol extracts of the fruits at two stages of maturity were prepared and investigated by various antioxidants analyses such as total antioxidant activity, reducing power and radical scavenging assays (DPPH, nitric oxide and hydrogen peroxide). Its total phenol, flavonoid and tannin contents were also determined. Spondias pinnata fruit extracts exhibited effective antioxidant activity and its IC50 values of the unripe fruits were 65, 66, 72.23, 83.25, 66.75 ?g/ml and ripe fruits were 124.24, 92.50, 97.66, 144.10, 72.25 ?g/ml, for total antioxidant activity, reducing power, DPPH radical scavenging, nitric oxide radical scavenging and hydrogen peroxide scavenging assays respectively. The extracts, especially unripe fruit extract had good amounts of total phenolic and flavonoid contents which might contribute the antioxidant activities considerably. It is evident from the study that the fruits of S. pinnata possessed potent antioxidant activity and it can be considered as a good dietary choice among the underutilized fruits as well as common fruits. Therefore, wild mango may be a good choice of antioxidants of plant origin for dietary and pharmaceutical uses.


Author(s):  
A. N. Gulyaeva ◽  
M. S. Voronina ◽  
N. V. Makarova

Confectionery - food products, usually with a high sugar content, characterized by high calorie content and digestibility. They are divided into groups: sugar, flour confectionery, chocolate, cocoa. The following types of products are used as the main raw materials for the preparation of confectionery products: flour (wheat, rye, corn, rice, oatmeal, etc.), sugar, honey, fruits and berries, milk and cream, fats, eggs, yeast, starch, cocoa, nuts, food acids, gelling agents, flavoring and aromatic additives, food dyes and baking powder. The high content of carbohydrates, proteins and fats, as well as polyunsaturatedfatty acids and some vitamins determines the significant value of confectionery products. The influence of shelf life on biscuit semi-finished products prepared according to the classical recipe using pomace powder and concentrated juice of black currant and blueberry berries is shown. Methods used in the experimental part: measurement of the total phenolic content using the Folin-Chekelau reagent, the total content of flavonoids and anthocyanins, the level of free radical capture DPPH (2,2-diphenyl-1-picrilhydrazyl), the total antioxidant activity by the FRAP method and the antioxidant activity in the linoleic acid system. It was found that the content of phenolic substances, flavonoids, anthocyanins and antioxidant activity is greatly influenced by high humidity and a constant light source. These indicators are significantly reduced, but when stored in a vacuum, this decrease in indicators can be slowed down.


2020 ◽  
Vol 1 (12) ◽  
pp. 112-118
Author(s):  
O. A. Voronina ◽  
◽  
A. A. Savina ◽  
N. S. Kolesnik ◽  
N. V. Bogolyubova ◽  
...  

The influence of fattening conditions on the digestive and metabolic processes in animals is actively studied to increase the production of animal food. The aim of the study was to estimate the total amount of water-soluble antioxidants in the blood serum of Duroc boars depending on the duration of fattening. Experiments were conducted on 102 animals to confirm the results of laboratory studies, as well as determination of the total antioxidant activity of pig blood serum by amperometric method. For the first time, a significant difference in antioxidant activity was found in blood samples of Duroc boars with the duration of their fattening from 81 to 101 days.


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