scholarly journals Optimization of sample preparation for determination of antioxidant parameters from one grape berry

2014 ◽  
Vol 20 (3-4) ◽  
Author(s):  
Gy. Lukácsy ◽  
É. Stefanovits-Bányai ◽  
N. Papp ◽  
L. Kocsis
Keyword(s):  
Stainless Steel ◽  
Grape Berry ◽  
Steel Plates ◽  
Total Polyphenols ◽  
Total Anthocyanin ◽  
Grape Berries ◽  
Berry Quality ◽  
Total Antioxidant ◽  
Antioxidant Parameters

Berry quality is an important issue in wineprocessing, however evaluating characteristics in a single berry level is very complex. The Phenolic compound analysis is more challenging because of the limited amount of material and a mixture of skin, pulp and seed. No clear protocol exists for evaluating these compounds from single berries. The aim of our investigation was to develop such a protocol. Single whole grape berries samples were homogenized in 20 replicates by 5 different methods. The most effective method was when berry was placed in a mortar and was crushed with a pestle under liquid nitrogen until seeds were clearly visible. Seeds were then taken from the mortar and crushed between two stainless steel plates with a hammer, and returned to the mortar without residues. Homogenization continued until the sample had a powdery appearance. The homogenized samples were taken for further analysis such as total polyphenols, total anthocyanin contents and total antioxidant capacity. Our results demonstrate that single berries could be processed and that the homogenates were suitable for taking chemically uniform subsamples.

scholarly journals Relations between polyphenols content and antioxidant activity in vine grapes and leaves

2009 ◽  
Vol 26 (Special Issue) ◽  
pp. S25-S32 ◽  
Author(s):  
J. Balík ◽  
M. Kyseláková ◽  
N. Vrchotová ◽  
J. Tříska ◽  
M. Kumšta ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Plasmopara Viticola ◽  
Total Polyphenols ◽  
Antioxidant Power ◽  
Grape Berries ◽  
Caftaric Acid ◽  
Lateral Shoots ◽  
Total Antioxidant ◽  
Ferric Reducing Antioxidant Power ◽  
Botryotinia Fuckeliana

The occurrence and content of some polyphenols and the antioxidant activity of compounds present in grape berries, stems and leaves of <i>Vitis vinifera</i> L. were evaluated. Three white and three blue varieties of grapevine were investigated. The contents were determined of <i>trans</i>-resveratrol, <i>trans</i>-piceid, caftaric acid, tryptophan, catechin, epicatechin, total polyphenols, and flavanols, both in healthy material and in the samples of the plant material infested with microorganisms (<i>Botryotinia fuckeliana</i> Whetzel anamorph <i>Botrytis cinerea</i> Pers.; Uncinula necator (Schw.) Burr; <i>Plasmopara viticola</i> (Berk. & M.A. Curtis) Berl & De Toni). The antioxidant activity of the extracts obtained was determined by different methods: FRAP (Ferric Reducing Antioxidant Power), DPPH (2,2-diphenyl-1-picrylhydrazyl radical) and TAC-PCL (Total Antioxidant Capacity of Photochemiluminescence). The content of <i>trans</i>-resveratrol varied between 0.3–2.3 mg/kg and 0.7–12.1 mg/kg in non-infested and infested grape berries, respectively. The content of <i>trans</i>-piceid between 0.6–2.9 mg/kg and 1.5–6.3 mg/kg in non-infested and infested grape berries, respectively. The content of trans-resveratrol varied between 2.5–10.3 mg/kg and 3.7–20.9 mg/kg in healthy and in infected leaves, respectively. The content <i>trans</i>-piceid varied between 11.3–58.4 mg/kg and 18.5–60.9 mg/kg in the healthy and in the infected leaves, respectively. The highest content of trans-resveratrol was found in stems (16.3–276.3 mg/kg). In young lateral shoots, the highest levels of <i>trans</i>-piceid (12.6–99.7 mg/kg) and caftaric acid (474–2257 mg/kg) were determined. The infested grape berries showed a higher antioxidant activity, which was most closely correlated with the content of total polyphenols (correlation coefficient = 0.8336–0.9952).

scholarly journals Diurnal variation of the chemical composition and its repercussion on the biological activity polyphenolics of Salvia officinalis aerial parts

2019 ◽  
pp. 7-21
Author(s):  
Safa Rguez ◽  
amel Msaada ◽  
Majdi Hammami ◽  
Mejda Daami Remadi ◽  
Ikbel Chayeb ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Phenolic Compounds ◽  
Diurnal Variation ◽  
Biological Activities ◽  
Salvia Officinalis ◽  
Total Polyphenols ◽  
Methanolic Extracts ◽  
Aerial Parts ◽  
Total Antioxidant

This study reported the diurnal variation of the chemical composition and biological activities of phenolic compounds of Salvia officinalis cultivated in Tunisia. The HPLC determination of different phenolic compounds showed that the amounts of total polyphenols reach its maximum at 7 am. Estimation of the antioxidant activity of different methanolic extracts of Salvia officinalis showed that the extract of 5 pm had the most effective antiradical power against DPPH and the best iron reducing capacity. The strongest total antioxidant capacity was recorded for extracts of 12 and 5 pm. The methanol extracts of sage also have a capacity to reduce the appetence of Spodoptera littoralis larvae. This activity did not vary with the harvesting time.

scholarly journals Assessment of Genetic Diversity of Edible Honeysuckle Monitored through RAPD in Relative to Bioactive Substances

Agronomy ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 868
Author(s):  
Marcela Cehula ◽  
Jiří Mlček ◽  
Tünde Juríková ◽  
Jana Žiarovská ◽  
Oleg Paulen ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Random Amplified Polymorphic Dna ◽  
Soil Conditions ◽  
Neighbor Joining ◽  
Agglomerative Hierarchical Clustering ◽  
Total Polyphenols ◽  
Bioactive Substances ◽  
The Czech Republic ◽  
Total Antioxidant

This study aimed to analyze the genetic diversity of selected cultivars and clones of Lonicera sp. (edible honeysuckle) from two countries with different climatic and soil conditions. Accordingly, the determination of total polyphenols content (TPC) and total antioxidant activity (TAA) in fruits of Lonicera sp. in 2018–2019 was performed. Applied statistical methods evaluating TPC and TAA were: correlation and regression, ANOVA, and agglomerative hierarchical clustering. The neighbor-joining method and gel images analysis (PyElph software, Pavel and Vasile, Bucharest, Romania) were used for genetic analysis. The average TPC of all cultivars and clones was 5.32 mg L−1 in the year 2018 and 3.78 mg L−1 in 2019. The average TAA values of all samples in 2018 were 8.24 mg L−1, and 9.27 mg L−1 in 2019. Statistically significant correlations between years and cultivars and clones were found. Based on the lengths and number of fragments by random amplified polymorphic DNA (RAPD)-PCR’s, it was found that ‘clone 5’ and ‘clone 7’ were genetically close to the grown cultivars from the Czech Republic. Therefore, edible honeysuckle fruits are a valuable source of important nutrients for the human body and its health.

scholarly journals Adjustment of K+ Fluxes and Grapevine Defense in the Face of Climate Change

2021 ◽  
Vol 22 (19) ◽  
pp. 10398
Author(s):  
Houssein Monder ◽  
Morgan Maillard ◽  
Isabelle Chérel ◽  
Sabine Dagmar Zimmermann ◽  
Nadine Paris ◽  
...  
Keyword(s):  
Defense Mechanisms ◽  
Grape Berry ◽  
Transport Systems ◽  
Negative Consequences ◽  
Wine Quality ◽  
Grape Berries ◽  
Berry Quality ◽  
The Face ◽  
Abiotic Constraints ◽  
Adverse Environmental Conditions

Grapevine is one of the most economically important fruit crops due to the high value of its fruit and its importance in winemaking. The current decrease in grape berry quality and production can be seen as the consequence of various abiotic constraints imposed by climate changes. Specifically, produced wines have become too sweet, with a stronger impression of alcohol and fewer aromatic qualities. Potassium is known to play a major role in grapevine growth, as well as grape composition and wine quality. Importantly, potassium ions (K+) are involved in the initiation and maintenance of the berry loading process during ripening. Moreover, K+ has also been implicated in various defense mechanisms against abiotic stress. The first part of this review discusses the main negative consequences of the current climate, how they disturb the quality of grape berries at harvest and thus ultimately compromise the potential to obtain a great wine. In the second part, the essential electrical and osmotic functions of K+, which are intimately dependent on K+ transport systems, membrane energization, and cell K+ homeostasis, are presented. This knowledge will help to select crops that are better adapted to adverse environmental conditions.

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