The aim of this study is to evaluate the content of phenolics: the total
phenols (TP), flavonoids (TF), anthocyanins (TA), as well as the total
antioxidant capacity (TAC) in three sour cherry ...cultivars (Prunus cerasus L.)
introduced to the southeast Serbia climate conditions. Among the researched
sour cherries, ?Oblacinska? cultivar contained the highest amounts of all
groups of phenolics, followed by ?Cigancica? > ?Marela?. A significant
difference were observed in the phenolic content among different cultivars
and growing seasons (p<0.05), and the phenolic compounds were significantly
higher in the growing season 2009. The examined cultivars possess a high
antioxidant capacity, and all phenolics of highy correlation with TAC. The
following compounds were identified and quantified using HPLC-DAD: 4
anthocyanins, the most abundant of which was cyaniding-3-glucoside in
?Marela? and ?Oblacinska?, and cyanidin-3-glucosylrutinoside in ?Cigancica?,
and 4 hydroxycinnamic acids, the most abundant of which was neochlorogenic
acid in all sour cherry cultivars. The growing and ripening process on the
tree of sour cherry cv. Oblacinska was evaluated, also. The results showed
significant increases in total phenols during the ripening, the total
anthocyanins and total antioxidant capacity and 4 quantified anthocyanins,
however the neochlorogenic acid decreased during the ripening. The study
indicated that the growing and climate conditions in southeast Serbia are
convenient for introducing sour cherry cultivars.
nema
The biologically active compounds in wine, especially phenolics, are responsible for reduced risk of developing chronic diseases (cardiovascular disease, cancer, diabetes, etc.), due to their ...antioxidant activities. We determined the contents of total phenolics (TP) and total flavonoids (TF) in selected Serbian white wines by colorimetric methods. Total antioxidant activity (TAA) of the white wines was analyzed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity assay. Medas beli had the highest content of TP, TF and TAA. The radical scavenging capacity (RSC) and total antioxidant activity (TAA) of white wines were 15.30% and 1.055 mM Trolox equivalent, respectively. Total phenolic (TP) and total flavonoid (TF) contents in white wines ranged from 238.3 to 420.6 mg gallic acid equivalent per L of wines and 42.64 to 81.32 mg catechin equivalent per L of wines, respectively. A high and significant correlation between antioxidant activity and total phenolic content was determined in wines (R2 = 0.968, p < 0.01). For the individual polyphenols determination we used a high performance liquid chromatography (HPLC)-diode array detection (DAD) technique. The majority of white wine polyphenols was represent by four hydroxycinnamic acids (HCAs).
The reaction between NaAsO2 and oxalic acid was studied by pH-metric and conductometric measurements, applying the methods of continual variation and pH-metric and conductometric titration. It was ...found that oxalic acid forms a complex anion of the type AsOC2O4-. The relative stability constant of the complex at ionic strengths, I, of 0.10 (log Kr = 4.70), 0.20 (log Kr=4.51), 0.50 (log Kr = 4.24) and 0 (log K 0 = 5.05) and thermodynamic parameters were calculated using the data obtained by pH-metric measurements at 25.0?0.1?C (DH = 10.5 kJ mol-1, DG = -29.0 kJ mol-1, DS = 133 J mol-1 K-1).
Reakcija NaAsO2 sa oksalnom kiselinom ispitana je merenjem pH i provodljivosti, metodom kontinualne varijacije i pH-metrijskim i konduktometrijskim titracijama. Nadjeno je da oksalna kiselina gradi kompleks AsOC2O4-. Na osnovu pH-metrijskih merenja izracunata je relativna konstanta stabilnosti kompleksa na 25?0.1?C pri jonskim jacinama od 0,10 (log Kr = 4,70), 0,20 (log Kr = 4,51), 0,50 (log Kr = 4,24) i 0 (log Kr,0 = 5,05), kao i termodinamicki parametri reakcije kompleksiranja na 25?0,1?C (DH = 10,5 kJ mol-1, DG = = -29,0 kJ mol-1, DS = 133 J mol-1 K-1).
Three table grapes and 4 wine grapes collected from a southern Serbian vineyard were evaluated and compared for their antioxidant properties and phenolic profile. Among the varieties tested, ...‘Cabernet Sauvignon’ contained the highest total phenolic content with 173.6 mg/100 g of fresh weight. Also, the total flavonoid and antocyanin content of ‘Cabernet Sauvignon’ was significantly higher from the other. ‘Cabernet Sauvignon’ and ‘Merlot’ had the strongest DPPH· radicals scavenging activity (1,318.6 and 1,282.0 μmol Trolox equivalent/100 g, respectively). ‘Cabernet Sauvignon’, ‘Merlot’, ‘Prokupac’, ‘Vranac’, ‘Muscat Hamburg’, and ‘Ribier’ grape varieties were found to be rich in malvidin-3-
O
-glucoside, while ‘Cardinal’ grape variety was found to be rich in peonidin-3-
O
-glucoside. The following compounds were also identified and quantified using HPLC-DAD: 2 flavan-3-ols and 4 hydroxycinnamic acids in all grape samples. The results suggested that phytochemicals in the selected table and wine grapes have potent antioxidant activities in correlation with phenolic content.
The kinetic method for the determination of phosphate microamounts was described. The developed method is based on catalytic effect of phosphate on sodium pyrogallol-5-sulphonate （PS） by dissolved ...oxygen. The reaction was followed spectrophotometrically by measuring the rate of change in the values of the absorbance of the oxidation product at 437 nm. The optimum reaction conditions are PS （0.44×10^-3 mol·L^-1） and HClO4 （3.6×10^-6 mol·L^-1） at 25 ℃. Following this procedure, phosphate can be determined with a linear calibration graph up to 0.23 μg·mL^-1. The interference effect of several species was also investigated and it was found that the most common cations and anions did not interfere with the determination. The developed procedure was successfully applied to the determination of phosphate in natural waters and soil.
DETERMINATION OF HEAVY METALS IN SOUR CHERRY USING BY ICP-OES Obradovic, Mirjana V; Mitic, Milan N; Pavlovic, Aleksandra ...
International Multidisciplinary Scientific GeoConference : SGEM,
01/2010, Letnik:
2
Conference Proceeding, Journal Article
Three sour cherries cultivare, Marela, Oblacinska and Cigancica, collected from a south Serbia were evaluated and compered for their content of heavy metals. Inductively coupled plasma optical ...emission spectrometry (ICP-OES) is widely recognized as a suitable technique for the determination of heavly metals. The content od Cd and Pb are in intervale 0.066-0.399 and 3.466-7. 1 99 mu g/l 0Og fresh weight of sour cherry.
The antioxidant capacity and the phenolic content of 3 dried red currant samples from different geographical regions were studied. Three solvent systems were used (methanol, ethanol, and acetone) at ...the same concentrations (70%) and with 100% deionized water in presence 0.1% HCl. The antioxidant capacity of the dried fruit extracts was evaluated using DPPH radical scavenging assays. The efficiency of the solvents used to extract phenols from the 3 dried red currant samples varied considerably. The polyphenol content of the dried red currant samples was 3.26 to 12.68 mg gallic acid equivalent/g dried fruit. The high phenolic content was significantly correlated with the high antioxidant capacity. The following compounds were identified and quantified using HPLC with photodiode-array detection: 3 anthocyanins, 2 flavonols, 2 flavan-3-ols, and 3 hydroxycinnamic acids in all samples. Generally, red currant fruits are a rich source of phenolics, which shows an evident antioxidant capacity.
The content of phenolics: total phenols (TP), flavonoids (TF), anthocyanins (TA) and hydroxycinnamic acid as well as the total antioxidant capacity (TAC) in nine commercial red fruit juices (sour ...cherry, black currant and red grape) produced in Serbia were evaluated. The total compounds content was measured by spectrophotometric methods, TAC was determined using DPPH assays, and individual anthocyanins and hydroxycinnamic acids was determined using HPLC-DAD methods. Among the examined fruit juices, the black currant juices contained the highest amounts of all groups of the phenolics and exhibited strong antioxidant capacity. The amount of anthocyanins determined by HPLC method ranged from 92.36 to 512.73 mg/L in red grape and black currant juices, respectively. The anthocyanins present in the investigated red fruit juices were derivatives of cyanidin, delphinidin, petunidin, peonidin and malvidin. The predominant phenolic acid was neoclorogenic acid in sour cherry, caffeic acid in black currant, and rho-coumaric acid in black grape juices. Generally, the red fruit juices produced in the Serbia are a rich source of the phenolic, which show evident antioxidant capacity.
This study reveals the affordances and limitations of introducing a new instructional framework- archival-based pedagogy-into a digital literacies course for English language arts educators in the ...fall of 2020 in the midst of COVID-19. Its purpose was to document how seven students in the course went about choosing archival content for the podcasts they created as part of their final project. The conceptual framework of artifactual critical literacy guided the study's methodology, analysis, and interpretation of the participants' descriptions of how the archival artifacts they selected became centerpieces in their podcasts and reflected their personal and/or professional identities. Findings from the study are presented through the seven participants' narrative reflections, created during the spring of 2021. Implications are discussed for furthering archival-based pedagogy as a curricular alternative to traditional online teaching and learning.
PDF
