scholarly journals The Rate of Decolorization of a Radical Ion Reagent Was Used to Determine the Phenolic Content of Various Food Extracts

2013 ◽  
Vol 2013 ◽  
pp. 1-6
Author(s):  
Arthur Bradley
Keyword(s):  
Experimental Data ◽  
Gallic Acid ◽  
Light Absorption ◽  
Phenolic Content ◽  
Aqueous Alcohol ◽  
Semilog Plot ◽  
Deep Blue ◽  
Food Components ◽  
Straight Line

Polyphenols are among the most valuable and widely studied food components. In the laboratory, they are readily extractable with aqueous alcohol. An aliquot rapidly decolorizes a measured portion of ABTS, a stable deep blue radical ion. The semilog plot of light absorption versus time is typically a straight line, and an immediately evident slope provides rapid classification in terms of gallic acid equivalents. Experimental data are presented to show general agreement with the literature. The disproportionate concentration of antioxidant in the skins and peels of fruits, vegetables, and nuts is given special attention.

ANTIOXIDANT ACTIVITIES OF EXTRACTS FROM THE LEAVES AND STEM BARKS OF Artocarpus scortechinii KING

2015 ◽  
Vol 77 (2) ◽  
Author(s):  
Shajarahtunnur Jamil ◽  
Norazah Basar ◽  
Norzafneza Mohd Arriffin
Keyword(s):  
Ethyl Acetate ◽  
Gallic Acid ◽  
Phenolic Content ◽  
Ethyl Acetate Extract ◽  
Antioxidant Activities ◽  
Radical Scavenging ◽  
Dry Weight ◽  
Calibration Graph ◽  
Total Phenolic ◽  
Scavenging Capacity

The antioxidant activities of extracts (n-hexane, dichloromethane, ethyl acetate and methanol) from the leaves and stem barks of Artocarpus scortechinii were evaluated using various biochemical assays. The quantification of the Total Antioxidant Capacity was measured using ferric reducing antioxidant potential (FRAP) and 2,2'-azino-bis(3-ethyl-benzothiazoline-6-sulphonic acid) (ABTS) assays. While, the qualitative of The Total Phenolic Content (TPC) was determined via standard gallic acid calibration graph which was expressed as mg gallic acid equivalent (GAE)/g of dry weight (dw) using Folin Ciocalteau’s reagent. Among all the extracts tested, the methanolic extract of the stem barks showed the highest phenolic content with TPC value of 136.84 mg GAE/g dry weight (dw). FRAP results were expressed as mM equivalent to FeSO4.7H2O by calculating from the standard FeSO4.7H2O calibration graph. The ethyl acetate extract of the stem barks showed the most significant reducing potential in the range between 0.27-2.47 mM FRAP. ABTS+˙ radical scavenging capacity showed that the ethyl acetate extract of the stem barks had the highest scavenging capacity at concentration 1.0 mM with percentage of 90.9%.

scholarly journals TOTAL POLYPHENOLIC CONTENT AND ANTIOXIDANT ACTIVITY OF SILYBUM MARIANUM CULTURES GROWN ON DIFFERENT GROWTH REGULATORS

2017 ◽  
Vol 9 (4) ◽  
pp. 44 ◽  
Author(s):  
Hattem Mekky ◽  
Samah El Sohafy ◽  
Rasha Abu El-khair ◽  
Amr El Hawiet
Keyword(s):  
Antioxidant Activity ◽  
Gallic Acid ◽  
Growth Regulators ◽  
Phenolic Content ◽  
Wild Plant ◽  
Total Phenolic ◽  
Silybum Marianum ◽  
Polyphenolic Content ◽  
Trolox Equivalent ◽  
Total Polyphenolic Content

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.

scholarly journals Optical Kossel Lines and Fluorescence in Photonic Liquid Crystals

Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 541
Author(s):  
Vladimir A. Belyakov
Keyword(s):  
Experimental Data ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Light Absorption ◽  
Fluorescence Polarization ◽  
Direct Connection ◽  
X Ray ◽  
Optical Analog ◽  
Theoretical Results ◽  
Observation Results

We propose a general analytical way to describe the fluorescence peculiarities in photonic liquid crystals (revealing themselves as an optical analog of the X-ray Kossel lines in conventional crystals) based at the localized optical edge modes existing in perfect photonic liquid crystal layers. The proposed approach allows us to predict theoretically the properties of optical Kossel lines in photonic liquid crystal (fluorescence polarization, spectral and angular fluorescence distribution, influence of the light absorption in liquid crystal, and, in particular, existing the optical Borrmann effect if the absorption in liquid crystal is locally anisotropic). Comparison of the theoretical results and the known experimental data shows that the theory reproduces sufficiently well the observation results on the fluorescence in photonic liquid crystals. For confirming a direct connection of the optical Kossel lines to the localized optical edge modes in perfect photonic liquid crystal, we propose the application of time-delayed techniques in studying the optical Kossel lines.

scholarly journals The effects of plant density and irrigation on phenolic content in cauliflower 

2017 ◽  
Vol 44 (No. 4) ◽  
pp. 178-185 ◽  
Author(s):  
Alina Kałużewicz ◽  
Jolanta Lisiecka ◽  
Monika Gąsecka ◽  
Włodzimierz Krzesiński ◽  
Tomasz Spiżewski ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Ferulic Acid ◽  
Gallic Acid ◽  
Caffeic Acid ◽  
Phenolic Acids ◽  
Plant Density ◽  
Phenolic Content ◽  
Sinapic Acid ◽  
Dry Weight ◽  
Coumaric Acid

This study was conducted to study the influence of plant density and irrigation on the content of phenolic compounds, i.e., phenolic acids and flavonols in cv. ‘Sevilla’ cauliflower curds. Levels of phenolic acids and flavonols were in the range of 3.0–6.2 mg and 25.4–87.8 mg/100 g of dry weight, respectively, depending on plant density and irrigation. Of the phenolic acids, caffeic acid was detected in the highest amount, followed by p-coumaric acid, sinapic acid, gallic acid, and ferulic acid. Of the two flavonols detected, the levels of quercetin were higher than those of kaempferol. The content of the detected phenolic acids (with the exception of ferulic acid) and both flavonols increased with increasing plant density. Furthermore, the concentration of phenolic compounds (with the exception of ferulic acid) was significantly higher under irrigation.

The Effect of Heating Temperature on Total Phenolic Content, Antioxidant Activity, and Phenolic Compounds of Plum and Mahaleb Fruits

2019 ◽  
Vol 15 (11-12) ◽  
Author(s):  
Kashif Ghafoor ◽  
Isam A. Mohamed Ahmed ◽  
Süleyman Doğu ◽  
Nurhan Uslu ◽  
Gbemisola J. Fadimu ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Phenolic Compounds ◽  
Gallic Acid ◽  
Total Phenolic Content ◽  
Phenolic Content ◽  
Heating Temperature ◽  
Dry Weight ◽  
Total Phenolic ◽  
Dihydroxybenzoic Acid ◽  
Different Temperatures

AbstractThe effect of heating at different temperatures (60, 80, 90, 110, and 130 °C) on the total phenolic content, antioxidant activity, and phenolic compounds present in plum and mahaleb fruits was investigated. The antioxidant activity values and total phenolic contents of fresh plum (93.82% measured by DPPH method, 787.79 mg gallic acid equivalent (GAE)/100 g dry weight determined by Folin method) and mahaleb fruits (81.80%, 634.47 mg GAE/100 g dry weight) were higher than plum and mahaleb fruits dried at different temperatures (p < 0.05). Generally, the heating process caused a reduction in both total phenolic content and antioxidant activity for plum and mahaleb. While (+)-catechin (92.62 mg/kg), 1,2-dihydroxybenzene (132.15 mg/kg), gallic acid (107.01 mg/kg), and 3,4-dihydroxybenzoic acid (74.59 mg/kg) are the key phenolic compounds in fresh plum, (+)-catechin, 3,4-dihydroxybenzoic acid, 1,2-dihydroxybenzene, and syringic and caffeic acids were the major phenolic compounds of mahaleb fruits. The polyphenol content of fruits and the class of phenolics present are significantly affected by heating temperature.

An Electronic Model of a Neural Correlate to Experience Obtained When the Stimulus Object is a Straight Line or a Circle

1967 ◽  
Vol 25 (1) ◽  
pp. 189-202 ◽  
Author(s):  
Kristian Holt-Hansen
Keyword(s):  
Experimental Data ◽  
Brain Function ◽  
Stimulus Object ◽  
The Other ◽  
Neural Correlate ◽  
Close Analogy ◽  
Straight Line ◽  
Electronic Model ◽  
Close Relationship ◽  
The Brain

An attempt was made to present an electronic model of the neural correlate to the experiences of straightness and circularity on the basis of experimental data. Two sets of experiments were described. In one Ss had numerous kinds of experience when the stimulus object was a straight line or a circle. These experiments demonstrated a close relationship between a straight line and a circle in experience. The other set of experiments consisted of adjusting the electric voltages fed into a cathode ray oscilloscope so that the displays on the screen corresponded closely to some of the experiences reported by subjects in the first set of experiments. A plausible working hypothesis was put forward on the basis that the electronic functions underlying the working of a cathode ray oscilloscope suggest a close analogy with the brain function underlying the experiences obtained when the stimulus object is a straight line or a circle.

scholarly journals Evaluation of content of phenolics in Salvia species cultivated in South Moravian Region / Hodnotenie obsahu fenolov vo vybraných druhoch rodu Salvia L. pestovaných v Juhomoravskom kraji

2015 ◽  
Vol 62 (s9) ◽  
pp. 18-22
Author(s):  
A. Muráriková ◽  
K. Kaffková ◽  
S. Raab ◽  
J. Neugebauerová
Keyword(s):  
Gallic Acid ◽  
Plant Material ◽  
Phenolic Content ◽  
Salvia Officinalis ◽  
Total Phenolic ◽  
Total Phenols ◽  
Spectrophotometric Methods ◽  
Salvia Fruticosa ◽  
Standard Compound ◽  
Salvia Triloba

Abstract In this study, total phenolic content (TPC) and rosmarinic acid (RA) of 37 samples sage (Salvia L.) of extracts were determined using spectrophotometric methods. The amount of total phenols was analysed with Folin-Ciocalteu reagents. Gallic acid was used as a standard compound and the total phenols were expressed as mg.g−1 gallic acid equivalents of dried plant material. The values of the extracts displayed substantial differences. All of the investigated species except Salvia jurisicii (990.79 mg GAE. g−1 d.w.) exhibited higher content of phenolics. Among the studies, species demonstrated the highest content of phenol, followed in sequence by Salvia tomentosa, Salvia fruticosa, Salvia triloba, Salvia officinalis ‘Extrakta’, Salvia officinalis. TPC varied from 990.79 to 4459.88 mg GAE. g−1 d.w. in the extracts. The total amount of RA was between 0.88 and 8.04% among species. Salvia tomentosa, Salvia verticillata and Salvia officinalis ‘Extrakta’ had the highest content of RA. The high content of phenolic compounds indicated that these compounds contribute to the antioxidant activity.

Optimization of Drying and Extraction Process of Pereskia bleo Leaves in Determining Antioxidant Properties Utilizing Pareto ANOVA

2014 ◽  
Vol 548-549 ◽  
pp. 96-100
Author(s):  
Shareena Fairuz Abdul Manaf ◽  
Nur Shahidah Ab Aziz ◽  
Syawal Abdullah ◽  
Rafeqah Raslan ◽  
Fazlena Hamzah ◽  
...  
Keyword(s):  
Gallic Acid ◽  
Total Phenolic Content ◽  
Phenolic Content ◽  
Antioxidant Properties ◽  
Herbal Medicines ◽  
Extraction Process ◽  
Total Phenolic ◽  
Drying Time ◽  
Standard Curve ◽  
Three Factor

Pereskia Bleois commonly used among the local traditional medicine practitioners to prevent or treat cancer by consuming the leaves either raw or taken as a concoction brewed from fresh leaves. However, more research, regulation and standardization are required before herbal medicines can be recommended as effective and safe therapies. The objectives of this study are to obtain the optimum drying parameter and to identify the concentrations of phenolic content expressed as gallic acid equivalents (GAEs) inPereskia bleoleaves. Pareto ANOVA method was used to study the optimum condition and the total phenolic content via F-Test using three samples for variance and three-factor with replication. Taguchi ANOVA was performed using SN ratio with L9 orthogonal array to accommodate the three factor level. The drying time were tested for 3 hours, 4 hours and 5 hours. The result shows that drying time is the significant factor in drying process and followed by drying temperature and solvent volume used. The drying experiments were conducted at operating temperature of 35 °C, 40 °C and 45 °C. While the extraction were conducted at different volume using methanol of 150 ml, 180 ml and 200 ml. The standard curve of total phenolic content was based on the gallic acid compound. The total phenolic content in C2 was at the most suitable for being used as antioxidant for consumption in human body with drying time of 5 hours at 45 °C by using 180 ml of methanol for extraction ofP.bleoleaves.

scholarly journals DETERMINATION OF TOTAL PHENOLIC CONTENT FROM PLANT EXTRACTS USED IN COSMETIC PURPOSE

2021 ◽  
Vol 21 (1) ◽  
pp. 247-260
Author(s):  
SIMONA DOBRINAS ◽  
ALINA SOCEANU
Keyword(s):  
Measurement Uncertainty ◽  
Gallic Acid ◽  
Acid Concentration ◽  
Plant Extracts ◽  
Total Phenolic Content ◽  
Phenolic Content ◽  
Limit Of Detection ◽  
Total Phenolic ◽  
Spectrometric Method ◽  
Calibration Equation

Spectrometric analysis belongs to a group of measurement methods used for their simplicity and large selectivity to solve various problems of analytes. The total phenolic content of different plant extracts used for cosmetic purpose was determined by a slightly modified version of traditionally Folin-Ciocalteau method. The objective of this work was the validation of UV-Vis spectrometric method, investigation of uncertainty sources when measuring gallic acid concentration and evaluation of the calibration equation effect on measurement uncertainty of UV– Vis spectrophotometer. Validation was performed by studying analytical curve linearity (R2=0.9995) and range (37.5 – 225 mg L-1), estimated limit of detection (LOD, 0.11mg L-1) and limit of quantification (LOQ, 0.37 mg L-1), precision (%RSD, 0.14 – 1.34), recoveries (83-110%) and stability (%RSD, 0.8 – 2.83). To obtain more representative values for precision, recoveries and stability simultaneous replicates at different times, on different matrices including plant (marigold, chamomile and lavender) were performed during the study period. The validated method was successfully applied to determine TPC in marigold extracts. For chamomile and lavender extracts, the spectrometric method presented only acceptable precision, among all the performance parameters studied. The sources of the gallic acid concentration measurement uncertainty include purity, volume of flasks, mass and the calibration equation. The results indicated that the uncertainty components from purity were the smallest. An important source of the uncertainty was the mass.The volumes of the volumetric flasks had only modest effect on the uncertainty. The contribution of calibration equation is the greatest from all sources.

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