Validation of Spectrophotometric Methods for the Determination of Total Polyphenol and Total Flavonoid Content

2017 ◽  
Vol 100 (6) ◽  
pp. 1795-1803 ◽  
Author(s):  
Petra Matić ◽  
Marija Sabljić ◽  
Lidija Jakobek

Abstract The aim of this study was to validate spectrophotometric methods for the measurement of total polyphenol (TP; via the Folin–Ciocalteu method) and total flavonoid (TF) content [via the aluminum chloride (AlCl3) method]. Validation parameters of these methods were determined, including linearity, sensitivity, precision (intra-assay and intermediate), accuracy, LOD, and LOQ. For the validation process, groups of polyphenol standards were used, including phenolic acids (gallic, p-coumaric, caffeic, and chlorogenic acids), flavan-3-ols [(+)-catechin and procyanidins B1 and B2], flavonols (quercetin and quercetin-3-rutinoside), and dihydrochalcones (phloretin and phloretin-2-glucoside). Obtained validation parameters were within acceptable ranges with high determination coefficients, reasonably low LODs and LOQs, and high slopes in the calibration curves for both methods, except for phloretin and phloretin-2-glucoside, for which there were low slopes in the calibration curves for the AlCl3 method. To evaluate differences in polyphenol content, the validated spectrophotometric methods were used to determine TP and TF content in wines (Plavac, Graševina, and Vranac) and juices (blueberry, strawberry, and blackcurrant juice) according to the polyphenol calibration curves. Polyphenol contents were different for both methods in all wines and juices.

2021 ◽  
Author(s):  
Suciu Felicia ◽  
Roșca Adrian Cosmin ◽  
Lupu Carmen ◽  
Popescu Antoanela ◽  
Badea Victoria

"The history of medicinal plants is associated with the evolution of civilization. In all regions of the world, the history of nations shows that these plants have always occupied an important place in medicine, in cosmetic products, and culinary preparations. The paper aims to determine the total polyphenols in different parts of the species Lysimachia nummularia L. In our study, we focused on the extraction of polyphenolic compounds in different solvents. The solvents used in the extraction were: 40% ethanol, concentrated methanol, in water. The total polyphenol content was determined by spectrophotometric methods, a method from the European Pharmacopoeia 10.0, with minor modifications. The total polyphenol content of different extracts varied depending on the extraction process. Different parts of the plant and different solvents were used in the determinations carried out to establish the optimal extraction method for the organs of Lysimachia nummularia L."


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Ahmad Mohammad Salamatullah ◽  
Khizar Hayat ◽  
Fohad Mabood Husain ◽  
Mohammed Asif Ahmed ◽  
Shaista Arzoo ◽  
...  

Coffee is an intricate mixture of thousands of chemical compounds that are accountable for its flavor and aroma. Roasting is a key step in the processing of coffee beans. This study assessed the effect of microwave roasting (MW) and extraction solvents (ES) on the total polyphenol content, total flavonoid content, and antioxidant activity of coffee beans. The untreated and microwave-roasted (MR) coffee beans showed a total polyphenol content of 40.40 and 35.15 mg GAE/gm DW, respectively, when methanol was used as the solvent for extraction. Similarly, for the untreated coffee beans, the methanol extracted coffee had a significantly ( p < 0.05 ) higher total flavonoid content (39.34 mg CE/g DW) as compared to ethanol (34.82 mg CE/g DW). The obtained IC50 for the untreated and microwave-roasted samples as extracted by methanol were 4.13 and 5.68 mg/mL, respectively, while the IC50 values of untreated and microwave-roasted samples extracted by ethanol were 4.59 and 6.24 mg/mL, respectively. Untreated coffee beans exhibited a higher reducing power (1.237) than that of the microwave-roasted ones (0.839) when extracted with methanol. Chlorogenic acid was the major (2.31–2.68%) phenolic compound found in all the coffee samples whether it was untreated or microwave-roasted. Vanillin demonstrated the lowest (0.118–0.166%) phenolic compound found in the coffee bean samples. These results might be helpful for obtaining the maximum health benefits from coffee.


10.5219/1694 ◽  
2021 ◽  
Vol 15 ◽  
pp. 1104-1111
Author(s):  
Iveta Čičová ◽  
Natália Čeryová ◽  
Marek Šnirc ◽  
Jarmila Horváthová ◽  
Helena Lichtnerová ◽  
...  

Garlic (Allium sativum L.) is one of the most commonly grown vegetables and thanks to its sensory properties, it has an important place in numerous world cuisines. Garlic is also known for its health-promoting properties, which are attributed to its chemical composition. The health benefits of garlic depending on the content of biologically active compounds, which vary between cultivars and geographical areas. Seven cultivars of garlic, namely Sukoradsky, Zahorsky, Germidour, Mojmir, Karel IV., Arkus, Makoi, were analyzed in this study. This study aimed to determine the total polyphenol content, total flavonoid content, and antioxidant activity of garlic. Studied characteristics were analyzed by the UV-VIS spectrometry method. Total polyphenol content ranged from 430.26 to 640.04 mg GAE.kg-1 FW. Total flavonoid content ranged from 10.29 to 60.49 mg CE.kg-1 FW. Antioxidant activity measured by ABTS assay ranged from 1.098 to 1.955 mmol TE.kg-1 FW. Antioxidant activity measured by FRAP assay ranged from 0.63 to 1.467 mmol.kg-1 FW. Highest TPC, TFC, and AA were determined in the cultivar Mojmir. The lowest TPC and TFC were determined in the cultivar Zahorsky. The lowest AA was determined in the cultivar Sukoradsky. High positive correlations were determined between individual parameters.


Author(s):  
Simona Ioana VICAS ◽  
Livia BANDICI ◽  
Alin Cristian TEUSDEA ◽  
Gheorghe Emil BANDICI

In this paper, our objective was to investigate extraction efficiency of polyphenols with antioxidant capacity from two varieties of grapes (white-Muscat Ottonel (MO) and red-Pinot Noir (PN)) using pulsed electric field (PEF). Grapes were harvested in the Crisana Santimreu vineyard in 2015. The grapes were declustered and crushed, and have been divided into three parts. A part was treated in PEF, the second one was homogenized, and then was treated in PEF and the last part remained untreated, representing the control samples. The bioactive compounds, like total polyphenol content and total flavonoid content, were determined by the spectrophotometric method. The antioxidant capacity of the samples was determined by three methods (DPPH, FRAPand TEAC). Our results show that the application of PEF to the crushed grapes increases the total polyphenol content 2.28 and 3.15 times and the total flavonoid content 7.17 and 5.29 times for MO and PN, respectively. Also, the antioxidant capacity was significantly increased when it was compared with the control sample. When the treatment in PEF was applied on homogenized grapes both bioactive compounds and antioxidant capacity were significantly increased compared to the samples treated in PEF for crushed grapes. In the present research work, we demonstrated that the application of PEF to two different grape varieties significantly increased the level of total polyphenols and flavonoids and also the antioxidant capacity. The application of PEF to homogenized grapes was more efficient.


2021 ◽  
Vol 3 (2) ◽  
pp. 126-136
Author(s):  
Anita Puspa Widiyana ◽  

Validation as a quality control for the content of chemical compounds from natural ingredients. One of the chemical constituents is the flavonoids which are found in the Imperatacylindrica roots and Centella asiatica leaves. This study aims to ensure the analysis method meets the requirements and determines the levels of flavonoids. The research stages included extraction, validation and determination of total flavonoid. Extraction was carried out by immersing dry simplicia in 96% ethanol solvent for 3x24 hours. The solvent is evaporated using a rotary evaporator until a thick extract is formed. Validation testing includes linearity, accuracy, precision, LOD and LOQ. Determinationof the total flavonoid was carried out by measuring the absorption at a maximum wavelength of 428.2 nm. The validation results includethe correlation coefficient (R) of 0.998, precision % RSD <2 %, %accuracy 99,53-97,98%, LOD 3.02ppm and LOQ 9.15 ppm. The total flavonoid of the ethanol extract of Imperata cylindrica roots was 36.39 ± 0.08 mg/g QE and Centella asiatica leaves was 102.10 ± 0.08 mg/g QE. The conclusion is that the method used met the validation requirements and the total flavonoid content of the ethanol extract of Centella asiatica leaves was higher than Imperata cylindrica roots


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