scholarly journals Evaluation of total polyphenol content, total flavonoid content, and antioxidant activity of Plectranthus amboinicus leaves

Author(s):  
N Q Nguyen ◽  
L V Minh ◽  
L H Trieu ◽  
L M Bui ◽  
T D Lam ◽  
...  
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.


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.


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.


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