scholarly journals Total Polyphenol and Flavonoid Content and Antioxidant Capacity of Some Varieties of Persea americana Peels Consumed in Cameroon

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Ruth Edwige Kemadjou Dibacto ◽  
Boris Ronald Tonou Tchuente ◽  
Maxwell Wandji Nguedjo ◽  
Yves Martial Tongue Tientcheu ◽  
Emilienne Carine Nyobe ◽  
...  

Fruit peels are increasingly being used as functional foods nowadays. Peelings of twelve varieties of Persea americana fruits consumed in Cameroon were investigated for their phenolic compounds (polyphenols and flavonoids) using three solvents systems, water, ethanol: water (50 : 50 v / v ), and ethanol, and antioxidant activity using total antioxidant capacity (TAC), ferric reducing antioxidant power (FRAP), and 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging methods. Total polyphenol, flavonoids, and antioxidant potential of the peels significantly varied with P. americana variety and also with the extraction solvents in the order ethanol > ethanol: water > water. Total phenolic content varied from 2407 (Fuerte florid) to 673 (Semil) mg GAE/g DM, respectively, while flavonoids varied from 986 to 119 mg QE/g DM for Fuerte florid and Hickson varieties, respectively. TAC, respectively, varied between 132.87 and 126.85 mg AAE/g DM with Hass and Semil varieties, respectively. The highest DPPH scavenging capacity was recorded for the ethanolic extract with Lula (86.33%) and the least for the aqueous extract with the Semil (30.11%) variety. With FRAP, the highest capacity was obtained with hydroethanolic extract of Fuerte florid (0.43 mg AAE/g DM) and the least for aqueous extract with the Semil (0.269 mg AAE/g DM) variety. In conclusion, varieties of avocado peels are a good source of antioxidants. Solvent extraction significantly affected the concentration of bioactive compounds but not the potency of the antioxidants. A weakly positive correlation but not significant between the quantity of polyphenol, flavonoid, and antioxidant capacity of avocado peelings was obtained in this study.

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Sathsara T. Deyalage ◽  
Indira Wickramasinghe ◽  
Nimesha Amarasinghe ◽  
Gayan Thilakarathna

Green leafy vegetables (GLVs) are abundant in bioactive compounds and constitute a crucial part of a balanced diet. Sri Lankan green leafy vegetables which are edible and available for consumption have not been thoroughly investigated, whilst their consumption can deflate the risk of arising several degenerative diseases, such as cancer and cardiovascular diseases. The present study was aimed at evaluating the antioxidant capacities of the leafy vegetables, Gymnema lactiferum (Kurignan), Wattakaka volubilis (Aguna), and Argyreia populifolia (Girithilla), with different thermal treatments (70°C, 120°C, and 170°C) which are used in domestic cooking processes. Heat treatments significantly affect the antioxidant capacity and polyphenolic content of most vegetables analyzed, either increasing or decreasing the concentration of these compounds. In the presence of thermal treatments, Gymnema lactiferum (14.52-20.28 mg GAE/g DW) and Wattakaka volubilis (19.75-27.13 mg GAE/g DW) showed a significantly higher ( p < 0.05 ) total phenolic content. The temperature treatment did not alter the ABTS radical scavenging activity in Gymnema lactiferum. In contrast, an increment of ferric reducing antioxidant power (41.26-54.85 mg TE/g DW) and DPPH radical scavenging activity (0.11-0.26 mg TE/g DW) was observed. Wattakaka volubilis treated at 170°C appeared to have a significantly higher amount ( 104.93 ± 1.41   mg TE/g DW) of ferric reducing antioxidant power compared to its raw form. All cooking processes with their corresponding thermal treatments caused a significantly lower ( p < 0 ) amount of antioxidant capacity in Argyreia populifolia.


2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Armelle D. Tchamgoue ◽  
Lauve R. Y. Tchokouaha ◽  
Protus A. Tarkang ◽  
Jules-Roger Kuiate ◽  
Gabriel A. Agbor

Diabetes mellitus is a metabolic disorder of glucose metabolism which correlates with postprandial hyperglycemia and oxidative stress. Control of blood glucose level is imperative in the management of diabetes. The present study tested the hypothesis thatCostus afer, an antihyperglycemic medicinal plant, possesses inhibitory activity against carbohydrate hydrolyzing enzymes. Hexane, ethyl acetate, methanol, and water extracts were prepared from the leaf, stem, and rhizome ofC. aferand subjected to phytochemical screening, assayed forα-amylase andα-glucosidase inhibitory activities and antioxidant capacity (determined by total phenolic and total flavonoids contents, ferric reducing antioxidant power (FRAP), and DPPH radical scavenging activity). All extracts inhibitedα-amylase andα-glucosidase activities. Ethyl acetate rhizome and methanol leaf extracts exhibited the best inhibitory activity againstα-amylase andα-glucosidase (IC50: 0.10 and 5.99 mg/mL), respectively. Kinetic analysis revealed two modes of enzyme inhibition (competitive and mixed). All extracts showed antioxidant capacity, with hexane extracts exhibiting the best activity. DPPH assay revealed that methanol leaf, rhizome, and ethyl acetate stem extracts (IC50< 5 mg/mL) were the best antioxidants. The presence of bioactive compounds such as flavonoids, alkaloids, phenols, and tannins may account for the antioxidant capacity and carbohydrate hydrolyzing enzyme inhibitory activity ofC. afer.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Ademola O. Ayeleso ◽  
Oluwafemi O. Oguntibeju ◽  
Nicole L. Brooks

This study was carried out to investigate thein vitroantioxidant potentials of the leaves and fruits ofNauclea latifolia, a straggling shrub or small tree, native to tropical Africa and Asia. Hot water extracts of the leaves and fruits ofNauclea latifoliawere assessed for their total polyphenolic, flavanol, and flavonol contents as well as 1-diphenyl-2-picrylhydrazyl (DPPH) scavenging ability, ferric reducing antioxidant power (FRAP), Trolox equivalence antioxidant capacity (TEAC), and oxygen radical absorbance capacity (ORAC) assays. The aqueous extract of the leaves was found to contain higher level of total polyphenols (11.63±0.023 mg GAE/g), flavanol (1.45±0.10 mg CE/g), and flavonol (2.22±0.37 mg QE/g) than the extract of the fruits with values of1.75±0.02 mg GAE/g (total polyphenol),0.15±0.01 mg CE/g (flavanol), and1.00±0.13 mg QE/g (flavonol). Similarly, the aqueous extract of the leaves also exhibited higher DPPH (IC5020.64 mg/mL), FRAP (86.10±3.46 μmol AAE/g), TEAC (94.83±3.57 μmol TE/g), and ORAC (196.55±0.073 μmol TE/g) than the extract of the fruits with DPPH (IC50120.33 mg/mL), FRAP (12.23±0.40 μmol AAE/g), TEAC (12.48±0.21 μmol TE/g), and ORAC (58.88±0.073 μmol TE/g). The present study showed thatNauclea latifoliahas strong antioxidant potentials with the leaves demonstrating higherin vitroantioxidant activities than the fruits.


Author(s):  
Nur Fatimah Lasano ◽  
Asmah Rahmat ◽  
Nurul Shazini Ramli ◽  
Mohd Fadzelly Abu Bakar

Objective: This study aimed to evaluate the effect of oven and microwave drying on total phenolic content (TPC), total flavonoid content (TFC), and antioxidant capacity of unfermented and fermented tea developed from Strobilanthes crispus leaves.Methods: TPC and TFC were estimated using a spectrophotometric method, while antioxidant capacity was determined using ferric reducing antioxidant power assay and 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay. Camellia sinensis (tea plant), that is, used for the production of all varieties of commercial tea and fresh S. crispus leaves were served as controls in this study.Results: The highest antioxidant activity and TPC were observed in S. crispus tea developed from microwave-dried leaves, while the highest TFC was observed in oven-dried tea. Unfermented S. crispus tea showed significantly higher values (p<0.05) for antioxidant activity, TPC, and TFC as compared to fermented S. crispus tea. A strong and moderate correlation was observed between antioxidant activity and TPC as well as TFC values.Conclusion: The present work clearly showed that S. crispus tea developed from microwave-dried leaves able to preserve the polyphenols and hence contribute to excellent antioxidant capacity. Incorporation of unfermented S. crispus tea in the diet can be a good source of natural antioxidant.


Author(s):  
Minh Phuoc Nguyen

Noni (Morinda citrifolia L.) fruit is highly evaluated as an important herb with a good source of natural antioxidant against various ailments as well as maintain overall good health. It’s normally disposed due to unpleasant aroma from the ripened fruit. There is limited literature mentioned to the decomposition of this valuable fruit during thermal processing. Hence this reseach aimed to evaluate the possible degradation of total phenolic (mg GAE/100 g), total flavonoid (mg QE/100 g), DPPH radical-scavenging ability (mM TE/100 g), FRAP ferric reducing antioxidant power assay (mM TE/100 g) in raw, dried and roasted noni pulp tea. The highest contents of functional constituents and antioxidant capacity were noticed in the raw sample; meanwhile decreased dramatically in the roasted one. However, degradation of noni flavonol glycosides during roasting could produce aglycone metabolites, which in turn, may lead to increased bioavailability. Owing to degradation of phytochemical and antioxidant ability by harsh thermal treatment, it’s necessary to be careful in drying and roasting to limit detrimental effect in herbal noni tea production.


Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2746
Author(s):  
Giuseppe Squillaci ◽  
Carla Zannella ◽  
Virginia Carbone ◽  
Paola Minasi ◽  
Veronica Folliero ◽  
...  

The purpose of the current study was to determine the phenolic composition, antioxidant, and antimicrobial activities in grape cane extracts from typical cultivars of Southern Italy. Aqueous extracts at different pHs (1–13) were prepared from “Aglianico”, “Fiano”, and “Greco” grape canes. The results demonstrated that an alkaline pH (13.00) produced the best polyphenol-rich extracts, as the total phenolic content was more than double when compared to the respective extracts prepared at pH 1.00. “Greco” grape canes gave the highest quantity of phenolic compounds at each pH, ranging from 42.7 ± 0.4 to 104.3 ± 3.0 mg Gallic Acid Equivalents (GAE)/g Dry Extract (DE) from pH 1.00 to 13.00. The Radical Scavenging Activity (RSA) and the Ferric Reducing Antioxidant Power (FRAP) were measured. The highest antioxidant activity was showed by “Greco” extract at pH 7.00. Seventy-five compounds were identified in the extracts by HPLC-MS with six of them described for the first time in grape canes. Procyanidins were highly abundant in extracts at pH 7.00, whereas stilbenoids were the most represented compounds at pH 13.00. Very strong antiviral activity against herpes simplex viruses was recorded for the extracts at pH 7.00 and 13.00 that were active in the early stages of infection by acting directly against the viral particles. The overall results suggest that grape canes, currently underutilized, can be usefully valorised by providing active extracts to use as antioxidant and antiviral agents.


Botanica ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 76-87
Author(s):  
Aziza Lfitat ◽  
Hind Zejli ◽  
Abdelkamel Bousselham ◽  
Yassine El Atki ◽  
Badiaa Lyoussi ◽  
...  

AbstractWe conducted this study to determine and compare the content of phenolic compounds and flavonoids in the argan and olive leaves as well as their antioxidant capacity in aqueous, methanolic, and ethyl acetate extracted fractions. In vitro antioxidant activity was evaluated in comparison with synthetic antioxidants by assessing DPPH• radical scavenging capacity, ferric reducing antioxidant power, scavenging ability by inhibiting the β-carotene/linoleic acid emulsion oxidation, and by the ABTS radical scavenging activity assay. Total phenolic content in argan samples ranged from 221.69 ± 2.07 to 1.32 ± 0.01 mg GAE/g DW and in olive samples from 144.61 ± 0.82 to 1.21 ± 0.02 mg GAE/g DW. Total flavonoids content in argan samples varied from 267.37 ± 1.12 to 25.48 ± 0.02 mg QE/g DW, while in olives from 96.06 ± 0.78 to 10.63 ± 0.05 mg QE/g DW. In vitro antioxidant studies strongly confirmed the antioxidant potency of argan and olive leaves and their richness in secondary metabolites that are effective in free radicals scavenging and metal chelating capacities, indicating their antioxidant power.


2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Marieta Hristozkova ◽  
Liliana Gigova ◽  
Maria Geneva ◽  
Ira Stancheva ◽  
Ivanina Vasileva ◽  
...  

Abstract Mycorrhizal fungi, algae and cyanobacteria are some of the most important soil microorganisms and major components of a sustainable soil-plant system. This study presents for the first time evidence of the impact of green alga and cyanobacterium solely and in combination with arbuscular mycorrhizal fungi (AMF) on plant-antioxidant capacity. In order to provide a better understanding of the impact of AMF and soil microalgae on Ocimum basilicum L. performance, changes in the pattern and activity of the main antioxidant enzymes (AOEs), esterases and non-enzymatic antioxidants including phenols, flavonoids, ascorbate, and α-tocopherols were evaluated. The targeted inoculation of O. basilicum with AMF or algae (alone and in combination) enhanced the antioxidant capacity of the plants and the degree of stimulation varied depending on the treatment. Plants in symbiosis with AMF exhibited the highest antioxidant potential as was indicated by the enhanced functions of all studied leaf AOEs: 1.5-, 2- and more than 10-fold rises of superoxide dismutase (SOD), glutathione-S-transferase (GST) and glutathione reductase (GR), respectively. The greatest increase in the total esterase activity and concentration of phenols, flavonoids and ascorbate was marked in the plants with simultaneous inoculation of mycorrhizal fungi and the green algae. 2,2-diphenyl-1-pycril-hydrazyl (DPPH) free radical scavenging method and ferric reducing antioxidant power (FRAP) assay proved the increased plant antioxidant capacity after co-colonization of green algae and mycorrhizae.


2019 ◽  
Vol 48 (2) ◽  
pp. 265-270
Author(s):  
Shakuli Kashyap ◽  
PB Rao ◽  
P Mishra ◽  
Supriya

The antioxidant potential of aerial parts of eight medicinal plant species were investigated by 1,1- diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, Ferrous ion-chelating (FCA) and ferric reducing antioxidant power assays in five different concentrations and the mean values ranged from 20.39 to 83.01%, 17.21 to 48.62% and 11.70 to 21.65 μg Trolox equivalent/mg extract, respectively. Total phenolic and flavonoid contents ranged from 4.83 to 10.46 μg, gallic acid equivalent/mg extract and 1.12 to 13.11 μg quercitin equivalent/mg extract. Enzymatic antioxidants (Unit/mg fresh weight): superoxide dismutase, catalase and peroxidase values ranged from 14.86 to 49.81, 60.00 to 141.33 and 0.25 to 0.60, respectively. Considering the overall assay M. Pudica can be considered as the potent candidate for displaying antioxidant activity among the experimental plants.


2013 ◽  
Vol 76 (7) ◽  
pp. 1218-1225 ◽  
Author(s):  
YOLANDA RUIZ-NAVAJAS ◽  
MANUEL VIUDA-MARTOS ◽  
ESTHER SENDRA ◽  
JOSÉ A. PEREZ-ALVAREZ ◽  
JUANA FERNÁNDEZ-LÓPEZ

The aim of this work was to determine (i) the antioxidant capacity of Thymus moroderi, Thymus piperella, Santolina chamaecyparissus, and Sideritis angustifolia essential oils (EOs) by means of four different antioxidant tests (the 2,2′-diphenyl-1-picrylhydrazyl radical scavenging method, the ferrous ion–chelating ability assay, the ferric reducing antioxidant power test, and the thiobarbituric acid reactive species test) and (ii) the antifungal activity against molds and yeast of these EOs by the agar dilution and the microdilution methods. T. piperella EO showed the lowest 50% inhibitory concentration by the 2,2′-diphenyl-1-picrylhydrazyl radical scavenging method (9.30 mg/ml) and by the thiobarbituric acid reactive species test (6.30 mg/ml) and the highest value by the ferric reducing antioxidant power test (2.64 Trolox equivalent antioxidant capacity), while S. chamaecyparissus showed the lowest 50% inhibitory concentration in the ferrous ion–chelating ability assay (3.94 mg/ml). All EOs had a substantial inhibitory effect on all assayed yeast strains. S. angustifolia EO had the lowest MICs (2.5 μl/ml) for the yeasts Saccharomyces cerevisiae, Debaryomyces hansenii, Rhodotorula mucilaginosa, and Pichia carsonii. As regards antifungal activity, S. angustifolia EO at high concentrations was the most effective EO in reducing the growth of Alternaria alternata, Penicillium chrysogenum, and Mucor racemosus, while S. chamaecyparissus was the best inhibitor of the molds Aspergillus flavus and Mucor circinelloides. The results obtained in this study suggest the possibility of using these essential oils as natural antioxidant food preservatives.


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