scholarly journals Comparative Examination of Antioxidant Capacity and Fingerprinting of Unfractionated Extracts from Different Plant Parts of Quinoa (Chenopodium quinoa) Grown under Greenhouse Conditions

Antioxidants ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 238
Author(s):  
Dayana Buitrago ◽  
Ivon Buitrago-Villanueva ◽  
Ricardo Barbosa-Cornelio ◽  
Ericsson Coy-Barrera

Integrated surveys of metabolic profiles and antioxidant capacity from Chenopodium quinoa have been limited and have particularly focused on an examination of seeds and leaves. According to this, the main aim of the present study was to address an evaluation of the antioxidant activity of crude ethanolic extracts from different plant parts (leaves, stems, roots, flowers, and seeds) harvested at different times during growth and processed by two distinct drying methods: Air-drying and freeze-drying. In order to characterize the resulting extracts, the total content of phenolics (TPC) and flavonoids (TFC) was then measured through the Folin–Ciocalteu method, while antioxidant capacity was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH•) free radical scavenging and ferric-reducing antioxidant power (FRAP) methods. Parallel to this evaluation, extracts were profiled by LC-DAD-ESI-MS. Data analysis was supported by statistics. Most of the extracts obtained from freeze-dried samples showed higher TPC values ranging from 6.02 to 43.47 milligram of gallic acid equivalents per gram of plant material and a TFC between 1.30 and 12.26 milligram of quercetin equivalents per gram of plant material. After statistical analysis, a low correlation between TPC and TFC values was observed regarding antioxidant capacity from DPPH and FRAP measurements of both drying methods. A multivariate analysis showed that antioxidant components and antioxidant capacity in C. quinoa changed during growth and between plant parts and drying methods. These changes need to be taken into consideration when comparing the production/accumulation of beneficial bioactive compounds in this pseudocereal.

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.


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.


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.


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.


Author(s):  
Marcin Dziedziński ◽  
Joanna Kobus-Cisowska ◽  
Daria Szymanowska- Powałowska ◽  
Kinga Stuper- Szablewska ◽  
Marlena Baranowska

Scots pine (Pinus sylvestris L.) shoots have been increasingly commonly used as functional food or its component, the shoots contain various active components, unknown from other raw materials. The objective of the study was to assess the influence of the drying method on the content of bioactive compounds and antioxidative and antimicrobial activity of pine shoots. It was demonstrated that freeze drying (PSL), vacuum drying (PSP) and natural drying (PSN) have significant impact on the physicochemical properties, content of bioactive compounds and antioxidative activity of the prepared ethanol-water extracts. The content of the studied compounds varied significantly in the tested shoots. In spectrophotometric testing the highest total flavonoid content was demonstrated in the PSP sample, at 5.51 mg quercetin/g dw. On the other hand, the reducing capacity was as follows: PSN>PSP>PSL in the range from 13.4 to 5.73 mg gallic acid/g dw. However in assay conducted using HPLC methods the highest content of polyphenols characterized extract from freeze-dried raw material (9151.15 µg/g), followed by vacuum-dried (8264.57 µg/g), and the lowest content of phenolic compounds was found in convection-dried shoots (7621.76 µg/g). The studied extracts demonstrated antioxidative properties, both in ferric reducing antioxidant power assay (FRAP) as well as in free radical quenching measurement (DPPH). All of the studied extracts demonstrated antimicrobial and fungicidal properties, and they were particularly efficient in the case of gram-negative bacteria.


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.


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.


2021 ◽  
Vol 50 (8) ◽  
pp. 2207-2218
Author(s):  
Wan Najiyah Hanun Wan Nasir ◽  
Nurul Najiha Ain Ibrahim ◽  
Kuo Hao Woon ◽  
Azliana Abu Bakar Sajak ◽  
Noor-Soffalina Sofian-Seng ◽  
...  

Curcuma aeruginosa Roxb. is one of the plants from the Zingiberaceae family which the rhizome has been used for medicinal purposes. However, the biological properties of the leaves have not been fully explored. Therefore, this study was conducted to evaluate the effects of different drying methods and solvents on total phenolic content, antioxidant and anti-hyperglycemic activities of C. aeruginosa leaf extract. Samples were dried by oven drying (OD) and freeze drying (FD), and then extracted using different ratios of ethanol:water (100:0, 50:50 and 0:100). The amount of phenolic content (TPC) was determined using a spectrophotometer. Antioxidant activity was tested using the Free Radical Scavenging (DPPH) test and the Ferric Reducing Antioxidant Power assay (FRAP), while the anti-hyperglycemic test was evaluated by determining the percentage of α-glucosidase inhibition. The results showed that FD at 100:0 and 50:50 concentrations had the highest phenolic content (30.88 and 33.06 mg GAE/g extract, respectively) and highest antioxidant activity value (38.24 and 42.46 mg TEAC/g extract, respectively). For DPPH, FD at 50:50 showed the highest inhibition of 71.48% compared to other extracts. Whereas FD at 100:0, 50:50 and 0:100 showed the highest α-glucosidase inhibition of 25.65, 30.78 and 27.65%, respectively. However, compared to Quercetin, the extract showed mild anti-hyperglycemic activity. The results indicated that FD is the best method of drying while 50:50 showed as the best solvents. Positive correlation between TPC with antioxidant and anti-hyperglycemic activities showed that C. aeruginosa leaf has potential as a source of natural antioxidant with the presence of phenolic compounds.


2020 ◽  
Vol 15 (2) ◽  
pp. 1934578X2090452
Author(s):  
Marta Pasławska ◽  
Kinga Sala ◽  
Agnieszka Nawirska-Olszańska ◽  
Bogdan Stępień ◽  
Elżbieta Pląskowska

Lemon thyme contains several bioactive health-promoting compounds of high antioxidant capacity—such as polyphenols, carotenoids, and chlorophyll—which may undergo degradation during drying in incorrect processing conditions. This work is aimed at evaluating the impacts of different drying techniques and parameters on the chemical and physical properties of lemon thyme. In the experiment, lemon thyme leaves are dried using two traditional hot-air methods, convective drying (temperature 70°C or 80°C, air velocity 2 m/s), and fluidized bed drying (temperature 70°C or 80°C, air velocity 5–10 m/s); as well as two innovative drying methods, microwave-assisted fluidized bed (MFB) drying (microwaves at a power of 240 or 440 W, air temperature 40°C, air velocity 5–10 m/s) and microwave-vacuum (MV) drying (microwaves at a power of 240 or 440 W, under vacuum at 4–6 kPa). The kinetics of water delivery are described using the Page Model. After drying, the nutritional composition of the material is analyzed: polyphenol (total content and polyphenols profile by ultra-performance liquid chromatography), carotenoid, and chlorophyll total content, as well as antioxidant capacity (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt [ABTS+] and ferric reducing antioxidant power [FRAP]). Color changes ( L*, a*, b*, ΔE) are also analyzed using the visible effects of lemon thyme pigment disintegration. It is found that the MV drying method is the best for lemon thyme preservation, as it has the shortest process time and the highest retention of polyphenols (78.90%-82.14%), chlorophylls (51.54%-52.68%), antioxidant capacity (47.83%-48.63% of ABTS+ and 20.85%-45.45% of FRAP), and presented the least color change ( ΔE = 25.57-28.32). For preserving carotenoids, the most protective method is MFB (retention 68.46%-70.61 %).


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Nagendra Prasad ◽  
Bao Yang ◽  
Kin Weng Kong ◽  
Hock Eng Khoo ◽  
Jian Sun ◽  
...  

Nypa fruticansWurmb. is one of the important underutilized fruit of Malaysia, which lacks scientific attention. Total phenolics, flavonoid content, and antioxidant capacities from endosperm extracts ofNypa fruticans(unripe and ripe fruits) were evaluated. Endosperm extract of unripe fruits (EEU) exhibited the highest phenolics (135.6 ± 4.5 mg GAE/g), flavonoid content (68.6 ± 3.1 RE/g), and antioxidant capacity. Free radical scavenging capacity of EEU as assessed by 2-2′-azino-bis (3-ethylbenz-thiazoline-6-sulfonic acid (ABTS) and 1,1-diphenyl-2-picryl hydrazyl (DPPH) radicals showed inhibitory activity of78±1.2% and85±2.6%, respectively. Beta carotene bleaching coefficient of EEU was higher (2550±123), when compared to endosperm extract of ripe fruits (1729±172). Additionally, EEU exhibited high antioxidant capacity by phosphomolybdenum method and ferric reducing antioxidant power values. Eight phenolic compounds fromNypa fruticansendosperm extracts were identified and quantified by ultra-high-performance liquid chromatography. Chlorogenic acid, protocatechuic acid, and kaempferol were the major phenolic compounds. Thus this fruit could be used as a potential source of natural antioxidant.


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