scholarly journals In Vitro Antioxidant Activity and FTIR Characterization of High-Molecular Weight Melanoidin Fractions from Different Types of Cocoa Beans

Antioxidants ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 560 ◽  
Author(s):  
Oracz ◽  
Zyzelewicz

Melanoidins from real foods and model systems have received considerable interest due to potential health benefits. However, due to the complexity of these compounds, to date, the exact structure of melanoidins and mechanism involved in their biological activity has not been fully elucidated. Thus, the aim of this study was to investigate the total phenolic content, antioxidant properties, and structural characteristics of high-molecular weight (HMW) melanoidin fractions isolated by dialysis (>12.4 kDa) from raw and roasted cocoa beans of Criollo, Forastero, and Trinitario beans cultivated in various area. In vitro antioxidant properties of all studied HMW cocoa fractions were evaluated by four different assays, namely free radical scavenging activity against DPPH● and ABTS●+ radicals, ferric reducing antioxidant power (FRAP), and metal-chelating ability. Additionally, the structure–activity relationship of isolated HMW melanoidin fractions were analyzed using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). The results show that roasting at a temperature of 150 °C and a relative air humidity of 0.3% effectively enhances the total phenolics content and the antioxidant potential of almost all HMW cocoa melanoidin fractions. The ATR-FTIR analysis revealed that the various mechanisms of action of HMW melanoidins isolates of different types of cocoa beans related to their structural diversity. Consequently, the results clearly demonstrated that HMW cocoa fractions isolated from cocoa beans (especially those of Criollo variety) roasted at higher temperatures with the lower relative humidity of air possess high antioxidant properties in vitro.

Author(s):  
Venkanna Banothu ◽  
Uma Adepally ◽  
Jayalakshmi Lingam

Objective: To estimate the in vitro total phenolics, flavonoids contents, antioxidant and antimicrobial activities of various solvent extracts from the medicinal plant Physalis minima Linn.Methods: The crude bioactive were extracted from the dried powder of Physalis minima using methanol, ethyl acetate, chloroform and hexane solvents. Total phenolic content (TPC) and total flavonoid content (TFC) were estimated using Folin-Ciocalteu and aluminium chloride colorimetric methods respectively. 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2’-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and ferric reducing antioxidant power (FRAP) assays were used to determine the in vitro antioxidant capacity. The antimicrobial assay was done through agar well diffusion; minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined using broth microdilution methods against the Gram-negative bacteria (Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris) and Gram-positive bacteria (Staphylococcus aureus).Results: TPC expressed as gallic acid equivalents (GAE) ranged from 60.27±1.73-151.25±2.50 mg GAE/g dry weight, and TFC expressed as quercetin equivalents (QE) ranged from 56.66±0.80-158.84±2.30 mg QE/g dry weight. Methanol extract showed the highest antioxidant activity followed by ethyl acetate, chloroform, hexane extract and the IC50 values of methanol extract for scavenging DPPH and ABTS free radicals were 280.23±5.75-173.40±0.38µg/ml, respectively. All the extracts have shown potent antimicrobial activity for the zone of inhibition ranged from 9-35 mm; MICs and MBCs values ranged from 0.125-4.0 and 0.25-8.0 mg/ml, respectively towards tested pathogenic species.Conclusion: The comprehensive analysis of the present results demonstrated that Physalis minima possess high potential antioxidant properties which could be used as a viable source of natural antioxidants in treating infections caused by above-mentioned pathogens.


2014 ◽  
Vol 9 (1) ◽  
pp. 1934578X1400900 ◽  
Author(s):  
Rúben Silva ◽  
Isabel S. Carvalho

This study analyzed the antioxidant properties of Portulaca oleracea L., known as purslane. The samples (leaves, flowers and stems) were collected at two different locations in Portugal: Tavira (L1) and Vendas Novas (L2). Assays for total antioxidant activity, total phenolic content and ferric-reducing antioxidant power were conducted and, for both locations, significantly higher values ( P<0,05) were observed for stems (508.8 and 982.3 mg AAE/100 g DW, 1008.6 and 2285.5 mg GAE/100 g DW, 121.0 and 166.3 mg TE/100 g DW, respectively for each location), than in leaves or flowers. In the DPPH assay, the three-plant parts from L2 reached the 50% inhibition rate in lower concentrations than plants from L1. On the other hand, higher concentrations of total monomeric anthocyanins were found in samples from L1 (95.5, 88.8 and 86.0 mg/L) than in samples from L2 (81.7, 70.5 and 59.8 mg/L). The same was true for phenolic acids, estimated by liquid-chromatography, where methanol extracts were used. Phenolic extracts from all three-plant parts from both locations showed protective effects on DNA against hydroxyl radicals. This work suggests the possibility of benefit to human health from its consumption, related to the high antioxidant activity of purslane, even the stems, usually discarded in daily consumption.


2019 ◽  
Vol 88 (4) ◽  
Author(s):  
Ewa Kochan ◽  
Grażyna Szymańska ◽  
Izabela Grzegorczy-Karolak ◽  
Piotr Szymczyk ◽  
Monika Sienkiewicz

The present study was performed to investigate the antioxidant properties of callus and suspension culture extracts of <em>Panax quinquefolium</em> (American ginseng). The ginsenoside content and the total phenolic content (TPC) in these cultures were also examined. The total amount of the nine studied saponins was found to be 2.08, 1.69, and 0.202 mg g<sup>−1</sup> dry weight in red callus line (RCL), green callus line (GCL), and suspension cultures, respectively, by HPLC analysis. The TPC was estimated using the Folin–Ciocalteu method. The TPC of the suspension culture extracts was approximately 36.7% and 17.6% higher than that of the RCL and GCL, respectively. The antioxidant activity of the extracts was evaluated using the in vitro ABTS [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)] and FRAP (ferric reducing antioxidant power) assays; the methanolic <em>P. quinquefolium</em> suspension culture extracts demonstrated stronger antioxidant activity than that of the callus cultures.


2021 ◽  
pp. 2150017
Author(s):  
Zimbili Mkhize ◽  
Pule Silent Seboletswe ◽  
Hugues Kamdem Paumo ◽  
Pone Kamdem Boniface ◽  
Lebogang Maureen Katata-Seru

This study describes the synthesis of Protorhus longifolia methanolic leaf extract-loaded Eudragit nanoparticles (NPs) and assessment of their antioxidant activity comparative to the free methanolic extract. The latter was also analyzed for its total phenolic content (TPC) and total flavonoid content (TFC). The extract-loaded NPs were obtained through the emulsification solvent evaporation process and systematically characterized using the dynamic light scattering, entrapment efficiency, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. The antioxidant power was determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing ability of plasma (FRAP) in vitro model systems. Screening of the different classes of secondary metabolites was carried out through chemical reaction tests. Identification of the potential antioxidants was performed using the gas chromatography-mass spectrometry (GC-MS) technique and the database of National Institute Standard and Technology (NIST). The characterization techniques showed spherical-like particles having an average size of 150[Formula: see text]nm and zeta potential of [Formula: see text]22[Formula: see text]mV. The percentage of entrapped methanolic extract was determined to be 83%. The antioxidant assay demonstrated that this methodology persuaded an efficient concentration-dependent potential. This study indicates that nanoformulation of the Protorhus longifolia extracts leads to a suitable system for the enhancement of antioxidant activity. The appraisal of other pharmacological activities of the nano-encapsulated Protorhus longifolia methanol extract is under process.


2015 ◽  
Vol 45 (6) ◽  
pp. 818-828 ◽  
Author(s):  
Olufunmilayo Sade Omoba ◽  
Oluwadamilola Olamiiposi Dada ◽  
Sule Ola Salawu

Purpose – This paper aims to focus on the antioxidant properties and consumer acceptability of biscuits produced from pearl millet (PM)–tiger nut (TN) composite blends, with the aim of encouraging the use of these under-utilised food crops in producing value-added products with nutraceutical potential. Design/methodology/approach – PM grains and TN seeds were processed into flour and blended at ratios: 15:85 (A), 20:80 (B), 25:75 (C), 30:70 (D), 35:65 (E), 40:60 (F), 45:55 (G), of PM to TN using response surface methodology. The antioxidant properties of the biscuits produced from the flour blends were determined using standard methods, and data obtained were subjected to analysis of variance (ANOVA); differences of means were separated using Duncan multiple range test. The biscuits were subjected to sensory evaluation using 50 untrained panellist and results statistically analysed. Findings – The total phenolic content (TPC-mg/GAE) of PM–TN flour blends ranged from 2.65-4.95 (A-G), with an average TPC of 3.85. In PM–TN biscuits, total phenolic values ranged from 1.20-3.42 (A-G), with an average of 2.39. The 2,2′-azino-bis(3-ethyl benzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activities (μmolTEAC/g) of PM–TN flour blends ranged from 26.7-36.4 (A-G), and the values for biscuits ranged from 28.5-38.6 (A-G). There was a highly significant correlation, r = 0.811(p < 0.001) and r = 0.913 (p < 0.001) between phenolic content and antioxidant activity for flour and biscuit, respectively. The effect of in vitro digestion of biscuits on the antioxidant assays viz-a-viz: TPC and ABTS radical scavenging activities were also investigated. The order of phenolic release was enzymic > aqueous > ethanolic digest for TPC, while for ABTS, the order of release was enzymic > ethanolic > aqueous. The highest values for antioxidant properties were found in the simulated in vitro enzyme digested biscuits. Consumer acceptability revealed that the overall acceptability scores of the biscuits were not significantly different except for biscuit sample G. Originality/value – The paper has demonstrated the antioxidant potentials and consumer acceptability of PM–TN biscuits. It also shows the effect of in vitro digestion on the antioxidant activities of the biscuit and its potential health benefit, as a source of antioxidant.


2011 ◽  
Vol 83 (2) ◽  
pp. 501-505 ◽  
Author(s):  
Makoto Anraku ◽  
Takeshi Fujii ◽  
Yuko Kondo ◽  
Eijiro Kojima ◽  
Toshiyuki Hata ◽  
...  

Molecules ◽  
2021 ◽  
Vol 26 (18) ◽  
pp. 5523
Author(s):  
Szymon Poliński ◽  
Sylwia Kowalska ◽  
Patrycja Topka ◽  
Aleksandra Szydłowska-Czerniak

In this study, dark chocolates (DCh) containing zinc lactate (ZnL) were enriched with extracts from elderberries (EFrE), elderflowers (EFlE), and chokeberries (ChFrE) to improve their functional properties. Both dried plant extracts and chocolates were analyzed for antioxidant capacity (AC) using four different analytical methods: 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), cupric ion-reducing antioxidant capacity (CUPRAC), and ferric-reducing antioxidant power (FRAP), while total phenolic content (TPC) was determined by Folin–Ciocalteu (F–C) assay. An increase in antioxidant properties of fortified chocolates was found, and the bioaccessibility of their antioxidants was evaluated. The highest AC and TPC were found in ChFrE and chocolate with chokeberries (DCh + ChFrE) before and after simulated in vitro digestion. Bioaccessibility studies indicated that during the simulated digestion the AC of all chocolates reduced significantly, whereas insignificant differences in TPC results were observed between chemical and physiological extracts. Moreover, the influence of plant extracts on physicochemical parameters such as moisture content (MC), fat content (FC), and viscosity of chocolates was estimated. Furthermore, scanning electron microscopy with dispersive energy spectroscopy (SEM-EDS) was used to analyze surface properties and differences in the chemical composition of chocolates without and with additives.


2020 ◽  
Vol 13 (9) ◽  
pp. 262
Author(s):  
Daniil N. Olennikov ◽  
Aina G. Vasilieva ◽  
Nadezhda K. Chirikova

Fragaria viridis Weston or creamy strawberry is one of the less-known species of the Fragaria genus (Rosaceae family) with a wide distribution in Eurasia and is still in the shadow of more popular relatives F. ananassa (garden strawberry) or F. vesca (wild strawberry). Importantly, there is a lack of scientific knowledge on F. viridis compounds, their stability in the postharvest period, and bioactivity. In this study, metabolites of F. viridis fruits in three ripening stages were characterized with high-performance liquid chromatography with photodiode array and electrospray ionization triple quadrupole mass spectrometric detection (HPLC-PAD-ESI-tQ-MS). In total, 95 compounds of various groups including carbohydrates, organic acids, phenolics, and triterpenes, were identified for the first time. The quantitative content of the compounds varied differently during the ripening progress; some of them increased (anthocyanins, organic acids, and carbohydrates), while others demonstrated a decrease (ellagitannins, flavonols, etc.). The most abundant secondary metabolites of F. viridis fruits were ellagitannins (5.97–7.54 mg/g of fresh weight), with agrimoniin (1.41–2.63 mg/g) and lambertianin C (1.20–1.86 mg/g) as major components. Antioxidant properties estimated by in vitro assays (2,2-diphenyl-1-picrylhydrazyl radical (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) cation radical (ABTS), ferric reducing antioxidant power (FRAP), and oxygen radical absorbance capacity (ORAC)) showed good antioxidant potential in all ripening stages of F. viridis fruits. The pilot human experiment on the effect of F. viridis fruit consumption on the serum total antioxidant capacity confirmed the effectiveness of this kind of strawberry. Postharvest storage of ripe fruits at 4 °C and 20 °C lead to declining content in the majority of compounds particularly ascorbic acid, ellagitannins, and flavonols, with the most significant loss at room temperature storage. These results suggest that F. viridis fruits are a prospective source of numerous metabolites that have potential health benefits.


Antioxidants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1747
Author(s):  
Hayat Ouassou ◽  
Mohamed Bouhrim ◽  
Noureddine Bencheikh ◽  
Mohamed Addi ◽  
Christophe Hano ◽  
...  

Caralluma europaea (Guss.) N.E.Br. (C. europaea), is a medicinal plant used traditionally to treat diabetes mellitus (DM) in Morocco. This study aimed to investigate the in vitro antioxidant properties, glucose diffusion effects, α-amylase inhibitory activity, and pancreatic protective effects of C. europaea in experimental alloxan-induced diabetes in mice. Total phenolic contents were determined by Folin–Ciocalteu colorimetric method, total flavonoid contents were measured by aluminum chloride colorimetric assay, and tannins contents were determined by employing the vanillin method. C. europaea ethyl acetate fraction exhibited high antioxidant potential in terms of radical scavenging (DPPH) (IC50 = 0.22 ± 0.01 mg/mL), β-carotene bleaching activity (IC50 = 1.153 ± 0.07 mg/mL), and Ferric-reducing antioxidant power. Glucose diffusion was significantly inhibited by the ethyl acetate fraction at 60,120and 180 min, while the aqueous extract did not have this inhibitory effect when compared with the control group. Potent α-amylase inhibitory activity was observed in the ethyl acetate fraction and the aqueous extract in vitro and in vivo using STZ-diabetic rats. On the other hand, the administration of the ethyl acetate fraction (60 mg/kg) significantly attenuated alloxan-induced death and hyperglycemia in treated mice. Furthermore, histopathological investigations revealed that the ethyl acetate fraction protected islets of Langerhans against alloxan-induced tissue alterations. These results suggest that C. europaea exhibited an important antihyperglycemic effect via the inhibition of glucose diffusion and pancreatic α-amylase activity. In addition, the antidiabetogenic effect of C. europaea might be attributed to their polyphenol and flavonoid compounds, which could be reacted alone, or in synergy, to scavenge the free radicals produced by the alloxan.


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