scholarly journals Determination of minerals, vitamin content and antioxidant activity of cucumber and watermelon fruits from South-Western part of Nigeria

Author(s):  
Modupe A. Omoniyi ◽  
Aduradara M. Alli
Chemosensors ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 76
Author(s):  
Aleksey V. Tarasov ◽  
Ekaterina I. Khamzina ◽  
Maria A. Bukharinova ◽  
Natalia Yu. Stozhko

In contemporary bioanalysis, monitoring the antioxidant activity (AOA) of the human skin is used to assess stresses, nutrition, cosmetics, and certain skin diseases. Non-invasive methods for skin AOA monitoring have certain advantages over invasive methods, namely cost-effectiveness, lower labor intensity, reduced risk of infection, and obtaining results in the real-time mode. This study presents a new flexible potentiometric sensor system (FPSS) for non-invasive determination of the human skin AOA, which is based on flexible film electrodes (FFEs) and membrane containing a mediator ([Fe(CN)6]3–/4–). Low-cost available materials and scalable technologies were used for FFEs manufacturing. The indicator FFE was fabricated based on polyethylene terephthalate (PET) film and carbon veil (CV) by single-sided hot lamination. The reference FFE was fabricated based on PET film and silver paint by using screen printing, which was followed by the electrodeposition of precipitate containing a mixture of silver chloride and silver ferricyanide (SCSF). The three-electrode configuration of the FPSS, including two indicator FFEs (CV/PET) and one reference FFE (SCSF/Ag/PET), has been successfully used for measuring the skin AOA and evaluating the impact of phytocosmetic products. FPSS provides reproducible (RSD ≤ 7%) and accurate (recovery of antioxidants is almost 100%) results, which allows forecasting its broad applicability in human skin AOA monitoring as well as for evaluating the effectiveness of topically and orally applied antioxidants.


2021 ◽  
Author(s):  
Syarifah Ramadhani Lubis ◽  
Subandi Subandi ◽  
Muntholib Muntholib ◽  
Jamilah Abbas ◽  
Tjandrawati Mozef

Author(s):  
FAVIAN BAYAS-MOREJON ◽  
ANGELICA TIGRE ◽  
RIVELINO RAMON ◽  
DANILO YANEZ

Objective: The increase in chronic and degenerative diseases and the use of synthetic antioxidants such as (butylated hydroxyanisole (BHA) or butylated hydroxytoluene (BHT)) are being restricted because they can be considered carcinogenic. Therefore, there is a growing interest in the search for natural antioxidants, especially from plants, due to their content in different bioactive compounds, such as antioxidants and antimicrobials. To evaluate the antibacterial and antioxidant activity of Baccharislatifolia extracts. Methods: For the determination of the antimicrobial activity of extracts of leaves, root, stem and flowers of Baccharislatifolia (Bl), the disk plate diffusion method was used, the strains of Listeria, Salmonella and E. coli were studied; antibiotics Penicillin G and Ciprofloxacin were the controls. For the antioxidant activity, a solution of H2O2 (Abs at 230 nm) was prepared in Potassium Phosphate Monobasic-Sodium Hydroxide buffer. Results: The antimicrobial activity against Listeria and Salmonella, showed that the extracts of leaves and flowers were more effective with inhibition zones>15 mm and>20 mm respectively. In front of E. coli, the extracts of flowers and stem were the best with zones>7.0 mm. Antibiotics studied inhibited the development of Listeria and Salmonella. However, E. coli isolates were resistant. In the antioxidant activity, the flower extract of Bl in 60 mg/ml presents a higher effect with 47.25%. Conclusion: Bl extracts from leaves and flowers were more efficient both in their antimicrobial and antioxidant capacity.


2015 ◽  
Vol 13 (1) ◽  
Author(s):  
Wojciech Koch ◽  
Tomasz Baj ◽  
Wirginia Kukula-Koch ◽  
Zbigniew Marzec

AbstractThe determination of phenolic acids’ and flavonoids’ content in daily food rations (DFRs) of a selected group of male and female students and the development of chromatographic conditions is the primary goal of the study. The presence of 7 phenolic components were confirmed in the prepared extracts from all diets reconstructed within a period of 3 years. The highest concentrations were determined for hesperidin (124 and 55.6 mg for women and men, respectively), naringin (47.6 mg in female and 37 mg in male diets) and chlorogenic acid (19.7 and 19.8 mg for women and men). The antioxidant potential of the daily food rations, measured with a DPPH test, was higher for women (range 47.1‒78.8%) than for men (range 34.5‒78.0%) and was found to strongly correlate with the total phenolics content of the samples (Folin-Ciocalteu test) (correlation coefficient 0.90).


2019 ◽  
Vol 79 (3) ◽  
pp. 452-459 ◽  
Author(s):  
F. R. G. Silva ◽  
T. M. S. Matias ◽  
L. I. O. Souza ◽  
T. J. Matos-Rocha ◽  
S. A. Fonseca ◽  
...  

Abstract The study aimed to evaluate the antimicrobial activity, antioxidant, toxicity and phytochemical screening of the Red Propolis Alagoas. Antimicrobial activity was evaluated by disk diffusion method. Determination of antioxidant activity was performed using the DPPH assay (1.1-diphenyl-2-picrylhydrazyl), FTC (ferric thiocyanate) and determination of phenolic compounds by Follin method. Toxicity was performed by the method of Artemia salina and cytotoxicity by MTT method. The phytochemical screening for the detection of allelochemicals was performed. The ethanol extract of propolis of Alagoas showed significant results for antimicrobial activity, and inhibitory activity for Staphylococcus aureus and Candida krusei. The antioxidant activity of the FTC method was 80% to 108.3% hydrogen peroxide kidnapping, the DPPH method showed an EC50 3.97 mg/mL, the content of total phenolic compounds was determined by calibration curve gallic acid, resulting from 0.0005 mg/100 g of gallic acid equivalent. The extract was non-toxic by A. salina method. The propolis extract showed high activity with a higher percentage than 75% inhibition of tumor cells OVCAR-8, SF-295 and HCT116. Chemical constituents were observed as flavonones, xanthones, flavonols, and Chalcones Auronas, Catechins and leucoanthocyanidins. It is concluded that the extract can be tested is considered a potential source of bioactive metabolites.


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