scholarly journals Quantification of phenolic compounds, evaluation of physicochemical properties and antioxidant activity of four date (Phoenix dactylifera L.) varieties of Oman

2015 ◽  
Vol 10 (3) ◽  
pp. 346-352 ◽  
Author(s):  
S.S. Al Harthi ◽  
A. Mavazhe ◽  
H. Al Mahroqi ◽  
S.A. Khan
Author(s):  
Habchi A. ◽  
Dekmouche M. ◽  
Hamia C. ◽  
Saidi M. ◽  
Yousfi M. ◽  
...  

This study was designed to evaluate the antioxidant activity of phenolic compounds for six cultivars of date from In Saleh region (Phoenix dactylifera L.), which were extracted by reflux with solvents, 80% methanol and 70% aceton after the phenolic and flavonoid content were estimated. The total phenolic content (TPC) and total flavonoid content (TFC) of the extracts were measured using Folin–Ciocalteau and aluminum chloride colorimetric methods, respectively. Antioxidant activity acetone/H2O and methanol/H2O extracts using ABTS, DPPH, FRAP, TAC and CUPRAC assays. The results showed that methanolic solvent reflux gives better yields. The highest level of phenolic compounds for all dates varieties was found in the 80% methanol extract. This level ranged from 8.04 ± 0.14 to 46.81 ± 1.22 mg GAE/100 g fresh weight and flavonoid content was observed relatively low for both two solvents. However, extraction into 70% acetone gave the highest antioxidant activity with all assay. These results showed that dates had strongly scavenging activity on DPPH reaching 3.12 µg/mL in methanol/H2O from Cul1 (6.9 µg/mL with ascorbic acid), also on ABTS reaching 6.51 µg/mL in acetone/H2O from Cul2 (104.98 µg/mL with ascorbic acid).


2020 ◽  
Vol 13 (8) ◽  
pp. 1556-1569
Author(s):  
Sami Sedraoui ◽  
Ashraf Badr ◽  
María Gretel Michel Barba ◽  
Alain Doyen ◽  
Zouhair Tabka ◽  
...  

2019 ◽  
Vol 121 ◽  
pp. 402-409 ◽  
Author(s):  
A. Alahyane ◽  
H. Harrak ◽  
J. Ayour ◽  
I. Elateri ◽  
A. Ait-Oubahou ◽  
...  

Nova Scientia ◽  
2020 ◽  
Vol 12 (24) ◽  
Author(s):  
Rey David Vargas Sánchez ◽  
Evelin Martínez Benavidez ◽  
Javier Hernández ◽  
Gastón Ramón Torrescano Urrutia ◽  
Armida Sánchez Escalante

In this study the effect of pollen source (mesquite and catclaw) on the sensory characteristics (appearance, color, aroma, taste, consistency and visible impurities), and physicochemical properties of raw propolis, and the phenolic content and biological activities of propolis extracts (PEs) was determined. The phenolic composition of PEs was determined by the total phenolic (TPC), flavone and flavonol (FFC), and flavanone and dihydroflavonol content (FDC). The individual phenolic components were analyzed by HPLC-DAD. The antioxidant activity was determined by the ferric-reducing power (FRAP) and free-radical scavenging activity (FRS). The antibacterial activity was evaluated against Gram-positive (Staphylococcus aureus and Listeria innocua) and Gram-negative (Echerichia coli and Salmonella thyphimurium) bacteria. The results showed that sensory characteristic and physicochemical properties of mesquite and catclaw propolis complied with international quality regulations. Fifteen phenolic compounds were identified, of which pinocembrin, naringenin, galangin, chrysin and quercetin were found a high concentration (> 3 mg/g). Mesquite propolis had the highest phenolic content (TFC and FDC), as well as antioxidant activity (> 2.5 mg Fe (II) equivalent/g; > 40% of DPPH radical inhibition) and antibacterial activity against Gram-positive bacterias in the order S. aureus > L. innocua (> 50% of inhibition for both bacterias at 500 µg/mL). These results indicating that pollen source affect the sensory characteristics and physicochemical properties of propolis, as well as the biological activity of their extracts.


2019 ◽  
Vol 8 (2) ◽  
pp. 179-184
Author(s):  
Siti Warnasih ◽  
◽  
Ade Heri Mulyati ◽  
Diana Widiastuti ◽  
Zuniar Subastian ◽  
...  

Red Sayer is one of the date varieties from the United Arab Emirates. This variety is one type of dates that is imported into Indonesia and used as processed date palm juice producing waste, namely date seeds. Date seeds can be made into some coffee that is rich in antioxidants and does not contain caffeine. The purpose of this study is to determine the chemical characteristics, antioxidant activity, total phenol, and caffeine contents in coffee of the Red Sayer variety date seeds. Coffee of date seeds is made into powder and then analyzed for its contents of water, ash, protein, fat, carbohydrates and total sugar, besides its antioxidant activity, total phenol, and caffeine levels. The results of the analysis obtained are, as follows: 4.42±0.01% water, 1.17±0.04% ash, 8.55±0.64% protein, 7.34±0.07% fat, 78.52±0.76% carbohydrate, 16.39±0.01% total sugar, 23.81±0.22 µg/mL antioxidant activity (IC50) and 340.65±1.53 mg GAE / 100g total phenol, while caffeine is not detected. Red Sayer date seed coffee, therefore, can be a source of carbohydrates and natural antioxidants that does not contain caffeine.


2009 ◽  
Vol 15 (6) ◽  
pp. 583-590 ◽  
Author(s):  
I. Ben Thabet ◽  
S. Besbes ◽  
M. Masmoudi ◽  
H. Attia ◽  
C. Deroanne ◽  
...  

This study is a contribution to valorise date palm sap (Phoenix dactylifera L.) by elaboration of high quality syrup. Sap was concentrated by evaporation and the obtained product was characterized by its physicochemical, rheological, thermal, sensory properties and by its antioxidant activity. Syrups from date palm sap have a good nutritional value marked by high amounts of sugars (58—75 g/100 g fresh matter basis), minerals (2.1—2.6 g/100 g fresh matter basis) and phenolics (147.61—224.55 mg of ferulic acid equivalents/kg fresh weight). Syrup also presents an antioxidant activity that appears related to total phenolic content. Rheological properties indicate that syrup preserves a Newtonian behavior from 10 °C to 55 °C well modeled by Arrhenius equation. Hedonic evaluation showed that consumers’ appreciation of date palm syrup was not significantly different to the most known sap syrup: maple syrup.


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