The Effect of Cultivar Variation on Total Phenolic Contents and Antioxidant Activities of Date Palm Fruit (Phoenix Dactylifera L.)

Abstract

Date palm fruit (Phoenix dactylifera L.) is generally consumed in form of dry fruits (Tamr stage); however, fresh date palm fruit in Khalal stage is currently of interest due to its high total phenolic contents (TPCs) and antioxidant activities. Therefore, this study aimed to investigate the water based extraction conditions such as temperature (30-90°C), shaking time (0.5-6 hours) and solid-to-liquid ratio (100-500 mg/mL) of date palm fruit in Khalal stage. This will help to establish extraction protocol for future food applications. Under optimized extraction conditions, TPCs and antioxidant activities of cell culture originated (CO) and seed originated (SO) date palm fruit were compared to examine the effect of cultivar variation. The results suggest that optimization of extraction conditions was reached using the concentration of 100 mg/ mL, extraction temperature of 50°C, and shaking time of one hour. Under these extraction conditions, CO exhibited TPCs of 3.47±0.33 mg GAE/g DW as well as antioxidant activities of 0.0025±0.00, 16.13±0.81 and 123.21±9.77 µmol TE/g DW measured by DPPH radical scavenging, FRAP and ORAC assays, respectively. Interestingly, SO exhibited higher TPCs (3.87±0.23 mg GAE/g DW) and antioxidant activities (0.0021±0.00, 19.23±0.80 and 185.68±9.29 µmol TE/g DW by DPPH radical scavenging, FRAP and ORAC assays, respectively).The findings from this study will promote consumption of date palm fruits in Khalal stage as healthy food and support its future development for food. Also, this will enhance the growth of date palm fruit with its attendant economic benefits.

The Effect of Steaming and Fermentation on Nutritive Values, Antioxidant Activities, and Inhibitory Properties of Tea Leaves

“…Antioxidant activities were analyzed via 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, ferric ion reducing antioxidant power (FRAP), and oxygen radical absorbance capacity (ORAC) assays using well-established protocols [ 25 , 26 , 27 , 28 ]. The DPPH radical scavenging assay utilizing DPPH in 95% ( v / v ) aqueous ethanol and the Trolox standard (0.01–0.64 mM) was performed as previously described [ 25 , 28 ]. The FRAP assay utilizing FRAP reagent and the Trolox standard (7.81–250.00 µM) was determined according to the previously reported procedures [ 26 , 28 ].…”

“…The DPPH radical scavenging assay utilizing DPPH in 95% ( v / v ) aqueous ethanol and the Trolox standard (0.01–0.64 mM) was performed as previously described [ 25 , 28 ]. The FRAP assay utilizing FRAP reagent and the Trolox standard (7.81–250.00 µM) was determined according to the previously reported procedures [ 26 , 28 ]. The ORAC assay utilizing fluorescein reagent and the Trolox standard (3.12–100.00 µM) was analyzed as previously described [ 27 , 28 ].…”

“…The FRAP assay utilizing FRAP reagent and the Trolox standard (7.81–250.00 µM) was determined according to the previously reported procedures [ 26 , 28 ]. The ORAC assay utilizing fluorescein reagent and the Trolox standard (3.12–100.00 µM) was analyzed as previously described [ 27 , 28 ].…”

A Comparison of the Nutritional and Biochemical Quality of Date Palm Fruits Obtained Using Different Planting Techniques

“…The extraction of date palm fruits was optimized as previously described [ 54 ]. Briefly, the powdery samples (1 g) were dissolved in distilled water (10 mL), incubated in a 50°C for 1 h using a temperature controlled water bath shaker (a WNE45 series from Memmert GmBh, Eagle, WI, USA), and centrifuged at 3800× g for 15 min using a refrigerated centrifuge (a Hettich ® ROTINA 38R from Andreas Hettich GmbH, Tuttlingen, Germany).…”

In Vitro Phytotherapeutic Properties of Aqueous Extracted Adenia viridiflora Craib. towards Civilization Diseases

“…Three methods for the determination of antioxidant activities were performed, including 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, ferric ion reducing antioxidant power (FRAP), and oxygen radical absorbance capacity (ORAC) assays as previously described [ 55 ]. The extract concentrations used in the antioxidant determination were chosen to be in the range of a standard curve.…”