Determination of the antioxidant capacity, total phenolic and flavonoid contents of seeds from three commercial varieties of culinary dates

Abstract

Date seeds are a major waste product of the date industry that could offer potentially valuable material for the production of useful food ingredients. The aim of the present study was to investigate the seeds of three date varieties of the UK market (Deglet Nour, Khouat Allig, and Zahidi) for their proximate composition, total phenolic (TPC), total flavonoid (TFC) contents and total antioxidant capacity (TAC) with a view to their eventual industrial application. Carbohydrates were present in the highest concentrations varying between 74.13 and 76.54 g 100 g-1 of date seed powder (DSP) on dry weight (DW) basis, followed in descending order by fats (7.64-8.84 g 100 g-1) and proteins (4.35-5.51 g 100 g-1). Potassium was found in high amounts with values ranging between 280.55 and 293.13 mg 100 g-1. The majority of the total phenolic content (2058-2984 mg GAE 100 g-1) was assumed to be composed of flavonoids (1271-1932 mg CAE 100 g-1). These families of dietary phenolics may be the major ones responsible for the high antioxidant capacity reported in date seeds, which varied from 12540 and 27699 µmol TE 100 g-1. These results suggest that date seeds can be considered a potential raw material for natural, active ingredients for food applications as well as an unexplored source of novel nutraceuticals and dietary supplements.

Palm date (Phoenix dactylifera) seeds: A rich source of antioxidant and antibacterial activities

“…The total phenolic content was 2 014.37 ± 212.05 and 2 060.40 ± 176.0 mg GAE 100 g -1 DW while the total flavonoid content was 83.98 ± 1.10 and 94.97 ± 1.36 mg QE 100 g -1 DW for Sukkari and Khalas, respectively. The total phenolic content of PDS found here is in agreement with Mistrello et al (2014), who studied the total phenolic content in seeds of three date varieties of the UK market and reported a range between 2 058 and 2 984 mg 100 g -1 . A review report conducted by Al-Farsi& Lee (2008a) showed that PDS has average phenolics of 3 942 mg 100 g -1 .…”

Effect of date palm (Phoenix dactylifera ) seed extract as a dietary supplementation on growth performance immunological haematological biochemical parameters of common carp

“…() and Mistrello et al. (). Also, the levels of protein and total lipid measured in this study were higher than other studies.…”

“…In addition, DPS extract shows an ability to restore the normal functional status of poisoned liver, and also to provide protection against carbon tetrachloride hepatotoxicity in rats (Al‐Qarawi, Mousa, Ali, Abdel‐Rahman & El‐Mougy, ). In addition, date seed as a major by‐product of date fruit (about 10% of the fruit) contains phenolic and flavonoid substances which possess antioxidant activities (Al‐Farsi & Lee, ; Habib et al., ; Mistrello, Sirisena, Ghavami, Marshall & Krishnamoorthy, ).…”

Assessment of antioxidant and antibacterial activity of Phoenix dactylifera L. seed extracts: Perspective for the development of new foods

“…Our data confirm previous results reported by Thouri et al 53 who found in their study on two varieties (Korkobbi and Arechti) a high content of TPCs and flavonoids in the aqueous extract with regards to different solvents used for extraction: aqueous extract > methanol > aqueous acetone > absolute acetone. Mistrello et al 54 found TPCs and flavonoids contents ranged between 20.58-29.83 mg GAEq/g and 12.71-19.32 mg QEq/g on three varieties (Zahidi, Deglet Nour and Khouat Allig). These results were higher than those reported by Metoui et al 55 , who found on 12 varieties from Tunisia that Khadhouri variety contained the highest TPCs (95.32 mg GAEq/g), whereas Lemsi had the lowest TPCs (51.30 mg GAEq/g).…”