Palm date (Phoenix dactylifera) seeds: A rich source of antioxidant and antibacterial activities
Abuelgassim Omer Abuelgassim, Mohamed A. El‐Tayeb, Farid S. Ataya
Abstract
Two varieties of palm date seeds (PDS), Sukkari and Khalas, were examined for their antioxidant and antibacterial activities. Total phenol content was 2 014.37 ± 212.05 and 2 060.40 ± 176.0 mg GAE 100 g-1 dry weight (DW); and total flavonoid content was 83.98 ± 1.10 and 94.97 ± 1.36 mg QE 100 g-1 DW for Sukkari and Khalas, respectively. PDS extracts showed potential scavenging activity against ABTS, DDPH, and hydroxyl radical; the calculated IC50s were 431.17 ± 12.45, 400 ± 10.87 and 680 ± 18.12 µg for Sukkari, and 476 ± 20.25, 302.24 ± 14.08 and 284.18 ± 11.62 µg for Khalas, respectively. PDS extracts did not show potential activity against superoxide anion. Both extracts showed a high percentage of reducing power as the calculated FRAP (ferric reducing antioxidant power) concentrations were 12.66 ± 1.08 and 16.14 ± 1.94 mmol ascorbic acid equivalent 100 g-1 for Sukkari and Khalas, respectively. Bacillus subtilis showed a remarkable sensitivity to PDS extracts; the inhibition zones were 21 ± 0.82 and 22 ± 0.67 mm for Sukkari and Khalas, respectively. PDS extracts possess good antioxidant and antibacterial activity, and therefore PDS could be effectively used as a natural source of antioxidants and to be detected against gram-positive bacteria.