Evaluation of antioxidant, antihemolytic and antibacterial potential of six Moroccan date fruit (Phoenix dactylifera L.) varieties

Abstract

The research aimed to examine the antioxidant, anti-hemolytic and antimicrobial activities of six Moroccan date fruit varieties. Estimation of total phenolic and flavonoid contents revealed that, Bousrdoun (537.07 mg GAE/100 g DW) and Jihl (208.53 mg RE/100 g) had the highest phenolic and flavonoid contents, respectively. Among the date fruit varieties tested for antioxidant activities, Jihl had the highest activity compared to other varieties. It had an inhibitory concentration (IC50) value of 2.05 g/L for DPPH scavenging activity and a ferric reducing power of (860.89 μmol TE/100 g DW). As well as a high protective effect against AAPH-induced erythrocyte hemolysis with a hemolysis half-time of 210.99 min. The antibacterial capacity of various extracts was investigated against Gram positive (Bacillus subtilis ATCC 6633, Bacillus cereus ATCC 29213, Staphylococcus aureus ATCC 25923) and Gram negative bacteria (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Salmonella abony NCTC 6017). The Bousrdon and Jihl extracts were found to be more potent inhibitory activities with MIC values ranging between 2.5 mg mL−1 and 10 mg mL−1 for all bacterial strains tested. These results suggested that date fruit extract, especially Jihl and Bousrdon extract, is not only an important source of antioxidants, which possess a high protective effect of membrane against free radical, but also a potential source of antibacterial components.