Comparative analysis of chemical, mineral and in-vitro antibacterial activity of different varieties of date fruits from Saudi Arabia

Three important varieties of dates (Sukri, Barhi, and Rothana), grown in Saudi Arabia were analyzed for their chemical, mineral and anti-bacterial activity. Among all the varieties analyzed, the Sukri dates had the highest moisture (16%), carbohydrate (80.65 mg/g) and the phenolic content (1.24 mg GAE/100 g) whereas, the ash content was the lowest (2.22%). The mineral content analyzed by ICP OES reveals that all three varieties contain an appreciable amount of essential macro and micro nutrients. They contain a good amount of potassium; the maximum amount of K (8171.24 mg/kg) was recorded in Barhi dates. Besides that, all three varieties of dates contain a good amount of Se, Cu, P, Fe, Mn. The comparative analysis of the GC MS chromatogram reveals that there were only five compounds that were present in all three varieties. The bioactive compounds Mannoic and Lactone were detected in all three varieties. The fruits contain some important groups of sugar, alcoholic sugar, aromatic hydrocarbon, phenol(s) and esters. The extracts of dates were assed for their antibacterial activity against 6 important strains of human pathogenic bacteria. The strains of E. coli-ATCC25922, B. subtilis-ATCC6633, S. aureus-ATCC25923, were observed to be highly sensitive to most of the extracts whereas S. pyogenes and S. flexeneri (clinical isolates) showed moderate sensitivity to some extracts. The variety Sukri was found to be superior to the other two varieties in terms of sugar and phenolic contents, in addition, the methanol extract of Sukri dates showed excellent antibacterial activity against most of the bacteria evaluated. These varieties of dates prove to have immense potential to be utilized as a therapeutic agent for curing mineral deficiency also can be explored for developing antibacterial agents.

Keywords: Anti-bacterial activity; Date palm; GCMS; ICP OES; Mineral content.