Chemical Analysis and Biological Activity of Natural Preservative from Beet root (Beta vulgaris) Against Foodborne Pathogens and Spoilage Organisms

Abstract

Proximate and elemental analysis of Beta vulgaris was carried out using standard procedures. Ethanolic and aqueous extract of the root were analysed qualitatively and quantitatively for  phytochemicals. The agar well diffusion assay was employed to determine the antibacterial activity of both ethanolic and water extracts of Beta vulgaris. Carbohydrate, protein, fat/oils, ash and moisture content were 9.50±0.01, 1.58±0.00, 0.23±0.00, 1.43±0.01 and 88.69±1.20 % respectively. The mineral content ranged from 1.90±0.01 to 15.98±0.01 %  with calcium being the lowest and manganese the highest. Phytochemicals analysis showed the presence of tannins (6.00mg/100 g), saponins (3.60 mg/100g), alkaloids (127.60 mg/100g), flavonoids (6.40 mg/100g), glycosides (0.651 mg/100g), steriods (16.30 mg/100g) and terpenoids (116.30 mg/100g). Antimicrobial activity test showed that the ethanol extract was more effective than the aqueous extract. The most susceptible organisms were Bacillus subtilis (MIC, 19.5 µg/ml) among the Gram-positive bacteria and Escherichia coli (MIC, 39.1 µg/ml) among the Gram-negative food-borne pathogens. Beet root extract with its broad spectrum biologic acttivity can be harnessed as a food preservative.