Antibacterial Screening of Origanum majorana L. Oil from Tunisia

International audienceTwo methods (agar diffusion and broth microdilution) were used to assess the antibacterial activity of Origanum majorana L. oil of Tunisian origin against 10 bacteria. The results showed that this oil was active against all of the tested strains. The most susceptible were Escherichia coli, Streptococcus A, Shigella dysenteria and Salmonella enteritidis. The least susceptible one was Pseudomonas aeruginosa

Effect of Saccharomyces cerevisiae fermentation on the colorants of heated red beetroot extracts

The aim of the present study was to evaluate the effect of the inoculation of the heated aqueous red beetroot extracts (30, 50 and 60°C) by different concentrations of Saccharomyces cerevisiae (0.50, 0.75 and 1.00%). The optimum experimental temperature value and S. cerevisiae concentration were found to be 50°C and 0.50% for both sugar consumption and pigment preservation. The antioxidant capacity measured by ABTS•+ assay (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical cation) shows that this extract present an appreciable activity (EC50= 10.77 μg.mL-1) above the tested samples. The betalains compounds were analyzed and identified using UPLC LTQ Orbitrap MS method. Betalains (vulgaxanthin I, betanin, isobetanin, betanidin and neobetanin) were determined in the fermented extract.Keywords: Red beetroot, fermentation, Saccharomyces cerevisiae, betalain compoundsAfrican Journal of Biotechnology Vol. 12(7), pp. 728-73