Sappan Heartwood (Caesalpinia sappan L.) Extract as a Natural Antimicrobial used in Beetroot Juice by Accelerated Solvent Extraction

Abstract

After accelerated solvent extraction using ethanol-water solvent (at a weight ratio of 3 to 1) at extraction temperatures of 60C, 120C, and 180C for 5 min under 1500 psi extraction pressure, the brazilin content in the extracts was determined and also the obtained sappan heartwood extracts (SHE) were used to inhibit some pathogenic bacteria in food, including B. cereus, E. coli, S. aureus, and S. Typhimurium, using agar disc diffusion method. According to the findings of this study, the average yield of SHE using ethanol-water solvent at different extraction temperatures of 60C, 120C, and 180C was 9.16, 13.64 and 16.81%, respectively, providing that the brazilin compound was found in the extracts to be approximately 3.36, 2.69 and 2.68%, respectively. SHE samples were found to be antibacterial against all bacteria tested. These extracts' minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) at 37°C for E. coli were 3.91 and 5.64-6.51 mg/ml, respectively; S. aureus, 3.69-3.91 and 3.69-3.91 mg/ml, respectively; B. cereus, 0.150.16 and 0.20 mg/ml, respectively, and S. Typhimurium, 0.96 and 1.31-1.96 mg/ml, respectively. SHE obtained at 120C extraction temperature were suitable and selected for addition into beetroot juice stored at 4C for 7 days and 37C for 24 hr, with the lowest SHE concentrations found to completely and simultaneously kill B. cereus, E. coli, S. aureus, and S. Typhimurium in beetroot juice being 11.73 and 3.91 mg/ml, respectively.