Antibacterial Comparison of Kale and Red Spinach Extracts at Different Stage of Maturity Against Pathogenic Bacteria

Vegetables greens that are harvested just after the cotyledon leaves have develop are called microgreens. Microgreen are currently in trending and gaining popularity due to high concentration of bioactive components that are generally related with human health. Due to scarce information available regarding antimicrobial compounds in microgreens, this study focused on determining the antimicrobial activity of kale and red spinach microgreens against B. subtilis and E. coli in comparisons with their mature plant. Ethanol extraction was conducted to obtain the crude extract. Agar disc diffusion method were used to determine the diameter of inhibition zone of plant extract. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) used microdilution with different concentration ranged from 1000 mg/ml to 31.25 mg/ml to evaluate the lowest concentration that can inhibit and kill the selected bacteria after incubation. Microgreens of kale and red spinach showed more effectiveness compared to their mature plants towards targeted bacteria in agar disc diffusion method. MIC and MBC value for all extract ranged from 62.5 mg/ml to 125 mg/ml. Hence, microgreens showed potential natural antimicrobial agent that can help to substitute the synthetic antimicrobial medicine in the future.