Antioxidant and Antibacterial Properties of Aqueous Extract of Senduduk (Melastoma malabathricum L.) Leaf from Indonesia for Food Additive

Abstract

Background and Objective: Recent studies show that senduduk (Melastoma malabathricum L.) leaf extract contains phenolic compounds that could possibly be used as a food preservative. However, the study of extraction methods using edible solvents has been poorly explored. This study was conducted to investigate the impact of various maceration techniques for the extraction of senduduk leaves on antioxidant and antibacterial activity. Material(s) and Method(s): The maceration conditions explored were distilled water (T1), distilled water with shaking (T2), ethanol 25% in distilled water (T3) and ethanol 25% in distilled water with shaking (T4). Result(s): The result showed that shaking application resulted in lower extract activity. The extract obtained from distilled water was not significantly different to the extract obtained from ethanol 25% in percent yield (11.69 and 9.83%, respectively), antioxidant activity (64.15 and 69.62 mg BHTE g-1, respectively) and antibacterial activity. All extracts had antibacterial activity against tested Gram-positive bacteria (Bacillus cereus, Staphylococcus aureus and Listeria monocytogenes) and Gram-negative bacterium (Pseudomonas aeruginosa). The highest zone of inhibition was pointed out by the extract obtained from distilled water (15.16, 14.88, 12.10 and 15.56 mm for B. cereus, S. aureus, L. monocytogenes and P. aeruginosa, respectively). However, the extracts had no inhibitory activity toward the Gram-negative bacteria: Escherichia coli and Salmonella Typhimurium. Conclusion(s): The senduduk leaf extracted using distilled water without shaking has the potential to generate an extract that can be used as an antioxidant and antibacterial agent.Copyright © 2019 Suharyanto et al.