Abstract
BACKGROUND: Applications for antimicrobials derived from the mangosteen (Garcinia mangostana L.) plant are presently
restricted by high production costs. Extraction from cultivation or processing waste streams using a solvent-free approach
could lessen to permit commercial applications in food processing and preservation.
RESULTS: Phenolics were extracted from mangosteen bark, leaf and fruit pericarp in methanol and in water using response
surface methodology to optimize recovery. Initial examination of antimicrobial effects revealed a lack of antimicrobial activity
against fungi and weak activity against the Gram-negative bacteria Escherichia coli and Salmonella typhimurium. In contrast,
extracts prepared from bark or fruit pericarp exhibited strong pH-dependent bacteriostatic and bactericidal effects against
Listeria monocytogenesandStaphylococcus aureus. Activity was slightly weaker in aqueous extracts due to lower concentrations
of tartaric acid esters and flavonols than in methanolic extracts. Measurement of propidium iodide uptake and ATP leakage
indicated that the extracts induced damage to the membrane of Gram-positive bacteria.
CONCLUSION: Extracts of mangosteen bark and fruit pericarp contain mixtures of phenolic compounds with activity against
Gram-positive bacteria, notably Listeria monocytogenes. Extraction of phenolics from mangosteen waste could yield fractions
for potential applications in the formulation of low-cost processing aids or sanitizers for the food industry.
c 2013 Her Majesty the Queen in Right of Canada, as represented by the Minister of Agriculture and Agri-Food Canada,Journal
of the Science of Food and Agriculturec 2013 Society of Chemical Industry