Antimicrobial Activity of Quercus mongolica Leaf Ethanol Extract and Organic Acids against Food-borne microorganisms

식중독균에 대한 신갈나무 잎 추출물과 유기산의 항균효과

  • Kong, Young-Jun (Laboratory Agriculture products processing Regional Crop Experiment Station, Kangwon-Do Research and Extension Services) ;
  • Park, Boo-Kil (Division of Food and Biotechnology, Kangwon National University) ;
  • Oh, Deog-Hwan (Division of Food and Biotechnology, Kangwon National University)
  • 공영준 (강원도 농업기술원) ;
  • 박부길 (강원대학교 식품생명공학부) ;
  • 오덕환 (강원대학교 식품생명공학부)
  • Published : 2001.04.30

Abstract

This study was conducted to determine the optimal extraction condition of temperatures and kinds of extraction solvent, and antimicrobial activity of ethanol extract of Quercus mongolica leaf and organic acid against foodborne microorganisms. The antimicrobial activity of ethanol extract at $60^{\circ}C$ for 6 hour against foodborne microorganisms was stronger than those at $30^{\circ}C\;and\;90^{\circ}C$. Also, the ethanol extract showed stronger antimicrobial activity than those of water and methanol extract. The minimal inhibitory concentrations of the ethanol extract of Quercus mongolica leaf against B. cereus and L. monocytogenes, was $62.5{\sim}125\;{\mu}g/mL$ but, the minimal inhibitory concentration was $250\;{\mu}g/mL$ against S. typhimurium and P. aeruginosa and over $500\;{\mu}g/mL$ against E. coli O157:H7, respectively. The minimal inhibitory concentrations of the lactic, citric, acetic acid and the ethanol extract of Quercus mongolica leaf against B. cereus and L. monocytogenes was 2500, 5000, 1250 and $125\;{\mu}g/mL$, respectively. The combined effect of each organic acid and the ethanol extract against B. cereus was not observed but, synergistic effect was observed against L. monocytogenes. In the meantime, when the ethanol extract was combined with each organic acid at sub-lethal concentration, the combination did not increase the inhibitory effect of the most active single compound alone against E. coli O157:H7, respectively.