• Journal of the East Asian Society of Dietary Life
• /
• v.12 no.3
• /
• pp.241-248
• /
• 2002

The dried Prunus mume, an alkaline food abundant in organic acids (citric acid, malic acid and tartaric acid), has been largely used in both folklore remedies and Chinese herbal medicine for a long time. This study was performed to investigate the antimicrobial activity of the dried Prunus mume. The fractionation of the methanol extracts from Prunus mume was conducted using petroleum ether, chloroform, ethyl acetate and butanol, respectively. The antimicrobial activity of the Prunus mume extracts was then determined against food-borne pathogens using a paper disc method. The ethyl acetate extract showed the strongest antimicrobial activity against the eigth food-born pathogens used in this present study. Diaion HP 20 column chromatography was performed to remove some sugars that might inhibit the antimicrobial activity of Prunus mume. The strongest antimicrobial activity of ethyl acetate fraction of Prunus mume was shown against Staphylococus aureus. The growth inhibition curve was determined using ethyl acetate extracts of Prunus mume against Staphylococus aureus, which showed the growth inhibition up to 72 hours at 1,000 ppm concentration.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.33 no.8
• /
• pp.1268-1272
• /
• 2004

The 70% ethanol extract from cactus Chounnyouncho (Opuntia humifusa) was fractionated subsequently by hexan, chloroform, ethyl acetate, buthanol and water. The ethyl acetate fraction exhibited strong antimicrobial activities by paper disk diffusion method on the five strains of food born bacteria Bacillus subtilis, Staphylococcus aureus subsp. aureus, Escherichia coli, Salmonella typhimurium and Pseudomonas fluorescens. It has a heat resistance to show inhibitory effect after heat treatment at 11$0^{\circ}C$ for 1 hr. The ethyl acetate fraction showed almost perfect growth inhibition at over 700 ppm on the tested strains.

• Plant Resources
• /
• v.8 no.2
• /
• pp.96-102
• /
• 2005

As part of developing natural food preservatives, the antimicrobial effect of ethanol and water extracts from the Cruciferous vegetable was examined Korean traditional Brassica juncea Coss. was used widely as an ingredient of Kimchi, a natural flavoring and spice for a long time. Antimicrobial activities were examined against 15 microorganisms which were food-born pathogens and/or food poisioning microorganisms and food-related bacteria and yeasts. Ethanol extract from leaf mustard showed an antimicrobial effect in most of the strains used in the present study. The lowest minimum inhibitory concentration (MIC) were seen in Bacillus subtilis and Bacillus natto at 10 mg/ml. MIC of water extract was 40-60 mg/ml for bacteria and yeast. Antimicrobial activity of the ethanol extract was not disappeared by the heating at $121^{\circ}C$ for 15 min and not affected by pH.

• The Korean Journal of Food And Nutrition
• /
• v.12 no.2
• /
• pp.133-141
• /
• 1999

Juice of Dongchime a Korean traditional vegetable food fermented with lactic acid bacteria has been traditionary used as broth for Naengmyon a Korean cold noodles with broth. This study was carried out to demonstrate the growth inhibition of two food born pathogens Listeria monocytogenes and Escherichia coli O157:H7 in Naengmyon-broth containing Dongchimi-juice fermented with high antibacterial lactic acid bacteria Lactobacillus homohiochii B21 and Leuconostoc mesenteroides C16. Naengmyon-broth were made with beef broth and Dongchimi-juice fermented with lactic acid bacteria and the changes in viable cell counts of the inoculated pathogens in Naengmyon-broths were investigated during storage at 2$0^{\circ}C$ and 1$0^{\circ}C$. In Naengmyon-broth of 100% Dongchimi-juice stored at 2$0^{\circ}C$ the numbers of Listeria monocyto-genes and Escherichia coli O157:H7 were rapidly decreased from 106CFU/ml to 106CFU/ml in 8 hours and 40 hours respectively. In Naengmyon-broth containing 50% Dongchimi-juice their numbers were also rapidly decreased though the decreasing rates were not so fast as those in 1005 Dongchimi-juice. In Naengmyon-broth containing 10% Dongchimi-juice the growths of the two pathogens were markedly inhibited compared with those in 100% beef broth though some growths were occurred in early phase. But in Naengmyon-broth of 100% beef broth their growths were very fast from early. Antibacterial ac-tivity of the Dongchimi-juice was more distinct at 2$0^{\circ}C$ than at 1$0^{\circ}C$ and was more active against Listeria monocytogenes than against Escherichia coli 157:H7.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.35 no.2
• /
• pp.219-223
• /
• 2006

In this study the antimicrobial activity of the extract from leaves of lotus (Nelumbo nucifera) was evaluated in comparison with benzoic acid. The $70\%$ ethanol extract was fractionated subsequently by hexane, chloroform, ethyl acetate, butanol and water, and the antimicrobial activity of each dried fraction was tested by paper disk diffusion method. The ethyl acetate fraction exhibited strong antimicrobial activity on the five strains of food born bacteria e.g. Bacillus subtilis, Staphylococcus aureus subsp. aureus, Escherichia coli, Salmonella Typhimurium and Pseudomonas nuorescens. The antimicrobial activity of the fraction was stronger than benzoic acid and showed no appreciable difference between on $Gm^+$ and $Gm^-$ bacteria. Heat treatment of the fraction at $110^{\circ}C$ for 1 hr did not change the degree of inhibitory effect. The ethyl acetate fraction showed almost perfect growth inhibition on the tested strains at over 800 ppm.

• Proceedings of the Korean Society of Food Hygiene and Safety Conference
• /
• 2002.05a
• /
• pp.160-161
• /
• 2002

• Journal of Food Hygiene and Safety
• /
• v.36 no.4
• /
• pp.324-330
• /
• 2021

In this study, the microbial levels on mixed vegetable salads, fresh fruits, and frozen fruits distributed in Korea were comparatively analyzed by food group, region, and quarter. Samples were collected from big markets in large cities from 2018 to 2019 and used for microbiological analysis. The levels of aerobic bacteria for mixed vegetable salads, fresh fruits, and frozen fruits were 6.48, 5.07, and 3.78 log CFU/g, respectively. As a result of analyzing the quarterly contamination levels of aerobic bacteria, the first quarter contamination level was 5.12 log CFU/g while the second quarter showed 6.26 log CFU/g, the third quarter 5.73 log CFU/g, and the fourth quarter 4.42 log CFU/g. A higher number of aerobic bacteria was observed in the second and third quarters when the temperature was higher. There was no difference in the number of bacteria by region. The levels of the coliform group were 1.98 - 3.93 log CFU/g in all samples, and Escherichia coli was detected at 1.38 log CFU/g in 3 out of 27 mixed vegetable salads. Since the mixed vegetable salad and fresh fruit used in this study exceeded the standard (3 log CFU/g) for unheated foods and E. coli was detected in three fresh fruits, stricter hygiene management in the manufacturing stage of salads and fresh fruit is required.