• Preventive Nutrition and Food Science
• /
• v.5 no.3
• /
• pp.131-135
• /
• 2000

The inhibitory effect of various organic acids on the growth and survival of Escherichia coli O157:H7 in tryptic soy broth with 0.6% yeast extract at 37$^{\circ}C$ or 4$^{\circ}C$ was determined. Minimal inhibitory pHs of acetic acid, citric acid, fumaric acid, hydrochloric acid and lactic acid were 5.0, 4.0, 4.5, 4.0 and 4.5, respectively. Acetic acid (0.012 m) showed the strongest antimicrobial activity, based on the pH values or equivalent molar concentrations, followed by lactic acid (0.0006 M), fumaric acid (0.004M) and citirc acid (0.004 M), respectively, E. coli O157:H7 with an initial inoculum of {TEX}$10^{7}${/TEX} CFU/ml and {TEX}$10^{5}{/TEX} CFU/ml in tryptic soy broth supplemented with 0.6% yeast extract, acidified to target pH with citric, fumaric and lactic acids at 37$^{\circ}C$, was completely inactivated after 7 d and 5 d incubation, respectively, except for the acetic acid (9 d). The bactericidal effect decreased at the same pH when the incubation temperature a was reduced from 37$^{\circ}C$ to 4$^{\circ}C$. The pH values of 0.2% acetic (pH 5.1), 0.6% citric (pH 4.2) and 0.4% lactic acid (pH 4.3) in TSBYE were almost correspondent to the minimal inhibitory pH values on E. coli O157:H7 of acetic (pH 4.0), citric (pH 4.0) and lactic acids (pH 4.5).

• Korean Journal of Food Science and Technology
• /
• v.35 no.6
• /
• pp.1169-1173
• /
• 2003

Growth of a newly emerging pathogen, Arcobacter butzleri, in domestic raw meat was evaluated by various sanitizing agents. One percent of acetic acid, citric acid, lactic acid, and trisodium phosphate (TSP) added to the cell suspension of six A. butzleri strains inhibited their growth within ten minutes, and especially the lactic acid inhibited growth within five minutes. One percent of all the acids at the culture broth inhibited growth completely within one hr. 0.1% of the acids inhibited growth within 72 hr, whereas two percent of TSP had the same effect in one hr. Among the acids, lactic acid had the strongest inhibition activity. Hydrogen peroxide, sodium hypochlorite, and ethanol showed lower inhibiting activities than the above agents. While garlic extract and lactic acid bacteria culture also inhibited A. butzleri, onion extract did not. Therefore, food-borne poisoning of A. butzleri in raw meat could be prevented by organic acid and trisodium phosphate treatments.

• Microbiology and Biotechnology Letters
• /
• v.30 no.3
• /
• pp.241-246
• /
• 2002

Seven lactic acid bacteria showing highly inhibitory activities against Salmonella gallinarum, Staphylococcus aureus, and Escherichia coli were isolated from Korean native chickens. The inhibitory activities were insensitive to various pretenses indicating that the inhibitory substance is not proteinaceous. The culture broths seem to contain other inhibitory substances in addition to lactic acid. The metabolic profile of organic acids produced by Lactobacillus pentosus K34 was investigated by GC-MSD and 28 different organic acids were detected in the culture broth. Compared with the prominent lactic acid, acetic acid, formic acid, the thirdly most abundant phenyllactic acid showed high inhibitory activity against S. gallinarum. After pHs of the acids were adjusted to S, the inhibitory activities of lactic acid, acetic acid, formic acid against S. gallinarum were greatly reduced while the inhibitory activity of phenyllactic acid was unchanged. The inhibitory activity of the phenyllactic acid was specifically high against S. gallinarum and S. aureus but very low against yeast and mold.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.17 no.4
• /
• pp.59-65
• /
• 2009

The antimicrobial activity-possessing materials were screened in the cell free supernatant (CFS) of fourteen lactic acid-fermenting strains isolated from pig's intestine. Each cell free supernatant of cultured strains was treated with various proteinases, heat, and/or alkali (NaOH). The antimicrobial activities were remained even after the enzyme and heat treatment but disappeared after neutralization with 1M NaOH, implying that the materials would be organic acids rather than proteins. Further purification of CFS through solid phase extraction using Sep-pak $C_{18}$ Cartridges and high performance anion exchange chromatography using Bio-LC system revealed that four organic acids, such as oxalic acid, citric acid, lactic acid, and acetic acid, were the main materials for the activity. Lactic acid was the highest amount in all organic acids, ranging from 54% to 77%. This strongly implies that the lactic acid would be the primary material for the antimicrobial activity in all tested strains.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.32 no.8
• /
• pp.1177-1185
• /
• 2003

The contents of organic acids in traditional and modified fermented foods were compared, and propionic acid produced during fermentation was investigated. Organic acids in traditional and modified soy sauces were lactic acid, acetic acid, citric acid, formic acid, succinic acid and oxalic acid while propionic acid was found in traditional soy sauces only. Similarly, lactic acid, acetic acid, citric acid, oxalic acid, formic acid, succinic acid and propionic acid were found in traditional and modified soy paste. The organic acids in traditional and modified kochujang were citric acid, acetic acid, formic acid, lactic acid, malic acid, oxalic acid and succinic acid while propionic acid was not found in modified kochujang. The major organic acid in persimmon and commercial (fermented) vinegars was acetic acid. Propionic acid was uniquely found in persimmon vinegars. Also, content of tannic acid in persimmon vinegars was 366.9 ∼ 909.8 mg%.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.23 no.2
• /
• pp.293-297
• /
• 1994

The effect of organic acids on growth and heat resistance of Listeria monocytogenes Scott A were investigated. The growth of L. monocytogenes was inhibited in Tryptic Soy Broth(TSB) with 0.1 or 0.2% of acetic , tartic , propionic , citric and lactic acid at 35$^{\circ}C$, respectively. The growth of l. Monocytogenes did not occur in TSB with 0.2% of acetic acid or propionic acid during 48h of incubation. The heat resistance of L.monocytogenes was affected by kind of organic acid, ph and heating substrate. L.monocytogenes showed more heat resistant in TSB with various organic acids than in 0.1M sodium phosphate with the same organic acids. Heat resistance decreased as pH of heating substrate decreased . Surface-adherent microcolony was more heat resistant than planktonic cell of L. monocytogenes. Propionic and lactic acids more affected on heat resistance of L.monocytogenes than acetic , tartaric and citric acids.

• Asian-Australasian Journal of Animal Sciences
• /
• v.23 no.6
• /
• pp.700-707
• /
• 2010

Effects of protease-resistant antimicrobial substances (PRA) produced by Lactobacillus plantarum and Leuconostoc citreum on rumen methanogenesis were examined using the in vitro continuous methane quantification system. Four different strains of lactic acid bacteria, i) Lactococcus lactis ATCC19435 (Control, non-antibacterial substances), ii) Lactococcus lactis NCIMB702054 (Nisin-Z), iii) Lactobacillus plantarum TUA1490L (PRA-1), and iv) Leuconostoc citreum JCM9698 (PRA-2) were individually cultured in GYEKP medium. An 80 ml aliquot of each supernatant was inoculated into phosphate-buffered rumen fluid. PRA-1 remarkably decreased cumulative methane production, though propionate, butyrate and ammonia N decreased. For PRA-2, there were no effects on $CH_4$ and $CO_2$ production and fermentation characteristics in mixed rumen cultures. The results suggested that PRA-1 reduced the number of methanogens or inhibited utilization of hydrogen in rumen fermentation.

• Journal of Microbiology and Biotechnology
• /
• v.12 no.6
• /
• pp.936-942
• /
• 2002

When used in combination with organic acids, Pediococcus acidilactici K10 or its bacteriocin was effective in inhibiting Escherichia coli O157:H7 in vitro and in situ. P. acidilactici K10, a strain of bacteriocin-producing lactic acid bacteria (LAB), was previously isolated from kimchi in our laboratory, and the molecular weight of its bacteriocin was estimated to be around 4,500 Da by SDS-PAGE. Initially, P. acidilactici K10 and its bacteriocin could not inhibit E. coli O157:H7, when used alone. However, when they were used together with organic acids such as acetic, lactic, and succinic acids, they greatly inhibited E. coli O157:H7 in vitro. Based on these in vitro results, a real sample test with ground beef was conducted at $4^{\circ}C$ with acetic acid (0.25%) or lactic acid (0.35%) alone, and then in combination with P. acidilactici K10 (10^5 CFU/g of sample). Combined treatment of P. acidilactici K10 with lactic acid showed the most inhibitory effect: a 2.8-$log_{10}$-unit reduction of E. coli O157:H7 in ground beef during storage at $4^{\circ}C$. This result suggests that the combination of bacteriocin-producing P. acidilactici K10 and organic acids has great potential as a food biopreservative by inhibiting the growth of E. coli O157:H7.

• The Korean Journal of Food And Nutrition
• /
• v.7 no.1
• /
• pp.45-50
• /
• 1994

This study was carried out to Investigate the effects of Panax ginseng, Ganoderma lucidum extract and crude polysaccharide of G. lucidum on the growth of lactic acid bacteria. p. ginseng extract contained 60.7% carbohydrate and 27.5% protein, whereas G. lucidum contained 35.9% carbohydrate and 46.3% protein. The total sugar and protein content of crude polysaccharide of G. lucidum were 47.2% and 15.2%, respectively. Two amino acids(hg, Trp) were detected in p. ginseng extract and 11 amino acids (hg, Trp, Ua, Lys, Ser, etc.) in C. lucidum extract. By the addition of p. ginseng, 5. lucidum extract and crude polysaccharide, the cia. p. ginseng was more effective on the growth of 1. casei an: G. lucidum was more effective on that of S. thermophilus. The effect of free amino acids on the growth of tactic acid bacteria was also examined. Arginine and lysine stimulated the growth of L. casei, whereas Lysine, serine, arginine, and glutamic acid stimulated the growth of 5. thermophilus.

• Journal of Korean Medicine for Obesity Research
• /
• v.22 no.2
• /
• pp.115-124
• /
• 2022

Objectives: In this study, we investigated physicochemical characteristics and antioxidant activity of Artemisia argyi H. fermented with lactic acid bacteria. Methods: The A. argyi water extract was fermented using lactic acid bacteria isolated from kimchi at 30℃ for 96 h. To evaluate the physicochemical characteristics, we investigated pH, total acidity, viable cells, free sugars, free organic acids, and free amino acids contents during fermentation. In addition, we examined antioxidant activity of fermented Artemisia argyi H. by measurement of 2,2-diphenyl-1-(2,4,6-trinitrophenyl)-hydrazinyl (DPPH) and 2,2'-azubi-bus-3-ethylbenzothiazoline-6-sulfonic acid (ABTS⁺) scavenging activities. Results: During fermentation time, pH of fermented A. argyi was decreased from 4.57 to 3.22, and total acidity was increased from 0.39% to 1.63%. The number of lactic acid bacteria fermented A. argyi was increased from 1.28×10⁷ CFU/ml to 3.75×10⁸ CFU/ml during fermentation time. The free sugars of fermented A. argyi were confirmed glucose and sucrose. In addition, the organic acid content of fermented A. argyi was the highest in oxalic acid and lactic acid. In the composition of free amino acids, content of ornithine increased from 4.4 mg/100 g to 18.8 mg/100 g compared with non-fermented A. argyi. Furthermore, DPPH and ABTS⁺ radical scavenging activities of fermented A. argyi increased in a dose-dependent manner. Conclusions: In conclusion, our data suggest that lactic acid fermentation of A. argyi could be used as a functional food for antioxidants.