• Food Science of Animal Resources
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• v.31 no.6
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• pp.928-934
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• 2011

The objective of this study was to characterize the lactate metabolism and lipolysis in Emmental cheese made of Korean raw milk throughout the ripening periods; 14 d at $10^{\circ}C$, 42 d at $23^{\circ}C$, and 30 d at $4^{\circ}C$. Emmental cheese was made using a commercial starter culture with propionic acid bacteria (PAB) and without PAB as a control on the pilot plant scale. Changes in the contents of five organic acids (citric, lactic, formic, acetic, and propionic acid) and individual free fatty acids (FFAs) were measured using HPLC/PDA and GC/FID. As a result of propionic fermentation by PAB, the concentration of acetic acid and propionic acid increased up to 1.5 and 6.1 g/kg, respectively and the most dramatic increased occurred when incubated in the hot room ($23^{\circ}C$). Lactic, citric, and formic acid contents were 2.6, 2.5 and 0.8 g/kg at the end of ripening, respectively. As a result of lipolysis, the amount of total FFAs was 6,628.2 mg/kg. Compared to the control, levels of individual FFAs from butyric (C6:0) to linoleic (C18:2) acids increased significantly (p<0.05) during the ripening period. Especially, 65.1% of total FFAs was released in the $23^{\circ}C$ room and the most abundant FFAs were palmitic (C16:0), stearic (C18:0) and oleic acid (C18:1). These results demonstrated that the lipolysis of Emmental cheese was strongly affected by bacterial lipase from PAB.

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

• Journal of The Korean Society of Grassland and Forage Science
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• v.11 no.1
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• pp.53-59
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• 1991

This experiment was conducted to investigate the effects of propionic acid and wilting on fermentation quality of Italian ryegrass silage. Grass material was wilted for a day before ensiling and propionic acid(0. 0, 0. 2. 0. 5 and 0.8 7~ of fresh matter) was applicated at ensiling time. Chemical composition, fermentation acids, pH, microbial population and distribution of the nitrogen contents were evaluated. The results obtained are summarized as follows: 1. The contents of dry matter and water soluble carbohydrate in the silage were increased by wilting, and crude fibre, NDF and ADF were decreased with increasing propionic acid levels. 2. The pH values of the silage increased by increasing DM content, but decreased with increasing propionic acid levels. Lactic acid content lowed in wilted silage, and acetic acid and butyric acid formation were decreased with increasing propionic acid levels. 3. Total nitrogen content in the silage was i n ~ r e a s e d ( ~ < . 05) by addition of propionic acid and wilting, and was the highest in the prewilting-0.8 Q propionic acid applicated silage. The production of NHBN was decreased with propionic acid and was the lowest in the 0.8 % treated silage. 4. The number of total bacteria and yeasts were estimated $10^6~10^7$, $10^2~10^3$ respectively. Moulds number were decreased with increasing propionic acid levels.

• Journal of Food Hygiene and Safety
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• v.27 no.4
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• pp.449-455
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• 2012

The purpose of this study is to evaluate antimicrobial effects of organic acid and some natural occurring antimicrobials against Staphylococcus aureus isolated from various origins (vegetables, peanut, pea leaf, kim-bab, person, perilla leaf, and animal) and to calculate their MIC and MBC values. Five organic acids (acetic, lactic, citric, malic, and propionic acid), three essential oils (carvacrol, thymol, and eugenol), and two other natural antimicrobials (nisin and cinnamic acid) were evaluated for their antimicrobial effects against 113 strains of S. aureus using combination treatments. Propionic acid (7%), nisin (1%), thymol (1%), carvacrol (1%) showed antimicrobial activities against S. aureus strains in agar disc diffusion test. And, carvacrol, thymol, and nisin were found to be the most effective with the lowest MIC values of 0.0313%, 0.0625%, and 0.0625% against S.aureus, respectively. Propionic acid (0.2313%) and citric acid (0.6000%) were the most effective among organic acids tested. Therefore, these five antimicrobials were selected for next combination treatments. Combination of propionic acid and citric acid were showed the strongest inhibitory effectiveness against S. aureus among combination treatments. These results suggest that organic acid such as propionic and citric acid, and natural occurring antimicrobial such as nisin, carvacrol, and thymol might be possibly used as preservatives for inhibiting S. aureus in foods.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.4
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• pp.487-493
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• 1995

This study was carried out to select useful chemicals to control pathogens inciting soybean-sprout rot. Pathogen strains were isolated from decaying soybean seedlings. The isolated strains were identified as Pseudomonas spp. (Pse. strains) through microbiological test, however, no rot-inciting fungus was isolated. Eight food additives were tested with different concentrations in controlling pathogens and harmfulness. Five chemicals(over 5% cone.) including sodium hypochlorite apparently inhibited the growth of Pse. strains on media plate, however, sodium hypochlorite was discarded due to its severe germination inhibition. Propionic acid and acetic acid inhibited the growth of Pse. strains more effectively than calcium propionate and sodium propionate relatively. As no harmful effect on seed germination and no growth retard of soybean sprouts were observed by those chemicals with lower concentration(0.5∼1.0%), these chemicals were considered to be applicable to sprout rot control judged by the effectiveness and permissible concentration as food additives.

• Journal of the Korean Home Economics Association
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• v.9 no.2
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• pp.30-33
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• 1971

1. The present paper deals with the composition of organic acid in Porphyra tenera, roasted Porphyra tenera and Undaria pinnatifida. 2. There are little differences in the composition of organic acids among three of them, Porphyra tenera, roasted Porphyra tenera and Ucdaria pinnatifida. Butyric, propionic, acetic, fumaric, succinic, lactic, oxalic, malic, citric and unknown two acids were identifled by silica gel colcumn chromatography. 3. All of volatile organic acid, namely butyric, propionic and acetic acid in Porphyra tenera were decreased during the raosting.

• Korean Journal of Plant Resources
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• v.19 no.5
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• pp.606-611
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• 2006

Decay during soybean sprout culture detracts their quality as well as increases their production costs. This study was done to determine the effects of acetic and propionic acids on growth and morphological characters of the sprouts. The soybean seeds of 3 cultivars (cv. Eunhakong, Pungsannamulkong and Orialtae) imbibed for 2 minutes at their different concentrations (0, 0.1 and 0.2%) were soaked for 6 hours in 4 ppm BA solution after the first 5.5 hour water imbibition and 0.5 hour aeration, and cultured at $20^{\circ}C$. On the 6th day, harvested soybean sprouts were classified into 4 categories on the base of hypocotyl length;>7cm, 4 to 7cm,<4cm and not germinated, and their morphological characters, fresh weights, lesion spots on cotyledons were measured or analyzed. The stronger concentration the higher rate of longer than 4cm although there was no significant difference between the two acids. Pungsannamulkong showed the longest hypocotyls but Eunhakong did the thickest ones, and Orialtae did the greatest total fresh weight, in which all the characters were not influenced by the two acids and their concentrations. Lesion spots on the cotyledons were equal to the two acids although less in their treatments than in no treatment. Utilization of propionic acid was more desirable Dan acetic acid through their treatment cost analysis.

• Fire Science and Engineering
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• v.21 no.4
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• pp.32-37
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• 2007

An accurate knowledge of the flash point is important in developing appropriate preventive and control measures in industrial fire protection. The lower flash points for the 2-propanol+acetic acid and 2-propanol+-n-propionic acid systems were measured by Cleveland open cup apparatus. The experimental data were compared with the values calculated by the Raoult's law, the Wilson equation and the NRTL(non random two liquids) equation. The calculated values based on the Wilson and NRTL equations were found to be better than those based on the Raoult's law. And the predictive curve of the flash point prediction model, based on NRTL equation described the experimentally-derived data were more effective than the case of the Wilson equation.

• Korean journal of food and cookery science
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• v.9 no.4
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• pp.257-260
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• 1993

For the purpose of supplying the information to improve the acceptability of soy paste as the condi-ment, we investigated the changes of free sugar, volatile and nonvolatile organic acids during improved soypaste fermentation. The results were as follows; Free sugars were increased in order of glc> xyl>ara>gal. Acetic, formic, butyric, and propionic acid in volatile organic acids were detected. And total contents were increased until 60 day. In 180 day, contents of volatile organic acids were high in order of acetic>propionic> butyric> formic. The contents of succinic and glutaric acid in nonvolatile organic acids were predominent and increased in order of succinic>glutaric>lactic. Tartaric>citric>malic acid were produced in the next order.

• The Korean Journal of Pharmacology
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• v.5 no.1
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• pp.17-22
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• 1969

Oxygen consumption by Clonorchis sinensis (C.S.) was observed in a medium of valuable pH of KRP, lack of certain electrolytes of KRP and of glucose, acetic acid or propionic acid was added to KRP. The results were as follows. 1. In a different solutions, KRP with or without $0.4%-glucose$, $0.9%-saline$ solution, the variation of oxygen consumption by C.S. was not significant. 2. Oxygen consumption by C.S. was inhibited by the solution of KCI, $CaCl_2$, or $MgSO_4$ in a 0.9% solution of saline. 3. Under the acidity, oxygen consumption was enhanced but under the alkality, it was inhibited. 4. Oxygen consumption by C.S. was inhibited by acetic acid or propionic acid in KRP solution. 5. C.S. keeping in KRP solution for a long duration, oxygen cosumption was reduced in the course of time.