• Korean Journal of Fisheries and Aquatic Sciences
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• v.21 no.4
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• pp.269-275
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• 1988

Inhibitory effects on bacterial growth by using lysozyme and mixtures of it with other antibacterial substances (sodium hexametaphosphate and sodium pyrophosphate) were investigated against the 7 kinds of hacterial strains isolated from putrefied surumi products. The growth inhibitory concentrations of lysozyme and lysozyme + sodium hexametaphosphate + sodium pyrophosphate against the bacteria were added to kamaboko, imitation crab meat and fried surumi, then viable cell count, pH and VBN were examined during the storage at $30^{\circ}C$ for 7 days. Lysozyme showed growth inhibitions against 6 of 7 isolates and the inhibition effect of mixture of antibacterial substances was multiplied against all the isolates compare with those of its individual use. Growth inhibitory effect of the substances on the bacteria was high in order of lysozyme + sodium pyrophosphate + sodium hexametaphosphate, lysozyme + sodium hexametaphosphate, lysozyme + sodium pyrophosphate and lysozyme. The most effective inhibitory concentration of mixture of the antibacterial substances in kamaboko and imitation crab meat was $0.05\%$ of lysozyme, $0.5\%$ of sodium pyrophosphate and $0.1\%$ sodium hexametaphosphate. But the bacterial growth was slightly inhibited in fried surumi even if the same concentration of the dipped mixture and the effect of the mixture was less than that of $0.2\%$ sorbic acid.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.7
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• pp.1009-1013
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• 2012

We investigated the antibacterial effects of Opuntia ficus indica extracts on foodborne pathogens, Escherichia coli O157:H7 and Listeria monocytogenes, on the medium of sliced apples. Pathogens were inoculated on sliced apples and immersed for 10 min in Opuntia ficus indica extracts. Each sample was packaged and stored at $4^{\circ}C$ and $21^{\circ}C$ for 8 days. The populations of E. coli O157:H7 and L. monocytogenes significantly decreased with increasing extract concentration (p<0.05). In particular, L. monocytogenes was reduced to non-detectable levels after 2 days in 50 mg/mL treatment at $4^{\circ}C$ and $21^{\circ}C$ Opuntia ficus indica extracts therefore have antibacterial effects on the two foodborne pathogens. Sensory evaluation results indicated that treated apples had better sensory characteristics than did the control. Therefore, the results suggest that Opuntia ficus indica extracts could be useful as a natural food preservative to improve microbial safety.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.2
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• pp.127-131
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• 2006

A study was carried out to produce antimicrobial peptides from zein treated with pretenses of six kinds. Among the pretenses of six kinds, zein hydrolysate treated with pepsin showed the highest antimicrobial activity. The zein hydrolysate with pepsin was fractionated with membrane filter (30,000 10,000 and 3,000 molecular weight cut-off) and antimicrobial activity was measured for each fractions. Antimicrobial activity appeared greatly in the fraction below 3,000 (molecular weight cut-off) . The fraction was re-fractionated by HPLC and substances of two peaks collected as a sample to measure antimicrobial activity. All of both peaks showed the antimicrobial activity but 1st peak exhibited a consistently higher antimicrobial activity than 2nd peak. Minimum inhibitory concentrations (MIC) were between 2.5 and 3.0 mg/mL. The peptide was heat-stable since antimicrobial activity was maintained after treated with heat for 20 min at $121^{\circ}C$. N-terminal amino acid sequence of peptide fractionated by HPLC was leucine, glutamic acid, proline, phenylalanine, aspartic acid and argenine. These results indicated that peptide isolated from zein hydrosate with pepsin can use as a natural preservative ingredient in food industry.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.7
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• pp.1053-1058
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• 2003

The solvent extracts of Houttuynia cordata root, which were extracted by using several solvents with different polarities, were prepared for utility as a natural preservatives. The antimicrobial activity was investigated by disc diffusion method against 22 microorganisms consisting of food borne pathogens, food poisioning microorganisms and food-related bacteria. The extraction yields were 15.7%, 3.7%, 0.13%, 0.5% and 5.9% in ethanol, chloroform ethylacetate, butanol and aqueous fractions, respectively. Antimicrobial activities were shown in ethanol, ethylacetate and butanol fraction of Houttuynia cordata root. However chloroform and aqueous fractions showed weak antimicrobial activity against the tested bacteria. Among the four fractions, ethylacetate fraction showed the strongest antimicrobial activities against microorganisms tested, such as B. megaterium, E. coli, K. pneumoniae and S. typhimurium. The polyphenolic compounds widely occuring in the traditional medicine plants have been reported to possess high antimicrobial activity. The polyphenolic compound in ethylacetate and butanol fraction were 35.9% and 16.0%, ethanol, chloroform and aqueous fraction were 5.0%, 2.3% and 1.7%, respectively. There are some relationship between antimicrobial activity and polyphenol content in natural plants. The ethylacetate fraction could be suitable for the development of a food preservative.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.6
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• pp.663-669
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• 2007

The solvent extracts of Sargassum muticum, which were extracted by using several solvents with different polarities, were prepared for use as natural preservatives. The S. muticum extract with 80% ethanol was sequentially fractionated with n.hexane, dichloromethane, ethylacetate, and butanol. In order to effectively screen for natural preservatives agents, we first investigated the antioxidant activities such as DPPH radical scavenging capacity, superoxide radical scavenging capacity, and xanthine oxidase inhibitory activity of the S. muticum extracts. Through the screening system, we found that dichloromethane and ethylacetate fraction had high antioxidant activity with increments of the extract concentration. The antimicrobial activities and cell growth inhibition were investigated for each strain with the different concentrations of S. muticum extracts. Antimicrobial activities were shown in ethanol, dichloromethane, and n.hexane fractions of S. muticum. However, butanol, ethylacetate and water fractions showed weak antimicrobial activity against the tested microorganisms. Among the five fractions, dichloromethane fraction showed the highest antimicrobial activities against microorganisms tested, such as Bacillus sublitis, Listeria monocytogenes, Staphylococcus aureus, Escherichia coli, Salmonella Enteritidis and Pseudomonas aeruginosa. The polyphenolic compounds from ethanol, n.hexane, dichloromethane, ethylacetate, butanol, and water fractions were 63.96 mg/g, 8.49 mg/g, 28.11 mg/g, 172.64 mg/g, 114.56 mg/g, and 34.91 mg/g, respectively. The dichloromethane fraction could be suitable for development as a food preservative.

• Korean Journal of Food Science and Technology
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• v.40 no.6
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• pp.712-716
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• 2008

In an effort to evaluate Salmonella food safety using combinations of preservation techniques, its viabilities when exposed to HCl, acetic acid, and the oxidative agents (hydrogen peroxide and butyl hydrogen peroxide), were analyzed using sub-lethal heat-shocked Salmonella Typhimurium at $56^{\circ}C$. 2D gel electrophoresis and MALDI-TOF MS analyses were also conducted to determine the expression and repression of proteins in heat-shocked cells. Heat-shocked S. Typhimurium evidenced a reduction of viable counts by 1-2 log CFU/mL. However, viality of non heat-shocked S. Typhimurium decreased markedly by 5-6 log CFU/mL at a pH 4 in response to acid and oxidative stresses. Sub-lethal heat treatment greatly increased the resistance of S. Typhimurium against acid and oxidant agents. As for 2D gel electrophoresis and protein identification via MALDI-TOF MS, 17 major proteins in non heat-shocked S. Typhimurium were detected, and only 13 proteins among these proteins were detected in heat-shocked S. Typhimurium. The heat shock proteins such as DnaK and small heat shock proteins were included, and may be associated with the resistance of S. typhimurium against exposure to acids and oxidants. Therefore, even though the promising hurdle technology using the combined mild treatments including heat was applied to S. Typhimurium, the proper heat treatment to reduce its crossprotection activity toward the following preservative agents might be considered.

• Journal of Life Science
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• v.19 no.1
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• pp.52-57
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• 2009

This study was carried out to investigate the antioxidative and antimicrobial activities of Celastrus orbiculatus (CO). CO was extracted with methanol and then further fractionated with n-hexane (COMH), butanol (COMB), methanol (COMM) or aqueous (COMA) to get active fractions. The antioxidative activity of fractions from CO was investigated by measuring the scavenging activities of CO against DPPH radical, peroxynitrite ($ONOO^-$) and reactive oxygen speicies (ROS). Among the various solvent fractions, the COMB showed a marked scavenging effect against DPPH radical, peroxynitrite ($ONOO^-$) and reactive oxygen species(ROS). The antimicrobial activity was increased in proportion to its concentration by the paper disk method. Among the various solvent fractions, the COMM and COMB fractions of CO showed strong antimicrobial activities. The results suggest that The CO may be suitable for development as a food preservative and alternative antioxidant.

• Korean Journal of Clinical Laboratory Science
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• v.49 no.4
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• pp.359-365
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• 2017

There is greater standardization of quality control for microscopic examination of urine than for physicochemical test. In this study, we investigated whether it is possible to control the sediment accuracy by microscopic examination through the real thing by preserving the essential sediment with glutaraldehyde, which is required for the rationality of sediment quality control. A urine specimen was prepared using 2.5% glutaraldehyde as a preservation solution. Samples treated with urine preservatives confirmed the morphological deformation of the cells for four weeks at intervals of one week and confirmed whether they should be preserved for 4 weeks thereafter. After preparing the required sediment slide, two more slides were produced; one was stored in a refrigerator for, and the other was stored at room temperature. The morphological deformation of the specimen was confirmed. Glutaraldehyde has the effect of preserving the refrigerated essential sediments and storing them for up to 8 weeks, refrigerated storage after slide production, stabilized by 3 days. Moreover, after treatment with preservatives, the production of the slide and comparison between the measured values between the laboratories and examiners showed a low consistency. In conclusion, we showed that the urine sediment components can be preserved, and it can be used for quality control and education through real objects.

• Journal of Food Hygiene and Safety
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• v.24 no.4
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• pp.332-337
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• 2009

Most propionic acid is added to food (especially breads) as preservatives and its form is sodium or calcium salt. Most countries admitted propionic acid as food preservatives but a tolerance limit is somewhat different according to countries. Recoveries of the official method for propionates reported as 50.0~60.0%. Accordingly new rapid determination method for propionates was developed using formic acid added sodium chloride (5 g) and ether (formic acid : ether = 1 : 2) as the extraction solvent to improve the official method with the complex processes. Propionate was dissolved from the samples with formic acid omitting steam distillation and ion exchange procedure. Then propionate in formic acid was extracted with ether and sodium chloride again. A $1\;{\mu}l$ aliquot of the filtrate of ether was analyzed by gas chromatograph. Recoveries from sample A and B fortified with propionic acid sodium salt were 85.0 % and 90.0 %, respectively.

• Korean Journal of Food Science and Technology
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• v.17 no.3
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• pp.146-154
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• 1985

Low-salted Kochuzang was made by the replacement of a part of NaCl with 4% ethanol as the preservative. Comparative analysis were performed for general components in 7 kinds of low-salted Kochuzang. The activities of ${\alpha}-and{\beta}-amylase$ and protease were high in ripened Kochuzang of low salt concentration in case of addition of alcohol. The changes of total sugar and pH were remarkably decreased when alcohol and salt were added. Total acid contents showed a remarkable increase when alcohol was not added, and in case of salt concentration. Total nitrogen contents were not remarkably changed, but the contents of amino nitrogen and ammonia nitrogen were increased in case of low salt conuntration with alcohol. Reducing sugar contents were increased in case of low salt concentration and alcohol added. Alcohol contents were not remarkably changed in case of addition of alcohol, but when alcohol was not added and low salt concentration they showed a remarkable increase(about 2.2%). A good Kochuzang may be produced by adding 4% alcohol to a low salted one (5.1% content in Kochuzang) in seventy days of the fermentation.