• Korean journal of food and cookery science
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• v.15 no.4
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• pp.410-417
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• 1999

Antimicrobial activity of Plantain(Plantago asiatica L.) was investigated. Methanol extract of dried Plantain was fractionated to hexane, chloroform, ethylacetate, butanol and aqueous fraction. Ethylacetate fraction among these fractions showed the highest inhibitory effect on the microorganisms such as B. subtilis, E. coli, and V. parahaemolyticus at 500 $\mu\textrm{g}$/disc. Ethylacetate fraction was further fractionated into 8 fractions by silica gel column and thin layer chromatography(TLC). The results showed that ethylacetate fractions No. 2 and 3 had the highest anti-microbial activity. They were mixed again, re-separated, and seven fractions were obtained. Among them, No.4 and 6 fraction had the highest inhibitory effect on the microorganisms, which were then separated into four fractions. In the 3rd fractionation, No.4 fraction was identified as hexadecanoic acid by HPLC, $^1$H-NMR and GC-MS.

• Korean journal of food and cookery science
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• v.12 no.2
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• pp.129-137
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• 1996

The purpose of this study was that to estimate the microbial and sensory quality by the method and time of holding in the step of holding of Cow's Knee Broth, Stir-Fry Pork and Cooked Cuttlefish that were provide at the industry foodservice establishment, then to suggest safer feeding by the reasonable holding method. The results are as follows: Cow's Knee Broth: holding at room temperature was shown that the number of mi- crobiology by passage of the holding time was higer than the case of holding at steam table, but it was lower after reheating it. As a result of sensory test, it was exellent to holding at steam table and to reheat after holding room temperature within four hours and six hours each. Stir-Fry Pork: as a result of microbial analysis, in the case of holding at the steam table microbes increased safer two hours, but after four and six hours they little reduced. In the case of holding at room temperature the number of microbes increased according to the passage of time. As a result of sensory analysis, its taste of room temperature holding was fine until four and six hours each. Cooked Cuttlefish: as a microbial analysis, it was shown that the amount of total plate counts of room temperature holding ten times as high as the latter after six hours. As the result of sensory analysis, the cold holding was better until six hours and the room temperature holding was fine just until two hours. As a result of food poisoning bacteria, it was negative in every test in sample against Salmonella, Staphylococcus aureus, Vibrio parahaemolyticus.

• Journal of the Korean Society of Food Culture
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• v.11 no.4
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• pp.465-473
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• 1996

The purpose of this study was to evaluate microbiological hazards in the steps of production, transportation and selling of hamburger and sandwich that were marketed in CVS, then to identify methods of control. The reasults are as follows: As the reasult of operation surroundings of manufacturerand reserch of circulation, $4{\sim}6$ hours are needed from manufacturer to CVS. Also transportation car mean temperature was $10^{\circ}C$ which exceeds the standard of $7^{\circ}C$ or below. Hamburger: Critical control points identified were purchasing, cooking, post-preparation, transportation and holding at CVS. As the reasult of microbial analysis following the case of holding methods and reheating at CVS, microbes of cold holding and reheat after cold holding was within standard value. But in the case of room temperature microbes exceeded standard value. Sandwich: Critical control points identified were purchasing, cooking, post-preparation, transportation and holding at CVS. As the reasult of microbial analysis following the case of holding methods and reheating at CVS, total plate counts of cold holding and reheat after cold holding was within standard value. But in the case of room temperature holding after 24 hours total plate counts exceeded standard value. In the case of room temperature holding the number of microbes increased according to the passage of time. As a reasult of food poisoning bacteria, it was negative in every test in sample against V. parahaemolyticus, Salmonella, S. aureus.

• Food Science and Preservation
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• v.11 no.1
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• pp.117-121
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• 2004

We investigated antimicrobial effects of commercial vinegar on the harmful food-born organisms. As a result, antimicrobial effects of brown rice vinegar showed stronger than persimmon and artificial vinegar. In 10${\mu}$L/mL concentration of brown rice vinegar was completely inhibited about 5 strains except for V. parahaemolyticus, it was inhibited 15${\mu}$L/mL concentration. Therefore vinegars were effective for inhibition acitivity against food borne organisms. S. aureus and E. coli treated with 25${\mu}$L/mL concentratioin brown rice vinegar was observed by scanning electron micrographs(SEM). The cells were expanede and a part of cell wall was completely destructed by brown rice vinegar.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.5
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• pp.691-697
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• 2021

Vibrio parahaemolyticus associated with acute hepatopancreatic necrosis disease (Vp_AHPND) and Enterocytozoon hepatopenaei (EHP) are the two most important pathogens in shrimp aquaculture and they have caused enormous losses to the shrimp industry worldwide. In ponds, the major target organ for the two pathogens is the hepatopancreas, and infection with EHP is a known potential risk factor for Vp_AHPND infection. This study aimed to develop a PCR (polymerase chain reaction)-based diagnostic method for simultaneously detecting Vp_AHPND and EHP. The newly developed PCR diagnostic method could be used to test various samples, such as seawater, shrimp, and feces. The diagnostic method exhibited high sensitivity and specificity for both pathogens. This will help reduce the potential economic losses that may have been caused by the two major shrimp pathogens, Vp_AHPND and EHP, and will allow for the efforts and time spent combatting them to be dedicated elsewhere.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.6
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• pp.861-869
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• 2020

This study was conducted to investigate the suitability of frozen oysters as a raw material for the preparation of seafood products by measuring the concentrations of harmful microorganisms and chemicals in thawed flesh. The microbial concentrations in thawed oysters were 2.3-5.0 log CFU/g for viable cell counts, not detected (ND)-1.0 log CFU/g for coliform bacteria, and ND for Escherichia coli and pathogenic bacteria such as Staphylococcus aureus, Salmonella spp., Listeria monocytogenes, Vibrio parahaemolyticus, Enterohemorrhagic Escherichia coli (EHEC), and Clostridium perfringens. In frozen oysters, the heavy metal concentration for viable cell counts was ND-0.030 mg/kg, for lead was ND-0.393 mg/kg, and for cadmium was 0.021-0.597 mg/kg. Benzo(a)pyrene, shellfish poison (paralytic shellfish and diarrhetic shellfish poisons), and radioactivity were not detected in the thawed oysters. These results suggest that frozen oysters can be safely used as a raw material for the preparation of seafood products.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.6
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• pp.851-860
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• 2020

Shrimp in seasoned soy sauce (S-SS) is a popular seafood product in Korea, but it could be potentially hazardous; thus, this study was conducted to investigate its safety. Commercial S-SS were collected and analyzed for pH, volatile basic nitrogen (VBN), hygenic indicator microorganisms (viable cell count, coliforms, and Escherichia coli), food poisoning bacteria (Staphylococcus aureus, Vibrio parahaemolyticus, and Listeria monocytogenes), preservatives (dehydroacetic acid, sorbic acid, benzoic acid, and its salt, parahydroxybenzoate), tar colorants, and sensory properties. Domestic and foreign standards were also investigated for S-SS. Commercial S-SS ranged from to 6.2-7.3 for pH, 13.7-39.1 mg/100 g for VBN, and 4.6-6.9 log CFU/g for viable cells. The coliforms and E. coli of commercial S-SS were from ND to 3.4 log CFU/g and negative, respectively. Food poisoning bacteria, preservatives, and tar colorants were not detected in commercial S-SS. Only the coliform count and presence of E. coli in commercial S-SS exceeded the set standards of vietnam, while all items were within domestic and foreign standards.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.5
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• pp.495-504
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• 2022

This study examined the antimicrobials properties of bacteria using the minimum inhibitory concentration method. The bacteria were isolated from 30 shellfish (oysters and short neck clams) collected from Jawol-myeon, Ongjin-gun, Incheon and Iwon-myeon, Taean-gun, Chungcheongnam-do, on the west coast of Korea. A total of 528 bacteria were isolated from June to October 2020 and were classified into land-originating (LB; 264 strains) and marine-originating (MB; 264 strains) bacterial groups. Of the LB strains, 10 genera were identified, of which nine were Enterobacteriaceae. All MB strains were identified as species of the genus Vibrio spp.. Antimicrobial resistance to one or more agents was observed in 77.3% of the LB strains, and 90-100% of them were resistant to ampicillin Escherichia spp. were not resistant to ampicillin. The overall multidrug resistance rate of the LB strains was 49.2%, with 85 resistance patterns. Antimicrobial resistance to one or more agents was observed in 98.1% of the MB strains, because most of the V. alginolyticus and V. parahaemolyticus strains were resistant to ampicillin. The overall multidrug resistance rate of the MB strains was 1.9% with 19 resistance patterns.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.4
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• pp.431-436
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• 2022

For the safety assessment of microbiological and chemical hazards in katsuobushi, fifteen samples of katsuobushi were purchased from supermarkets. The contamination levels of total viable bacteria, coliforms, Escherichia coli, and nine pathogenic bacteria [Staphylococcus aureus, Salmonella spp., Listeria monocytogenes, Bacillus cereus, Vibrio parahaemolyticus, Clostridium perfringens, Enterohemorrhagic E. coli (EHEC), Yersinia enterocolitica and Campylobacter jejuni/coli] were quantitatively or qualitatively assessed. Additionally, the heavy metals (total and methyl mercury) content, radioactivity (¹³¹ I, ¹³⁴ Cs⁺ and ¹³⁷ Cs) were quantitatively assessed. Microbial and chemical analyses were performed using standard methods in Korean food code. The contamination level of total viable bacteria was 2.70 (1.18-4.42) log CFU/g. Coliforms, E. coli and S. aureus were not detected in any samples. Other eight pathogenic bacteria were negative in all samples. The contamination levels of total and methyl mercury were 0.366 (0.227-0.481) and 0.120 (0.002-0.241) mg/kg, respectively. In addition, radioactivity was not detected in any samples. The results will be helpful in revitalizing domestic use and boosting exports of katsuobushi because the microbiological and chemical safety of katsuobushi has been assured. Furthermore, the results may be used as a basis for performing chemical and microbial risk assessments of katsuobushi.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.1
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• pp.133-139
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• 2023

The advantage of biofloc technology (BFT) in aquaculture is in the prevention of pathogenic transmission. In this study, we performed an investigation on viral, bacterial, and microsporidian parasite infections targeting a total of 194 whiteleg shrimp Litopenaeus vannamei reared in seven BFT-farms on the west coast of Korea in 2021. Hepatopancreatic and cuticular epithelium and pereiopods tissues of shrimp were tested for the four pathogens, Enterocytozoon hepatopenaei (EHP), Vibrio parahaemolyticus causing Acute Hepatopancreatic necrosis disease (VP_AHPND), white spot syndrome virus (WSSV), and hepatopancreatic parvovirus (HPV). The microsporidian parasite EHP was detected in the hepatopancreatic tissue of BFT whiteleg shrimp in the Ganghwa region, whereas no other pathogenic bacteria or virus was detected on the shrimp in the seven BFT-farms. As a result of bacterial flora in the rearing water of BFT whiteleg shrimp using DNA microbiome technology, V. chemaguriensis and V. alfacsensis were contained at 0.05% and 0.01%, respectively, but no VP_AHPND was detected. These findings will serve as a basis for supporting safe BFT-aquaculture of whiteleg shrimp.