• KSBB Journal
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• v.24 no.3
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• pp.273-278
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• 2009

The purpose of this work was to investigate the antibacterial activity of Lactobacillus plantarum YK-9 isolated from fermented Kimchi. Morphological and biochemical characteristics of L. plantarum YK-9 were examined. Phylogenetic analysis using 16S rRNA sequencing was performed to identify the strain, and the strain could be assigned to Lactobacillus plantarum, designated as L. plantarum YK-9. The strain was registered in GenBank as [FJ669130]. During the incubation period of L. plantarum YK-9, the changes of bacterial growth and residual organic acids were monitored. HPLC was used to confirm the organic acids produced in the cultures as metabolites. L. plantarum YK-9 produced both lactic acid and acetic acid, which were responsible for the pH decrease during growth. Initial pH 7.0 of the cultures decreased to 3.6 at the incubation after 72 hours, and concentrations of lactic acid and acetic acid increased to approximately 588.7 mM and 255.5 mM, respectively. The antibacterial activities against food-poisoning causing bacteria were examined with 20-fold concentrated culture supernatants from L. plantarum YK-9, and the antibacterial effects were clearly observed against all the bacteria tested in this work.

• Journal of Life Science
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• v.18 no.6
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• pp.776-781
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• 2008

To develop natural food preservatives, methanol and water extracts were prepared from the Suaeda maritima and their antibacterial activities were examined against 12 microorganisms which were food borne pathogens bacteria, food poisoning microorganisms and food-related bacteria. Methanol extracts exhibited antibacterial activities for the 5 Gram positve and 7 Gram negative bacteria by agar diffusion method, The antibacterial activities and cell growth inhibition were investigated on each strain with the different concentrations of Suaeda maritima extracts. Antibacterial activities were shown in root, stem, furit extracts of Suaeda maritima. However stem and fruit extracts showed weak antibacterial activity against the tested microorganisms. Root extracts showed the highest antibacterial activities against microorganisms tested, such as Bacillus cereus,Bacillus subtilis, Vibrio parahaemolyticus, Staphylococcus aureus. The highest antibacterial activity against bacteria test was found in the methanol extract.

• Journal of Food Hygiene and Safety
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• v.17 no.1
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• pp.31-35
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• 2002

According to food poisoning statistic data of 2000, the food poisoning outbreaks have occurred mainly by meat (27.9%), shellfish and its processed products (26.0%), and ready-to eat meals (24.0%) such as Kimbap and packed lunch boxes. The major causative flood poisoning bacteria were Salmonella spp. (35.6%), Staphylococcus aureus(11.3%) and Vibrio parahaemolyticus (3.2%). In this study, we conducted the isolation and enumeration for S. aureus in Kimbap. This monitoring data will be applied to the following study, risk assessment. The Kimbap samples were collected from department stores, convenient stores and snack bars located in Seoul, Busan, Daejeon, and Gwangju. The overall isolation rate of S. aureus from 214 Kimbap samples was 34.1% and the average count was 623 cells. Enterotoxin typing test for isolates showed 42.5%, 4.1% and 2.7% for type, A, B and C, respectively. There was no significant seasonal difference in S. aureus isolation, but the average count in summer(793 cfu/g) was 1.8 times higher than that of winter(446 cfu/g).

• Journal of Dairy Science and Biotechnology
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• v.40 no.3
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• pp.103-109
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• 2022

Lactic acid bacteria with antibacterial activity can be effectively used as probiotics to inhibit the growth of harmful bacteria that cause food spoilage or food poisoning. In this study, Pediococcus pentosaceus M132-2, isolated from soybean paste, was analyzed for its effects on three major contaminating fungi. M132-2 was confirmed to exert antifungal activity by inhibiting the growth of all three fungi tested. In addition, M132-2 displayed excellent salt resistance and low temperature tolerance. Thus M132-2 can survive at the salinity level in cheese and at the low temperatures used in the aging process. Finally, when supernatant from an M132-2 culture was applied to Gouda cheese, the growth of contaminating fungi was significantly inhibited. Consequently, M132-2 may be useful for the prevention of spoilage of various foods, including cheese.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.21 no.2
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• pp.97-104
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• 1988

Condensed phosphates have been used in various meat products to enhance the water holding capacity, to improve texture and to prevent the development of off flavors and off odors. This study was intended to observe the effects of poly - and pyrophosphate on the growth of sanitary indicative bacteria and food poisoning bacteria. The bacteriostatic effect of poly - and pyrophosphates against Gram positive bacteria was much stronger than that of against Gram negative organisms. The effective inhibitory concentration of sodium polyphosphate on the growth of bacteria was varied by species such as $0.3\%$ to Staphylococcus aureus, $0.9\%$ to Salmonella, and more than $1.0\%$ to Escherichia coli in nutrient broth. When Staphylococcus aureus suspension was treated with $0.5\%$ sodium polyphosphate at $35^{\circ}C$ for 1 hour, the release of UV-absorbing substances from the organism was confirmed. However no significant effect was observed in Escherichia coli under the similar condition. When alaska pollack fillets were dipped in $ 3.5\%$ sodium polyphospahate at $2^{\circ}C$ for 1 min. prior to freezing, the viable cell count and coliform MPN's of the frozen product were decreased with the range of 30 to $50\%$ in comparison with those of control.

• Korean journal of food and cookery science
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• v.32 no.6
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• pp.762-772
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• 2016

Purpose: Adolescence is a critical period for growth and development; hence, knowledge about good food habits is essential amongst children. This study was conducted to investigate prevalence of awareness among food sellers, which could probably influence children's health and perceptions on food around schools towards adulterated food management beliefs, competencies, and food safety practices. Methods: Data was collected from 195 dealers around 25 elementary, middle and high schools in Daegu and Gyeongbuk provinces using a self-administered questionnaire in July and August, 2015. The data was analyzed using frequency analysis, one-way analysis of variance, $x^2$-test, factor analysis, and reliability analysis by SPSS Statistics (ver. 23.0). Results: A total of 121 people (62.1%) reported satisfaction of providing information and education on adulterated food. The perception of hazardous substances was found to be related to food poisoning bacteria and viruses (65.6%), heavy metals (42.1%), environmental hormones (36.4%), residual pesticides (27.2%), and irradiated food (26.7%). The perceived score on hygiene practices for processed food seller was $4.04{\pm}0.56/5.00$ and for cooked food seller was $4.09{\pm}0.45$. The capacity of adulterated food management practice of food sellers was significantly correlated with food knowledge on adulteration and public relation capacity, necessity of adulterated food management, and perception of hygiene practices (p<0.01). Similarly, knowledge and public relation capacity were significantly different according to ages (p<0.01). The perception of the necessity of adulterated food management was significantly different according to education levels (p<0.05), and the evaluation of hygiene practices was significantly different according to age (p<0.01). Conclusion: In order to solve the problem of adulterated food, which is one of the four social evils, and to strengthen the capacity of children to solve social problems, various practices like campaign on health promotion, goof food habits, education, and adulterated food management, should be actively promoted not only for children but also for food sellers around the schools.

• Journal of Food Hygiene and Safety
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• v.37 no.4
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• pp.232-237
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• 2022

The present study investigated the bactericidal effects of chlorine dioxide (CD) and electrolyzed water (EW) on pathogenic bacteria, such as Bacillus cereus, Staphylococcus aureus, Salmonella Typhimurium, and Escherichia coli O157:H7, by treatment them with CD and EW, respectively, for 0, 2, 4, 6, 8, and 10 min. Additionally, the sensitivities of Gram-positive (B. cereus and S. aureus) and Gram-negative (S. Typhimurium and E. coli O157:H7) to CD and EW were compared, respectively. In CD, the D-values for B. cereus, S. aureus, S. Typhimurium, and E. coli O157:H7 were 1.85±0.64, 2.06±0.85, 2.26±0.89, and 2.59±0.40 min, respectively. In EW, the D-values for B. cereus, S. aureus, S. Typhimurium, and E. coli O157:H7 were 2.13±0.32, 1.64±0.64, 1.71±0.32, and 1.86±0.36 min, respectively. All strains decreased consistently for 10 min in both CD and EW. However, the D-values of each bacterial species did not differ significantly between CD and EW (P>0.05). When comparing the bactericidal effect of CD and EW, no difference in D-value was observed, even though the pH and available chlorine concentration of CD were significantly lower than those of EW. These data could be used for the application of CD and EW in the food industry, considering characteristics such as the selection of optimal disinfectants, determination of optimal concentrations, and sensitivity to disinfection targets.

• Journal of Dairy Science and Biotechnology
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• v.35 no.1
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• pp.55-72
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• 2017

The second article of 'Effects of heat treatment on the nutritional quality of milk,' titled 'Destruction of microorganisms in milk by heat treatment' and authored by Dr. Seong Kwan Cha, who worked at the Korea Food Research Institute, covers the heat-stable microorganisms that exist in milk after pasteurization. The article focusses on the microbiological quality of raw milk and market milk following heat treatment, and is divided into four sub-topics: microbiological quality of raw milk, survey and measurement of microorganisms killed in raw milk, effect on psychrophilic and mesophilic microorganisms, and effect of heat treatment methods on thermoduric microorganisms. Bacillus spp. and Clostridium spp. are sporeforming gram-positive organisms commonly found in soil, vegetables, grains, and raw and pasteurized milk that can survive most food processing methods. Since spores cannot be inactivated by LTLT (low temperature long time) or HTST (high temperature short time) milk pasteurization methods, they are often responsible for food poisoning. However, UHT (ultra high temperature) processing completely kills the spores in raw milk by heating it to temperatures above $130^{\circ}C$ for a few seconds, and thus, the UHT method is popularly used for milk processing worldwide.

• Journal of environmental and Sanitary engineering
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• v.20 no.1 s.55
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• pp.12-22
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• 2005

This study was performed to survey distribution of microorganisms and food-borne pathogenic bacterium in order to estimate microbiological safety in seonsik and saengsik. Total aerobic bacteria was detected over $10^5\;CFU/g$ in raw materials($4.3\%$) and products($35.7\%$) of saengsik. Coliforms were detected over $10^2\;CFU/g$ in seonsik products($27.3\%$) and in raw materials($4.3\%$) and products($35.7\%$) of saengsik. Cl. perfringens was detected in saengsik products($4.8\%$). B. cereus was detected in raw materials($12.5\%$) and products($18.2\%$) of seonsik and raw materials($13.0\%$) and products($23.8\%$) of saengsik. Concentration and detection rate of microorganisms in products were higher than raw materials. These results show some food hygiene problems but do not cause food poisoning because concentration of Clostridium perfringens and B. cereus were lower than $10^5\;CFU/g$.

• Journal of Environmental Science International
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• v.22 no.12
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• pp.1625-1631
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• 2013

In manufacturing of flatfish skin collagen peptide (FSCP) and flatfish protein hydrolysate (FPH) by reuse of dead flatfish from fish farm in Jeju island, the industrial process was optimized with the laboratory scale research and the on-field process. Segmented unit processes from raw material incoming to shipment were established to produce commercial product of FSCP and FPH. Total plate counts of FSCP were twenty five times of FPH, but food poisoning bacteria were not detected in two samples. FSCP and FPH were safe from heavy metal such as Pb(II), Cd(II) and Hg(II). The residual contents of antibiotics and disinfection matter in FSCP and FPH were not detected. The optimized process for mass production made the one-third of the running time and two times of the yield. From economic analysis, the production cost was estimated to 22,000 and 12,000 won/kg for FSCP and FPH, respectively. Therefore the product from the reuse of dead flatfish was expected to have a considerable competitive price and high added-value functional food material compared with other commercially available fish products.