• Journal of Microbiology and Biotechnology
• /
• v.33 no.9
• /
• pp.1162-1169
• /
• 2023

16S rRNA short amplicon sequencing-based microbiota profiling has been thought of and suggested as a feasible method to assess food safety. However, even if a comprehensive microbial information can be obtained by microbiota profiling, it would not be necessarily sufficient for all circumstances. To prove this, the feasibility of the most widely used V3-V4 amplicon sequencing method for food safety assessment was examined here. We designed a pathogen (Vibrio parahaemolyticus) contamination and/or V. parahaemolyticus-specific phage treatment model of raw oysters under improper storage temperature and monitored their microbial structure changes. The samples stored at refrigerator temperature (negative control, NC) and those that were stored at room temperature without any treatment (no treatment, NT) were included as control groups. The profiling results revealed that no statistical difference exists between the NT group and the pathogen spiked- and/or phage treated-groups even when the bacterial composition was compared at the possible lowest-rank taxa, family/genus level. In the beta-diversity analysis, all the samples except the NC group formed one distinct cluster. Notably, the samples with pathogen and/or phage addition did not form each cluster even though the enumerated number of V. parahaemolyticus in those samples were extremely different. These discrepant results indicate that the feasibility of 16S rRNA short amplicon sequencing should not be overgeneralized in microbiological safety assessment of food samples, such as raw oyster.

• Journal of Food Hygiene and Safety
• /
• v.29 no.3
• /
• pp.211-216
• /
• 2014

Bacillus cereus was isolated in 155 of 4,318 food samples from 2012 to 2013. Of the isolates, 140 isolates were performed antimicrobial disk test against garlic, cinnamon, ginger, and green tea extracted at two different temperature, $25^{\circ}C$ and $70^{\circ}C$. The isolates from Powdered Red Pepper showed frequently to 48.65%, and followed by Agriculture Products (31.08%) and Kimchi (25.61%). The isolation rate of Cooked Foods in the Restaurant supposed to causing food poison was 1.17%. Analysis of antimicrobial activity showed that $25^{\circ}C$ garlic extract, $25^{\circ}C$ green tea extract, and $70^{\circ}C$ green tea extract resisted against all 140 isolates and the others resisted against some isolates. Antimicrobial activity was depended on the temperature; garlic > green tea > cinnamon in $25^{\circ}C$ and green tea > garlic > cinnamon in $70^{\circ}C$. The correlation analysis of each extracts showed that geen tea extract was different significantly with garlic and cinnamon extracting in $25^{\circ}C$ and with only garlic extracting in $70^{\circ}C$ at p < 0.05.

• Journal of Food Hygiene and Safety
• /
• v.31 no.2
• /
• pp.99-106
• /
• 2016

This study was aimed to assess microbiological contamination level of Liriope platyphylla farms (A, B, and C) located in Cheongyang, Chungnam province. Specimens sampled from those farms and L. platyphylla tuberous roots were assessed for sanitary indication bacteria such as total aerobic bacteria, coliforms, and Escherichia coli and pathogenic bacteria such as Escherichia coli O157:H7, Listeria monocytogenes, Salmonella spp., Staphylococcus aureus and Bacillus cereus, quantitatively and qualitatively. As a result, those farms are not contaminated by E. coli O157:H7, L. monocytogenes, Salmonella spp., at all. And S. aureus was only found qualitatively from workers' gloves at a farm. As a whole, those farms (soil, harvest container, harvester, cleanser, washing water and tray) were maintained in a low level of microbiological contamination. However a cleanser was contaminated by coliforms ($4.35log\;CFU/100cm^2$), and it is required to improve farm hygiene. Microbiological contamination level of L. platyphylla tuberous root was decreased in the postharvest process including washing and drying.

• Culinary science and hospitality research
• /
• v.23 no.6
• /
• pp.20-26
• /
• 2017

To guarantee the safety of rice cake production, the Hazard Analysis Critical Control Points system was applied to the production process. The purpose of this study was to analyze the microbiological hazards of the manufacture of rice cakes, and establish critical limits in the process of the manufacturing rice cakes. To control the microbiological hazards, the sterilization process was set to a critical limit. The process of manufacturing rice cakes can reduce these microbiological hazards during the steaming process. A microorganism test for each specimen was conducted three times and compared with before and after steaming processes. The finished product was conducted by microbiology experiment and the validity of the steaming process was verified. The results were determined to be capable of reducing the biological element of Critical Control Point via the steaming process. Microbiology such as aerobic plate count, coliform, Escherichia coli(E. coli), Listeria monocytogenes, Enterohemorrhagic E. coli, Salmonella spp., Bacillus cereus, Staphylococcus aureus and Clostridium perfringens was evaluated by the experimental method of Korean Food Standards Codex. Aerobic plate count was reduced by steaming process, and no microorganism were detected. All rice cakes in the finished product were judged to be safe for both the Escherichia coli and general bacteria. In conclusion, it suggested that a HACCP plan was necessary for management standard and systematic approach in the establishment of critical limit, problem resolution, verification method, education, and records management. Based on this study, it is intended to provide a baseline for improving quality control standards and improving hygiene levels for small manufacturers.

• 한국포장학회:학술대회논문집
• /
• 2007.04a
• /
• pp.1-38
• /
• 2007

• Food Industry And Nutrition
• /
• v.4 no.3
• /
• pp.48-54
• /
• 1999

• Proceedings of the Korean Sanitation Conference
• /
• 2005.12a
• /
• pp.69-75
• /
• 2005

• Journal of Food Hygiene and Safety
• /
• v.14 no.3
• /
• pp.293-304
• /
• 1999

The purpose of this study was to evaluate the microbiological quality, and to assure the hygienic safety of the food production in the university food service facility located in Seoul in accordance with the Hazard Analysis Critical Control Point(HACCP) concepts. In the hygienic state assessment of kitchen, it has revealed that it was very important to remove water from the kitchen floor and to establish standard method for disinfection of cooking utensils. And foodservice workers were required to have training program for the safe handling of food and utensils since they did treat food without hygienic gloves. The kitchen layout had to be improved because the near distance of table with heating unit and shelf might cause the growth of microorganisms when prepared food was kept on the shelf. In terms of the timetemperature measurement and microbiological quality assessment during each of the food production phases, most of sengchae (raw vegetable dish) and namul (cooked vegetable dish) were treated within danger zone for food safeness ($5~60^{\circ}C$). It has shown that the microbiological quality of raw materials was very much inferior at the time of receiving based on the TPC($10^{5}~10^{7}$), coliform($10^{3}~1O^{6}$), which was not acceptable level(TPC:$10^{6}$, coliform:$10^{3}$) suggested by Solberg. Microbiological growth has increased in the both of sengchae and namul considerably during most of food production phase. Therefore, it is extremely important to reduce holding and serving time and to avoid treating food within the danger zone for food safeness. In addition, the prevention of cross-contamination during mixing the ingredients with improper equipments and with insanitary treatments by workers was also important to keep the food safety in this speciqic university foodservice facility.

• Safe Food
• /
• v.6 no.4
• /
• pp.3-12
• /
• 2011

• Korean Journal of Microbiology
• /
• v.54 no.3
• /
• pp.308-308
• /
• 2018