• Journal of Food Hygiene and Safety
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• v.34 no.4
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• pp.361-366
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• 2019

In this study, microbial contamivation semisulcospira libertine and effect of sedimentation treatment of major bacterial and fungal pathogens were investigated. The total aerobic bacteria, coliforms, Escherichia coli, Staphylococcus aureus, and yeast and mold present in raw and water-dipped Semisulcospira libertine were enumerated using the standard plate count methods on using the standard plate method on potato dextrose agar (PDA), 3M Petrifilm for coliforms / E. coli, 3M Petrifilm for S. aureus, and plate count agar (PCA), respectively. In analysis of microbial contamination of raw Semisulcospira libertine, the total aerobic bacteria, coliforms, and yeast and mold were monitored as 6.40, 2.70, and $6.79{\log}_{10}CFU/g$, respectively. Both E. coli and S. aureus were not detected (detection limit: 10 CFU/g). However, Semisulcospira libertine dipped in ground water for 3 hours had higher contamination levels of all natural indigenous microorganisms than raw Semisulcospira libertine. Especially, E. coli was detected as $2.46{\log}_{10}CFU/g$ in the ground water-dipped Semisulcospira libertine. The total aerobic bacteria in the ground water-dipped Semisulcospira libertine was not significantly reduced (p>0.05) compared to that in the raw Semisulcospira libertine. Moreover, coliforms were significantly increased (p>0.05) in all water-dipped Semisulcospira libertine. Only fungi were slightly reduced (less than 0.2 log) (p>0.05) in the tap water-dipped Semisulcospira libertine by comparison with the raw Semisulcospira libertine. The results of this study suggest that the use of chemical sterilizing agents and other physical methods in the washing stage will be necessary for the microbial reduction in raw Semisulcospira libertine because the use of sediment removal treatment by ground or tap water did not affect the microbiological safety of the raw Semisulcospira libertine.

• Food Science of Animal Resources
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• v.18 no.4
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• pp.301-306
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• 1998

Four low fat ground beef groups containing 10% fat plus 0, 5, 10 and 20% additional cooked lod rice and a control ground beef containing 30% fat were prepared and the analysis for microbiological and oxidative stability were conducted. During 6 days of storage at 4$^{\circ}C$ microbial analysis including total plate count and coliform groups were performed and 2-thiobarbituric acid reactive substance (TBARS) absorbances were measured. The growth rate of total aerobic bacteria and coliform groups tended to increase with the increase in fat content and the amount of added cooked lod rice. Development of oxidative rancidity were not significantly different between 10 and 30% fat ground beef but among the 10% ground beef the rancidity development significantly(p<05) decreased with the in-crease in the amount of added cooked old rice. Low fat ground beef groups were not stable over 3 days during storage at 4$^{\circ}C$.

• Food Science of Animal Resources
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• v.42 no.4
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• pp.639-654
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• 2022

The current study investigated the effects of the most suitable modified atmosphere packaging (MAP) on the physicochemical, microbiological, and sensory properties of fermented dry sausages during 45 days of refrigeration (4℃) storage period. Treatments were vacuum-packed (control), 25% CO₂/75% N₂ (MAP1), 50% CO₂/50% N₂ (MAP2), 70% CO₂/30% N₂ (MAP3), and 100% CO₂ (MAP4). All MAP samples regardless of their CO₂ composition significantly (p<0.05) decreased in pH, a_w, total plate count, and lactic acid bacteria count values as compared to the vacuum-package during storage. The Enterobacteriaceae count in all MAP packaging was significantly (p<0.05) lower than the vacuum-packed samples and counts in MAP3 and MAP4 samples were markedly (p<0.05) lower than all other treatments in prolonged storage of 15 and 45 days. Based on the thiobarbituric acid reactive substance content at day 15 and 30 storage time, treatments are ranked as follows: Vacuum-packed>MAP1>MAP2>MAP3>MAP4. The a^* of MAP4 was higher than all other treatments. In the final storage days, no variation was exhibited (p>0.05) among treatments in lactic acid aroma and sourness, and MAP2 samples had the lowest (p<0.05) overall acceptability. The use of MAPs with an increase in the CO₂ from MAP1 to MAP4 samples can help in better microbial inhibition than vacuum package, and 70% CO₂/30% N₂ (MAP3) and 100% CO₂ (MAP4) were effective to maintain several quality parameters (a_w, pH, microbial inhibition, stability against lipid oxidation, and instrumental color traits) and extend the shelf life of dry fermented sausage.

• Korean Journal of Microbiology
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• v.43 no.3
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• pp.201-209
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• 2007

The CFDA (6-carboxyfluorescein diacetate) direct viable count method and plate count (PC) method using conventional nutrient broth (NB) medium and $10^{-2}$ diluted NB (DNB) medium were applied to samples collected from Mt. Yongdoo In Andong, in an effect to determine the number of living bacteria pine mushroom forest soil. The number of living bacteria determined via plate count in NB medium comprised $5{\sim}8%$ of the CFDA direct viable count, and the bacteria in the DNB medium comprised $40{\sim}47%$. This result indicated that viable but nonculturable (VBNC) bacteria existed in the pine mushroom forest soil at a high percentage. The phylogenetic characteristics of the VBNC bacterial populations in the samples of pine mushroom (Tricholoma matsutake) forest soil were analyzed via the direct extraction of DNA and 16S rDNA-ARDRA. The 115 clones from pine mushroom forest soil were clustered into 31 different RFLP phylotypes by ARDRA. Based on the 16S rDNA sequences, the 31 ARDRA clusters were classified into 6 phylogenetic groups: ${\alpha}-,\;{\beta}-,\;{\gamma}-Proteobacteria$, Acidobacteria, Actinobacteria and Firmicutes. Among these bacterial populations, approximately 85% were classified as members of phylum Acidobacteria. The Acidobacteria phylum was shown to exist abundantly in the pine mushroom forest soil.

• Journal of Environmental Health Sciences
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• v.32 no.4 s.91
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• pp.316-323
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• 2006

This study was performed to assess the microbial contamination level for the processing of sandwich products in the middle of Gyeongnam province from December 2004 to January 2005. A total of 85 samples were collected from 5 sandwich shops. These samples were tested sanitary indication bacteria, such as aerobic Plate count(APC), coliforms, and Escherchia coli and pathogenic bacteria such as Escherichia coli O157:H7, Salmonella spp., Listeria monocytogenes, and Staphylococcus aureus. As a result of APC and coliform count ranged 0-4.59 $log_{10}$ CFU/(ml, g, 100 $cm^2$, hand) and 0-3.86 $log_{10}$ CFU/(ml, g, 100 $cm^2$, hand), respectively. Especially, the highly contaminated items for APC were confirmed 1.64-4.59 $log_{10}$ CFU/g to employees', raw materials and sandwich in all items. Escherichia coli was isolated from 5 samples. Listeria monocytogenes and Staphylococcus aureus were detected in 1 sample and 11 samples from utensil, raw materials and sandwiches, respectively. However, Escherichia coli O157:H7 and Salmonella spp. were not detected in anywhere. For the production of safety sandwich, education of sanitation for employees, control of raw materials, and continuous monitoring for microorganism will be required.

• Food Science and Preservation
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• v.19 no.1
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• pp.62-66
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• 2012

With the rapid growth of fresh-cut produce market, the South Korean fresh-cut industry is facing the challenge of ensuring food safety. As the estimation of the microbial numbers in fresh-cut produce processing lines (tools, and equipment) using the conventional microbiological techniques takes days, so there is a need for faster and easier monitoring methods. This study was conducted to investigate the use of ATP bioluminescence assay to measure the degree of microbial contamination from three actual fresh-cut processing lines. The samples collected from frech-cut vegetables, and fresh-cut fruits processing plants were tested for the estimation of the bacterial number, using the ATP bioluminescence and microbiological methods. The result of former was transferred to log RLU/100 $cm^2$, and that of the latter was transferred to log CFU/100 $cm^2$. A positive linear correlation between the ATP bioluminescence assay value and aerobic-plate count was found for fresh-cut processing lines, with a correlation coefficient of 0.8772 (n=50). The results of this study indicate that ATP bioluminescence assay can be used to monitor microbial contamination in fresh-cut produce processing plants, and can help improve the hygiene therein.

• Environmental Engineering Research
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• v.22 no.1
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• pp.55-60
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• 2017

Provision of safe, accessible, and good water quality in the community is an important step towards reducing various waterborne illnesses. However, improving the quality of water should include spreading awareness to the public regarding the importance of cleaning their household water tanks. The aim of this study was to investigate the microbial quality of water of household water tanks in Dubai. The water samples from household water tanks were collected from forty houses, and a questionnaire was given to the residents to determine the history of the water tanks. The membrane filtration technique was used to quantify heterotrophic and total coliform bacteria on plate count agar and the violet red bile agar respectively. The overall results of this study have shown that 18 out of total 40 household water tanks contained different types of bacteria concentration level beyond local and widely accepted international standards. The overall results of this study indicated that there is a lack of awareness among residents regarding the importance of maintaining proper sanitation and hygiene of the household water tanks.

• Journal of Life Science
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• v.19 no.6
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• pp.751-755
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• 2009

This study was attempted to provide basic data for effective sanitization of sprouts. Sanitization treatments were performed by dipping four sprouts (alfalfa, broccoli, clover and red radish) into chlorine water. Microbial analyses were composed of the total plate count (TPC), coliform count, and E. coli count. All examined sprouts exhibited high levels of TPC ($10^{7}$ CFU/g) and coliform ($10^{6}$ CFU/g). E. coli was detected in broccoli and red radish sprouts in the range of $10^3{\sim}10^4$ CFU/g. Among chlorine water sanitization, the microbial reduction was largest in 100 ppm chlorine water, and its TPC and coliform counts decreased to $8.0{\times}10^5{\sim}2.7{\times}10^6$ CFU/g and $4.3{\times}10^5{\sim}4.6{\times}10^5$ CFU/g, respectively. E. coli was not detected in all sprouts that were given 100 ppm chlorine water treatment. The effective dipping time in 100 ppm chlorine water treatment was 30 min and 60 min, in which TPC were below the microbiological safety limits of ${\times}10^{6}$ CFU/g. Coliform counts were decreased to $9.1{\times}10^4{\sim}2.4{\times}10^5$ CFU/g when the sprouts were dipped for 30min, and kept the similar level after that time. These levels exceeded the microbiological safety limits of $10^{3}$ CFU/g. E. coli was not detected in samples by 100 ppm chlorine water treatment.

• Korean Journal of Food Science and Technology
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• v.31 no.5
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• pp.1196-1202
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• 1999

This work was to determine the microbial and physico-chemical changes of HTST-pasteurized soymilk using microwave energy. Soymilk was HTST pasteurized$(at\;90^{\circ}C\;for\;20\;sec)$ by three methods: by heating in a stainless steel tube immersed in a hot water bath(MP0), by heating in a microwave cavity to a defiled temperature and then holding in a hot water bath(MP1), and by both heating and holding in a microwave cavity(MP2). The microbial quality based on the total plate count was in the order of MP0, MP2 and MP1. The three samples pasteurized by different methods showed the similar microbial quality with respect to the coliform count, psychrotrophic bacterial count and phosphatase activity. The destruction of trypsin inhibitor was in the order of MP0, MP1 and MP2. There were no significant differences in pH, titratable acidity, viscosity and vitamin $B_2$ content before and after pasteurization and among the different pasteurization methods. The similar or higher quality retention of the MP1 or MP2 supports the possibility of using microwave energy for the HTST pasteurization of soymilk and other fluid food products.

• Journal of Nutrition and Health
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• v.37 no.8
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• pp.712-721
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• 2004

The objective of this study was to evaluate the microbiological quality of heating and after-heating processed foods for implementation of a HACCP system in day-care center foodservice operations. The evaluating points were microbial assessment and temperature of foods during receiving, cooking, and serving in heating process. In non-heating process, in addition to monitoring microbial assessment of food during preparation, cooking, and serving steps, the microbial populations of employees' hands and utensils and serving temperature were also evaluated. Microbiological quality was assessed using 3M Petrifilm$^{TM}$ to measure total plate count and coliforms for foods and utensils and Staphylococcus aureus for hands in five Gumi day-care centers. Microbiological quality assessment for foods and utensils is summarized as follows. Microbiological quality of the heating processed foods was satisfactory for cooking and serving steps. The internal temperature of food was above 74$^{\circ}C$. However, temperature control before the serving step was not achieved due to inappropriate time management between the cooking and serving steps. In the after-heating process, the total plate counts of boiled mungbean sprouts salad, blanched spinach salad, com vegetable salad were below the standard at the serving step. The majority of samples showed that coliforms exceeded the norm, which is thought to be the result of the cross-contamination from utensils. These results suggest that it is essential to educate employees on the importance of hand washing and of avoiding cross-contamination by using clean, sanitized equipment to serve food in the after-heating process. Establishing Sanitation Standard Operating Procedures (SSOPs) is an essential part of any HACCP system in day-care center foodservice operations.