• Food Science and Preservation
• /
• v.15 no.4
• /
• pp.606-611
• /
• 2008

Myungran Jeotkal, Korean fermented seafood, and its ingredients(hot red pepper powder, ginger, garlic, and seasoning mix) were irradiated with 0, 0.5, 1.0, 2.0, and 5.0 kGy of gamma rays and stored at 4C for 4 weeks to determine changes in microbiological and sensory characteristics. Water activities of Myungran Jeotkal, hot red pepper powder, ginger, garlic, and seasoning mix were 0.89 0.56, 0.98, 0.99, and 0.07, respectively. Myungran Jeotkal was observed to be initially contaminated. Total aerobic bacteria, yeast and mold, and coliform levels were 6.7, 4.3, and 3.6 log CFU/g, respectively. Irradiation at 2 kGy afforded approximately a 4 log reduction in total aerobic bacteria, and a 3 log drop in both yeast and mold levels and coliform bacteria(P<0.05). No viable microbial cells were detected in Myungran Jeotkal after 5 kGy of irradiation(at a detection limit of 101 CFU/g). The total aerobic bacterial level in red pepper powder was 6.3 log CFU/g and this component, of the tested ingredients, contributed most to the microbial contamination of Myungran Jeotkal. The initial count of total aerobic bacteria, 6.3 log CFU/g, was significantly reduced to 4.5 log CFU/g after irradiation(P<0.05). Sensory evaluation showed that gamma irradiation of up to 5.0 kGy did not adversely affect overall acceptability of Myungran Jeotkal or its ingredients during cold storage. Therefore, gamma irradiationwas effective to extend the shelf-life of Myungran Jeotkal.

• Journal of Food Hygiene and Safety
• /
• v.30 no.2
• /
• pp.178-188
• /
• 2015

Microbial quality of baked egg products was evaluated by counting the levels of sanitary indicative bacteria (aerobic plate counts, coliforms, and E. coli), L. monocytogenes and Salmonella spp. at the critical control points (CCPs) of manufacturing process. In addition, the survival and growth of foodborne pathogens in various egg products (cheese, tuna, tteokgalbi, pizza omelets, baked egg, and steamed egg) were investigated at 4, 10, and $15^{\circ}C$. The contamination level of aerobic plate counts decreased from 4.67 log CFU/g at CCP 1 to 0.56 log CFU/g at CCP 3 in baked egg products. No coliforms and E. coli were detected at all CCPs. Although L. innocua and Salmonella spp. were identified at CCP 1, no L. monocytogenes and Salmonella spp. were detected in the final products. The contamination levels of aerobic plate counts and coliforms in egg strips and number of aerobic plate counts in Tteokgalbi omelet are higher than the microbiological standard of processed egg products. At $10^{\circ}C$, the growth of all pathogens was not prevented in omelet and baked egg, but the populations of S. Typhimurium and E. coli were reduced in steamed egg at $10^{\circ}C$, regardless of the presence of other pathogens. The growth of L. monocytogenes was faster than that of S. Typhimurium and E. coli in omelet. More rapid growth of S. Enteritidis than S. Typhimurium was observed in egg products, indicating the greater risk of S. Enteritidis than S. Typhimurium in egg products.

• Journal of Food Hygiene and Safety
• /
• v.30 no.4
• /
• pp.350-358
• /
• 2015

This study was designed to evaluate the sanitary characteristics of sea water in a part of the south coast, Korea and to check the seawater which is in compliance with the recommended bacteriological criteria for shellfish cultivation. The samples of sea water were collected at 14 sampling stations established in the survey area between March 2014 and October 2014. Food poisoning caused by seafood consumption is often associated with pathogenic microorganisms originated from fecal contamination. Therefore, fecal coliform is very important criteria for evaluating the safety of fisheries in coastal areas. The range of geometric mean (GM) and the estimated 90th percentile values of total coliform were 4.1~83.1 MPN/100 mL, and 11.7~834.1 MPN/100 mL, respectively. The GM and the estimated 90th percentile values of fecal coliform were 2.5~22.7 MPN/100 mL and 2.5~170.0 MPN/100 mL, respectively. Therefore, the bacteriological safety of seawater at this shellfish-growing area met with the Korean Shellfish Sanitation Program (KSSP) criteria for a growing area. However, the values are seasonally exceed the KSSP criteria, suggesting that the monitoring and evaluation of seawater quality is very important in shellfish-growing area.

• Food Engineering Progress
• /
• v.14 no.4
• /
• pp.316-321
• /
• 2010

The efficacy of the ozonated water (0.1, 0.2, 0.4, 0.6, and 1.0 ppm) in reducing the risk of food-borne disease was investigated in this study. After inoculation of Listeria monocytogenes (ATCC 19112), Salmonella enterica subsp. enterica biovar Typhimurium (ATCC 12598), Escherichia coli O157:H7 (ATCC 43890) to lettuce, spinach, and beef, inhibition effect with different washing concentrations, time, and methods with ozonated and tap water were evaluated. As a result, there were 2.16 to 3.85 log CFU/mL reduction in different foods and 7 log CFU/mL reduction on cutting boards after watering with ozonated water. Higher than 0.2 ppm of ozonated water treatment reduced the growth of food-borne disease bacteria with increasing washing time and ozone concentration. These results suggested that the ozonated water treatment effectively improved the microbiological quality and food safety.

• Journal of Korean Society of Environmental Engineers
• /
• v.32 no.7
• /
• pp.722-729
• /
• 2010

Over the last decades, much consideration has been given to microbiological and chemical risks, especially when wastewater was reclaimed as water resources for urban water, irrigation water and recreational water etc. We investigated the performance of UV-based processes such as UV and UV/$H_2O_2$ for both the removal of pharmaceuticals and personal care products (PPCPs) as an emerging chemical and the inactivation of pathogen with bench-scale experimental study. 38 kinds of PPCPs including antibiotics and analgesics were detected from secondary effluent used as tested water. Bench-scale experimental study showed that UV process would require considerable UV dose for the effective PPCPs removal. Contrarily, PPCPs removal efficiency significantly improved by the combination of $H_2O_2$ with UV even at a lower UV dose and, moreover, their removal efficiency increased with the increased initial $H_2O_2$ concentration. Besides naproxen (>89%), concentrations of all the investigated PPCPs decreased by more than 90% of their initial concentrations under $923\;mJ/cm^3$ of UV dose and 6.2 mg/L of $H_2O_2$. Previous studies showed that this operational condition could get 4~5 log inactivation for Total coliform, indicating that UV/$H_2O_2$ process will be appropriate to comply with the criteria of California Title 22 for Total coliform.

• Journal of Food Hygiene and Safety
• /
• v.10 no.2
• /
• pp.111-131
• /
• 1995

Quality changes of sausages in refrierated storage for 60 days were investigated. Nine types of sausages produced in Korea were stored at 4$^{\circ}C$(3~5$^{\circ}C$), and then chemical, microbiological, and sensory characteristics were evaluated on every 10 days. The proximate analysis showed considerable variation in fat (23.97%, 17.10~30.20%) with less variation in moisture (51.96%, 48.10~56.30%) and protein (12.96%, 11.40~13.95%), pH value decreased over time averaging from 6.31 to 6.22 with no significant difference. Water activity was consistent over refrigerated storage averaging 0.95. Volatile basic nitrogen (VBN) values were still within 20 mg% though VBN for all types significantly increased over time (p<0.05). Thiobarbituric acid (TBA) values were well below 1.0 though TBA showed significant differences among storage periods (p<0.05). Standard plate counts (SPCs) significantly increased during storage (p<0.05) while coliform group was not counted in all cases. SPCs reached 104 CFU/g in two types after 50 days' storage and were below 105 CFU/g in all types after 60 days' storage. Instrumental texture analysis showed that springiness, adhesiveness, and hardness signficantly decreased over time (p<0.05) while no change was observed in external color. significantly decreased over time the 60-day storage period (p<0.05) while cohesiveness, chewiness and gumminess did not change. Lightness, redness and yellowness of the internal Hunter color significantly decreased over time (p<0.05) while no change was observed in external color. Sensory profile showed that flavor, taste, texture and overall acceptable after 60 days' storage at 4$^{\circ}C$. However, the shelf-life of the samples should be decided in the consideration of the growth rate other spoilage flora coupled with the bacterial growth after 50 days' storage.

• Journal of Food Hygiene and Safety
• /
• v.24 no.4
• /
• pp.348-351
• /
• 2009

This study was designed to estimate the effect of ethanol addition on shelf-life extension and changes in growth of total aerobic bacteria in fresh wet noodles. The wet noodle was made with addition of 0, 1 and 2% ethanol. During the storage at $10^{\circ}C$, wet noodles were monitored changes in the total numbers of aerobic bacteria. A 6 log cfu/g was applied as a standard for microbiological quality of foods. As a result, the shelf-lifes of wet noodle with addition of ethanol at the standard were 9.17 days at no ethanol, 15.02 days at 1% ethanol and 27.03 days at 2% ethanol. The respective percentage increases in the shelf-life observed at both 1 and 2% ethanol addition were 63.8% and 194.8% comparing with no ethanol treatment. Consequently, addition of ethanol into fresh wet noodle inhibited growth of total aerobic bacteria and extended shelf-life.

• Journal of agriculture & life science
• /
• v.50 no.4
• /
• pp.169-177
• /
• 2016

This study was carried out to compare microbiological and hygienic quality characteristics of the products reached expiration date among meat products distributing in markets. A total of 20 meat products(6 hams, 3 bacons and 11 sausages) were examined for analyses of pH, Aw, TBARS, VBN, total aerobic microbial counts, and meat colors. The pH values of samples were between 5.33 and 6.59. The water activity (Aw) of samples ranged 0.90-0.93. TBARS and VBN values of samples were 0.11-0.59 and 2.37~14.75, respectively. The contaminated levels of total aerobic bacteria were less than 2.80 CFU/g. In meat color, L*, a*, and b* values of samples were in the range of 56-72, 5.2-34 and 0.7-16, respectively. It is suggested that the quality difference of meat products is attributed to the different additives and manufacturing processes. Therefore, we suggest that the results of this study are not only applied for evaluation of the microbiological and hygienic safety but also served as fundamental information for re-establishing the shelf-life of meat products.

• Korean Journal of Soil Science and Fertilizer
• /
• v.45 no.4
• /
• pp.560-564
• /
• 2012

This study was undertaken to assess the microbiological quality and prevalence of pathogens in organic vegetables produced in Korea. A total of 189 organically grown vegetable samples (perilla leaf 50, lettuce 50, tomato 39, cucumber 50) were analyzed for the presence of aerobic plate count, Escherichia coli O157:H7, Salmonella spp., Staphylococcus aureus, Listeria monocytogenes, and Yersinia enterocolitica. The total aerobic plate counts were in the range of 4.2 to $7.7log\;CFU\;g^{-1}$ for perilla leaf, 5.0 to $8.0log\;CFU\;g^{-1}$ for lettuce, 4.0 to $7.5log\;CFU\;g^{-1}$ for tomato, and 6.6 to $8.6log\;CFU\;g^{-1}$ for cucumber. The highest counts were found in cucumber. E. coli O157:H7, Salmonella spp., S. aureus, L. monocytogenes, and Y. enterocolitica were not detected from any organically grown vegetable samples. This research suggests that continuous monitoring in organic vegetables is required to improve fresh produce safety.

• Animal Bioscience
• /
• v.36 no.10
• /
• pp.1596-1603
• /
• 2023

Objective: Sous-vide cooking offers several advantages for poultry meat, including enhanced tenderness, reduced cooking loss, and improved product yield. However, in duck meat, there are challenges associated with using the sous-vide method. The prolonged cooking time at low temperatures can lead to unstable microbial and oxidative stabilities. Thus, we aimed to assess how varying sous-vide cooking temperatures and durations affect the physicochemical and microbial characteristics of duck breast meat, with the goal of identifying an optimal cooking condition. Methods: Duck breast meat (Anas platyrhynchos) aged 42 days and with an average weight of 1,400±50 g, underwent cooking under various conditions (ranging from 50℃ to 80℃) for either 60 or 180 min. Then, physicochemical, microbial, and microstructural properties of the cooked duck breast meat were assessed. Results: Different cooking conditions affected the quality attributes of the meat. The cooking loss, lightness, yellowness, Hue angle, whiteness, and thiobarbituric acid reactive substance (TBARS) values of the duck breast meat increased with the increase in cooking temperature and time. In contrast, the redness and chroma values decreased with the increase in cooking temperature and time. Cooking of samples higher than 60℃ increased the volatile basic nitrogen contents and TBARS. Microbial analysis revealed the presence of Escherichia coli and Coliform only in the samples cooked at 50℃ and raw meat. Cooking at lower temperature and shorter time increased the tenderness of the meat. Microstructure analysis showed that the contraction of myofibrils and meat density increased upon increasing the cooking temperature and time. Conclusion: Our data indicate that the optimal sous-vide method for duck breast meat was cooking at 60℃ for 60 min. This temperature and time conditions showed good texture properties and microbial stability, and low level of TBARS of the duck breast meat.