• Journal of Food Hygiene and Safety
• /
• v.29 no.4
• /
• pp.268-277
• /
• 2014

This study assessed microbiological hazards at postharvest stage of dropwort farms (A, B, C, D, E, F, G, H, I) located in 4 different areas in Korea. The samples were assessed for sanitary indication bacteria (total aerobic bacteria, coliform, and Escherichia coli) and pathogenic bacteria (Escherichia coli O157:H7, Listeria monocytogenes, Staphylococcus aureus and Bacillus cereus). Total aerobic bacteria and coliform in 9 dropwort farms were detected at the levels of 0~7.00 and 0~4.25 log CFU/g, mL, of $100cm^2$. In particular, microbial contamination in worker's hand showed higher than cultivation environment factors. Escherichia coli was detected in several farms of soil, irrigation water, washing water and worker's hand and also, dropwort in these farms was contaminated with E. coli (positive reaction). In case of pathogenic bacteria, B. cereus was detected at the highest levels in soil. S. aureus was detected qualitatively from only one sample of dropwort washed by water. E. coli O157:H7 and L. monocytogenes were not detected. Although dropwort pass through 2 process (trimming and washing), the microbial contamination was not differ significantly before and after which indicates that current washing system was not effect on reduction of microorganism. From these results, the postharvest environment and workers have been considered as cross-contamination factors. Thus, processing equipments and personal hygiene should be managed to reduce the microbial contamination of dropwort. Accordingly management system such as good agricultural practices (GAP) criteria is needed for the safety of dropwort

• Korean Journal of Food Science and Technology
• /
• v.33 no.5
• /
• pp.525-528
• /
• 2001

This study was conducted to estimate the contents of heavy metals in some health foods available on Korean markets. The samples were digested with microwave system, then analyzed using GF-AAS for the contents of lead (Pb), cadmium (Cd) and arsenic (As). The contents of mercury (Hg) were determined using a mercury analyzer. The average values of Hg, Pb, Cd and As in calcium (Ca) health foods were 0.007, 1.08, 0.02 and 0.48 mg/kg respectively. Those values in chitosan health foods were 0.001, 0.36, 0.01 and 0.03 mg/kg respectively. Those values in propolis health foods were 0.013, 4.96, 0.01 and 0.13 mg/kg, respectively. The health foods that contained cow bone powders had the highest lead contents. Based on the variation in lead contents of those products, it could be possible that they might be contaminated through raw materials and/or manufacuring process. Some propolis products were also very high in lead contents. There could be risks for some population, especially the aged who overtake those health foods, to have heavy intake of lead. Therefore, we established the lead standards of 3.0, 2.0 and 5.0mg/kg less than for Ca, chitosan and propolis health foods respectively, based on the Codex method.

• Journal of Food Hygiene and Safety
• /
• v.13 no.4
• /
• pp.441-447
• /
• 1998

This study was performed to investigate the changes of amount of S. typhimurium during cooking processes using pork and japchae (a Korean food which is made from meat, vegetables and noodles), and to support a practical application to develop a hazard analysis critical control point (HACCP) model. The pork was purchased in a retail shop, cut ($0.5\;cm\;{\times}\;10\;cm\;{\times}\;10\;cm$, 25 g), tested for Salmonella contamination (results: negative), inoculated with S. typhimurium ($10^{7}\;CFU/g$), then treated in various conditions related to cooking. Mter thawing for 24 hours in various conditions, the number of S. typhimurium was increased to $10^{10}\;CFU/g$ at a refrigerated temperature ($4~10^{\circ}C$), and to $10^{21}\;CFU/g$ at room temperature ($22~29^{\circ}C$). Mter thawing in a microwave oven for 40 seconds, the number of S. typhimurium increased to $10^{8}\;CFU/g$. During the thawing period, the number of S. typhimurium increased over time. At the refrigerated temperature, the number of the bacteria was $10^{10}\;CFU/g$ after 24 hours, $10^{13}\;CFU/g$ after 48 hours, and $10^{20}\;CFU/g$ after 72 hours. At room temperature the number of bacteria reached $10^{11}\;CFU/g$ in 2 hours, $10^{15}\;CFU/g$ in 4 hours, $10^{16}\;CFU/g$ in 8 hours, $10^{18}\;CFU/g$ in 12 hours, and $10^{21}\;CFU/g$ in 24 hours. Mter cooking in a frying pan (150{\pm}7^{\circ}C$) for 3 minutes, the bacterial count was $10^{16}\;CFU/g$. After cooking in hot water for 20 minutes, the bacterial count was $10^{7}\;CFU/g\;at\;60^{\circ}C,\;10^{6}\;CFU/g\;at\;63^{\circ}C,\;and\;10^{4}\;CFU/g\;at\;65^{\circ}C$. The fried pork was mixed with cooked vegetables, noodles, sesame oil, sesame seeds, and seasonings to make Korean japchae. This process took $10{\pm}2$ minutes. The bacterial count in the japchae increased to $10^{7}\;CFU/g$ from the count of $10^{6}\;CFU/g$ of the fried pork before it was mixed with the other ingredients. These results indicate that the amount of S. typhimurium is effected by various different cooking processes. This study can suggest that pork should be cooked in water at over $65^{\circ}C$ for 20 minutes in order to prevent food poisoning, if the pork is contaminated with S. typhimurium. The presence of S. typhimurium in the raw pork is identified in an HA for japchae, and the primary CCP for japchae is inadequate cooking (cooking method and time/temperature). We need to standardize time-temperature-size and amount of pork in cooking japchae, because pork is usually cooked in ordinary frying pans when we make this food.

• Journal of Food Hygiene and Safety
• /
• v.26 no.4
• /
• pp.417-423
• /
• 2011

Salted Cabbage products purchased from different companies at 4 different districts in South Korea were detected in this study. Cabbage and salt are the main materials for kimchi manufacture. The results of general bacteria contaminated in the samples were $1.4{\times}10^5$, $6.4{\times}10^5$, $1.7{\times}10^7$, $3.6{\times}10^7$ CFU/g in cabbage and $2.7{\times}10^3$ CFU/g in salt, respectively. The results of coliforms were detected as $2.4{\times}10^4$ CFU/g, and there was no Escherichia coli in any sample. Staphylococcus aureus was detected in cabbage as $9.9{\times}10^2$, $8.0{\times}10^1$, and $3.0{\times}10^3$ CFU/g, Bacillus cereus was also found in cabbage as $4.1{\times}10^3$ and $1.0{\times}10^1$ CFU/g. The results of Campylobacter jejuni and Vibrio paraheamolyticus were $2.4{\times}10^6$ and $1.0{\times}10^4$ CFU/g in cabbage, respectively. $1.0{\times}10^3$ CFU/g for Yersinia enterocolitica was determined in salt. In case of Listeria monocytogenes, the results were $1.5{\times}10^1$, $1.1{\times}10^2$, and $4.5{\times}10^1$ CFU/g in cabbage. Total batcteria ranged from $1.4{\times}10^1$ to $4.4{\times}10^5$ CFU/g were detected in salting solution, from $1.5{\times}10^4$ to $1.2{\times}10^8$ CFU/g in dehydrated salted-cabbage, from $9.4{\times}10^4{\sim}1.3{\times}10^8$ CFU/g in minced salted-cabbage. The results of E. coli in samples from different companies were different from one to anther. The results of the contamination of S. aureus and B. cereus showed positive in salting solution and dehydrated salted-cabbage at a portion of companies. V. paraheamolyticus was detected in salting solution. The contamination of Y. enterocolitica ranged from $9.5{\times}10^2$ to $1.8{\times}10^3$ CFU/g in salting solution, from $1.7{\times}10^1$ to $2.7{\times}10^2$ CFU/g in dehydrated salted-cabbage, from $1.2{\times}10^2$ to $1.3{\times}10^8$ CFU/g in minced salted-cabbage. The contamination of L. monocytogenes ranged from $8.0{\times}10^2$ to $1.7{\times}10^4$ CFU/g in salting solution, from $2.8{\times}10^2$ to $1.2{\times}10^4$ CFU/g in dehydrated salted-cabbage. During the manufacture processing of Kim chi, microorganisms were detected in cabbages salted in different concentrations of salt solution at 8%, 10%, 12% and 15% for 5-20 hours. As the results, $3.5{\times}10^5-1.7{\times}10^6$, $3.4{\times}10^5-2.5{\times}10^6$, $5.4{\times}10^5-2.3{\times}10^6$, $4.0{\times}10^5-2.3{\times}10^6$ CFU/g were detected for E. coli in samples at different treatment conditions. $1.9{\times}10^4-4.1{\times}10^4$, $4.1{\times}10^3-2.8{\times}10^4$, $1.5{\times}10^3-7.8{\times}10^3$, $2.2{\times}10^4-6.6{\times}10^4$ CFU/g were detected for S. aureus in samples at different treatment conditions. Salmonella typhimurium was detected in salted cabbage with various salt concentration after salting for 5 hrs, the result ranged from $2.5{\times}10^5$ to $3.8{\times}10^6$ CFU/g, and change of microorganism was the smallest in salted cabbage under the concentration of salting solution at 10% for 15 hours. The cabbage salted in 10% salting solution for 15 hours were washed with water for 2 and 3 times, with chlorine for 3 times, and with acetic acid for 3 times. E. coli was detected in the samples washed with water for 2 and 3 times, washed with chlorine for 3 times. The contamination of S. aureus was $3.0{\times}10^5$ CFU/g in the samples washed with water for 2 times, $5.6{\times}10^3$ CFU/g in the samples washed with acetic acid for 3 times, $3.6{\times}10^5$ CFU/g in the samples washed with water for 3 times and same amount in the samples washed with chlorine for 3 times. According to the results, the contamination of S. aureus was $5.6{\times}10^3$ CFU/g lower in samples washed with chlorine and acetic acid than that in samples washed with water. In case of S. typhimurium, it has been detected in samples washed with water and chlorine, $3.0{\times}10^1$ CFU/g as the lowest concentration among all the samples was measured in the samples washed with acetic acid for 3 times.