• Journal of Food Hygiene and Safety
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• v.33 no.5
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• pp.325-329
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• 2018

This study developed a rapid detection method for Bacillus cereus in fresh-cut cabbages. Fresh-cut cabbage samples were inoculated at 1-, 2- and 3-Log CFU/g, and pathogens were enriched in tryptic soy broth containing 0.15% polymyxin B at $30^{\circ}C$, $37^{\circ}C$, and $42^{\circ}C$ to determine the detection limit and appropriate enrichment temperature for multiplex PCR detection. Enriched bacterial cells in enrichment broth were collected in a hydrophobic filter prior to DNA extraction for multiplex PCR. Filters were resuspended in distilled water, and DNA was extracted from the suspension. DNA samples were further analyzed by multiplex PCR. Detection limit of multiplex PCR was 5-Log CFU/mL. B. cereus cell counts were higher (P < 0.05) at $42^{\circ}C$ than other temperatures. Detection rate of 1-, 2-, and 3-Log CFU/g inoculated samples were 60%, 80%, and 100% after enrichment respectively. However, when enriched samples were filtered with hydrophobic membrane filter, detection rates became 100%, regardless of inoculation level. Results indicate a combination of enrichment with hydrophobic filtration improves rapid detection efficiency of B. cereus in fresh-cut cabbage by multiplex PCR.

• Food Science and Preservation
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• v.21 no.5
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• pp.676-687
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• 2014

This study investigated the quality changes in cabbage brined with deep sea water salt and in a commercial brined cabbage product. The subject cabbages were separated into two groups: those manufactured in the Lab (ML) and the commercial brined cabbage product (CP). Each group had three brining treatments: with sun-dried salt (S, CS), refined salt (R, CR), and deep sea water salt (D, CD). The salinity level of the ML group was 2.1~2.3%, higher than that of the CP group (1.1~1.5%). The total plate count (TPC) was detected as 5.0 log CFU/g with the S, R, and D treatments at Day 7, but the growth rate of the TPC with the CS, CR, and CD treatments was faster than that with the S, R, and D treatments (6.9~7.7 log CFU/g). A lactic acid bacteria (LAB) level of 5.0~6.6 log CFU/g was also detected in the S, R, and D samples, but only 7.0~7.6 log CFU/g was detected in the CP groups at Day 14. The instrumental hardness levels of the cabbage brined with the deep sea water salts (D and CD) were 3,971 g and 3,932.4 g, respectively, which were significantly higher than those of the samples that were salted with sun-dried salt and refined salt (p<0.05). As for the sensory attributes, S, D, and CD maintained their marketability scores until the end of the storage period for all the properties. CD presented the highest total free amino acid (478.9 mg%), glutamic acid (107.0 mg%), citric acid (428 mg%), and sodium (189 ppm) contents.

• Food Science and Preservation
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• v.24 no.1
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• pp.36-43
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• 2017

The aim of this study was to provide the quality index of salted Korean cabbage in a short-term distribution system. Salted Korean cabbages were packaged with or without 2% salt water, and then distributed in a conventional system (CVS) and a cold-chain system (CCS) for 6 h. The material temperature of samples with and without salt water gradually increased to $19.57^{\circ}C$ and $19.43^{\circ}C$ in a CVS, respectively and to $10.73^{\circ}C$ and $12.90^{\circ}C$ in a CCS, respectively. Salinity of the materials in a CCS did not change, whereas salinities of the materials in a CVS were 1.2 and 1.7 fold higher, respectively. Also, a slight increase in acidity was observed in both packaging materials in a CCS. In the case of a CVS, total aerobic bacteria and lactic acid bacteria increased to 7.62 log CFU/g and 6.77 log CFU/g in the materials with salt water, respectively, whereas the number of total aerobic bacteria and lactic acid bacteria ranged between 5.62-5.85 log CFU/g and 4.33-4.83 log CFU/g in the materials without salt water, respectively. However, significant microbial changes were not observed in a CCS as distribution time increased. CCS with salt water packaging was effective in achieving microbial control and maintaining physicochemical quality. Salinity, aerobic bacteria, and lactic acid bacteria can be useful as quality indices for a CVS, and acidity can be useful as quality index for a CCS.

• Korean Journal of Food Science and Technology
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• v.50 no.1
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• pp.28-36
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• 2018

Studies on suspected endocrine disrupting pesticide (EDP) residues in agricultural products were carried out in 2016 in Busan, Korea. Twelve different EDPs, ranging in concentration between 0.003-2.049 mg/kg, were detected in 19.5% of 462 samples. About 0.2% of agricultural product samples exceeded the maximum residue limits (MRLs). Risk indices of all of the EDPs were less than 10% of the acceptable daily intake (ADI). The outcomes indicated that the risk groups at highest risk of exposure to diazinon (found in Korean cabbages) and carbendazim (found in apples) were females aged 40 to 49 and young males less than 10 years old, respectively. Based on the stochastic assessment at $95^{th}$ percentile (P95), risk index in these risk groups accounted for 8.38 and 2.98% of ADIs. The results showed that the occurrence of EDP residues in agricultural products could not be considered a public health problem.

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