• Journal of Applied Biological Chemistry
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• v.61 no.4
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• pp.391-395
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• 2018

There is an increasing concern over arsenic (As) contamination of paddy soil and rice with regard to food safety. This study was conducted to investigate total and inorganic As concentration in one hundred husked and polished rice samples collected at the non-contaminated paddy soil in Korea. Arsenic species in rice samples were extracted using 1% nitric acid ($HNO_3$) with a microwave oven and were measured using high performance liquid chromatography coupled with inductively coupled plasma-mass spectrometry. Mean concentrations of total As in husked rice and polished rice were 0.18 and $0.11mg\;kg^{-1}$, respectively. Also, average inorganic As concentrations in husked rice and polished rice were 0.11 and $0.07mg\;kg^{-1}$, respectively. These levels are lower than the standard guideline value 0.35 and $0.2mg\;kg^{-1}$ for inorganic As in husked and polished rice recommended by Codex Committee on Contaminants in Foods and Ministry of Food and Drug Safety, respectively. The mean of the inorganic As ratio for the total amount of As was 0.65 and 0.67 for husked rice and polished rice, respectively, and the range was from 0.08 to 1.0. For health risk assessment, the average value of cancer risk probability was $9.24{\times}10^{-5}$ and ranged from $2.30{\times}10^{-5}$ to $1.90{\times}10^{-5}$. Therefore, human exposure to As through dietary intake of surveyed rice samples might considered to be a low health risk.

• Journal of Environmental Impact Assessment
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• v.32 no.3
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• pp.157-165
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• 2023

In Korea, a major contaminant of farmland soils in the vicinity of abandoned mines is arsenic, for which the general soil reclamation method is contaminated soil stabilization and cover the stabilized soil with clean soil at a thickness of 40 cm. In a previous pot experiment study we confirmed the feasibility of a lower thickness (20 cm) of covering soil for such reclamation in abandoned coal mines, where arsenic contamination levels are generally lower than in metal mines. In this subsequent study a field experiment including rice plant cultivation in field test plots was conducted. For over 4 months, the transfer of arsenic from the contaminated soil to the unpolished rice grains was reduced by 44% when a clean soil covering with a thickness of 20 cm was applied. The maximum decrease (56%) was shown when the stabilization process was performed before the covering. These results reveal a lower thickness of clean soil covering has a high feasibility and it can increase cost-efficiency in the reclamation of an abandoned coal mine.

• Analytical Science and Technology
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• v.22 no.3
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• pp.201-209
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• 2009

Four heavy metals (Pb, Cd, As, and Hg) in 38 species (total 325 samples) of oriental animality medicines were monitored by inductively coupled plasma-mass spectrometry (ICP-MS) and automatic mercury analyzer (AMA). The detected concentration range of Pb, Cd, As was presented as $0.02{\mu}gkg^{-1}$ $(D.L){\sim}11.29mgkg^{-1}$, $0.01{\mu}gkg^{-1}$ $(D.L){\sim}2.50 mgkg^{-1}$, $0.12{\mu}gkg^{-1}$ $(D.L){\sim}5.27mgkg^{-1}$, respectively. In case of Hg, it the concentration range was $0.01{\sim}77.11mgkg^{-1}$ except one sample which exceeded detection limit. In all samples of Amydae Carapax and Gallnut, it was not detected over the maximum residue limits of metals. Pb is in charge of the greatest portion of contamination in 22 species of animality medicines, and in case of Hg, 54.46% of total samples were over the maximum residue limits. Therefore, environmental levels of Pb and Hg are needed to continue the researches and the studies for tracking pollution source are required.

• Journal of Food Hygiene and Safety
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• v.38 no.6
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• pp.409-419
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• 2023

Okadaic acid (OA) group toxins, including OA and its analogs, such as dinophysis toxins (DTXs), have been reported to cause diarrheal shellfish poisoning (DSP). These toxins are primarily produced by dinoflagellates and are accumulated in bivalves. Recently, the presence of Dinophysis sp., a causative alga of DSP, has been reported along the coasts of Korea, posing a potential risk of contamination to domestic seafood and exerting an impact on both the production and consumption of marine products. Accordingly, the European Food Safety Authority (EFSA) and the World Health Organization (WHO) have established standards for the permissible levels of OA group toxins in marine products for safety management. Additionally, in line with international initiatives, the domestic inclusion and regulation of DTX2 among the substances falling under the purview of management outlined by the 2022 diarrheal shellfish toxin standard have been implemented. In this study, we reviewed the physicochemical properties of OA group toxins, their various exposure routes (such as acute toxicity, genotoxicity, reproductive and developmental toxicity), and the relative toxicity factors associated with these toxins. We also performed a comparative assessment of the methods employed for toxin analysis across different countries. Furthermore, we aimed to conduct a broad review of human exposure cases and assess the international guideline for risk management of OA group toxins.

• Journal of Animal Science and Technology
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• v.44 no.3
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• pp.351-360
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• 2002

The Korean fresh pork loins in vacuum packaged were obtained from three different Korean export companies and investigated for microbiological and sensory properties. The fresh pork loins were stored at 2$^{\circ}C$ for 50 days and analyzed with an interval of 5$\sim$10 days. The results were as follows: The overall numbers of total plate counts and coliform bacteria were higher in swab method than in meat sampling method. The total plate counts in the loins from the company I were maintained low levels ($\prec$10$^5$ cfu/$cm^2$ or $\prec$10$^5$ cfu/g) for entire storage periods(50 days at 2$^{\circ}C$), whereas the loins from the company III had high levels when they were compared to the domestic standard for the allowance limit. The samples from the company III showed that total plate counts were over 106 after about 30 days when determined by meat sampling method and total plate counts were over 106 after 15 days when determined by swab method. The overall numbers of coliform bacteria were also significantly lowest in the samples from the company I, whereas they were highest in the company III. Therefore, all meat companies will have to make an effort to prevent bacterial contamination in each stage such as slaughtering, marketing and consumer in order to ensure the production of safe meat and the extension of shelf-life. For fresh products, scores of intramuscular fat were higher in samples form the companies II and III than those from the company I when visibly evaluated with the standard. There were no significant differences in scores of meat color, drip and fresh meat flavor. However, the samples from the company I had the lowest score of off-flavor and highest score of overall acceptability. For cooked products, there were no significant differences in meat flavor, off-flavor, juiciness and overall acceptability.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.1
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• pp.69-78
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• 2010

In order to investigate the degree of household dust contamination, 48 samples of household dust (24 from urban area and 24 from rural area) in Daegu city were collected in vacuum cleaner during January to February 2009. Samples were sieved below 100 ${\mu}m$, and 14 elements (Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, V, Zn) were analyzed using ICP after acid extraction. Results obtained from the source assessment of trace elements using enrichment factor showed that Ca, Fe, K, Mg, Mn, Na, and V were influenced by natural sources such as weathered rock and resuspended soil, while Cd, Cr, Cu, Ni, Pb and Zn were influenced by anthropogenic sources such as fuel combustion and waste incineration. Concentrations were remarkably higher in components from natural sources than in components from urban anthropogenic sources. Household dust in urban area was more affected by anthropogenic sources compared with that of rural area. Pollution index of heavy metals revealed that urban area was 1.8 times more contaminated with heavy metal components than rural area. The correlation analysis among trace elements indicated that components were correlated with natural sources-natural sources (Al-Mg, Al-Mn, Fe-Mn) and natural sources-anthropogenic sources (Al-V, Fe-Cr, V-Mn) in both urban area and rural area. Trace element components of rural area were more correlated than those of urban area. Houses that use oil for heating fuel had relatively higher contents of heavy metals rather than those using gas or electricity for heating fuel. Houses with children also had higher contents of heavy metals. In addition, the age of houses was found to influence the heavy metal levels in household dusts, with older houses (>10years) having higher concentrations than newer houses (<10years) and houses located near the major road (<10 m) were found to have relatively higher heavy metal levels in household dust.

• Food Science and Preservation
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• v.14 no.1
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• pp.35-41
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• 2007

As the consumption of environmentally friendly agricultural products increases, food safety is at the forefront of public health concerns. We analyzed the biological hazards of 26 species of leaf vegetables and 4 species of fruit according to types of cultivation (conventional or organic filming) and distribution system (giant retailers or organic food stores) using various culture media, automatic bacterial identification systems, and microscopy, Total bacterial count of unwashed agricultural product ranged from $5.2{\times}10^{3}\;to\;1.5{\times}10^{5}\;CFU/mL$ (from 0.1 g of agricultural products), and the average count dropped 25-fold (range, 8-60-fold) after water washing. Microbial levels of washed organic agricultural products were $6.0{\times}10^{2}-1.9{\times}10^{4}\;CFU/mL$, and were not significantly different f개m the microbial loads on conventionally farmed produce. There was no significant difference in bacterial count from agricultural produce purchased from giant retailers or organic food stores. Total microbial count of Chinese cabbage, welsh onion, red chicory and kale were comparatively high, and Enterobacter cloacae was isolated most frequently. Parasites were detected in agricultural products purchased from conventional farm products in the stores of giant retailers, and in organic food stores, and parasite prevalence was especially high in Chinese cabbages and welsh onion. The study indicated that cultivation methods and distribution systems did not cause significant differences in biological contamination levels of agricultural produce. Some vegetables and fruits were highly contaminated effective sanitizing methods to reduce these biological hazards are needed.

• Food Science of Animal Resources
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• v.29 no.1
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• pp.24-33
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• 2009

This study investigated the microbial contamination levels of raw meats used for short-ripened salami and changes in the microbial and physico-chemical properties of the product during storage at 10 and $25^{\circ}C$ for up to 120 days. The microbial counts of raw meats ranged between 2 and 4 Log CFU/g. Frozen-thawed sow meat showed higher total aerobe and Enterobacteriaceae counts than fresh chilled pork and pork back fat. Staphylococcus aureus was found in all raw materials except fresh chilled pork samples, and Clostridium perfringens was detected in a sample stored for 21 days at $25^{\circ}C$. The counts of total aerobes, lactic acid bacteria and Staphylococcus spp. decreased more rapidly at $25^{\circ}C$ than at $10^{\circ}C$ when the storage time was extended. The growth of Enterobacteriaceae, Pseudomonas spp., Clostridium spp., yeast, and mold were restricted to levels below 2 Log CFU/g during storage. The contents of salt, water, crude protein, crude fat, and ash of salami samples were 3.4, 33.4, 30.8, 32.7, and 4.3%, respectively, which were not affected by storage time or temperature. The pH value of the salami was initially 4.79 and increased to 5.02 and 5.26 after 120 days of storage at 10 and $25^{\circ}C$, respectively, whereas the water activity values decreased from an initial value of 0.91 to 0.90 and 0.88 after 120 days at 10 and $25^{\circ}C$, respectively. The TBA and VBN values increased slowly during storage. The redness value of the salami samples stored at $25^{\circ}C$ decreased more significantly than the samples stored at $10^{\circ}C$. With increased storage time, the values for the rheological characteristics of the salami in terms of hardness, brittleness, elasticity, cohesiveness, gumminess, and adhesiveness tended to decrease more remarkably at $25^{\circ}C$ than at $10^{\circ}C$. Based on sensory evaluation scores, it appears that short-ripened salami is no longer acceptable after 90 days at $10^{\circ}C$ and 30 days at $25^{\circ}C$.

• Journal of Food Hygiene and Safety
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• v.24 no.1
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• pp.56-62
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• 2009

Patulin, a mycotoxin mainly produced by Penicillium and Aspergillus, is found in various foods. In the present, a maximum acceptable level for patulin is established at $50{\mu}g/kg(ppb)$ in apple juices and apple concentrates in Korea. But patulin may be detected in foods produced with other fruits. In the present study, patulin contamination was analyzed in 520 samples of fruit juices and beverages, and 50 samples of fruit juice concentrates. High performance liquid chromatography(HPLC) was applied to quantitatively analyze patulin levels in samples and liquid chromatography-mass spectrometry(LC/MS/MS) was used to remove false positive results. The results showed that three samples of 520 fruit juices and beverages and five samples of 50 fruit juice concentrates were contaminated by patulin, $9.8-18.0{\mu}g/kg$ and $4.7-18.2{\mu}g/kg$ respectively. Contaminated samples were produced with apple, orange or pear. This indicates that it is necessary to extend the regulatory range of patulin. In the other hands, the present study confirmed the effectiveness of LC/MS/MS analytical method to remove false positive results.

• Korean journal of food and cookery science
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• v.26 no.3
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• pp.335-345
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• 2010

The objective of this study was to model the kinetics of S. aureus survival on high risk foods in school foodservice operations. After inoculating S. aureus ATCC25923 onto the various high risk foods, the effects of competitive microorganism, storage temperatures($25^{\circ}C$, $35^{\circ}C$), and initial contamination levels ($1.0{\times}10^2\;CFU/g$, $1.0{\times}10^5\;CFU/g$) on the growth of S. aureus were investigated. Lag time decreased and specific growth rate increased with a storage temperature ($25^{\circ}C$<$35^{\circ}C$) and with a higher initial inoculation level ($1.0{\times}10^2\;CFU/g$<$1.0{\times}10^5\;CFU/g$). Previously it was shown that S. aureus is a weaker competitor than other organisms, but it proliferates aggressively in a noncompetitive environment. However, in our study, when S. aureus was used to inoculate japchae (glass noodles with sauteed vegetables) and meat ball, the growth of S. aureus was similar and more active with competitive organisms than that without competitive organisms. Regardless of other factors, the initial level of S. aureus was a more significant factor of the growth. High inoculation levels of S. aureus were reached at 6 log CFU/g within 3 hours. An incubation temperature of $35^{\circ}C$ and the animal protein component of menu items also were identified as significant factors influencing the growth of S. aureus. Therefore, the duration of time meals are stored before serving should be considered a critical control point. Food service providers must control time and temperature to insure the safety of cooked foods.