• Journal of Food Hygiene and Safety
• /
• v.35 no.1
• /
• pp.51-59
• /
• 2020

This study evalutated the risk of foodborne illness from Vibrio spp. (Vibrio vulnificus and Vibrio cholerae) through sea squirt consumption. The prevalence of V. vulnificus and V. cholerae in sea squirt was evaluated, and the predictive models to describe the kinetic behavior of the Vibrio in sea squirt were developed. Distribution temperatures and times were collected, and they were fitted to probabilistic distributions to determine the appropriate distributions. The raw data from the Korea National Health and Nutrition Examination Survey 2016 were used to estimate the consumption rates and amount of sea squirt. In the hazard characterization, the Beta-Poisson model for V. vulnificus and V. cholerae infection was used. With the collected data, a simulation model was prepared and it was run with @RISK to estimate probabilities of foodborne illness by pathogenic Vibrio spp. through sea squirt consumption. Among 101 sea squirt samples, there were no V. vulnificus positive samples, but V. cholerae was detected in one sample. The developed predictive models described the fates of Vibrio spp. in sea squirt during distribution and storage, appropriately shown as 0.815-0.907 of R² and 0.28 of RMSE. The consumption rate of sea squirt was 0.26%, and the daily consumption amount was 68.84 g per person. The Beta-Poisson model [P=1-(1+Dose/β)^-α] was selected as a dose-response model. With these data, a simulation model was developed, and the risks of V. vulnificus and V. cholerae foodborne illness from sea squirt consumption were 2.66×10^-15, and 1.02×10^-12, respectively. These results suggest that the risk of pathogenic Vibrio spp. in sea squirt could be considered low in Korea.

• The Korean Journal of Food And Nutrition
• /
• v.23 no.3
• /
• pp.332-341
• /
• 2010

The chemical composition characteristics of jujube wine using different preparation methods including extraction in -soju (25%) and fermentation were investigated. The jujube wine was prepared by soaking in soju using- whole fruit(WJ-S1) or seed-removed fruit(WJ-S2). Fermentations of the jujube wine were started by using whole fruit(WJ-F1), seed-removed fruit(WJ-F2) or extracts of whole fruit(WJ-F3) after adding 24% sucrose. The pH of all samples decreased from a range of 4.92~5.42 at the start time to 3.66~4.97 after 100 days. The treatment WJ-F3 showed the lowest pH among all treatments. Total acid content was 0.67~1.01% at the initial stage and then changed to 0.51~0.88% after 100 days. Total sugar and reducing sugar contents were 1.20~13.8% and 0.50~4.45% at initial stage and then changed to 1.53~4.52% and 1.75~3.82% after 100 days respectively. These sugars decreased during the preparation and fermentation of the jujube wine. The amounts of free sugars including fructose, glucose, and sucrose ranged from 1.53~4.52% and treatment WJ-F3 showed the highest amount(1.95~13.64%) compared the other treatment. Glucose level were high in treatment WJ-S1 and WJ-S2, and fructose was increased in treatments WJ-F1, WJ-F2, and WJ-F3 after 60 days. Amino nitrogen content was 0.02~0.11% after 20 days and 0.07~0.14% after 40 days respectively. Solid content was 2.68~7.76% at the initial fermentation stage and changed to 4.81~9.73% after 100 days. Hunter color(L values) were 88.45~96.74 at the initial stage and then changed to 92.62~100.45 after 100 days. Preference tests a significant difference between the two types (extraction and fermentation) of jujube wine. And treatment WJ-S2 received the highest preference scores among the all treatments.

• Korean Journal of Environmental Agriculture
• /
• v.20 no.3
• /
• pp.155-161
• /
• 2001

This study was carried out to investigate cytotoxicity of paraquat or bentazone on NIH 3T3 fibroblasts, toxicity of paraquat or bentazone, and compensatory effects of 3-Methylcholanthrene(3-MC) on the rat liver. In order to MTT assay, the $5.0{\times}10^4$ cell/mL of NIH 3T3 fibroblast in each well of 24 multidish were cultured. After 24 hours, the cells were treated with solution of paraquat or bentazone(1, 25, 50, 100 ${\mu}M$ respectively). After the NIH 3T3 fibroblast of all groups were cultured in same condition for 48 hours. MTT assay were performed to evaluate the cytotoxicity of cell organelles. Paraquat or bentazone $MTT_{50}$ were 1668.97 ${\mu}M$ and 1506.97 ${\mu}M$, respectively. These $IC_{50}$ of paraquat or bentazone were decided low cytotoxicity by Borenfreund. In order to observe the toxicity and compensatory effects of paraquat or bentazone on the rat liver, Sprague-Dawley male rats were used as experimental animals and divided into paraquat or bentazone only treated group and simultaneous application group of paraquat or bentazone and 3-MC. At 30 min and 1, 3, 6, 12, 24, 48 and 96 hrs interval after each treatment, the animals were sacrificed by decapitation and liver were immediately removed, immersed in fixatives, and processed with routine method for light microscopic study. Paraffin sections were stained with H-E, PAM and Best Carmine. Under the light microscope, degenerative changes of hepatic lobules were frequently observed in portal area from 3 hrs after paraquat or bentazone treatment. All hepatic cells were induced degenerative change at 12 hrs and more severe degenerative change at 48 hrs after paraquat or bentazone treatment. Especially, hepatic cells of bentazone only treated group were distinctly showed pyknotic. Glycogen granules were increased in portal area at 3 hrs, all hepatic cells at 12 hrs and remarkably increased at 48 hrs after paraquat or bentazone treated group. But hepatic cells of bentazone only treated group were regeneration at 48 hrs from portal area and glycogen granules of hepatic cells of paraquat or bentazone and 3-MC combination treated group showed in central area only at 48 hrs. The results indicate that 3-MC may be decrease paraquat or bentazone cytotoxicity on the rat liver.

• Korean Journal of Ecology and Environment
• /
• v.43 no.2
• /
• pp.279-287
• /
• 2010

This study was to evaluate ecological conditions of Hyeongsan River watershed from April to September 2009. The ecological health assessments was based on Qualitative Habitat Evaluation Index (QHEI), water chemistry during 2000~2009, and the fish multi-metric model, Index of Biological Integrity (IBI). For the study, the models of IBI and QHEI were modified as 8 and 11 metric attributes, respectively. Values of IBI averaged 25.4 (n=6), which is judged as a "fair" condition (C) after the criteria of Barbour et al. (1999). The distinct spatial variation was found in the IBI. Physical habitat health, based on the values of QHEI, varied from 76 in the downriver (H6) to 150.5 in the headwater (H1) and was evidently more disturbed in the downriver reach. Values of BOD and COD averaged 2.4 $mgL^{-1}$ (range: 0.3~13.8 $mgL^{-1}$) and 4.3 $mgL^{-1}$ (scope: 0.6~12.8 $mgL^{-1}$), respectively during the study period. Total nitrogen (TN) and total phosphorus (TP) averaged 3.0 $mgL^{-1}$ and 103.5 ${\mu}gL^{-1}$, respectively, indicating a severe eutrophication, and the nutrients increased more in the downriver than the headwater. Overall, physical, chemical and IBI parameters showed a typical downriver degradation along main axis of the river from the headwater-to-the downriver. This was mainly attributed to livestock waste and residential influences along with industrial discharge from the urban region.

• Korean Journal of Ecology and Environment
• /
• v.43 no.1
• /
• pp.136-141
• /
• 2010

In situ experiments of Nutrient Enrichment Bioassays (NEBs) were conducted in the field along with in the laboratory to determine which nutrient limited phytoplankton growth as a indicator of primary productivity. For the NEBs, the water was sampled using a polyethylene-lined container and dispensed into 6 L water tank in the laboratory. The control (C, no nutrient spike) and six treatments of phosphorus (P), 2-fold phosphorus (2P), 4-fold phosphorus (4P), nitrate nitrogen ($NO_3$-N), 2-fold nitrate nitrogen ($2NO_3$-N), and phosphorus and nitrate nitrogen (P+$NO_3$-N) were set up in the lacustrine zone near the dam site, Daechung Reservoir in September, 2009 and analyzed the diel changes of total nitrogen (TN), total phosphorus (TP), and chlorophyll-$\alpha$ (Chl-$\alpha$) in the cubitainers. The short-term NEBs showed that algal response in the treatments spiked phosphorus (P, 2P, and 4P) were significantly (p < 0.05) greater than the response in the control (C), and nitrogen-spike. Also, the response in 4P-treatment was greater than those in the P- and 2P-treatments. In contrast, there was no significant differences (p > 0.20) between the $NO_3$-N and $2NO_3$-N treatment. The outcomes of the NEBs suggest that phosphorus limited the phytoplankton growth and nitrogen was not limited in this system. Furthermore, in the N + P treatments, the response was minimum, compared to all other treatments and the control, indicating that even if the system is evidently P-limited system, when added the nitrogen, the response showed the inhibition. Also, > 95% of observed long-term TN:TP ratios in the ambient water showed > 17, which is the criteria of P-limitation, supporting the P-limitation in the system. Overall, these results suggest that phytoplankton biomass near the dam is a direct linear function of P-loading near the watershed, if the phosphorus pool is mainly dissolved fraction.

• Journal of Life Science
• /
• v.20 no.1
• /
• pp.103-112
• /
• 2010

Pemetrexed has demonstrated clinical activity in non-small cell lung cancer (NSCLC) as well as other solid tumors. It transports into the cells via reduced folate carrier (RFC) and is polyglutamated by folypolyglutamate synthetase (FPGS). Pemetrexed directly inhibits several folate-dependent enzymes such as thymidylate synthase (TS), dihydrofolate reductase (DHFR), and glycinamide ribonucleotide formyltransferase (GARFT). We investigated the effects of genetic variations and the expression of RFC, FPGS, TS and DHFR enzymes on drug sensitivity to pemetrexed in NSCLC cells. Polymorphisms in RFC, FPGS, and DHFR were genotyped in four NSCLC cells - A549, PC14, HCC-1588, and H226. Real-time RT-PCR and Western blot was performed to evaluate mRNA transcripts and protein of these genes. The cytotoxicity of pemetrexed was measured by SRB assay. In PC14 and H226 cells, increased mRNA expressions of RFC and FPGS were associated with higher cytotoxicity to pemetrexed. 2R/2R genotype of TS and its increased mRNA expression were associated with drug resistance to pemetrexed in A549 cells, whereas 3R/3R genotype in TS with decreased mRNA expression was associated with higher sensitivity in H226 cells. After pemetrexed treatment, an inverse change of DHFR mRNA and protein expression was found. The strongest linkage disequilibrium (LD) was discovered between-1726C>T and -1188A>C SNP of DHFR gene. Our findings suggest the cytotoxic effect of pemetrexed may be associated with genetic polymorphisms and the expression level of genes involved in pemetrexed metabolisms in NSCLC cells.

• Journal of Life Science
• /
• v.27 no.2
• /
• pp.202-210
• /
• 2017

As an effort to find a potential biopreservative, we isolated bacterial strains producing bacteriocin from fermented foods. A strain was finally selected and characteristics of the bacteriocin were investigated. The selected strain was identified as Bacillus subtilis E9-1 based on the 16S rRNA gene analysis. The culture supernatant of B. subtilis E9-1 showed antimicrobial activity against Gram-positive bacteria. Subtilisin A, ${\alpha}$-chymotrypsin, trypsin and proteinase K inactivated the antimicrobial activity, which means its proteinaceous nature, a bacteriocin. The bacteriocin activity was fully retained at the pH range from 2.0 to 8.0 and stable at up to $100^{\circ}C$ for 60 min. Solvents such as ethanol, isopropanol and methanol had no effect on the antimicrobial activity at the concentration of 100% but acetone and acetonitrile reduced the activity at up to 100% concentration. Cell growth of four indicator strains was dramatically decreased in dose-dependent manner. Listeria monocytogenes was the most sensitive, but Enterococcus faecium was the most resistant. Bacillus cereus and Staphylococcus aureus showed the medium sensitivity. The bacteriocin showed its antimicrobial activity against B. cereus and L. monocytogenes via bactericidal action. The number of viable cells of L. monocytogenes started to reduce after addition of bacteriocin to the minced beef. The bacteriocin was purified through acetone concentration, gel filtration chromatography and RP-HPLC. The whole purification step led to a 6.82 fold increase in the specific activity and 6% yield of bacteriocin activity. The molecular weight of the purified bacteriocin was determined to be 3.3 kDa by MALDI-TOF/TOF mass spectrometry.

• Korean Journal of Food Science and Technology
• /
• v.27 no.6
• /
• pp.909-914
• /
• 1995

In order to investigate gelation properties of Gelation Properties of ${\alpha}-lactalbumin$(${\alpha}-La$), gelling times and protein solubilities of ${\alpha}-La$ gels prepared in 0.1 M Tris-HCI buffer(pH 8.0) followed by heating at $90^{\circ}C$ for 40 minutes under different ${\alpha}-La$ concentration, NaCl, $CaCl_2$, N-ethylmaleimide(NEM), and dithiothreitol(DTT) concentration were measured. Gelling times decreased with increasing concentration of ${\alpha}-La$, NaCl, $CaCl_2$, and DTT, but increased with increasing concentration of NEM. ${\alpha}-La$ solutions made from all treatments were gelled within 40 minutes with the exception of NEM at $20{\sim}50\;mM$. Solubilities decreased with increasing concentration of ${\alpha}-La$, NaCl, $CaCl_2$, and DTT, but the solubility of NEM-modified gels increased with increasing concentration of NEM. As the results, solubilities In standard buffer were $10.4{\sim}51.3%$, $9.2{\sim}35.4%$, $11.1{\sim}35.0%$, $8.0{\sim}9.5%$, and $96.8{\sim}56.2%$, respectively. Solubilities in standard buffer containing 8 M urea and 0.5% SDS were higher than those in standard buffer, and were $41.8{\sim}81.3%$, $41.9{\sim}64.1%$, $43.5{\sim}69.8%$, $29.6{\sim}38.5%$, and $77.4{\sim}98.9%$, respectively. Solubilities in the presence of DTT were almost close to 100% in all conditions. These results indicates that the gelation rate and solubility are influenced by many factors, i.e. protein concentration, kind and concentration of salts, concentration of thiol reagents. The solubility of gel decreased with increasing the gelation rate.

• Korean Journal of Food Science and Technology
• /
• v.34 no.2
• /
• pp.141-150
• /
• 2002

Owing to a need for simple extraction and purification for analysis of water soluble vitamins in food samples by RP-HPLC with UV-detector, the methods of bromelain and protease hydrolysis and $C_{18}$ Sep-Pak solid phase extraction were employed. The recoveries of standard water soluble vitamins by the bromelain and protease hydrolysis and $C_{18}$ Sep-Pak solid phase extraction were significantly high compared to AOAC methods in most of vitamins. The contents of pyridoxal determined with protest in the pork was similar, but in the bromelain hydrolysis and AOAC method, was high compared to the results of reference. The niacinamide, thiamin and riboflavin determined with bromelain and protease hydrolysis showed similar values to the results of references. In the potato, pyridoxamine was detected in the AOAC method, which was not detected in the bromelain and protease hydrolysis methods. Pyridoxal contents in the protease hydrolysis and AOAC methods were very similar to the results of references. The recoveries of fortified standard vitamins in food samples were significantly high and accurate compared to those of AOAC methods. The extraction and purification with $C_{18}$ Sep-Pak solid extractor might be considered superior method for the determination of water soluble vitamins in food samples.

• Korean Journal of Food Science and Technology
• /
• v.35 no.1
• /
• pp.15-22
• /
• 2003

Nutritional compositions of three Tochukaso species (Paecilomyces tenuipes hosted by Larva and pupa, Cordyceps militaris, C. sinensis) were compared. Fruiting body and host fractions were separately analyzed. Fruiting body fraction of P. tenuipes (36.6%) hosted by larva was higher than that hosted by pupa (10.2%), an indication that the quality of the former is superior to the latter. Carbohydrate content of C. sinensis (39.6%) was $2.5{\sim}7$ times higher than those of others, probably due to the presence of polysaccharides. Protein and crude lipid contents of C. sinensis and C. militaris were 25.8 and 10.3%, and 75.1 and 3.9%, respectively. C. sinensis showed the lowest Ca content and $30{\sim}75$ times higher Fe content among the samples tested. Vitamin A content of C. militaris was 308.9 IU/100g, two fold higher than those of the other species. Saturated fatty acid content was the highest in P. tenuipes (pupa, 27.7%), whereas unsaturated fatty acid was the highest in P. tenuipes (larva, 83.3%). Aspartic acid, glutamic acid, and glycine were abundant in all species. Cordycepin content of C. militaris was $20{\sim}50$ times higher than those of the other species.