• Journal of the Korean Society of Food Science and Nutrition
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• v.14 no.2
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• pp.164-170
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• 1985

Yellowish modified wool, dithiocarbamate(DTC) wool, was synthesized by partial hydrolysis in 0.2 N-NaOH reacting with carbon disulfide to use as ${\alpha}-amylase$ immobilization matrix. ${\alpha}-amylase$ was immobilized reacting with sulfide group of DTC-wool by covalent binding within 1 hour. 0.5 gram of this preparation, $DTC-wool-{\alpha}-amylase$, contained 150 ug of enzyme protein and its specific activity was about 90% of the native one. General properties of $DTC-wool-{\alpha}-amylase$ were a little different from optimum temperature, optimum pH, heat stability, kinetic constants and activation energy. An apparent Michaelis constant and maximum velocity of $DTC-wool-{\alpha}-amylase$ were 5.56 mg/ml and 0.37 mg/ml. $min^{-1}$ respectively, while activation energy was 16.6 kcal/mole.

• Korean Journal of Environment and Ecology
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• v.23 no.5
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• pp.447-459
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• 2009

This study is intended to provide basic date for the efficient management of Pinus densiflora community by analyzing ecological characteristics of Pinus densiflora inhabiting Byeonsanbando National Park. According to investigations, P. densiflora community and P. densiflora-Quercus community are widely distributed, occupying 40.3% of the total area. 21 sites ($400m^2$per site) are selected for TWINSPAN analysis, and the result indicates that the whole community of P. densiflora and P. densiflora-Quercus can be classified into 8 types, and the age of P. densiflora is 40-50 years, which is similar to that of deciduous broad-leaved trees. The 8 community types are: P. densiflora community which competes with Quercus variabilis; P. densiflora community in which Fraxinus sieboldiana and Quercus serrata grow in the understory layer; P. densifloa community in which Q. serrata grow in the understory layer and Smilax china var. microphylla in the shrub layer respectively; P. densifloa community in which P. densiflora and F. sieboldiana grow in the understory layer; P. densiflora community which competes with Q. serrata and Carpinus tschonoskii; P. densiflora community which competes with Q. variabilis and Q. serrata; P. densiflora community in which Prunus sargentii grow; P. densiflora community in which Abies holophylla grow. P. densiflora community which competes with Q. variablis and C. tschonoskii seems to be in a stage of succession to deciduous broad-leaved community. The analysis indicates that Shannon diversity index is 0.2756-1.3879. It also indicates that there is a negative correlation between P. densiflora and Q. variabilis and C. tschonoskii; there is a positive correlation between P. densiflora and F. sieboldiana and Rhododendron schlippenbachii. These investigations show that the transformation of vegetation is already under way. There is a possibility that ecological succession can take place in 30.4% of the total area from P. densiflora to Quercus and deciduous broad - leaved trees. Therefore, it is recommended that the preservation and maintenance of P. densiflora be implemented by taking control of competing species which undermine the stability of P. densiflora forest community.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.8
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• pp.1197-1206
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• 2014

This study compared and analyzed the physiochemical and quality characteristics of young radish kimchi made with YR-FNC or YR-GC cultivated by organic farming as well as kimchi made with young radish cultivated by chemical composting/general farming (YR-Control). YR-Control showed higher contents of water and crude protein than YR-FNC and YR-GC kimchi but lower contents of crude ash, dietary fiber, and vitamin C. YR-FNC and YR-GC kimchi also showed higher contents of P and Cu than YR-Control but lower contents of N, K, Ca, Mg, Fe, and Zn. YR-Control fermentation progressed faster than that of YR-FNC or YR-GC after 24 days, and YR-Control more rapidly reached an appropriate pH. On the other hand, YR-FNC and YR-GC kimchi fermentation progressed slow and did not reach a pH level below 5.3. For period of fermentation, YR-Control and YR-FNC kimchi showed no significant difference in reducing sugar content, whereas that of YR-GC kimchi decreased significantly after 24 days of fermentation (P<0.002). YR-FNC and YR-GC kimchi showed 1.5~3 times higher total polyphenol and flavonoid contents than YR-Control at the beginning of fermentation, whereas YR-Control and YR-FNC kimchi showed a significant increase in total polyphenol and flavonoid contents during the fermentation period. By day 7 of fermentation, YR-FNC kimchi showed higher contents of lactic acid bacteria and total microbes than YR-Control. In the sensory evaluation, YR-FNC and YR-GC kimchi showed higher preference values than YR-Control. Therefore, kimchi made from young radish cultivated by organic farming has a longer freshness period than control kimchi and is characterized by excellent sensory quality, increased physiological contents, and improved beneficial health effects.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.4
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• pp.459-464
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• 2017

Biphenyl is used as an intermediate in the production of crop protection products, a solvent in pharmaceutical production, and as a component in the preservation of citrus fruits in many countries. Biphenyl is not authorized for use and also does not have standards or specifications as a food additive in Korea. National and imported food products are likely to contain biphenyl. Therefore, control and management of these products is required. In this study, a simple analytical method was developed and validated using HPLC to determine biphenyl in food. These methods are validated by assessing certain performance parameters: linearity, accuracy, precision, recovery, limit of detection (LOD), and limit of quantitation (LOQ). The calibration curve was obtained from 1.0 to $100.0{\mu}g/mL$ with satisfactory relative standard deviations (RSD) of 0.999 in the representative sample (orange). In the measurement of quality control (QC) samples, accuracy was in the range of 95.8~104.0% within normal values. The inter-day and inter-day precision values were less than 2.4% RSD in the measurement of QC samples. Recoveries of biphenyl from spiked orange samples ranged from 92.7 to 99.4% with RSD between 0.7 and 1.7% at levels of 10, 50, and $100{\mu}g/mL$. The LOD and LOQ were determined to be 0.04 and $0.13{\mu}g/mL$, respectively. These results show that the developed method is appropriate for biphenyl identification and can be used to examine the safety of citrus fruits and surface treatments containing biphenyl residues.

• Advances in pediatric surgery
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• v.16 no.1
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• pp.1-10
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• 2010

The members of the Korean Association of Pediatric Surgeons conducted a retrospective study of two hundred and twenty-two cases of intestinal atresia for the period from January 1, 2007 to December 31, 2009. Seventeen hospitals were involved. There were 76 duodenal, 65 jejunal, and 81 ileal atresias (3 colonic). The male to female ratio was 0.85:1 in DA and 1.34:1 in JIA. Ninety-four patients(43.3 %) were premature babies (DA 40.3 %, JA 64.6 %, IA 28.8 %), and 70 babies (32.0 %) had low birth weight (DA 38.7 %, JA 44.4 %, IA 16.0 %). Antenatal diagnosis was made in 153 cases (68.9 %). However, 27 infants (17.6 %) with antenatal diagnosis were transferred to the pediatric surgeon's hospitals after delivery. Maternal polyhydramnios was observed in 81 cases (36.59 %) and most frequent with proximal obstruction. In forty-four cases (19.8 %), only simple abdominal film was taken for diagnostic study. The associated malformations were more frequently observed in DA - 61.8 % in DA and 22.6 % in JIA. Meconium peritonitis, small bowel volvulus and intussusception were more frequently associated with ileal atresia. The overall mortality rate was 3.6 %. (Abbreviations: DA;duodenal atersia, JA;jejunal atresia, JIA;jejunoileal atresia, IA;ileal atrsia).

• Food Science and Preservation
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• v.23 no.5
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• pp.605-613
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• 2016

The quality and shelf life of sliced root of Platycodon grandiflorum (Doraji) treated by ozon-microbubble-heat shock (OMH) were investigated by combining modified-atmosphere packaging [MAP, ($50%O_2+15%CO_2+35%N_2$)]. The study was based on microbiological (total viable bacteria, fungi, Enterobacteriaceae and coliforms numbers), physicochemical and sensory changes. OMH treatment was effective in reducing microbial populations of the sliced Doraji, especially Enterobacteriaceae and coliforms reduced by 2 log CFU/g. However OMH-MAP treatment remained the aerobe and fungi numbers. Regarding the color, OMH-MAP delayed the change of Hunter $b^*$ and the sliced Doraji by OMH-MAP treatment exhibited lower decrease of flavor and overall acceptability compared to those by polypropylene packaging after tap water treatment (Control). The OMH and $50%O_2+15%CO_2$ MAP treatment gave better sensory quality and extended shelf-life for sliced Doraji (~3 days longer shelf-life than Control). Flavor was significantly related to overall acceptability at both Control and OMH-MAP, whereas total coliforms prevalence was associated with overall acceptability at only OMH-MAP. Therefore microbubble-heat shock treatment may improve microbial safety and sliced Doraji by OMH treatment can stored under $50%O_2+15%CO_2$ treatment for up to 7 days. Thus, OMH and MAP treatment may be used in maintaining the storage quality and marketability of sliced Doraji.

• Korean Journal of Food Science and Technology
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• v.17 no.5
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• pp.389-398
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• 1985

To shorten the processing of cheese slurry, four different slurries, ie, Control, Cheddar 1 and 2, and Italian-type that were made of Na-caseinates, cream, trace elements, lactic culture, and enzymes were fermented at $30^{\circ}C$ for 7days with daily stirring. PH, titratable acidity, soluble nitrogen, viable cell count, active SH groups, total volatile fatty acid, free fatty acid, electrophoretic patterns of degraded caseins, and viscosity were analyzed to investigate physicochemical properties of fermented slurries. Acid production was accelerated in the cheese slurries with protease than that without the enzyme and PH of the former was decreased after three days of fermentation to 4.90. The Change of titratable acidity agreed to PH patterns. Soluble nitrogen of the Control slurry was increased slowly for four days and then rapidly to 40% of total nitrogen while those containing protease to 70%. The protease of lactic cultures used (Streptococcus lactis and Streptococcus cremoris) broke down as-casein more rapidly than $\beta$-casein and most proteins were degraded to peptides and amino acids after three days of fermentation. Total volatile fatty acids were increased by added lipase and free fatty acids composition analyzed by GLC in cheddar slurry with 0.00001% lipase was similar to that of commercial cheddar cheese, while that in Italian-type slurry was a half of that in commercial Italian cheese. Active SH groups were increased in the cheese slurries with glutathione from fourth day of fermentation. The viscosity of slurries decreased very rapidly by addition of protease.

• Tuberculosis and Respiratory Diseases
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• v.56 no.3
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• pp.261-268
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• 2004

Background : The resurgence of tuberculosis and outbreaks of multidrug resistant (MDR) tuberculosis have increased the emphasis for the development of new susceptibility testing of the Mycobacterium tuberculosis for the effective treatment and control of the disease. Conventional drug susceptibility testings, such as those using egg-based or agar-based media have some limits, such as the time required and difficulties in determining critical inhibitory concentrations, but these are still being used in many diagnostic laboratories because of no better lternatives, considering cost and accuracy. To overcome these limits, a rapid and simple method for new susceptibility testing, using live and dead assays, was applied for a bacterial cell viability assay to distinguish dead from live bacterial cells based on two-color fluorescence. Materials and Methods Strains : Forty strains were used in this study, 20 susceptible to all antituberculosis drugs and the other 20 resistant to the four first line antituberculosis drugs isoniazid, rifampicin, streptomycin and ethambutol. Antibiotics : The four antibiotics were dissolved in 7H9 broth to make the following solutions: $0.1{\mu}g\;isoniazid(INH)/m{\ell}$, $0.4{\mu}g\;rifampicin(RMP)/m{\ell}$, $4.0{\mu}g\;streptomycin(SM)/m{\ell}$ and $4.0{\mu}g\;ethambutol(EMB)/m{\ell}$. Results : Live and dead Mycobacterium tuberculosis cells fluoresced green and red with the acridin (Syto 9) and propidium treatments, respectively. These results are very well accorded with conventional drug susceptibility testing by proportional method on Lowensen-Jensen media (L-J) containing 4 drugs (INH, RMP, EMB and SM), showing a 93.7 % accordance rate in susceptible strains and 95% in resistant strains. Conclusion : The results of the drug susceptibility testing using the live and dead bacterial cell assay showed high accordance rates compared with the conventional proportion method on L-J. This finding suggests that the live and dead bacterial cell assay can be used as an alternative to conventional drug susceptibility testing for M. tuberculosis strains.

• Journal of Animal Science and Technology
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• v.46 no.2
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• pp.165-172
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• 2004

This study was conducted to investigate changes in physico-chemical characteristics of Hanwoo carcass according to different castration and slaughtering ages. Total 75 Hanwoo calves(average 4 months old) were randomly assigned to Control(bulIs). Treatment I. Il , III. or IV(castrated on 4. 9. 12. and 16 months of age, respectively) and slaughtered at 7. 9. 12, 16, and 28 months of age. Moisture contents in M. Longissimus dorsi of both Hanwoo bulls and steers were decreased as the slaughtering age increased. Moisture contents in all steer groups were significantly(P <0.05) lower(average 68.63%) than that in bulls(72.18%) at 28 months of age. Crude fat contents tended to increase as the slaughtering age increased. Crude fat contents in Treatment III(castrated at 12 months of age) at 28 months of age were 10.24% which was the highest among all steer groups. Crude protein contents in M. Longissimus dorsi of Hanwoo bulls were around 23% regardless of slaughtering age. Water holding capacity(WHC) of both bulls and steers tended to increase as the animals aged. Steers showed rapid increase in WHC after 16 months of age and showed higher(78.39%)) WHC than bulls(70.00%) at 28 months of age. Palmitic acid(CI8: 0) contents in Hanwoo bulls were increased as the slaughtering age increased(20.92 \longrightarrow 24.22%) whereas stearic acid(CI8: 0) contents were decreased(I8.l5 \longrightarrow11.32%). Oleic acid(CI8: I). a major unsaturated fatty acid. significantly(P <0.05) increased(25.59 \longrightarrow 37.90%) when slaughtering age of Hanwoo increased. Changes in fatty acid composition in Hanwoo steers were similar to those in bulls except oleic acid contents were higher and stearic acid contents were lower than bulls at 28 months of age.

• Journal of Animal Science and Technology
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• v.46 no.5
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• pp.849-858
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• 2004

This study was carried out to investigate the effects of addition of citron peel powder(0.3%, 0.6%, 0.9%) on the quality characteristics of emulsion-type sausages. The pH, color, TBARS, residual nitrite content and textural properties were evaluated. The pH values of sausage containing citron peel powder were significantly(P<0.05) lower compared to those for control. The CIE $L^*$ and $a^*$ values of sausage containing citron peel powder tended to similar to control, but the CIE $b^*$ values were significantly(p<0.05) higher in the sausage containing citron peel powder. The TBARS values of sausage containing 0.9% citron peel powder were significantly(P<0.05) lower than those of control at 20, 40 and 60 days of storage. The residual nitrite content of sausage containing citron peel powder were significantly(P<0.05) lower compared to control. The hardness values of sausage containing citron peel powder were significantly(P<0.05) higher than those of control, but the cohesiveness, springiness and gumminess were significantly(P<0.05) lower in the sausage containing citron peel powder.