• Journal of Animal Environmental Science
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• v.16 no.3
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• pp.227-236
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• 2010

This study was conducted to develop an measuring system and method for fermentation degree of liquid swine manure by visible ray. The constituent changes of liquid swine manure were examined. pH gradually increased with time, but EC gradually decreased. Malodor strength decreased gradually with aeration treatment with time. Control needed more time to decrease malodor strength than aeration treatment. In aeration treatment, there was no germination of seeds (radish, chinese cabbage) up to 6 weeks and germination rate at 15th week was over 50%. However, in control, there was no germination up to end of experiment. Circular chromatography method showed that there was change after 10th week in aeration treatment but there was no change up to end of experiment in control. As a result, the fermentation degree of liquid swine manure would have relations among pH, EC, germination rate, malodor concentration, and reaction of circular chromatography. The simple analytical instrument for liquid swine manure consisted of a tungsten halogen and deuterium lamp for light source, a sample holder, a quartz cell, spectrometer for spectrum analyzer, a malodour measuring device, a software, etc. Results showed that the simple analytical instrument that was developed can approximately predict the fermentation degree of liquid swine manure by visible ray. Generally, the experiment proved that the simple analytical instrument was reliable, feasible and practical for analyzing the fermentation degree of liquid swine manure.

• Korean Journal of Food Science and Technology
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• v.6 no.1
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• pp.24-29
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• 1974

Deep fried instant noodles, biscuits, and cookies were prepared, using the same beef tallow as their fat ingredient. In addition to wheat flour and beef tallow, the common and major ingredients, the deep fried instant noodle contained 1.5% salt before frying, the biscuits 20.0% sucrose and 10.0% nonfat milk solid before baking, and the cookies 20.0% sucrose before baking. The three products and a portion of beef tallow, which was to be used as control, were stored in an incubator at $47.0{\pm}1.5^{\circ}C$. The peroxide value and the free fatty acid value of the control and the extracted fat were determined regularly during the storage period. The fat incorporated in the biscuits exhibited far greater stability to rancidity development than that of the control with regard to both peroxide value and free fatty acid value development. However, the fat incorporated in the deep fried instant noodles and the cookies showed much poorer stability than that of the control. Factors like a deep frying process and/or the presence of a significant amount of salt in the deep fried instant noodles appeared to promote the rancidity development of the fat incorporated in the product. On the other hand, Maillard type browning reaction products in the biscuits seemed to retard effectively the rancidity development of the fat incorporated in the product.

• Journal of Food Hygiene and Safety
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• v.30 no.3
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• pp.281-288
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• 2015

Vibrio is a genus of Gram-negative, curved, halophilic, and non-spore-forming bacteria. Some of the Vibrio species, such as V. cholerae and V. parahaemolyticus, often contaminate seafood products and occasionally cause human diseases when the seafood products are ingested. A total of 24 Vibrio strains were isolated from shrimp samples on Thiosulphate citrate bile salt sucrose (TCBS) media in this study. All of the 24 isolates were confirmed to belong to the genus Vibrio by using 16S rRNA gene sequence analyses. Vitek 2 system and species-specific polymerase chain reaction (PCR) methods were used to further identify a total of 29 Vibrio strains at the species level, including the 24 shrimp Vibrio isolates and five Vibrio reference strains. The specificities of the two methods to identify Vibrio strains at the species level were compared in this study. The species-specific PCR method was designed to detect five different Vibrio species, such as Vibrio cholerae, Vibrio parahaemolyticus, Vibrio vulnificus, Vibrio alginolyticus, and Vibrio mimicus. From the 24 Vibrio shrimp isolates, the Vitek 2 system method could identify 15 (62.5%) strains as Vibrio species and 7 (29.2%) strains as non-Vibrio species, but could not identify the rest 2 (8.3%) strains. But species-specific PCR method could identify 16 (66.7%) strains as Vibrio species and could not identify the rest 8 (33.3%) strains. Among the 24 Vibrio shrimp strains, these two methods could unanimously identify 7 (7/24, 29.2%) strains (2 V. parahaemolyticus, 4 V. alginolyticus, and 1 V. mimicus). Considering that such different identification results were obtained using the two different methods in this study, identification method for Vibrio species must be carefully chosen.

• Journal of Food Hygiene and Safety
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• v.34 no.1
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• pp.30-39
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• 2019

An analytical method was developed for the determination of sedaxane in agricultural products using liquid chromatograph-tandem mass spectrometry (LC-MS/MS). The samples were extracted with acetonitrile and partitioned with dichloromethane to remove the interference, and then purified by using silica SPE cartridges to clean up. The analytes were quantified and confirmed by using LC-MS/MS in positive ion mode using multiple reaction monitoring (MRM). The matrix-matched calibration curves were linear over the calibration ranges ($0.001-0.25{\mu}g/mL$) into a blank extract with $r^2$>0.99. For validation, recovery tests were carried out at three different concentration levels (LOQ, 10LOQ, and 50LOQ, n=5) with five replicates performed at each level. The recoveries were ranged between 74.5 to 100.8% with relative standard deviations (RSDs) of less than 12.1% for all analytes. All values were consistent with the criteria ranges requested in the Codex guidelines (CAC/GL 40, 2003) and Food Safety Evaluation Department guidelines (2016). The proposed analytical method was accurate, effective and sensitive for sedaxane determination in agricultural commodities.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.1
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• pp.33-46
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• 2010

We investigated and estimated at the characteristics of decomposition and by-products of N-Nitrosodimethylamine (NDMA) using a design of experiment (DOE) based on the Box-Behken design in an UV process, and also the main factors (variables) with UV intensity($X_2$) (range: $1.5{\sim}4.5\;mW/cm^2$), NDMA concentration ($X_2$) (range: 100~300 uM) and pH ($X_2$) (rang: 3~9) which consisted of 3 levels in each factor and 4 responses ($Y_1$ (% of NDMA removal), $Y_2$ (dimethylamine (DMA) reformation (uM)), $Y_3$ (dimethylformamide (DMF) reformation (uM), $Y_4$ ($NO_2$-N reformation (uM)) were set up to estimate the prediction model and the optimization conditions. The results of prediction model and optimization point using the canonical analysis in order to obtain the optimal operation conditions were $Y_1$ [% of NDMA removal] = $117+21X_1-0.3X_2-17.2X_3+{2.43X_1}^2+{0.001X_2}^2+{3.2X_3}^2-0.08X_1X_2-1.6X_1X_3-0.05X_2X_3$ ($R^2$= 96%, Adjusted $R^2$ = 88%) and 99.3% ($X_1:\;4.5\;mW/cm^2$, $X_2:\;190\;uM$, $X_3:\;3.2$), $Y_2$ [DMA conc] = $-101+18.5X_1+0.4X_2+21X_3-{3.3X_1}^2-{0.01X_2}^2-{1.5X_3}^2-0.01X_1X_2+0.07X_1X_3-0.01X_2X_3$ ($R^2$= 99.4%, 수정 $R^2$ = 95.7%) and 35.2 uM ($X_1$: 3 $mW/cm^2$, $X_2$: 220 uM, $X_3$: 6.3), $Y_3$ [DMF conc] = $-6.2+0.2X_1+0.02X_2+2X_3-0.26X_1^2-0.01X_2^2-0.2X_3^2-0.004X_1X_2+0.1X_1X_3-0.02X_2X_3$ ($R^2$= 98%, Adjusted $R^2$ = 94.4%) and 3.7 uM ($X_1:\;4.5\;$mW/cm^2$, $X_2:\;290\;uM$, $X_3:\;6.2$) and $Y_4$ [$NO_2$-N conc] = $-25+12.2X_1+0.15X_2+7.8X_3+{1.1X_1}^2+{0.001X_2}^2-{0.34X_3}^2+0.01X_1X_2+0.08X_1X_3-3.4X_2X_3$ ($R^2$= 98.5%, Adjusted $R^2$ = 95.7%) and 74.5 uM ($X_1:\;4.5\;mW/cm^2$, $X_2:\;220\;uM$, $X_3:\;3.1$). This study has demonstrated that the response surface methodology and the Box-Behnken statistical experiment design can provide statistically reliable results for decomposition and by-products of NDMA by the UV photolysis and also for determination of optimum conditions. Predictions obtained from the response functions were in good agreement with the experimental results indicating the reliability of the methodology used.

• Korean Journal of Agricultural Science
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• v.25 no.2
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• pp.216-224
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• 1998

This study was performed to offer the basic and applicable data for improvement of Korean cattle and dairy cattle, according to finding the genetic construction obtained from analysis of genetic polymorphisms of ${\beta}$-lactoglobulin and ${\kappa}$-casein loci related Korean cattle and Holstein cows using PCR-RFLP. Genomic DNA used in this study was prepared from the blood of 253 individuals of Korean cattle in Korean Native Cattle Improvement Center, NLCF, and the blood of 113 individuals of Holstein cows in National Livestock Research Institute. The results obtained are summarized as follows : 1. This study confirmed amplified products of 530bp and 262bp fragments obtained from the amplification of ${\beta}$-lactoglobulin and ${\kappa}$-casein loci in Korean cattle and Holstein breed by PCR. 2. The ${\beta}$-lactoglobulin AA genotype showed 153bp and 109bp fragments, and ${\beta}$-lactoglobulin AB genotype showed 153bp, 109bp, 79bp and 74bp fragments, and BB genotype showed 109bp, 79bp and 74bp fragments in amplified products of ${\beta}$-lactoglobulin loci with the restricted enzyme digestion of Hae III. 3. The ${\kappa}$-casein AA genotype showed a 530bp fragment, and ${\kappa}$-casein AB genotype showed 530bp, 344bp and 186bp fragments, and BB genotype showed 344bp and 186bp fragments in amplified products of ${\kappa}$-casein loci with the restricted enzyme digestion of Taq I. 4. On ${\beta}$-lactoglobulin genotypes and gene frequencies, Korean cattle were 6.72%, 26.09% and 67.19% for AA, AB and BB genotypes, and ${\beta}$-lactoglobulin A and B alleles were 0.197 and 0.803, and Holstein were 35.40%, 56.64% and 7.96% for AA, AB and BB genotypes, and ${\beta}$-lactoglobulin A and B alleles were 0.637 and 0.363, respectively. 5. On ${\kappa}$-casein genotypes and gene frequencies, Korean cattle were 46.25%, 39.13% and 14.62% for AA, AB and BB genotypes, and ${\kappa}$-casein A and B alleles were 0.658 and 0.342, and Holstein were 60.18% and 38.94% and 0.88% for AA, AB and BB genotypes, and ${\kappa}$-casein A and B alleles were 0.796 and 0.204, respectively. 6. As a consequence, the gene frequency was 0.197 and 0.803 for ${\beta}$-lactoglobulin A and B alleles, and 0.658 and 0.342 for ${\kappa}$-casein A and B alleles in Korea cattle, but was 0.637 and 0.363 for ${\beta}$-lactoglobulin A and B alleles, and 0.796 and 0.204 for ${\kappa}$-casein A and B alleles in Holstein, respectively.

• Journal of Food Hygiene and Safety
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• v.34 no.3
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• pp.227-234
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• 2019

An analytical method was developed for the determination of oxytetracycline in agricultural products using the QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method by liquid chromatography-tandem mass spectrometry (LC-MS/MS). After the samples were extracted with methanol, the extracts were adjusted to pH 4 by formic acid and sodium chloride was added to remove water. Dispersive solid phase extraction (d-SPE) cleanup was carried out using $MgSO_4$ (anhydrous magnesium sulfate), PSA (primary secondary amine), $C_{18}$ (octadecyl) and GCB (graphitized carbon black). The analytes were quantified and confirmed with LC-MS/MS using ESI (electrospray ionization) in positive ion MRM (multiple reaction monitoring) mode. The matrix-matched calibration curves were constructed using six levels ($0.001{\sim}0.25{\mu}g/mL$) and coefficient of determination ($r^2$) was above 0.99. Recovery results at three concentrations (LOQ, $10{\times}LOQ$, and $50{\times}LOQ$, n=5) were from 80.0 to 108.2% with relative standard deviations (RSDs) less than of 11.4%. For inter-laboratory validation, the average recovery was in the range of 83.5~103.2% and the coefficient of variation (CV) was below 14.1%. All results satisfied the criteria ranges requested in the Codex guidelines (CAC/GL 40-1993, 2003) and the Food Safety Evaluation Department guidelines (2016). The proposed analytical method was accurate, effective and sensitive for oxytetracycline determination in agricultural commodities. This study could be useful for safety management of oxytetracycline residues in agricultural products.

• Korean journal of food and cookery science
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• v.22 no.5 s.95
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• pp.642-649
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• 2006

The browning of soy sauce is caused by the reaction of amino-carbonyl between amino-compounds and reducing sugar. Only a few studies have investigated the formation of melanoidins in UHYUKJANG. The objectives of this study were to analyze the brown pigment of UHYUKJANG and to investigate the characteristics of UHYUKJANG in comparison with soy sauce and model melanoidins. The samples were ripened for 0, 60, 120, 180, 240, 300 and 360 days at 4$^{\circ}C$ and 20$^{\circ}C$. The pH, absorbance at 420 nm absorbance ratio of 400 to 500 nm and UV-VIS spectra as an index of color intensity were measured. Additionally, L, a and b values of the samples and the amount of 3-Deoxyglucosone(3DG) in the samples were measured. The pH of both soy sauce (from 6.26 to 5.52) and UHYUKJANG (from 6.13 to 5.11) rapidly decreased during the first 60 days of aging and was also affected by storage temperature. The absorbance of samples at 420 nm increased during the aging process, reaching its maximum after 180 days, regardless of sample and temperature. On the other hand, the intensity of brown color in the samples increased with increasing aging period according to the results of absorbance ratio (soy sauce: 1.37 to 5.29, UHYUKJANG: 1.37 to 5.02). The L value of soy sauce increased during the aging process and was maximized after 240 days at 4$^{\circ}C$ and 180 days at 20$^{\circ}C$, but decreased thereafter. There was no significant difference in L value of UHYUKJANG, regardless of aging period and temperature. On the other hand, the b value did not reveal any significant change during aging, but the a value increased until 120 days of aging in the other samples except for UHYUKJANG at 20$^{\circ}C$. The average amount of 3DG separated from soy sauce was 5.65 mg%, and from UHYUKJANG was 3.74 mg%. These results indicated that the browning of UHYUKJANG was also caused by melanoidins produced by the reaction of amino-carbonyl during the fermentation process.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.8
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• pp.542-548
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• 2014

Effects of bromide ($Br^-$) and iodide ($I^-$) concentrations, chlorine ($Cl_2$) doses, pH, temperature, ammonia nitrogen concentrations, reaction times and water characteristics on formation of iodinated trihalomethanes (I-THMs) during oxidation of iodide containing water with chlorine were investigated in this study. Results showed that the yields of I-THMs increased with the high bromide and iodide level during chlorination. The elevated pH significantly increased the yields of I-THMs during chlorination. The formation of I-THMs was higher at $20^{\circ}C$ than $4^{\circ}C$, $10^{\circ}C$ and $30^{\circ}C$. In chloramination study, addition of ammonium chloride ($NH_4Cl$) markedly increased the formation of I-THMs. Among the water samples collected from seven water sources including wastewater treatment plant (WWTP) effluent water (EfOM water), prepared humic containing water (HA water) and algal organic matter (AOM) containing water (AOM water), EfOM water generated the highest yields of I-THMs ($12.31{\mu}g/mg$ DOC), followed by HA water ($4.96{\mu}g/mg$ DOC), while AOM water produced the lowest yields of I-THMs ($0.99{\mu}g/mg$ DOC). $SUVA_{254}$ values of EfOM water, HA water and AOM water were $1.38L/mg{\cdot}m$, $4.96L/mg{\cdot}m$ and $0.97L/mg{\cdot}m$, respectively. The I-THMs yields had a low correlation with $SUVA_{254}$ values ($r^2$ = 0.002).

• Clinical and Experimental Pediatrics
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• v.50 no.1
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• pp.28-32
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• 2007

Purpose : Human angiotensin converting enzyme (ACE) gene shows an insertion/deletion polymorphism in 16 intron, and three genotypes are determined by whether a 287 bp fragment of the DNA is present or not; II, ID and DD genotype. DD genotype has been suggested as a risk factor of chronic nephrotic disease such as IgA nephropathy and diabetic nephropathy, various cardiovascular diseases and several other diseases. ACE activity increases in acute hepatitis, chronic persistent hepatitis, chronic active hepatitis and cirrhosis. On the other hand, patients with fatty livers have normal ACE activity. This study was designed to find out the relation between polymorphsims of the ACE genes and neonatal hyperbilirubinemia in Koreans. Methods : The genomic DNA was isolated from 110 full-term Korean neonates who had hyperbilirubinemia with no obvious causes (serum bilirubin$${\geq_-}12mg/dL$$) and 164 neonates of a control population (serum bilirubin <12 mg/dL). We performed polymerase chain reaction (PCR) to see the allele of the ACE gene. Electrophoresis was done in the PCR products in 1.5 percent agarose gel, and then DNA patterns were directly visualized under ethidium bromide staining. Results : ACE genotypes in the hyperbilirubinemia group are as follows; 26.36 percent for II, 53.64 percent for ID, 20.00 percent for DD, 0.532 for I allele and 0.468 for D allele. These distributions were not significantly different from those in the control group; 24.39 percent for II, 51.83 percent for DI, 23.78 percent for DD, 0.503 for I allele and 0.497 for D allele. Conclusion : In this study, ACE gene polymorphism was detected in the neonatal hyperbilirubinemia and control group. The most frequent genotype was ID. Our results indicate that the ACE gene polymorphism is not associated with the prevalence of neonatal hyperbilirubinemia in Koreans.