• Korean journal of food and cookery science
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• v.13 no.1
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• pp.7-15
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• 1997

The composition and polymeric structure of starch are the most important factors to determine the functional properties of rice. In an effort to relate the structural characteristics and its functional properties of starch in rice, molecular structural properties of starch from 6 rice cultivars were analysed. To relate the structure and function of starch the texture of Jeung-pyun made of rice were analyzed during retrogradation. The polymeric structure of rice starch was analyzed by debranching with isoamylase after gelatinization and fractionated with Sephadex G-75 gel filteration. The size fractionated debranched starch was categorized into four groups such as Fraction I, II, III and Intermediate Fraction depending in their max, The fractions with the max higher than 620 nm were designated as Fraction I, while those in the range of 600-620 nm and 540-600 nm as the Intermediate Fraction and Fraction II, respectively. The Fractions with the max lower than 540 were described as Fraction III. The average degree of polymerization (DP) of the Fraction I was estimated to be higher than 200, and those of other fractions, i.e. the Intermediate Fraction I, Fraction II and III were 150,45 and 25, respectively. The levels of Fraction I were varied from II to 35％ of total sugar. The Fraction I showed the linear relationship with the amylse contents, and the Intermediate Fraction, which might contain the mixture of short chain of amylose and debranched long chain of amylopectin, were measured to be in the range of 2.7∼8.4%. The levels of fraction II and III, both to be considered as the branches of amylopectin, were ranged 14.5∼23.6% and 39.7∼73.0%, respectively. The ratio of Fraction III to Fraction II describing the degree of branch or compactness of amylopectin was estimated to be around 4.0 for waxy varieties and around 2.0 for high amylose cultivars. With these results, it can be suggested that the degree of branch of the amylopectin may effect on amylose contents of starch or rice versa, To invertigate processing aptitude of different rice cultivars for the preparation of Jeung-pyun, its texture was analyzed by Instron, hardness, cohesiveness, elasticity, gumminess and chewiness of Jeung-pyun made of rice showed the significant relationship with the amylose content. Hardness was increased during retrogradation of product, but the relationship between hardness and amylose content due to not only difference in amylose content but also difference in structural characteristics of starch. In analysis of relationship between structure of rice starch and mechanical properties of Jeung-pyun during retrogradation elasticity did not show any relationship before retrogradation bur during retrogradation showed significant correlation. With these result, it can be suggested that the degree of branch of the amylopectin may effect on elasticity during retrogradation. However hardness, cohesiveness, gumminess and chewiness which were significant different before retrogradation, showed some correlation with structure of rice starch during retrigradation.

• Korean Journal of Food Science and Technology
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• v.32 no.5
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• pp.1158-1167
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• 2000

To produce ${\beta}-cyclodextrin({\beta}-CD)$, a cyclodextrin glucanotransferase(CGTase) producing Aspergillus sp. CC-2-1 was isolated from soil. The enzyme was purified and its enzymological characteristics were investigated. It was found that production of CGTase reached to the maximum when the wheat bran medium containing 0.1% albumin, 2% $(NH_4)_2S_2O_8$, 2% soluble starch and 0.2% $KH_2PO_4$ was cultured for 5 days at $37^{\circ}C$. The purity of CGTase was increased by 13.14 folds after DEAE-cellulose ion exchange chromatography and Sephadex G-100, G-150 gel filtration and the specific activity was 172.14 unit/mg. Purified enzyme was confirmed as a single band by the polyacrylamide gel electrophoresis. The molecular weight of CGTase was estimated to be 27,800 by Sephadex G-100 gel filtration and SDS-polyacrylamide gel electrophoresis. The optimum pH and temperature for the CGTase activity were 9.0 and $80^{\circ}C$, respectively. The enzyme was stable in pH $8.0{\sim}11.0$ at $60{\sim}80^{\circ}C$. The activity of purified enzyme was activated by $K^+,\;Cu^{2+}$ and $Zn^{2+}$. The activity of the CGTase was inhibited by the treatment with 2,4-dinitrophenol and iodine. The result suggests that the purified enzyme has phenolic hydroxyl group of tyrosine, histidine imidazole group and terminal amino group at active site. The reaction of this enzyme followed typical Michaelis-Menten kinetics with the $K_m$ value of 18.182 g/L with the $V_{max}$ of 188.68 ${\mu}mole/min$. The activation energy for the CGTase was calculated by Arrhenius equation was 1.548 kcal/mol.

• Journal of Nutrition and Health
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• v.45 no.5
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• pp.429-436
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• 2012

This study was performed to examine the characteristics of protein of red crab (Chionoecetes japonicus) shell powder hydrolyzed by commercial proteases. Red crab shell was digested by commercial proteases, such as Protamex (P), Neutrase (N), Flavourzyme (F), Alcalase (A), Protease M (PM) and Protease A (PA). Protein yield analyzed by Biuret assay, absorbance at 280 nm and brix revealed that PA was the enzyme having the highest proteolytic activity. SDS PAGE showed that molecular weight of proteins produced by protease treatments was various and below 150 kDa. Combinational treatment of proteases (PA + P, PA + PM, PA + F, PA + A) was tried whether these increase protein hydrolysis from red crab shell powder compared to a PA single treatment. Soluble protein content was similar, but amino acid concentration by combinational treatments was higher than PA single treatment [PA + P 247.4 mg/g > PA + F (206.4 mg/g) > PA + A (133.4 mg/g) > PA + PM (59.1 mg/g) > PA (54.9 mg/g)]. Amino acid composition by combinational treatments was slightly different. Most abundant essential amino acids were phenylalanine, glycine, alanine, and leucine, whereas tyrosine and cystine were not detected.

• Atmosphere
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• v.31 no.3
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• pp.267-282
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• 2021

Characteristics of carbonaceous components and organic compounds in PM_2.5 over the atmosphere of the Yellow Sea were investigated. PM_2.5 samples were collected onboard the meteorological research vessel, GISANG 1, over the Yellow Sea during the YES-AQ campaign in 2018 and 2019, respectively. The average concentrations of carbonaceous components in this region were 2.59 ± 1.59 ㎍ m^-3 for the OC, 0.24 ± 0.10 ㎍ m^-3 for the EC, 2.14 ± 1.30 ㎍ m^-3 for the WSOC and 1.17 ± 0.94 ㎍ m^-3 for the HULIS-C, respectively. The total concentration of 56 organic compounds (ΣOCs) accounts for 10% of OC. The main group among organic compounds were dicarboxylic acids which account for 57% of ΣOCs, followed by n-alkanoic acids accounting for 34% of ΣOCs. In n-alkanoic acid distribution, hexanoic (C_6:0) and octanoic (C_8:0) acids which are low molecular weight n-alkanoic acids and known as emitted from marine biogenic activities were dominant in this region. Furthermore, non-HULIS-C fraction increased when the air mass originated from the marine region rather than the continental region. When the Asian dust episode was observed, the WISOC concentrations along with the levoglucosan were increased, while the haze episodes caused the increase of WSOC, HULIC-S and DCAs. In this study, we found that the components of carbonaceous and organic aerosols in PM_2.5 over the Yellow Sea were changed with the specific air pollution episodes. It indicates that the physicochemical properties of PM_2.5 can be changed by the air pollution episodes in this region.

• Korean Journal of Ichthyology
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• v.33 no.2
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• pp.45-56
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• 2021

A male, presumed to be an intergeneric hybrid between Tanakia lanceolata and Rhodeus pseudosericeus, was collected in the Boryeong Daecheoncheon Stream flowing into the Yellow Sea in the Republic of Korea. Morphological and molecular phylogenetic analyses were performed to discriminate the definite origin of the estimated natural hybrid. As a result of the morphological analysis, the color of the dorsal and anal fin rays edges of the natural hybrid individual, the upper and lower body colors followed the morphological characteristics of T. lanceolata, and that blue longitudinal stripe in the center of the caudal peduncle, the incomplete lateral line, and the barbels absent followed the morphological characteristics of R. pseudosericeus. In addition, as a result of the cytochrome b (cytb) gene analysis of mitochondrial DNA (mtDNA), the natural hybrid showed a nucleotide sequence similarity of 99.82 to 100% with T. lanceolata, and the maternal species was identified as T. lanceolata. As a result of the recombination activating gene 1 (rag1) gene analysis of nuclear DNA (nDNA), the natural hybrid showed double peaks pattern reflecting both the single nucleotide polymorphism sites (38 bp) between T. lanceolata and R. pseudosericeus, and the paternal species was identified as R. pseudosericeus. Therefore, a natural hybrid estimated male of Acheilognathinae analyzed in this study was found to be an intergeneric hybrid between a female T. lanceolata and a male R. pseudosericeus.

• Food Engineering Progress
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• v.13 no.1
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• pp.1-7
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• 2009

Fermented functional onion juice was developed using lactic acid bacteria as a fermentation starter of onion. From the preliminary studies, we selected the bacterium KC-007 (named as Pediococcus pentosaceus based on morphological and physiological characteristics, carbon utilization pattern, and molecular genetic characteristics) as a fermentation starter. The optimum recipe of functional fermented onion juice based on manufacturing process and sensory evaluation were determined as 27% of fermentation liquer, 27% of apple juice, 3.7% of HFCS, 1.86% of $\beta$-cyclodextrin, 0.9% of oligosaccharide, 0.2% of apple flavor, 0.09% of citric acid, and 39.25% of water.

• The Korean Journal of Mycology
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• v.46 no.4
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• pp.415-425
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• 2018

To study the characteristics of yeasts, 433 strains of the genus Aureobasidium were isolated from the flowers collected from Jeolla-do in Korea, and the diversity of the strains was confirmed through molecular phylogenetic and morphological analyses. Based on phylogenetic analysis of LSU rDNA seguences, the Aureobasidium strains from the Jeolla-do province were classified into six groups. The dominant species of flower-derived yeasts were Groups A and D. Since Groups B, E, and F were found only in Jeollanam-do, we can infer that the Aureobasidium is distributed more widely in Jeollanam-do than in the Jeollabuk-do province. Through LSU and ITS rDNA sequence analyses, Group A was identified as A. pullulans, Group B as A. melanogenum, and Group F as a putative new species of Aureobasidium. Groups C, D, and E do not completely match with A. leucospermi, A. namibiae, or A. subglaciale by LSU or ITS rDNA analysis but are closely related to those species. Comparisons of colony morphology are likely to be more helpful in distinguishing Groups C and D. The results of this study can provide useful characteristics for future studies of the genus Aureobasidium.

• Korean Journal of Ichthyology
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• v.30 no.4
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• pp.185-193
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• 2018

From 2017 to 2018, the disease has been monitored at four culturing eel farms in Incheon and Gyeonggi region in Korea. As a result, diseases with gill congestion frequently occurred. This disease occurred regardless of size of eel, but the frequency and cumulative mortality were high in eels within 3 months after stocking. The infected fish showed pathological histopathological features such as intense congestion and dilation in the central venous sinus (CVS) of gill filaments and hemorrhages in liver and kidney. Hexagonal viral particles measuring about 70 nm in diameter was observed in nuclei and cytoplasm of gill vascular endothelial cells. Molecular biologic diagnosis by both PCR and genetic analysis has been revealed that the causative agent of this disease is Japanese eel endothelial cells-infecting virus (JEECV), the cause of viral endothelial cell necrosis of eel (VECNE), which is mainly reported in Japan. This study is the first report on the characteristics of JEECV and VECNE infection in domestic eel farms.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.931-937
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• 2018

Sutures are used not only for wound closure but also for oriental medicine field, beauty and even for plastic surgery. Especially, it is popular in the field of cosmetic surgery. In this paper, we produced sutures using PCL and PLLA with better strength than PDO sutures, which was widely used in the past. To learn about the mechanical characteristics of the PCL and PLLA sutures, the contraction change, tensile strength, and elongation were measured. And SEM was also analyzed for diameter and surface. The contraction change Ratio of sutures are stabilized after a certain period of time regardless of temperature. Also, it can be seen that the higher the temperature, the higher the contraction increase rate. And the rate change of mechanical properties is different according to the temperature before and after the glass temperature. Also the higher the temperature, the faster the molecular motion and the lower the tensile strength. The diameter of the PLLA and PCL sutures is opposite to the contraction change ratio. And it is considered that the sterilization temperature of PLLA sutures is best to set at $45^{\circ}C$ and the sterilization temperature of PCL sutures is best to set at $35^{\circ}C$.

• Analytical Science and Technology
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• v.19 no.3
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• pp.255-262
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• 2006

In this study, we attempted to evaluate the sorptive loss of VOC upon their contact with different material surfaces including clothing pieces. For the purpose of this study, we developed a method to evaluate such loss by employing a filter holder pack in the thermal desorption line of the GC/FID system. The calibration curves of different aromatic VOCs including benzene, toluene, and xylene were made by loading them at different quantities through the analytical line. A series of experiments were conducted repetitively to draw calibration data sets for all three materials covering glass fiber, cotton, and nylon. The results were then compared in terms of both material types and of VOC types. The extent of sorptive loss increased in a highly systematic manner across different materials such as glass fiber, cotton, and nylon. The patterns of sorptive loss also increased gradually across VOC type such toward in the direction of increasing molecular weights: benzene, toluene, and xylene. According to this experimental study, it is concluded that sorptive behavior of pollutint compounds like VOC can be controlled by the combined effects of both chemical properties and material characteristics.