• Korean Journal of Environmental Agriculture
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• v.36 no.3
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• pp.175-183
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• 2017

BACKGROUND:The Aromatic rice which is characterized by the flavor of Nurungji when cooked rice, and consumption is increasing recently. The purpose of this study was to investigate the physicochemical characteristics and aroma components of five aromatic rice cultivars according to transplanting time. METHODS AND RESULTS: Quantitative analysis of protein, fat, fatty acid and essential amino acid for five aroma rice cultivars(Hyangmibyeo 2 ho, Aromi, Mihyang, Aranghyangchal, Heughyang)and transplanting time was analyzed by crude protein analyzer, gas chromatography (GC), liquid chromatography (LC) and viscosity analysis was done by using rapid viscosity analyzer (RVA). The content of 2-acetyl-1-pyrroline (2AP) was determined by gas chromatography mass spectrometer. (GC-MS) As a result, the average protein and lipid contents were 6.5% and 2.4%, respectively. The content of essential amino acid showed the highest content at 104.4mg/g. There was no significant change in normal nutrients during the transplanting time. By RVA, cv.Hyangmibyeo 2 ho showed the highest peak and total setback viscosities and lowest breakdown viscosity in early transplantation. The content of 2AP in flavor varieties and transplanting time was quantitatively analyzed by GC-MS. Among the cultivars, Aromi showed the highest 2AP contents at $66.7{\mu}g/100gin$ normal transplanting time. CONCLUSION: cv.Aromi and Hyangmibyeo 2 ho were excellent physicochemical properties and 2AP components contents amongaromatic rice cultivars tested. Theiroptimaltime to transplant was at the beginning of June in the area of Miryang.

• Culinary science and hospitality research
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• v.22 no.2
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• pp.13-28
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• 2016

This study performed quantitative analysis of isoflavone glycoside contents on Buseoktae, Daewon, Wooram beans and cheonggukjang made of Buseoktae beans from the LC/MS/MS. Also, the experiment carried out by means of RSM(response surface methodology), which included 10 experimental points for the two independent variables addition(40, 55, 70 g) and time(2, 3, 4 min) from the beginning point to boil of cheonggukjang. These were optimized using a Face-centered central composite design. Daidzein contents were $212.16{\mu}g/mL$ in Buseoktae, $212.21{\mu}g/mL$ in daewon, $158.54{\mu}g/mL$ in wooram beans. Genistein contents were $318.84{\mu}g/mL$ in Buseoktae, $310.50{\mu}g/mL$ in daewon, $262.71{\mu}g/mL$ in wooram beans. Total isoflavone contents were $532.50{\mu}g/mL$ in Buseoktae, $524.19{\mu}g/mL$ in Daewon, $422.71{\mu}g/mL$ in Wooram beans. Isoflavone contents of Buseoktae and Daewon were quite similar, relatively contents of Wooram beans were low. Total isoflavone contents of Buseoktae cheonggukjang (for business use) was $430.10{\mu}g/mL$ in A ($32^{\circ}C$, 96 h fermentation), $460.09{\mu}g/mL$ in B ($36{\sim}40^{\circ}C$, 30 h fermentation), $417.46{\mu}g/mL$ in C cheonggukjang($36{\sim}38^{\circ}C$, 72 h fermentation), B cheonggukjang was just a bit more than A, C cheonggukjang. The estimated response surfaces confirmed that the amount and time had significant effects on taste. The optimum condition of Buseoktae cheonggukjang taste was predicted to be 55.20 g addition at 2.92 min.

• Microbiology and Biotechnology Letters
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• v.42 no.4
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• pp.317-323
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• 2014

Violacein has received much attention due to its various important biological activities, including broad-spectrum antibacterial and antifungal activity, anti-malarial, anti-tumoral, anti-oxidant, and anti-diarrheal activities. EP15224 strain isolated from forest soils in Korea was found to be a new species belonged to the genus Massilia based on its 16S ribosomal DNA sequences. The 16S ribosomal DNA of strain EP15224 displayed 97% homology with Massilia sp. BS-1, the nearest violacein-producing bacterium. Strain EP15224 produced bluish-purple pigment well in a synthetic MM2 medium containing glucose, $(NH_4)_2SO_4$, $Na_2HPO_4{\cdot}7H_2O$, $KH_2PO_4$, $MgSO_4{\cdot}7H_2O$, and 1 mM $\small{L}$-tryptophan. The chemical analysis of the pigment by LC/MS/MS showed that it is violacein with molecular weight of 343.34. This is the second report on the production of violacein by a Massilia species. In this study, the optimal culture conditions for violacein production were established under which 280 mg/l crude violacein was produced : glucose 2 g/l, $(NH_4)_2SO_4$ 1 g/l, $Na_2HPO_4{\cdot}7H_2O$ 2 g/l, $KH_2PO_4$ 1 g/l, $MgSO_4{\cdot}7H_2O$ 0.1 g/l, L-tryptophan 0.24 g/l, 25 ml medium in a 250 ml flask, with an inoculumn size of 10% (v/v), 72 h of cultivation with 250 rpm at $25^{\circ}C$.

• Culinary science and hospitality research
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• v.20 no.3
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• pp.37-49
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• 2014

In order to elucidate the usefulness of Lycopene, a cherry tomato variety, as a food material, the compositions of free amino acids, amino acid metabolites and polyphenol compounds were analyzed using HPLC and LC-MS/MS method. Lycopene contained eighteen free amino acids except for L-Cys and L-Try. L-Glu was the most abundant free amino acid, followed by L-Gln and L-Asp. The percentages of L-Glu, L-Gln and L-Asp of total free amino acid were 55.5%, 15.9% and 9.9% respectively. Lycopene contained essential amino acids with the exception of tryptophan. The following amino acid metabolites were found : ${\gamma}$-aminobutyric acid(GABA), carnitine(L-Car), o-phosphoethanolamine(o-Pea), hydroxylysine(Hyl) phosphoserine (p-Ser), N-methyl-histidine(Me-His), ethanolamine($EtNH_2$). Especially, GABA known as a neurotransmitter was present at a high level(305.99 mg/100 g dry weight). We identified the following polyphenol compounds in the cherry tomatoes : caffeic acid-hexose isomer I (CH I), caffeic acid-hexose isomer II (CH II), 3-caffeoylquinic acid(3-CQA), 5-caffeoylquinic acid(5-CQA), caffeoylquinic acid isomer(CQAI), quercetin-hexose-deoxyhexose-pentose(QTS), quercetin-3-rutinoside(Q-3-R), di-caffeoylquinic acid(di-CQA), tri-caffeoylquinic acid(tri-CQA), naringenin chalcone(NGC). Large quantities of Q-3-R and NGC known as bioactive compounds were found. These results revealed that Lycopene variety contained various nutritional and bioactive compounds and would be a potent functional food material.

• Journal of Ginseng Research
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• v.42 no.1
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• pp.21-26
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• 2018

Background: Furosine (${\varepsilon}$-N-2-furoylmethyl-L-lysine, FML) is an amino acid derivative, which is considered to be an important indicator of the extent of damage (deteriorating the quality of amino acid and proteins due to a blockage of lysine and a decrease in the digestibility of proteins) during the early stages of the Maillard reaction. In addition, FML has been proven to be harmful because it is closely related to a variety of diseases such as diabetes. The qualitative analysis of FML in fresh and processed ginsengs was confirmed using HPLC-MS. Methods: An ion-pair reversed-phase LC method was used for the quantitative analysis of FML in various ginseng samples. Results: The contents of FML in the ginseng samples were 3.35-42.28 g/kg protein. The lowest value was observed in the freshly collected ginseng samples, and the highest value was found in the black ginseng concentrate. Heat treatment and honey addition significantly increased the FML content from 3.35 g/kg protein to 42.28 g/kg protein. Conclusion: These results indicate that FML is a promising indicator to estimate the heat treatment degree and honey addition level during the manufacture of ginseng products. The FML content is also an important parameter to identity the quality of ginseng products. In addition, the generation and regulation of potentially harmful Maillard reaction products-FML in ginseng processing was also investigated, providing a solid theoretical foundation and valuable reference for safe ginseng processing.

• Journal of Microbiology and Biotechnology
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• v.26 no.11
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• pp.1943-1950
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• 2016

Polycyclic aromatic hydrocarbons (PAHs) are commonly present xenobiotics in natural and contaminated soils. We studied three (phenanthrene, naphthalene, and biphenyl) xenobiotics, catabolism, and associated proteins in Sphingobium chungbukense DJ77 by two-dimensional gel electrophoresis (2-DE) analysis. Comparative analysis of the growth-dependent 2-DE results revealed that the intensity of 10 protein spots changed identically upon exposure to the three xenobiotics. Among the upregulated proteins, five protein spots, which were putative dehydrogenase, dioxygenase, and hydrolase and involved in the catabolic pathway of xenobiotic degradation, were induced. Identification of these major multifunctional proteins allowed us to map the multiple catabolic pathway for phenanthrene, naphthalene, and biphenyl degradation. A part of the initial diverse catabolism was converged into the catechol degradation branch. Detection of intermediates from 2,3-dihydroxy-biphenyl degradation to pyruvate and acetyl-CoA production by LC/MS analysis showed that ring-cleavage products of PAHs entered the tricarboxylic acid cycle, and were mineralized in S. chungbukense DJ77. These results suggest that S. chungbukense DJ77 completely degrades a broad range of PAHs via a multiple catabolic pathway.

• The Korean Journal of Pesticide Science
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• v.15 no.3
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• pp.254-268
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• 2011

Fenoxycarb, pyriproxyfen and methoprene are juvenile hormone mimic insecticide. These insecticides have been widely used for mosquito, fly, scale insects, and Lepidoptera. The purpose of this study was to develop a simultaneous determination procedure of fenoxycarb, pyriproxyfen and methoprene residues in crops using HPLC-UVD/MS. These insecticide residues were extracted with acetone from representative samples of four raw products which comprised brown rice, apple, green pepper, and Chinese cabbage. The extract was diluted with saline water, and then n-hexane/dichloromethane partition was followed to recover these insecticides from the aqueous phase. Florisil column chromatography was additionally employed for final clean up of the extract. The analytes were quantitated by HPLC-UVD/MS, using a $C_{18}$ column. The crops were fortified with each insecticide at 3 levels per crop. Mean recovery ratios were ranged from 80.0 to 104.3% in four representative agricultural commodities. The coefficients of variation were less than 4.8%. Quantitative limit of fenoxycarb, pyriproxyfen, and methoprene was 0.04 mg/kg in crop samples. A HPLC-UVD/MS with selected-ion monitoring was also provided to confirm the suspected residues. The proposed simultaneous analysis method was reproducible and sensitive enough to determine the residues of fenoxycarb, pyriproxyfen and methoprene in the agricultural commodities.

• Korean Journal of Pharmacognosy
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• v.48 no.1
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• pp.70-76
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• 2017

Dendranthema spp are distributed in various regions in Korea. This report is the quantitative results of phenolic compounds on the 5 resources collected from all over the country. It was known that it has phenolic compounds, as an anticoagulant activities and immunoadjuvant activity of contribute to the cardiovascular effects. This was used for quantitative analysis of chlorogenic acid(CA), 3,5-Dicaffeoylquinic acid(3,5-DCA), 4,5-Dicaffeoylquinic acid(4,5-DCA) and linarin, with UPLC-PDA and LC-IT-TOF-MS. Extraction efficiency of compounds was compared by using ultrasonic extraction and reflux extraction with different extraction conditions (methods and time). In 50% MeOH extracs (30 mins) of Dendranthema zawadskii (Herb.) Tzvelev (SDZ), Dendranthema zawadskii var. yezoense (Maek.) Y.M.Lee & H.J.Choi (NDZ), Dendranthema zawadskii (Herb.) Tzvelev var. teuisectum (Kitag.) J. H. Pak (GDZ), Dendranthema careanum (H. $L{\acute{e}}v$. & Vaniot) Vorosch. (HDC) and Dendranthema zawadskii var. tenuisectum Kitag (PDZ), chlorogenic acid contents were 1.14‰, 6.95‰, 7.27‰, 1.47‰ and 2.64‰, 3,5-dicaffeoylquinic acid contents were 3.30‰, 5.60‰, 10.81‰, 2.67‰ and 1.50‰, 4,5-dicaffeoylquinic acid contents were 0.74‰, 1.93‰, 3.36‰, 0.61‰ and 0.43‰ and linarin contents were 3.90‰, 10.15‰, 0.15‰, 0.73‰ and 0.21‰, respectively.

• Journal of Applied Biological Chemistry
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• v.60 no.3
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• pp.249-256
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• 2017

The Monascus azaphilone (MAz) pigment is a well-known food colorant that has yellow, orange and red components. The structures of the yellow and orange MAz differ by two hydride reductions, with yellow MAz being the reduced form. Orange MAz can be non-enzymatically converted to red MAz in the presence of amine derivatives. It was previously demonstrated that mppE and mppG are involved in the biosynthesis of yellow and orange MAz, respectively. However, ${\Delta}mppE$ and ${\Delta}mppG$ knockout mutants maintained residual production of yellow and orange MAz, respectively. In this study, we deleted the region encompassing mppD, mppE and mppG in M. purpureus and compared the phenotype of the resulting mutant (${\Delta}mppDEG$) with that of an mppD knockout mutant (${\Delta}mppD$). It was previously reported that the ${\Delta}mppD$ strain retained the ability to produce MAz but at approximately 10% of the level observed in the wildtype strain. A chemical analysis demonstrated that the ${\Delta}mppDEG$ strain was still capable of producing both yellow and orange MAz, suggesting the presence of minor MAz route(s) not involving mppE or mppG. Unexpectedly, the ${\Delta}mppDEG$ strain was observed to accumulate fast-eluting pigments in a reverse phase high-performance liquid chromatography analysis. A LC-MS analysis identified these pigments as ethanolamine derivatives of red MAz, which had been previously identified in an mppE knockout mutant that produces high amounts of orange MAz. Although the underlying mechanism is largely unknown, this study has yielded an M. purpureus strain that selectively accumulates red MAz.

• Journal of Microbiology and Biotechnology
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• v.34 no.9
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• pp.1836-1847
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• 2024

Polyethylene terephthalate (PET), one of the most widely used plastics in the world, causes serious environmental problems. Recently, scientists have been focused on the enzymatic degradation of PET, an environmentally friendly method that offers an attractive approach to the degradation and recycling of PET. In this work, PET hydrolase from Streptomyces sp. W2061 was biochemically characterized, and the biodegradation of PET was performed using the PET model substrate bis (2-hydroxyethyl terephthalate) (BHET). PET hydrolase has an isoelectric point of 5.84, and a molecular mass of about 50.31 kDa. The optimum pH and temperature were 7.0 and 40℃, respectively. LC-MS analysis of the enzymatic products showed that the PET hydrolase successfully degraded a single ester bond of BHET, leading to the formation of MHET. Furthermore, in silico characterization of the PET hydrolase protein sequence and its predicted three-dimensional structure was designed and compared with the well-characterized IsPETase from Ideonella sakaiensis. The structural analysis showed that the (Gly-x1-Ser-x2-Gly) serine hydrolase motif and the catalytic triad (Ser, Asp, and His) were conserved in all sequences. In addition, we integrated molecular dynamics (MD) simulations to analyze the variation in the structural stability of the PET hydrolase in the absence and presence of BHET. These simulations showed the formation of a stable complex between the PET hydrolase and BHET. To the best of our knowledge, this is the first study on Streptomyces sp. W2061 to investigate the BHET degradation activity of PET hydrolase, which has potential application in the biodegradation of plastics in the environment.