• Korean Journal of Food Science and Technology
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• v.53 no.4
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• pp.382-390
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• 2021

In this study, solubilized yuzu pulp powder (EYP) was produced using enzyme treated yuzu pulp powder (YP) and used to manufacture yuzu granules (0-20% EYP content). The physicochemical, product stability, and functional properties of Yuzu granules were compared among five enzyme treatments. Among the five treatments, CL had the highest YP solubilization yield (48.68%). Microstructural observation of EYP using FE-SEM revealed that its surface became irregular and porous after enzymatic treatment. Compared to YP, EYP had 2 times lower insoluble dietary fibers and 3 times lower hemicellulose and cellulose content. Among the yuzu granules, IV (yuzu granules with 15% EYP) had an excellent water and oil holding capacity and flowability. IV granule had the highest narirutin and hesperidin content of 3.4 mg and 2.2 mg/g DW, respectively and the highest antioxidant (68.4%) and tyrosinase inhibitory activities (82.5%). Therefore, EYP or granule with EYP can be used as a functional component in food industry or pharmaceutical field.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.4
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• pp.564-572
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• 2015

Nutritional compositions, volatile compounds, and sensory attributes of Cynanchi wilfordii Radix were analyzed in order to examine its practical utilization as a food resource. In the proximate analysis, protein and lipid contents were shown to be 14.6 and 5.0 mg/100 g, respectively, in C. wilfordii Radix. Potassium was the most predominant mineral (809 mg/100 g), as determined by inductively coupled plasma-optical emission spectrometry in parallel with microwave acid digestion. Total phenolic content was found to be 410 mg/100 g. Further, arginine and linoleic acid were the most abundant amino acid and fatty acid of C. wilfordii Radix, respectively. To examine its functional properties, classical 2,2-diphenyl-1-picrylhydrazyl (DPPH) analysis was performed. As a result, the concentration of C. wilfordii Radix required to scavenge 50% of DPPH radicals was 1.16 mg of dried material. Lastly, in olfactory and sensory tests, ${\beta}$-eudesmol (woody odor) was the major flavor compound responsible for the bitter taste and sensory attributes of C. wilfordii Radix. Taken altogether, the above results provide important preliminary results for utilization of C. wilfordii Radix as a food resource.

• Applied Chemistry for Engineering
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• v.18 no.3
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• pp.234-238
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• 2007

Highly conducting Polypyrroles soluble in organic solvents were synthesized using functional doping agents, such as mixed dopants [sodium di(2-ethylhexyl)sulfosuccinate (DEHSNa) Naphthalenesulfonic acid (NSA), DEHSNa Toluenesulfonic acid (TSA), DEHSNa Dodecylbenzensulfonic acid (DBSA)] and mixed oxidants [$(NH_4)_2S_2O_8{\cdot}FeCl_3$, $(NH_4)_2S_2O_8{\cdot}Fe_2(SO_4)_3$]. Ppy-DEHS powder using an oxidant, such as $(NH_4)_2S_2O_8$ (10 wt%/vol.) showed higher solubility than the mixed dopant (DEHSNa NSA, 3 wt%/vol.) and mixed oxidant [$(NH_4)_2S_2O_8{\cdot}Fe_2(SO_4)_3$, 4 wt%/vol.] in DMF solvent. But Ppy-DEHS free standing film using a mixed dopant, such as DEHSNa NSA (16 S/cm) and a mixed oxidant, such as $(NH_4)_2S_2O_8{\cdot}Fe_2(SO_4)_3$ (13 S/cm) cast from DMF solvent showed higher electrical conductivity than $(NH_4)_2S_2O_8$ (2 S/cm). For the Ppy-DEHS films using various condition cast from DMF solvent, three dimensional various range hopping model (3D VRH ; $\{{\sigma}_{dc}(T)={\sigma}_oexp[-(T_o/T)^{1/4}]\}$) provided fit to the results of temperature dependence of electrical conductivity measurement.

• Applied Chemistry for Engineering
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• v.17 no.2
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• pp.177-182
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• 2006

In this work, we have prepared organophilic MMT having thermal stability by ion exchange reaction of various aromatic ammonium salts with MMT containing sodium ion. The organic modifiers having alkyl side chains and amine functional group were successfully synthesized by effectively introducing the surfaces of MMT via ion exchange reaction to form organophilic MMTs with a view to improve the reactivity and thermal stability. The WAXD patterns of organophilic MMT showed the more increased gallery spacing by $3.3{\AA}$ than that of the pristine MMT and also the onset of initial decomposition of organophilic MMT was $275^{\circ}C$ as determined by a thermogravimetric analysis. The polyimide (PI) nanocomposite films based on poly(amic acid) and organophilic MMT were prepared by a solution blending followed by cyclodehydration reaction. We have investigated the dispersity of organophilic MMTs in PI matrix by using WAXD and the effect of the organophilic MMT content on the mechanical properties of PI nanocomposite films was studied.

• Molecules and Cells
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• v.39 no.5
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• pp.426-438
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• 2016

Plant disease resistance occurs as a hypersensitive response (HR) at the site of attempted pathogen invasion. This specific event is initiated in response to recognition of pathogen-associated molecular pattern (PAMP) and subsequent PAMP-triggered immunity (PTI) and effector-triggered immunity (ETI). Both PTI and ETI mechanisms are tightly connected with reactive oxygen species (ROS) production and disease resistance that involves distinct biphasic ROS production as one of its pivotal plant immune responses. This unique oxidative burst is strongly dependent on the resistant cultivars because a monophasic ROS burst is a hallmark of the susceptible cultivars. However, the cause of the differential ROS burst remains unknown. In the study here, we revealed the plausible underlying mechanism of the differential ROS burst through functional understanding of the Magnaporthe oryzae (M. oryzae) AVR effector, AVR-Pii. We performed yeast two-hybrid (Y2H) screening using AVR-Pii as bait and isolated rice NADP-malic enzyme2 (Os-NADP-ME2) as the rice target protein. To our surprise, deletion of the rice Os-NADP-ME2 gene in a resistant rice cultivar disrupted innate immunity against the rice blast fungus. Malic enzyme activity and inhibition studies demonstrated that AVR-Pii proteins specifically inhibit in vitro NADP-ME activity. Overall, we demonstrate that rice blast fungus, M. oryzae attenuates the host ROS burst via AVR-Pii-mediated inhibition of Os-NADP-ME2, which is indispensable in ROS metabolism for the innate immunity of rice. This characterization of the regulation of the host oxidative burst will help to elucidate how the products of AVR genes function associated with virulence of the pathogen.

• Applied Chemistry for Engineering
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• v.26 no.3
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• pp.265-269
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• 2015

Chlorella vulgaris (C. vulgaris) is a spherical unicellular green algae and the diameter ranges from 2 to $10{\mu}m$. C. vulgaris possess nutritional excellence because it contains various functional materials including high protein contents, chlorophyll, carotenoid, and chlorella growth factor (CGF). In order to study effects of mutagen, ethyl methane sulphonate (EMS) was used as a chemical mutagen and some mutants could be obtained. We named 2 type mutants as E14 and E24 obtained after treating with EMS. In the cell growth, growth patterns of mutants were similar to those of the wild type. Chlorophyll contents of E14 and E24 increased up to 99 and 52%, respectively compared to those of the wild type. The carotenoid content of E14 increased to 7%, but the value of E24 decreased 5% compared to that of the wild type. For the lipid contents E24 increased to 23%, while E14 decreased 12% when compared to those of the wild type. As a result, there is no difference between the mutants and wild type in the cell growth, but considering that mutants contains more physiological materials than those of the wild type, we can expect the mutants of C. vulgaris could be used as important high added-value materials.

• Journal of Life Science
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• v.21 no.10
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• pp.1370-1376
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• 2011

To study the functional genomic analysis of a crenachaeon Sulfolobus acidocaldarius, we have constructed an auxotrophic mutant based on pyrEF, which encodes the pyrimidine biosynthetic enzymes orotate phosphoribosyltransferase and orotidine-5'-monophosphate decarboxylase. S. acidocaldarius was shown to be sensitive to 5-fluoroorotic acid (5-FOA), which can be selected for mutations in pyrEF genes within a pyrimidine biosynthesis cluster. Spontaneous 5-FOA-resistant mutants by ultraviolet, KH1U and KH2U, were found to contain two point mutations and a frame shift mutation in pyrE, respectively. Mutations at these sites from KH1U and KH2U decreased the activity of orotate phosphoribosyltransferase encoded by the pyrE gene and blocked the degradation of 5-FOA into toxic 5-FOMP and 5-FUMP that kill the cells. Therefore, KH1U and KH2U were uracil auxotrophs. Transformation of Sulfolobus-Escherichia coli shuttle vector pC bearing pyrEF genes from S. solfataricus P2 into S. acidocaldarius mutant KH2U restored 5-FOA sensitivity and overcame the uracil auxotrophy. This study establishes an efficient genetic strategy towards the systematic knockout of genes in S. acidocaldarius.

• Applied Chemistry for Engineering
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• v.26 no.4
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• pp.421-426
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• 2015

Arthrospira platensis (A. platensis) has been used in various fields including dietary supplements as it contains a high protein content and large amounts of unsaturated fatty acids. In addition, it has some pigments such as phycocyanin, myxoxanthophyll and zeaxanthin and thus has been used as a food additive and antioxidant substance. Nano-bubble hydrogen is to dissolve more than the saturation solubility in water by injecting the hydrogen gas in the nano-bubble hydrogen water. The nano-bubbles are known to possess higher antioxidant properties in addition to anticancer effects. In this paper, Arthrospira platensis was cultured in both a normal medium with distilled water and nano-bubble hydrogen water medium and their properties were compared. The cell growth and the content of chlorophyll and carotenoid in the nano-bubble hydrogen water was 15% higher than that of the control. The level of phycocyanin in nano-bubble hydrogen water was also 7% higher than that of the control. However, there were little differences in the lipid content between the nano-bubble and control. To determine the content of the antioxidants, the level of flavonoid and polyphenol were measured. The level of flavonoid in nano-bubble hydrogen water was found to be more than 70% increased when comparing to that of the control, while the level of polyphenol was similar to each other.

• Journal of the Korean Applied Science and Technology
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• v.33 no.3
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• pp.587-592
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• 2016

In this study, flexible acid treated single walled carbon nanotubes (A-SWCNTs) electrodes were fabricated by using gold coated PET substrate and spray coating technique. The acid-treatment method was conducted to introduce functional groups on the SWCNTs wall, which could improve dispersability of the SWCNTs and its electrochemical property. The electrochemical properties of flexible A-SWCNTs electrode were carried out by cyclic voltammetry(CV), electrochemical impedance were carried out by cyclic voltammetry(CV), electrochemical impedance spectroscopy(EIS) and galvanostatic charge/discharge (GCD) cycles. As a results, The specific capacitance value of the unbent A-SWCNTs electrode was $67F{\cdot}g^{-1}$, which decreased to $63F{\cdot}g^{-1}$ (94% retention) after 1000 GCD cycles. Interestingly, the specific capacitance of the unbent A-SWCNTs electrode with application of the 1000 GCD cycles was retained even after 500 bending to $30^{\circ}$ with 6000 GCD cycles.

• Microbiology and Biotechnology Letters
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• v.43 no.3
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• pp.275-279
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• 2015

Micro-algae are unicellular photosynthetic organisms and produce pigments such as chlorophyll and carotenoid. Chlorella contains a lot of protein and functional components like lipids, chlorophyll and carotenoids. In this study we induced mutants of Chlorella vulgaris (C. vulgaris) through ultraviolet radiation (UV-B) and selected two mutants by pigment (chlorophyll and carotenoids) content. We named the mutants ‘UBM1-2’, ‘UBM2-57’ and they were cultivated for 21-days. Cell growth, dry cell weight, protein content, lipid and pigments content were measured. The results indicated that the mutants displayed slower cell growth, lower dry cell weight and protein content than the wild type. However, for UBM1-2 the lipid content was 21% higher than the wild type. In addition, the mutants’ chlorophyll content was 37% and 89% higher than the wild type and the carotenoids content was 27% and 70% higher than the wild type, respectively.