• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.6
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• pp.912-920
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• 2015

The study was designed to investigate the effects of die temperature and $CO_2$ injection on the physical and antioxidant properties of extruded rice with tomato flour. Moisture content and screw speed were fixed at 25% and 150 rpm, respectively. Die temperatures and $CO_2$ injection were adjusted to 80, 110, and $140^{\circ}C$ and 0, and 300 mL/min, respectively. Specific mechanical energy input decreased as die temperature increased from 80 to $140^{\circ}C$. The expansion index increased, while bulk density decreased with $CO_2$ injection. All extrudates showed increased water soluble index (WSI) and water absorption index through the extrusion process. WSI increased as die temperature increased. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and total phenolic compounds increased as die temperature increased from 80 to $140^{\circ}C$. Total carotenoid and lycopene contents decreased through the extrusion process. Total carotenoid and lycopene contents upon 0 mL/min $CO_2$ injection and $140^{\circ}C$ die temperature were highest at $6.65{\mu}g/g$ and 2.69 mg/kg, respectively. In conclusion, $CO_2$ injection affects expansion properties while an increased die temperature leads to increased DPPH radical scavenging activity and total phenols.

• Korean Chemical Engineering Research
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• v.54 no.1
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• pp.114-119
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• 2016

In this study, we tried to add the conductivity to natural polymer like bacterial cellulose (BC) coated with the conductive polymer PEDOT:PEG, graphene and silver nano-wire (AgNW). Sulfuric acid of 10 to 20% was previously mixed with PEDOT:PEG and then the solution was electron spin-coated on the BC membrane. And then, additive coating with graphene and AgNW were done to improve conductivity, which was examined by hall effect. As the result, we confirmed a considerable improvement of conductivity compared to BC-coated film without sulfuric acid treatment as $2.487{\times}10^{10}$ vs $8.093{\times}10^{15}$ ($1/cm^3$), showing higher electron density with $3.25{\times}10^5$ times. Also, we identified that changed particle type to the polymer type by sulfuric acid using SEM analysis. For FT-IR analysis, it was confirmed that S-O radical ($1200cm^{-1}$) increased in the sulfuric acid treatment than non-treated sulfuric acid. As the method used very small amount of PEDOT:PEG, its transparency could be kept, and pre-treatment process of sulfuric acid will be able to simplify the production process.

• Korean Journal of Food Science and Technology
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• v.48 no.2
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• pp.159-164
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• 2016

This study was conducted to investigate the quality characteristics and antioxidant properties of cookies supplemented with 1-4% (w/w) persimmon leaf powder (PLP). pH and density of the cookie dough increased significantly with increase in PLP concentration (p<0.05). The moisture content, spread ratio, and loss rate of cookies decreased significantly with increase in PLP concentration (p<0.05). Lightness ($L^*$), redness ($a^*$), and yellowness ($b^*$) also decreased significantly with increase in PLP concentration (p<0.05). The use of PLP significantly increased the hardness of the cookies. Moreover, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical scavenging activities were significantly elevated (p<0.05). The consumer acceptance test indicated that addition of PLP at a concentration of up to 2% (w/w) garnered a favorable response from consumers with respect to softness, taste, and overall preference. On the basis of the overall observations, cookies supplemented with 2% (w/w) PLP were found to benefit from the functional properties of PLP, without compromising on consumer acceptance.

• Journal of the Korean Applied Science and Technology
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• v.34 no.1
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• pp.91-100
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• 2017

The object of this study was to measure the bioactivity and antioxidant activity of seed from Gardenia jasminoides Ellis fructus (GJE). GJE seeds were performed the extraction of them by chloroform:methanol (CM, 2:1, v/v), 70% ethanol and n-butanol. Sequentially, total phenol content, nitrogen oxide scavenging activity, antioxidant activity and lipid peroxidation inhibition activity of the extracts were investigated. Solvent extract bioactivity of increasing concentrations (0.2, 0.4, 0.6 mg/mL) were significantly increased (p<0.05). GJE seed extracts showed lower activity than positive control (ascorbic acid, BHA, trolox). The highest concentration of CM extracts was obtained in the same manner as the results of analysis of the total phenol contents of the GJE seed, and 70% ethanol extract showed the highest activity of reducing power. The water soluble carotenoids crocin and flavonoid were effective. As a result of this experiment. the seeds of GJE showed excellent antioxidant, and lipid peroxidation inhibitory properties.

• Tuberculosis and Respiratory Diseases
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• v.67 no.4
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• pp.318-324
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• 2009

Background: A diagnosis and treatment of chest wall tuberculosis (CWTB) is both difficult and controversial. The aim of this study was to collect information on the optimal treatment for CWTB. Methods: The clinical features, radiographic findings, and treatment outcomes of 26 patients, who underwent surgery and were diagnosed histopathologically, were retrospectively analyzed. Results: The most common presenting symptom was a palpable mass found in 24 patients (92.3%). In all patients, CT revealed a soft tissue mass that was accompanied by a central low density, with or without peripheral rim enhancement. The sensitivity and specificity of the bone scintigram for bone involvement were 87.5% and 100%, respectively. CWTB was diagnosed preoperatively by aspiration cytology and smear for acid-fast bacilli in five out of 11 patients. Twenty-three patients (88.5%) underwent a radical excision and three underwent incision/drainage or an incisional biopsy. The duration of antituberculous medication was 7.5${\pm}$3.98 months with a follow-up period of 28.2${\pm}$26.74 months. Among the 20 patients who completed their treatment, nine received chemotherapy for six months or less and 11 received chemotherapy for nine months or more. Two patients had a recurrence four and seven months after starting their medication. Conclusion: A 6 month regimen may be appropriate for CWTB patients who have undergone a complete excision.

• The Korean Journal of Financial Management
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• v.20 no.2
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• pp.73-94
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• 2003

In general, the interest rate is forecasted by the parametric method which assumes the interest rate follows a certain distribution. However the method has a shortcoming that forecasting ability would decline when the interest rate does not follow the assumed distribution for the stochastic behavior of interest rate. Therefore, the nonparametric method which assumes no particular distribution is regarded as a superior one. This paper compares the interest rate forecasting ability between the two method for the Monetary Stabilization Bond (MSB) market in Korea. The daily and weekly data of the MSB are used during the period of August 9th 1999 to February 7th 2003. In the parametric method, the drift term of the interest rate process shows the linearity while the diffusion term presents non-linear decline. Meanwhile in the nonparametric method, both drift and diffusion terms show the radical change with nonlinearity. The parametric and nonparametric methods present a significant difference in the market price of interest rate risk. This means in forecasting the interest rate and the market price of interest rate risk, the nonparametric method is more appropriate than the parametric method.

• Journal of the Korean Chemical Society
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• v.42 no.1
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• pp.84-91
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• 1998

Random copolymers of N-isopropyl acrylamide (NIPAAm) and acrylic acid (AAc) which exhibit temperature- and pH-responsive behavior were synthesized by free-radical polymerization. The copolymers were characterized by means of FT-IR spectrometry and titration. The influence of polyelectrolyte on the lower critical solution temperature (LCST) of pH/temperature-sensitive polymers was investigated in the pH range of 2-12. The LCSTs of PNIPAAm/water in poly(NIPAAm-co-AAc) were determined by cloud-point measurements. A polyelectrolyte complex was prepared by mixing poly(NIPAAm-co-AAc) with poly(allylamine) (PAA) or poly(L-lysine) (PLL) solutions as anionic and cationic polyelectrolytes, respectively. Back titration was performed to determine the content of AAc and to study the effect of comonomer ionization on the LCST. The LCSTs of PNIPAAm/water in the copolymers were strongly affected by pH, presence of polyelectrolyte, AAc content, and charge density on the polymer. The polyelectrolyte complexes were formed at neutral condition. The influence of more hydrophobic PLL as polyelectrolyte on the cloud-point of PNIPAAm/water in the copolymer was stronger than that of poly(allylamine) (PAA).

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.7
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• pp.920-925
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• 2009

This study evaluated the physicochemical and sensory characteristics of cookies containing various concentrations (0, 3, 6, and 9%) of cherry powder (obtained from ground fruit of Prunus serrulata L. var. spontanea Max. wils.). The pH of dough decreased with the addition of cherry powder, whereas the density of dough increased. The spread factor of control samples also evidenced significantly higher values than the other samples. The results of a hardness assessment demonstrated that the addition of cherry powder exerted a significant effect on cookie hardness. Lightness (L) and yellowness (b) of cookie color decreased as the concentration of cherry powder increased, whereas the redness (a) increased. The antioxidative activity measured by DPPH radical scavenging activity of cookie increased as the concentration of cherry powder increased. The cookies containing the 3 and 6% cherry powder had acceptable sensory properties, such as color, smell, taste, hardness, crispness, and overall acceptability. The results exhibited that adding the cherry powder into the cookie increased antioxidant activity, and the highest quality improvement was obtained by incorporating the 3 and 6% of cherry powder into the cookie formula.

• Applied Biological Chemistry
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• v.40 no.4
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• pp.283-288
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• 1997

The antioxidant activities of Korean Red Ginseng Extract(RGE) and ${\alpha}-tocopherol$, as reference compound, were tested with HPLC and fluorometry which measure the MDA after reacting an aqueous 1% linoleic acid buffer solution, and LDL(1 mg protein/ml) buffer solution with $H_2O_2{\;}and{\;}FeCl_2$. The generation of conjugated-diene in LDL(0.25 mg protein/ml) was also measured by spectrometry. MDA determination showed the antioxidant effect on linoleic acid oxidation with oxidation inhibition ratio of 71.8% and 76.1%, respectively, by addition of 1000 ppm RGE and 100 ppm ${\alpha}-tocopherol$. LDL(1 mg protein/ml) oxidation was inhibited by 25.2% and 21.2%, respectively, by addition of 200 ppm REG and 100 ppm ${\alpha}-tocopherol$. The generation of conjugated diene in LDL(0.25 mg protein/ml) was also inhibited by 44.2%, by addition of 50 ppm RGE.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.2
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• pp.273-278
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• 2017

This study was conducted to investigate the quality characteristics and antioxidant properties of cookies supplemented with 2~8% (w/w) Taraxacum coreanum powder (TCP). The pH and moisture content of cookie dough decreased significantly (P<0.05) while density was not influenced significantly by increasing levels of TCP. The spread ratio and loss rate of cookies increased significantly with increasing levels of TCP (P<0.05). Lightness, redness, and yellowness decreased significantly with higher amount of TCP (P<0.05). The use of TCP significantly increased hardness of cookies while 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activities were significantly elevated (P<0.05). The consumer acceptance test indicated that addition of 2% TCP had a favorable effect on consumer preferences in all attributes. Based on overall observations, cookies with 2% TCP can take advantage of the functional properties of TCP without sacrificing consumer acceptability.