• Journal of Adhesion and Interface
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• v.7 no.1
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• pp.16-22
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• 2006

In this work, the effect of cure temperature and time on the thermal stability and the exothermic cure reaction peak of a waterborne resol-type phenol-formaldehyde resin, which may be used for preparing phenolic sheet molding compounds (SMC), has been investigated using a thermogravimetric analyzer and a differential scanning calorimeter. The weight loss of waterborne phenol-formaldehyde resin was mainly occurred at three temperature stages: near $200^{\circ}C,\;400^{\circ}C$, and $500^{\circ}C$. The carbon yield at $750^{\circ}C$ for the cured resin was about 62%~65%. Their thermal stability increased with increasing cure temperature and time. Upon cure, the exothermic reaction was taken placed in the range of $120^{\circ}C{\sim}190^{\circ}C$ and the maximum peak was found in between $165^{\circ}C$ and $170^{\circ}C$. The shape and the maximum of the exothermic curves depended on the given cure temperature and time. To remove $H_2O$ and volatile components, the uncured resin needed a heat-treatment at $100^{\circ}C$ for 60 min at least prior to cure or molding. Curing at $130^{\circ}C$ for 120 min made the exothermic peak of waterborne phenol-formaldehyde resin completely disappeared. And, post-curing at $180^{\circ}C$ for 60 min further improved the thermal stability of the cured resin.

• Journal of the East Asian Society of Dietary Life
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• v.23 no.6
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• pp.733-741
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• 2013

The objective of this study is to prepare functional beverages with dandelion (Taraxacum mongolicum H.) extracts. As a result of sensory evaluation, 10% water extracts of dandelion containing beverage, which was the highest value of overall preference, was chosen for further examinations. Moisture content of developed beverage was $99.6{\pm}0.5%$ and sugar content decreased from 0.8 to $0.7^{\circ}Brix$ whereas pH increased from 3.4 to 3.7 by addition of 10% dandelion extracts. Total phenolic and flavonoid contents of beverage were $295.8{\pm}5.8mg/L$ and $122.8{\pm}18.4mg/L$, respectively. The developed beverage showed higher DPPH radical scavenging activity of $98.2{\pm}0.6%$ than the beverage without extract. Moreover, concentration of silibinin in the T. mongolicum H. beverage was $0.3{\pm}0.04mg/L$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.9
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• pp.1347-1355
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• 2015

In this study, the physicochemical properties, antioxidant capacities, and volatile flavor compounds of oriental melon wine prepared by freeze concentration after heat treatment (HA), ascorbic acid treatment (AAT), and heat and ascorbic acid treatment (HAAT) were investigated. During fermentation period, the melon wine by HAAT showed greater reduction of soluble solids and reducing sugar contents compared to other treatments. In addition, the melon wine treated with HAAT also showed a higher L value and lower browning index compared to other treatments. After aging, free sugar including fructose, and organic acids including citric acid, succinic acid, and malic acid were detected in all samples. For antioxidant activities and contents, HAAT treated wine showed greater antioxidant activities and total phenolic contents than those of others. In GC/MS analysis, a total of 33 volatile flavor compounds were identified. In the principal component analysis of volatile flavor compounds, principal components 1 and 2 represented 88.15% of the whole date distribution and showed opposite tendencies. Taken together, HAAT enhanced the antioxidant activities and sensory properties of oriental melon wine. Moreover, freeze concentration gave the different volatile flavor characteristics in oriental melon wine.

• Journal of Life Science
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• v.18 no.7
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• pp.992-998
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• 2008

We evaluated proanthocyanidin contents out of total polyphenolic compounds in two pine needle extracts prepared by combined extraction methods and compared their antioxidative activities. Amounts of total polyphenolic compounds of sub-supercritical hotwater precipitate (SSHP) and sub-supercritical hotwater supermatant (SSHS) were 225.4 and 116.6 mg/g, respectively. Amounts of proanthocyanidin of SSHP and SSHS were 9.9 and 3.6 mg/g, respectively. Thus, the ratio of proanthocyanidin contents over total polyphenolic compounds of SSHP and SSHS were 4.3 and 3.9%, respectively. Antioxidative activities ($IC_{50}$) of SSHP and SSHS measured by DPPH radical scavenging were 41.5 and $50.7\;{\mu}g/ml$, respectively. These results indicates that two combined extracts, SSHP and SSHS showed higher antioxidative activities than extract prepared by hot water or sub-supercritical. In conclusion, extraction procedures for SSHP and SSHS could be useful methods for preparing the effective components of functional food products.

• Journal of Life Science
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• v.18 no.2
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• pp.213-219
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• 2008

Flavonoids in pine needles are known to be effective scavengers of free radical. Especially, proanthocyanidin, a kind of flavonoids possesses cardiovascular protection and antioxidative activities. Here, we evaluated proanthocyanidin contents in total polyphenolic compounds of pine needle extracts prepared by using hot water, ethanol, hexane or sub-supercritical $CO_2$. Analyses of total polyphenolic compounds and proanthocyanidin in each extracts indicated that hot water extract contained the highest concentrations, but sub-supercritical extract contained the lowest concentrations. On the other hand, evaluation of proanthocyanidin contents in total polyphenolic compounds in each extracts showed that sub-supercritical extract possessed the highest content, but hot water extract possessed the lowest content. These results indicate that extracts containing high concentrations of both total polyphenolic compounds and proanthocyanidin could be obtained by using hot water or ethanol extractions. Furthermore, extract containing high content of proanthocyanidin out of total polyphenolic compounds could be achieved by using sub-supercritical extraction. Measurement of antioxidative activities of extracts showed that hot water extract possessed the highest activity. In this study, we prepared extracts from pine needles by four different methods and evaluated the antioxidative compounds in extracts that could be used for effective components of functional food products.

• Journal of Korean Society of Forest Science
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• v.50 no.1
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• pp.49-55
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• 1980

Monoterpenes, phenolic substances, growth substances and total nitrogen from normal needles and infested needles attacked by Thecodiplosis japonensis were compared for Pinus densiflora, Pinus thunbergii and Pinus rigida. The results obtained in this study were as follows: 1. Major monoterpene components in P. densiflora needles were ${\beta}$-phellandrene, ${\alpha}$-pinene and those in P. rigida needles were ${\beta}$-pinene and ${\alpha}$-pinene. In P. rigida resistant to this insect, infested needles showed higher ${\alpha}$-pinene, ${\beta}$-pinene and myrcene but lower camphene, limonene and ${\beta}$-phellandrene than normal needles. 2. Orcinol, catechol ferulic acid, salicylic acid and five unknowns were detected in P. rigida needles whereas orcinol, catechol, ferulic acid and four unknowns in P. densiflora needles. 3. Tryptophan, a precursor of IAA, was detected in larvae and also in gall tissues of both P. densiflora and P. thunbergii needles. This fact shows that growth substances may involve in gall formation by Thecodiplosis japonensis. 4. Total nitrogen contents per unit needle weight were neither significantly different between P. densiflora and P. rigida, nor between normal and infested needles.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.3
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• pp.363-368
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• 2013

The nutrients and antioxidative activities of fruits and leaves from Metasequoia glyptostroboides were investigated to provide basic data for the future development of functional foods. The nitrogen-free extract contents of fruit and leaves were 69.04% and 50.47%, respectively. Total phenolic content was higher in leaves (21.75 mg/GAE g) compared to the fruit (19.95 mg/GAE g). The mineral components of fruit and leaves mainly consisted of calcium (2,136.08 and 304.85 mg/100 g, respectively), potassium (1,355.53 and 1,144.04 mg/100 g, respectively), and phosphorous (426.30 and 350.50 mg/100 g, respectively). In terms of amino acid composition, aspartic acid, glutamic acid, proline, and leucine were relatively high, but methionine and cystine were low. The hot water extract from leaves was a more potent free radical-scavenger and had higher reducing activities than extracts from fruit. Thus, phenolics of M. glyptostroboides leaves can be utilized as an effective functional food substance for its natural antioxidant properties.

• Applied Chemistry for Engineering
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• v.19 no.1
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• pp.129-132
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• 2008

The purposes of this study were to investigate the physicochemical properties and component values of bamboo oil from Phyllostachys nigra var. henonis obtained by refining process. The tar concentration in the refined bamboo oil (RBO) was decreased to about 78% compared to crude Bamboo oil (CBO). The chromaticities of light, red, and yellow in RBO were 92.4 and 3.0, respectively. This result indicates that the chromaticity of light was increased with the decrease in the tar concentration in the Bamboo oil. The total concentrations of organic acid and phenolics compound in RBO were decreased to about 63% and 80%, respectively. The total concentration of free sugars was decreased to about 78% in RBO and the concentration of free sugar was in the order of lactose, fructose, and glucose. The palmitoleic acid and stearic acid concentrations were higher than that of other fatty acids. The concentration of total organic acid was decreased to about 88% through RBO. Among the various organic acids, the formic acid concentration was highest in the RBO. The minerals concentrations in the CBO were in the order of Ca, K, Na, and Fe. On the other hand, in the case of RBO, it was in the order of Ca, Fe, K, and Na.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.8
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• pp.985-991
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• 2008

This study was to investigated the changes of physiologically active components in germinated brown rice treated with chitosan (CGBR) and its anti-obesity effect in rat fed a high fat diet. Contents of physiologically active compounds such as total phenolic compounds, total dietary fiber, $\gamma$-aminobutyric acid (GABA), and total phytic acid in CGBR were significantly higher than those of traditional germinated brown rice (GBR). Lipase inhibitory activity of CGBR was higher than those of GBR and brown rice (BR). High fat diets containing CGBR, GBR, and BR were administered to three groups of male Sprague-Dawley rats for four weeks. All groups showed no significant difference in body weight, total abdominal fat, and plasma lipid levels. However, CGBR group appeared to have lower body weight gain and total abdominal fat level than other groups fed high fat diets containing GBR and BR. Total cholesterol and LDL-cholesterol contents in plasma of CGBR group were also lower than those of other groups. Thus, new germination method of brown rice using chitosan is a useful process, which utilizes plant defense responses to elevate the production of secondary metabolites and anti-obesity effect.

• Korean Journal of Food Science and Technology
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• v.38 no.4
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• pp.521-525
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• 2006

Korean ginseng was heat treated at various temperatures (110, 120, 130, 140 and $150^{\circ}C$) and times (1, 2, 3, 4, and 5 hr). The heat treated ginseng extract was analyzed for the total polyphenol content, total flavonoid content, DPPH free-radical scavenging, 5-HMF and ginsenoside. The total phenolics and flavonoid content increased with increasing treatment temperature and time. The highest total phenolics content was 29.46 mg/g (d.b) in $150^{\circ}C$ for 1hr (control: 2.68 mg/g). The highest total flavonoid content was 4.75mg/g (d.b) in $150^{\circ}C$ for 2hr (control: 0.39 mg/g). The antioxidant activity increased until $140^{\circ}C$ for 3 hours. An extension of the treatment time did not have any effect, and the antioxidant activity decreased at temperatures higher than $150^{\circ}C$ for more than 2 hours. The content of ginsenoside $Rg_1$, Re, $Rb_2$ and Rb3 rapidly decreased with increasing treatment temperature and time. Ginsenoside $Rg_3$ and $Rh_2$ were newly produced, or their contents increased with increasing treatment temperature and time.