• Journal of Korean Society of Forest Science
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• v.79 no.2
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• pp.115-126
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• 1990

This study was performed to find differences in phototaxis response of the larva, adult emergence, sex ratio and gall formation rate of Thecodiplosis japonensis Uchida et Inouye between two areas, north and south. Larvae from these two areas, Hweng-sung in north and Moo-an in south, both considered to be the sities of severe outbreak of the insect recently, were collected from the floor and transported to the entomology larboratory, Won-Kwang University in Iri, then overwintered. These larvae were used for various experimental purposes on various dates. The following results were obtained. 1. The sizes of larvae reached 2.45 in length, 0.70 in width for north, and 2.50 in length, 0.72 in width for sourth. It seems that the differents were not significant. 2. It is known that Leaving gall of larvae to the ground for the hibernation usually occurs on rainy days. For the larvae dispersion, the phototaxis response of the larvae was hypothesized. To check this, the author manipulated some different illumination intensities adjusting the distance between the glass tube in which 100 larvae were contained and electric bulb. The glass tubes were blackened all but except a small portion. The phototaxis responses between two areas seemed to be different particularly at low light intensities, 45, 145 and 1000 lux, The larvae from north assembled to the clear portion of the glass tube were more than 30 out of 100, however less than 30 in south sample regardless of the time passage. In either cases, the saturation points came after about 8 to 10 hours. If temperature units were used, the phototaxis curve= after 1 hour illumination between two areas provided significant differences. 3. The adult emergence of south area was lagged 10 days later than that of north area. The accumulated effective day-degrees of temperature for adult emergence were $934^{\circ}C$ for north area and $1180^{\circ}C$ for south area. The emerging duration of north area appeared to be in late May through the early of July and the peak emergence occurred in middle June that was approximately 15days earlier than that of south area. The sex ratio of female to male, regardless of area, was approximately 3 : 1. 4. The rates of gall formation of the red pine(Pinus densiflora Siebold et Zuccarini), 6-year-old seedlings, were as low as 9.94% for north area and 8.87% for south area. Through the close observation, the author presumed that the population reduction was greatly affected during the prepupa stage by relative moisture content and predators, such as spiders and ants presented on the ground.

• Journal of Korean Society of Forest Science
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• v.78 no.2
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• pp.151-159
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• 1989

The present study has been designed to define the effects of photosynthetically active radiation, leaf temperature, and water stress on photosynthesis and respiration of leaves of four oak species (Quercus mongolica, Quercus aliens, Quercus variabilis, and Quercus serrate). The results obtained are as follows : 1. The estimated light compensation points at which Pn approached zero were 38, 24, 20, and $18{\mu}Em^{-2}s^{-1}$ for Q. aliens, Q. variabilis, Q, mongolica, and Q. serrate, respectively. The light saturation points occurred at $500{\mu}Em^{-2}s^{-1}$ in three oak species except Q, aliens. 2. The maximum rates of Pn were 19.7, 15.2, 11.2, and 11.0 mg $CO_2$ $dm^{-2}h^{-1}$ for Q. variabilis, Q. serrate, Q. monglica, and Q. aliens leaves, respectively. 3. The transpiration rates of Q. variabilis and Q. serrate leaves were slightly higher than those of Q. mongolica and Q. aliens leaves at various photosynthetically active radiations(PAR), but cuticular transpiration rates at dark were similar in four oak species. 4. The optimum photosynthesis occurred at $25^{\circ}C$ in Q. aliens, Q. variabilis, and Q. serrate leaves, but $20^{\circ}C$ in Q. mongolica leaves. In four oak species, the net photosynthesis approached zero at about $40^{\circ}C$. 5. The dark respiration rates of leaves exhibited the following ranking of species : Q, variabilis > Q. mongolica > Q. aliens > Q. serrate. 6. The maximum productive efficiency (Pg/Rd) of leaves occurred highest in Q, serrate at $20^{\circ}C$, then in Q. mongolica at $20^{\circ}C$, then in Q, aliens at $25^{\circ}C$, and finally in Q. variabilis at $15^{\circ}C$. 7. The decrease of net photosynthesis in Q. serrate began at about -1.2 MPa, and then approached zero at -2.9 MPa of leaf water potential. The decrease of net photosynthesis began at 3% of water loss, and then approached zero at 17.5% of water loss. 8. As indicated by tissue-water relations parameters, it may be suggested that Q. aliens and Q. variabilis are more tolerant and favored on xeric forest soils than Q. mongolica and Q. serrate.

• Journal of Korean Society of Forest Science
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• v.6 no.1
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• pp.27-31
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• 1967

The bamboo is a plant whose culm grows straight up. This growing characteristics has been widely utilized in industry and craft. But the developments of handcraft making and horticultural techniques in recent years become to demand the bent bamboo culms. This study has been conducted at the experimental grove located at Hyunnae Ri, Okkye Myun, Myungju Gun, Kangwon Do since 1960. Although it has been known that the secret for which bamboo shoots complet growth within 40 odd days lies in their rhizomes, this writer felt the bamboo culm sheath might be another factor in addition. Hence some were stripped of sheath in this bending study as the following: 1. Time of sheath stripping. 2. Direction of sheath stripped for arbitrary bending. 3. Accuracy of bending following the size (growth) of bamboo shoots. The following results were obtained: 1. Bamboo shoots begin to appear in April. But the bamboo shot up in June showed the best bending result with 68% of bending efficiency. 2. Bending of the culm was facilitated by stripping off the sheath located on the side of the direction toward which bending was desired. By doing this, the culm could be bent as much as 90 degrees. But the culm totally stripped of sheath could be bent in any direction. 3. In order to determine the accuracy of bending of bamboo shoots growing, sheath were stripped off the shoots of which height ranged from 10 centimeter to 150 centimeters. The shoots with height of 110 centimeters showed the best result with 90%.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.1
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• pp.97-103
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• 2015

This study investigated changes in phenolic contents of different parts of Rhus verniciflua Stokes (RV) according to extraction conditions. Bark and xylem parts of RV were extracted at 80, 100, 120, 140, and $160^{\circ}C$ for 1, 3, and 5 h, respectively. Major phenolic compounds (gallic acid, protocatechuic acid, fustin, fisetin, sulfuretin, and butein) of RV were analyzed. The gallic acid, fisetin, sulfuretin, and butein contents significantly increased as extraction temperature increased. Protocatechuic acid and fustin contents increased as increasing extraction temperature to $120^{\circ}C$ and decreased afterward. The gallic acid, protocatechuic acid, and butein contents of bark were higher than those of xylem extracts. The optimal extraction conditions of gallic acid, protocatechuic acid, fustin, fisetin, sulfuretin, and butein were $160^{\circ}C/3h$ (380.22 mg%), $120^{\circ}C/1h$ (9.25 mg%), $100^{\circ}C/3h$ (206.97 mg%), $140^{\circ}C/5h$ (93.84 mg%), $140^{\circ}C/5h$ (16.07 mg%) and $160^{\circ}C/5h$ (1.49 mg%), respectively. These results suggest that the optimum extraction temperature and time considering RV extraction yield and cost are $140^{\circ}C$ and 3 h, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.3
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• pp.386-395
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• 2016

To develop a functional fermentation food from Rubus coreanus Miquel (Bokbunja) and chlorella mixtures, optimal lactic acid fermentation conditions were established, and quality properties based on physicochemical evaluation such as chemical compositions, free sugars, organic acids, and antibacterial activities were investigated. Regarding optimal fermentation strain selection, formation of lactic acid was best in Lactobacillus plantarum among the experimental strains (10 kinds), and the optimal fermentation temperature was $37^{\circ}C$. In addition, overall acceptability in the sensory evaluation was highest in the 5% chlorella mixture sample. Therefore, quality properties of the prepared sample under the established optimal fermentation conditions were investigated. Moisture, total sugar (dry basis), crude fiber (dry basis), and pH of fermented Rubus coreanus Miquel juice (RCM) with 5% chlorella mixture (RCM-C5) were reduced by 4.90%, 14.15%, and 0.32%, respectively, as compared with non-fermented RCM. Meanwhile, crude protein, crude fat, and crude ash (dry basis) of RCM-C5 were elevated by 13.75%, 0.18%, and 0.73%, respectively, as compared with RCM. The yellowness (b value) of color values was greater in RCM-C5 compared to RCM. The free sugar and organic acid contents of RCM-C5 were elevated by 0.97% and 616.30 mg%, respectively, as compared with RCM. In addition, the gram positive bacterium Staphylococcus aureus was elevated by 5.83% while gram negative bacteria Escherichia coli and Salmonella Typhimurium were elevated by 2.94% and 4.67%, respectively, as compared with RCM. In conclusion, the quality properties of RCM and chlorella lactic acid fermentation mixtures were improved compared with the general RCM product. Consequently, it is possible to apply fermented RCM as a functional fermentation food.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.1
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• pp.66-75
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• 2015

This study investigated eating behaviors (life-style, breakfast pattern, eating environment, snack pattern, and awareness of breakfast) by breakfast frequency (0~2 times, 3~6 times, and 7 times per week) of high school students (146 males and 165 females) in the Yongin region. The percentage of 'mother' as breakfast preparer increased with elevated breakfast frequency, whereas 'myself' was lower for females (P<0.001). Regarding reasons for skipping breakfast, 'getting more sleep' increased with elevated breakfast frequency, whereas 'loosing appetite' decreased in males (P<0.001). Regarding family reaction to skipping breakfast, 'advising' increased with elevated breakfast frequency in females (P<0.001). Skipping breakfast by eating snacks was higher in females (51.6%) than in males (35.6%), and skipping dinner was higher (53.4%) in females. Awareness of breakfast importance increased with elevated breakfast frequency in males (P<0.05) and females (P<0.001). Perception of correlation between health and breakfast was higher in females (54.8%) compared to males (43.9%), and the most important reason was 'energy supplement'. 'Eating now and will eat' increased with elevated breakfast frequency in males (P<0.001) and females (P<0.001), whereas sum of 'not eating now and will not eat' and 'eating now but will not eat' were 19.2% and 14.2% in males and females, respectively. Therefore, appropriate education programs emphasizing importance of eating breakfast and environmental improvement for regularly eating breakfast for high school students are highly required.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.1
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• pp.14-23
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• 2015

This study examined the glycemic indices (GIs) and glycemic loads of carbohydrate-rich snacks in Korea according to variety and cooking method. The most popular carbohydrate snacks (corn, potatoes, sweet potatoes, chestnuts, and red beans) from the Korean National Health and Nutrition Examination Survey nutrient database were cooked using a variety of conventional cooking methods (steaming, baking, porridge, puffing, and frying). The GIs of foods were measured in 60 healthy males after receiving permission from the University Hospital institutional review board (KMC IRB 1306-01). Blood glucose and insulin levels were then measured at 0, 15, 30, 60, 90, and 120 min after consuming glucose, and each test food contained 50 g of carbohydrates (corn: 170.0 g, potatoes: 359.7 g, sweet potatoes: 160.3 g, chestnuts: 134.8 g, red beans: 73.1 g). GI values for test foods were calculated based on the increase in the area under the blood glucose response curve for each subject. Steamed potatoes ($93.6{\pm}11.6$), corn porridge ($91.8{\pm}19.5$), baked sweet potatoes ($90.9{\pm}9.6$), baked potatoes ($78.2{\pm}14.5$), steamed corn ($73.4{\pm}9.9$), and steamed sweet potatoes ($70.8{\pm}6.1$) were shown to be considered high GI foods, whereas baked chestnuts ($54.3{\pm}6.3$), red bean porridge ($33.1{\pm}5.5$), steamed red beans ($22.1{\pm}3.2$), fried potatoes ($41.5{\pm}7.8$), and ground and pan-fried potatoes ($28.0{\pm}5.1$) were considered as low GI foods. The results suggest that the cooking method of carbohydrate-rich snacks is an important determinant of GI values.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.6
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• pp.791-799
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• 2015

This study was conducted to investigate the effects of water extract from Rosa multiflora and Rosa multiflora complex on lipid metabolism in rats fed a high cholesterol diet. Experimental rats were divided into four groups, which were composed of normal diet group (N group), high cholesterol diet group (HF group), high cholesterol and 5% Rosa multiflora diet group (HR group), and high cholesterol and Rosa multiflora complex diet group (HRC group). Rosa multiflora complex is composed of Duchesnea chrysantha, Salvia plebeia R. BR., and Sasa borealis. The serum triglyceride (TG) content of the HF group was significantly higher than that of the N group, whereas that of the HRC group was significantly lower. Serum high-density lipoprotein-cholesterol contents of the HR and HRC groups were significantly higher than that of the HF group. The serum total cholesterol and low-density lipoprotein- cholesterol contents of the HF group were significantly higher than those of the N group, and especially the atherogenic index of the HRC group was significantly reduced compared to the HF group. The liver TG and total cholesterol contents of the HF group were significantly increased compared to the normal diet group, while those of the HR and HRC groups were significantly decreased compared to the HF group. Fecal total lipid and total cholesterol contents of the HR and HRC groups were significantly increased compared to the HF group. Uridine 5'-diphospho (UDP)-glucuronyl transferase activity of the HR and HRC groups were increased compared to the HF group. Total bile acid contents of the HR and HRC groups were increased compared to the HF group, and that of the HRC group was significantly increased compared to the HF groups. These results suggest that Rosa multiflora supplementation has powerful health benefits due to UDP-glucuronyl transferase activity, bile acid, and lipid metabolism.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.1
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• pp.1-6
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• 2015

Atopic dermatitis (AD) is a form of allergic skin inflammatory characterized by late eczematous skin lesions. The incidence of AD is increasing, and it causes problems with administrative costs. Therefore, development of an AD treatment with no side effects is needed. The purpose of this study was to evaluate tuna heart ethanol extract (THEE), a functional extract from by-product of tuna. AD was induced by spreading 2,4-dinitrochlorobenzene (DNCB) on the backside of BALB/c mice. The effect of THEE was tested by measuring skin clinical severity score, secretion of cytokines and IgE, and proliferation. Secretion of $TNF-{\alpha}$, IL-4, IL-5, IL-13, and IgE significantly decreased in a THEE-independent manner. In contrast, levels of IL-10 and $IFN-{\gamma}$ significantly increased in mice sera and splenocytes. In addition, THEE alleviated AD symptoms compared to the DNCB only group. In conclusion, these results demonstrate that THEE has an inhibitory effect on AD and may be a useful substance for the development of cosmeceuticals.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.6
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• pp.921-927
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• 2015

The aim of this study was to investigate the effect of die temperature and repeated extrusion on physical properties of extruded white ginseng (EWG). The die temperature was adjusted to 100, 120, and $140^{\circ}C$, and extrusion was repeated under the same conditions with their corresponding samples. Specific mechanical energy input decreased as die temperature increased during extrusions. The secondary extruded white ginseng (SEWG) at a die temperature of $120^{\circ}C$ showed a higher expansion index than other extrudates. Elevation of both die temperature and repeated extrusion increased the specific length of extrudates. The highest apparent elastic modulus, breaking strength, and water solubility index obtained from SEWG at a die temperature of $100^{\circ}C$ were $7.53{\times}10^8N/m^2$, $7.49{\times}10^5N/m^2$, and 39.02%, respectively. When die temperature increased, water absorption index (WAI) decreased. The WAI of SEWG was higher than that of EWG. In conclusion, repeated extrusion affected physical properties of white ginseng and could be applied to produce improved quality of ginseng products.