• Korean Journal of Food Science and Technology
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• v.30 no.3
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• pp.562-568
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• 1998

Rice (Dongjin-byeo) added with black rices (Chindo and Suwon-415) was cooked and the changes of texture and color of this cooked rice were investigated by texture analyser and color & color difference meter. The hydration time to come to the equilibrium condition was at least 11 hr in black rices. The optimum ratio of water to cooked rice added with black rice was 1.6 (ratio of water to rice) and the hardness of cooked rice added with 5% Chindo black rice was $5.66\;kg_f$. Regardless of ratio of water to rice, Hunter a value increased as the ratio of black rice addition to rice increased, while L value decreased. The color elution rate of Suwon 415 was 4 times greater than that of Chindo black rice. The pH of the steep water of Suwon 415 at $20^{\circ}C$ during 120 min decreased from pH 6.40 to pH 6.16 as the steeping time increased. The optimum heating time by microwave oven of cooked rice added with black rice was between $90{\sim}120\;sec$ to recover the original texture after cold storage treatment of 7 days.

• Journal of Adhesion and Interface
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• v.14 no.3
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• pp.117-120
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• 2013

The prepreg material is a sheet of the reinforcement pre-impregnated with a resin. In this study, two types of prepreg were prepared with a general phenolic resin and the polyvinyl butyral (PVB) modified phenolic resin, respectively, with resin content of 40 wt%. After resin impregnation, the prepregs were heat treated in an oven to make them the B-stage. Surface morphology of the prepreg was observed by using a scanning electron microscope (SEM). Tack property of the prepreg is one of the major properties that govern the ability of prepreg to be laid up. In this study, the tack of prepreg was measured under various test parameters by a probe tact test. Test parameters were contact time, contact force and debonding rate. Most of the tack properties of the prepreg increased with the test parameters. Then tack properties exhibited a linear behavior with test parameters before a saturation point. Also, the tack of prepreg was investigated in relation with the fibrillation phenomena involved in the prepreg surface with the debonding rate.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.3
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• pp.435-442
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• 2010

This study was to investigate the quality characteristics of instant rice cake (Baekseolgi) with different concentrations of ginseng powder by molecular press dehydration (MPD) method. Baekseolgi was cooked using microwave oven, which is a useful cooking method because of reduced cooking time, even though it quickly takes moisture from food surface and lowers food quality. The result indicated that moisture content of Baekseolgi without ginseng powder was decreased; however, there was no significant difference in the Baekseolgi with ginseng powder with increased storage time for 24 hrs. The L value was decreased and a color value was increased with increasing concentrations of ginseng powder (p<0.05). There was no significant difference in the color values within the storage time. The hardness, gumminess, and chewiness of Baekseolgi without ginseng powder significantly changed as the storage time increased; in contrast, those of Baekseolgi with ginseng powder did not show such a significant change. The result of sensory evaluation showed that Baekseolgi with ginseng powder has higher scores in terms of color, flavor, taste, and overall acceptability than Baekseolgi without ginseng powder. Results of this study indicate the addition of ginseng powder to Baekseolgi improves moisture content, color value, and texture properties as well as sensory characteristics.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.5
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• pp.779-785
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• 1996

The qualities of bread and change of phytic acid during breadmaking with whole wheat flour were investigated. The ratios of ash contents in wheat flour and whole wheat flour were 0.41% and 1.57%, respectively. The ratios of fiber contents in wheat flour and whole wheat flour were 0.14% and 1.83%, respectively. In amino acid analysis, glutamic acid was determined to be 32~36g/100g protein, which was the highest. Lysine, glycine, arginine and aspartic acid were higher in whole wheat flour than those of wheat flour. Proline, glutamic acid, and phenylalanine were higher in wheat flour than those of whole wheat flour. The ratio of phytic acid content in wheat flour and whole wheat flour was 0.312% and 0.734%, respectively. The content of phytic acid during beadmaking was decreased approximately 65% after proofing, while this was almost constant in the process of oven baking. The content of phytic acid in bread with 3% yeast had less hydrolysis than that in bread with 5% yeast during breadmaking. The phytic acid content in the 0.1% yeast food was decreased more than the 0, 0.3, and 0.5% yeast food groups. As the amount of whole wheat flour increased, the volume of bread was decreased, and color became dark. The sensory evaluation was showed the quality of bread to be the highest when the amounts of coarse whole wheat flour and fine whole wheat flour was 20% and 30%, respectively. Though the amount of coarse whole wheat flour and fine whole wheat flour were increased up to 30% and 50%, respectively, external characteristics of bread was remained in normal.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.10
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• pp.1420-1426
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• 2006

To establish a rapid and effective method for the analysis of soy isoflavone which is known to have lots of variation in derivatives of glucoside, conversion rate from isoflavone conjugates to its aglycones, and decomposition of conversed aglycones were investigated with various acid hydrolysis conditions. A number of heating conditions for acid hydrolysis including heating at convection oven $(105^{\circ}C)$, water bath $(95^{\circ}C)$, heating block $(120^{\circ}C)$, and hot plate $(120^{\circ}C)$ were applied. Acid hydrolysis in heating block with reflux was chosen as the best heating condition. From the stability test of isoflavone aglycone during acid hydrolysis, genistein, daidzein, and glycitein did not show any significant changes in their contents for 60 min of hydrolysis. Ten to thirty milligram of sample per 1 mL HCl was the best ratio of sample to acid. As conclusion, acid hydrolysis for 60 min after addition of 15 mL HCl solution to 0.5 g soybean, and then fill up to 50 mL with methanol, followed by HPLC analysis was set as a final analysis method. From this method, isoflavone contents expressed as total aglycone of feed meal was the highest with content of $1288.5{\mu}g/g$ followed by those of dehulled meal.

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.3
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• pp.268-274
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• 1984

The purpose of this study was to investigate the physico-chemical effects of a potato starch and a purified potato starch under the condition of the microwave heating. They were exposed to the microwave energy in a 950 W, 2,450 MHz oven for 30 through 120 seconds. As the microwave heating time was increased, the contents of moisture and the crude fat of the samples were remarkably decreased irrespective of the starch composition, but on the other hand the contents of crude ash was slightly decreased and the crude protein was almost unchanged. The rings of crystallinity come to gradually changed in the X-ray diffraction pattern, and then the only 1 ring, of which interplanner spacing is wide, is changed strikingly. As the microwave heating time is increased, the starch granules which observed by a scanning electron microscope were broken partially with a special form, and the granules of purified potato starch were broken faster than those of potato starch. With the same condition that the microwave heating time was increased, while the gelatinization temperature comes to fall, the swelling power and the solubility were increased. Besides these, while the gelatinization temperature of the purified potato starch was lower than that of the potato starch, both the swelling power and the solubility of the purified potato starch is higher than those of the potato starch.

• Journal of Korean Society of Forest Science
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• v.88 no.1
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• pp.93-100
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• 1999

This study has been carried out to estimate aboveground and soil carbon contents in an average 39-year-old Quercus mongolica and 40-year-old Quercus variabilis stands in Chungju, Chungbuk. Ten sample trees were cut in each forest and soil samples were collected. Aboveground carbon content was estimated by the equation model $Wt=aD^b$ where Wt is oven-dry weight in kg and D is DBH in cm. Total aboveground carbon content was 48.85tonC/ha in Quercus mongolica stand and 57.49tonC/ha in Quercus variabilis stand. The proportion of each tree component to total aboveground carbon content was high in order of bolewood, branches, bolebark, and leaves in the two forests. Aboveground net primary production was estimated at 5.88tonC/ha in Quercus mongolica stand and 5.12tonC/ha in Quercus variabilis stand. Soil carbon content was 67.0tonC/ha in Quercus mongolica stand, 67.8tonC/ha in Quercus variabilis stand, and 54.7tonC/ha in Pinus densiflora stand. There was no significant difference in soil carbon content among the three forests.

• Journal of Hydrogen and New Energy
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• v.22 no.6
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• pp.749-758
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• 2011

The present work explores the performance and operation limit of electrodialysis cell for HI concentration in sulfur iodine thermochemical hydrogen production process, For this purpose, the electrodialysis cell was assembled with Nafion 117 as a PEM membrane and two activated carbon papers as the electrodes. HIx solution was prepared with composition of HI: $I_2$: $H_2O$ = 1: 0.5~2.5: 5.2 in molar ratio. The cell and its peripheral apparatus were placed in the specially designed convective oven in order to uniformly maintain the operation temperature. As operation temperature increased, the amount of water transport from anode to cathode increased, thus reducing HI molarity in catholyte. Meanwhile, the current efficiency was constant as about 90 %, irrespective of temperature change. The cell voltage increased with initial $I_2$ mole ratio as well as anolyte to catholyte mole ratio. Moreover the cell voltage overshot took place within 10 h cell operation, which is due to the $I_2$ precipitation inside the cell. From the analysis of $I_2$ mole ratio in the anolyte, it is noted that operation limit (in $I_2$ mole ratio) of the electrodialysis cell, arising from was measured to be 3.2, which is much lower than bulk solubility limit of 4.7.

• Journal of Korea Foresty Energy
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• v.7 no.1
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• pp.11-21
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• 1987

To estimate the biomass, net production and nutrient distribution of Pinus Koraiensis and Quercus mongolica stand, experimental plots located in Kwangju of Kyonggi-do were selected. Ten sample trees selected account of DBH distribution were felled and the diagram of oven-dry weight distrubution of leaves, branches and stems for each 1m segment was constructed. The logarithmic regression equations between dry weight of each component and the variable of $(DBH)^2$ H obtained. The standing crops were estimated to be as much as 152.07 and 156.02 tons of dry matter per hectare in P. koraiensis and Q. mongolica stand respectively. The net production was estimated as 24.66 and 20.35t/ha$\cdot$yr and the net assimilation rate was 1.90 and 3.42kg/kg$\cdot$yr in same order. Particulary large proportions of nitrogen. calcium and magnesium were found in soil of P. koraiensis stand, phosphours and potassium in overstory of it. At Q. mongolica stand, large proportions of nitrogen. phosphorus. potassium and magnesium were found in soil and calcium in overstory. The amounts of litter fall was 4.013t/ha$\cdot$8 months in P. koraiensis stand and 3.490t/ha$\cdot$8 months in Q. mongolica stand.

• Food Science and Preservation
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• v.20 no.4
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• pp.510-517
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• 2013

This study was conducted to investigate the antioxidant and antimicrobial activities of the hot-water and methanol extracts of raw and black Doraji to increase its utilization. In order to prepare the black Doraji, it was steamed for 15 days at a temperature of $60^{\circ}C$ and then it was dried at a temperature of $30^{\circ}C$ for 3 hr. The methanol extract from the black Doraji (BM) contained the highest levels of total polyphenols among the extracts, and the total polyphenol content of the extract from a black Doraji was higher than that of the extract from a raw Doraji. The total flavonoid contents of the hot-water extract from a black Doraji (BW) was the highest (7.94 mgQE/g) among the samples. The DPPH and ABTS radical scavenging activities increased according to the increase in the concentrations of the Doraji extracts. The BM has the highest radical scavenging activity among the extracts. Each extract showed a slight difference in the antibacterial activity according to the tested strains. The Black Doraji showed a higher antimicrobial activity compared to the raw Doraji. The hot-water extracts demonstrated higher activities than the methanol extracts, and the BW revealed the strongest activity. In this study, the black Doraji showed more effect of the antioxidant and anti-microbial activities than the raw Doraji. These results will provide fundamental data for improving the sitological value and the black Doraji can be used as a valuable resource for the development of nutraceutical foods.