• Korean Journal of Agricultural Science
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• v.6 no.1
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• pp.56-64
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• 1979

Two types of fiat-plate collector were designed and constructed for utilizing the solar energy as heating source of red pepper drying. It was performed to investigate the basic factors on using the collectors and the drying effect on various types of red pepper, and the results obtained are summarized as follows. 1. The optimum tilted angles of the collector in Daejeon area were ${\phi}-15^{\circ}$ in summer season and ${\phi}+15^{\circ}$ in winter season when it was adjusted two times per a year: 2. In the conditions during experiment period, average atmospheric temperature and relative humidity were $25.6^{\circ}C$ and 52.6%, respectively, and $42.0^{\circ}C$, 74.2% in the control chamber. The temperature in the drying chamber connected to the water heater was the highest but relative humidity in the chamber connected to the air heater was the lowest among the chambers. 3. The drying velocity of whole red pepper in the chamber connected to the water heater was the fastest as 2.3 times as compared to the whole type on the mat drying followed by air heater and control in decreasing order. The horizontally cut red pepper in the chamber connected to the water heater was dried exceedingly fast among twelve plots. 4. The content of capsaicine as pungent principle and of capsanthine as red pigment in the red pepper were reduced during drying but there were no differences significantly on the drying method, and it could not affect much on the quality of dried product.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.1
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• pp.23-31
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• 2013

Microwave remote sensing can help monitor the land surface water cycle and crop growth. This type of remote sensing has great potential over conventional remote sensing using the visible and infrared regions due to its all-weather day-and-night imaging capabilities. In this paper, a ground-based multi-frequency (L-, C-, and X-band) polarimetric scatterometer system capable of making observations every 10 min was developed. This system was used to monitor the wheat over an entire growth cycle. The polarimetric scatterometer components were installed inside an air-conditioned shelter to maintain constant temperature and humidity during the data acquisition period. Backscattering coefficients for the crop growing season were compared with biophysical measurements. Backscattering coefficients for all frequencies and polarizations increased until dat of year 137 and then decreased along with fresh weight, dry weight, plant height, and vegetation water content (VWC). The range of backscatter for X-band was lower than for L- and C-band. We examined the relationship between the backscattering coefficients of each band (frequency/polarization) and the various wheat growth parameters. The correlation between the different vegetation parameters and backscatter decreased with increasing frequency. L-band HH-polarization (L-HH) is best suited for the monitoring of fresh weight (r=0.98), dry weight (r=0.96), VWC (r=0.98), and plant height (r=0.96). The correlation coefficients were highest for L-band observations and lowest for X-band. Also, HH-polarization had the highest correlations among the polarization channels (HH, VV and HV). Based on the correlation analysis between backscattering coefficients in each band and wheat growth parameters, we developed prediction equations using the L-HH based on the observed relationships between L-HH and fresh weight, dry weight, VWC and plant height. The results of these analyses will be useful in determining the optimum microwave frequency and polarizations necessary for estimating vegetation parameters in the wheat.

• Food Science and Preservation
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• v.22 no.1
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• pp.84-90
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• 2015

The physicochemical properties and protease activities of spray-dried pineapple juice powders were investigated. The pH, soluble solids, and protease activity of the pineapple juice were pH 5.43, $12.8^{\circ}Brix$, and 4.82 unit/mL, respectively. The optimum pH and temperature of the protease activity from pineapple juice were pH 7.0 and $50^{\circ}C$, respectively. The microencapsulation of pineapple juice was achieved using maltodextrin and alginic acid through spray-drying. The L value and moisture content of the spray-dried powder were higher than those of the freeze-dried powder. The particle size of the freeze-dried powder ($501.57{\mu}m$) was higher than that of the spray-dried powder ($42.58-53.32{\mu}m$). The water absorption and water solubility of the powders were 0.41-0.87, and 90.45-99.76%, respectively. When compared, the protease activities were found to be in the following order : FD (1,297.47 unit/g) > SD-MA-1 (692.08 unit/g) > SD-MA-2 (664.66 unit/g) > SD-MA-3 (642.65 unit/g) > SD-M (633.51 unit/g). In the in vitro dissolution study measurements were conducted for 4 hr in pH 1.2 simulated gastric fluid and pH 6.8 simulated intestinal fluid, using a dissolution tester at $37^{\circ}C$ in 50 rpm. The protease survival of the 3.74-15.69% microencapsulated pineapple juice powders improved with an increase in the treatment concentration of alginic acid.

• Food Science and Preservation
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• v.16 no.5
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• pp.734-741
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• 2009

Response surface methodology (RSM) was used to optimize extraction conditions for functional components of buckwheat (Fagopyrum esculentum). A central composite design was applied to investigate the effects of three independent variables, namelyextraction temperature (X1), extraction time (X2), and ethanol concentration (X3), on responses including extraction yield (Y1), total phenolic content in the extract (Y2), $\alpha$-glucosidase inhibition activity (Y3), and acetylcholine esterase (ACE) inhibition activity (Y4). Data were analyzed using an expert design strategy and statistical software. The maximum yield was 24.95% (w/w) at $55.75^{\circ}C$ extraction temperature, 8.75 hextraction time, and 15.65% (v/v) ethanol. The maximum total phenolic yield was 222.45 mg/100 g under the conditions of $28.11^{\circ}C$ extraction temperature, 8.65 h extraction time, and 81.72% (v/v) ethanol. The maximum $\alpha$-glucosidase inhibition activity was 85.38% at $9.62^{\circ}C$, 7.86 h, and 57.58% (v/v) ethanol. The maximum ACE inhibition activity was 86.91% under extraction conditions of $10.12^{\circ}C$, 4.86 h, and 44.44% (v/v) ethanol. Based on superimposition of a four-dimensional RSM with respect to levels of total phenolics, $\alpha$-glucosidase inhibition activity, and ACE inhibition activity, obtained under various extraction conditions, the optimum ranges of conditions were an extraction temperature of $0-70^{\circ}C$, an extraction time of 2-8 h, and an ethanol concentration of 30-80% (v/v).

• Korean Journal of Food Science and Technology
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• v.14 no.4
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• pp.301-308
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• 1982

Chungkook-jang Koji was fermented with rice straw at $40^{\circ}C\;and\;50^{\circ}C$ for 72 hours. The changes of proximate composition, pH, titrable acidity, nitrogen compounds, protease activity and free-amino acids during the fermentation were investigated. Moisture, lipid and protein contents remained essentially unchanged during the fermentation. The pH was gradually increased from 6.4 to 7.46 and 7.82 at $40^{\circ}C\;and\;50^{\circ}C$, respectively, after 72 hour fermentation. Amino type and water soluble nitrogen increased as fermentation progressed. however, the former slightly decreased after 60 hour fermentation. Chungkook-jang fermented at $40^{\circ}C$ showed somewhat higher protease activity than $50^{\circ}C$. However, protease activity at both fermentation temperatures showed the same trend; that is, it increased until 48 hour fermentation and thereafter decrease. Free amino acid content of Chung-kook-jang after 72 hour fermentation at $40^{\circ}C$ was 6 times greater than that of the steamed soybean, while it was 2.5 times greater at $50^{\circ}C$. Based on these results. it seems that the optimum fermentation conditions for Chungkook-jang were $40^{\circ}C$ and 72 hours.

• Korean Journal of Food Science and Technology
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• v.41 no.1
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• pp.50-56
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• 2009

This study was carried out to determine the optimum extraction conditions for Ishige okamurai by comparing the yields, total phenolic compound content (TPC), and antioxidant properties of its 95%, 70%, 50% fermented ethyl alcohol and water extracts. Additionally, the effects of heat and pH treatments on the antioxidant properties of the extracts were evaluated by their TPC and 1,1-diphenyl-2-picrylhydrazyl(DPPH) radical scavenging capabilities. The yields of the extracts were greatest in the order of water > 50% > 70% > 95% fermented ethyl alcohol, and the TPC of the 70% (26.18%) and 50% fermented ethyl alcohol (27.56%) extracts were higher than those of the others. However, in terms of DPPH radical scavenging and ferrous-reducing power, the 70% fermented ethyl alcohol extract of Ishige okamurai showed the highest antioxidant effects. Additionally, in the results for the heat and pH treatments, the antioxidant properties of the 70% fermented ethyl alcohol extract were not influenced by the treatment conditions except at pH 10.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.6
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• pp.755-758
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• 2005

Wild grape is a traditional medicine plant in north-eastern part of Asia and has been known to have healing properties for various illnesses. This study was to determine the optimum extraction condition and antioxidant activity of ethanol extracts of wild grape (V. coignetiae) seed. Also, organic solvent fractions of hexane, chloroform, ethyl acetate and butanol were obtained from the ethanol extract of wild grape seed at different temperatures. Total ethanol extraction yield of wild grape seed ranged from $4\%\;to\;12\%$ depending on the ethanol concentration, extraction temperature and time condition. The highest extraction yield of $11.9\%$ was obtained at $90\%$ ethanol condition for 12 hour at $70^{\circ}C$. However, the strongest free radical scavenging effect $(RC_{50})$ with $20.93\mu g/mL$ was observed in $70\%$ ethanol extract of wild grape seed extracted for 6 hour at $70^{\circ}C,\;while\;RC_{50}\;with\;40.42$\mu g/mL$ was observed in $90\%$ ethanol extract for 12 hour at $70^{\circ}C$. Antioxidant activity of ethanol extracts of wild grape seed increased as total phenol contents increased. Among each fraction obtained from organic solvents, ethyl acetate fraction was found to have the strongest $RC_{50}\;(8.6\mu g/mL)$ and 636.77 mg GAE/g phenol contents .

• KSBB Journal
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• v.23 no.6
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• pp.463-469
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• 2008

During the last decade, monacolin-K biosynthesized by fermentation of red yeast rice (Monascus strains) was proved to have an efficient cholesterol lowering capability, leading to rapid increase in the market demand for the functional red yeast rice. In this study, the production medium composition and components were optimized on a shake flask scale for monacolin-K production by Monascus pilosus (KCCM 60160). The effect of three different soybean flours on the monacolin-K production were studied in order to replace the nitrogen sources of basic production medium (yeast extract, malt extract and beef extract). Among the several experiments, the production medium with dietary soybean flour to replace a half of yeast extract was very good for monacolin-K production. Plackett-Burman experimental design was used to determine the key factors which are critical to produce the biological products in the fermentation. According to the result of Plackett-Burman experimental design, a second order response surface design was applied using yeast extract, beef extract and $(NH_4)_2SO_4$ as factors. Applying this model, the optimum concentration of the three variables was obtained. The maximum monacolin-K production (369.6 mg/L) predicted by model agrees well with the experimental value (418 mg/L) obtained from the experimental verification at the optimal medium. The yield of monacolin-K was increased by 67% as compared to that obtained with basic production medium in shake flasks.

• Journal of Bio-Environment Control
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• v.17 no.4
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• pp.288-292
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• 2008

This study was conducted to identify the effects of irrigation amount to produce high quality melon fruit in fertigation culture. Irrigation amount of during fruit harvesting period was doubled at the low irrigation point ($(-45{\sim}50\;kPa$) treatment as 115 mm as than that of the high irrigation point ($-20{\sim}25\;kPa$) treatment. The plant growth rates such as stem length, leaf weight and plant height were a little diminished at the low irrigation point ($-45{\sim}50\;kPa$) than those of the other treatments. Internode length was however not affected by irrigation amount. Fruit weight was lighter at the low irrigation point ($-45{\sim}50\;kPa$) than that of at the high irrigation point and fruit height was shorter, but fruit diameter was not affected by irrigation amount. Fruit soluble solid was $0.9^{\circ}Bx$ higher at the low irrigation point ($-45{\sim}50\;kPa$) than at the high irrigation point ($-20{\sim}25\;kPa$) and net index was higher. Total marketable yield was highest by 3,937 kg/10a at the high irrigation point ($-20{\sim}25\;kPa$), but the excellent marketable yield was highest by 2,531 kg/10a at the low irrigation point ($-45{\sim}50\;kPa$). Inorganic contents of the soil N, K, Ca and Mg were not affected by irrigation amount. It was therefore thought that optimum irrigation point to produce high quality melon fruit by fertigation culture was $-45{\sim}50\;kPa$ at ripening stage.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.2
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• pp.79-86
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• 2016

The late-maturing black rice cultivar Shinnongheugchal from Jeollabuk-do Agricultural Research and Extension Service was used as the plant material for estimating growth characters, quality and yield from the vegetation period to harvest age. This study was performed to select an optimum combination of nitrogen level and planting density for the maximum yield of Shinnongheugchal. The plant height, number of tillers, and SPAD index were higher when the combination of 70 hills per $3.3m^2$ and 13 kg/10 a nitrogen level was used at 30 days after transplanting. The heading date for the combination of 70 hills per $3.3m^2$ and 15 kg/10 a nitrogen level, and 80 hills per $3.3m^2$ and 15 kg/10 a nitrogen level was August 22. The heading date for the other combinations was August 21. The combination of 70 hills per $3.3m^2$ and 13 kg/10 a nitrogen level yielded the highest number of tillers at 40 days after flowering. Even though the lodging index was increased with increasing nitrogen levels, field lodging did not occur until harvest time. Seed nitrogen concentration in the combination of 70 hills per $3.3m^2$ and 13 kg/10 a nitrogen level showed a significant difference when compared with the other combinations. The black rice yield varied significantly, and the highest yield was observed in the combination of 70 hills per $3.3m^2$ and 13 kg/10 a nitrogen level. The yield was significantly correlated with seed nitrogen concentration. The maximum yield was estimated to be 14.67 kg/10 a nitrogen level by using the regression equation. On average, the coloring degree of the black rice was higher at planting density of 70 hills per $3.3m^2$ than at 80 hills per $3.3m^2$. The highest yield of perfect black rice was obtained using the combination of 70 hills per $3.3m^2$ and 13 kg/10 a nitrogen level. Our findings demonstrate that a nitrogen level of 13-14 kg/10 a can be used to obtain the maximum yield from Shinnongheugchal with yield, cyanidin 3-glucoside content, and perfect black rice yield as the standard.