• Journal of Bio-Environment Control
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• v.15 no.3
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• pp.250-256
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• 2006

This experiment was conducted to investigate the hydroponic culture possibility and the optimal solution strength of 'Pechika' ever-bearing strawberry in summer highland. Maximum room temperature and minimum root zone temperature of plastic house were $30.8^{\circ}C\;and\;19^{\circ}C$ in highland respectively and $4^{\circ}C\;and\;3^{\circ}C$ lower than in level and. The growth of 'Pechika' was better in highland. There was effective in producing the good yield and fruit quality in highland and the deformed fruits also were decreased. The soluble solid and titratable acidity content increased in highland. Early growth was the most effective in standard solution $(EC\;0.75dS\;m^{-1})$ and had a tendency to be inhibition with increasing nutrient concentration. Standard solution was also the highest to yield about 2,064kg/10a among treatments, and 2/3S, 4/3S, 5/3S by turns. The browning roots and root activity increased when the solution strength was increased, especially in EC $1.25dS{\cdot}m^{-1}$. The soluble solids and acidity content of fruits were increased with higher solution strength. Therefor, the summer hydroponic culture of 'Pechika' ever-bearing strawberry was suitable in highland and effective in standard solution $(EC\;0.75dS{\cdot}m^{-1})$ in solution control.

• Journal of the Korean Wood Science and Technology
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• v.43 no.3
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• pp.400-409
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• 2015

This study examined the plant growth and development characteristics of leafy vegetables on the hydroponic substrates of waste wood chips, radiate pine chips, and mat type of waste wood chips. The bulk density of waste wood chips and radiata pine chips were $0.2g/cm^3$ and $0.16g/cm^3$, respectively. The moisture retention properties of both the radiata pine chips and waste wood chips were found to be similar but not better than those of the control rock wool and coco peat hydroponic substrates. The moisture retention property of the mat type was found to be the lowest. The chemical analysis of waste wood hydroponic substrates (w/v) was as follows.; The pH was 6.59, electric conductivity was 6.76 dS/m, total nitrogen content was 0.5%, C/N ratio was 113%, phosphorus was 10.1 ppm, potassium was 77 ppm, calcium was 531 ppm, magnesium was 49 ppm, and sodium was 96 ppm. The results from the radiata pine chemical analysis showed that it had a pH of 5.29, electric conductivity of 4.49 dS/m, total nitrogen content of 0.32%, C/N ratio of 180%, phosphorus of 6.4 ppm, potassium of 83 ppm, calcium of 97 ppm, magnesium of 29 ppm, and sodium of 59 ppm. Except for the plants grown in mat type, the developmental characteristics of the plants grown in rock wool and coco peat hydroponic substrates were similar. Based on the results of the experiment, waste wood resources may possibly be used as an organic solid medium in place of the existing rock wool and coco peat medium.

• Food Science and Preservation
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• v.14 no.1
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• pp.1-7
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• 2007

This study was conducted to determine if chlorine dioxide ($ClO_{2}$) gas might minimize microbial contamination of fresh produce. After exposing grapes to 20 ppm or 40 ppm of chlorine dioxide gas in a closed container, grapes treated with 20 ppm $ClO_{2}$ were packaged in Ny/PE/L-LDPE pouches, stapes treated with 40 ppm $ClO_{2}$ were placed in an empty corrugated box, and untreated control grapes were placed in a box with a sachet containing $ClO_{2}$ gas adsorbed to silica gel (a silica gel pad). The free volume of the sachet material allowed the release of $ClO_{2}$ gas into the headspace of packages containing fresh grapes. Control fruit not exposed to $ClO_{2}$, was placed in a box and stored at either $25^{\circ}C$ or $0^{\circ}C$. Fruit in Ny/PE/L-LDPE film treated with 20 ppm $ClO_{2}$ lost almost no weight during storage at either $25^{\circ}C$ or $0^{\circ}C$. Such fruit had a lower soluble solid content than did other fruit samples. Titratable acidity tended to fall rapidly during storage at either $25^{\circ}C$ or $0^{\circ}C$. Anthocyanin content of grapes decreased over 21 days at $25^{\circ}C$ but increased over 10 weeks at $0^{\circ}C$. The total microbial count of grapes treated with $ClO_{2}$ gas and silica gel pads were lower than controls at $25^{\circ}C$. Fruit treated with 20 ppm $ClO_{2}$ and packaged in Ny/PE/L-LDPE pouches had lower microbial counts than other fruit samples when stored at $0^{\circ}C$. The silica gel pad did not significantly improve total microbial count (compared to untreated control samples) at $0^{\circ}C$. This result may be attributed to a higher rate of diffusion of $ClO_{2}$ gas at room temperature.

• Food Science and Preservation
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• v.23 no.2
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• pp.174-179
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• 2016

This study was to prepared vinegars using three kinds of pear cultivar with different maturities, 'Wonhwang', 'Niitaka', and 'Chuhwangbae', and investigate their physicochemical characteristics and antioxidant activities. Result showed that the firmness of 'Wonhwang' was much lower than other pear cultivars. No significant difference in soluble solid content was found among three pear cultivars. The total acidity of 'Chuhwangbae' pear vinegar was 4.89~7.98%, which was higher than that those of 'Wonhwang' and 'Niitaka' vinegars. The color of 'Niitaka' vinegar had a lower lightness and redness values, but a higher yellowness value, compared with the other two vinegars. The free sugar contents were mainly composed of fructose, glucose, and sorbitol, with the greatest content of sorbitol in all three peer vinegars. The total phenolics and flavonoids contents were 35.2~55.3 and 8.4~14.4 mg/100 mL, respectively. Antioxidant activity had a positive correlation with total phenolic contents. The DPPH free radical scavenging and $ABTS^+$ radical scavenging activity were 45.0~62.1% and 73.8~78.2%, respectively. From these results, we confirmed that immature pear cultivars such as 'Wonhwang', 'Niitaka' and 'Chuhwangbae' could be used as a raw materials to prepare vinegar regardless of maturity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.2
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• pp.234-243
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• 2013

The aim of this study was to evaluate the quality characteristics and antioxidative properties of cookies supplemented with mulberry pomace (0%, 4%, 8%, 12%). The bulk density, spread ratio, and leavening rate of cookies decreased with increasing amounts of mulberry pomace. The lightness and b value (of the Hunter color system) decreased based on the amount of mulberry pomace. The pH of cookies decreased (acidity increased) with increasing mulberry pomace. The soluble solid content increased according to the amount of added mulberry pomace, but the amount of reducing sugars decreased. In texture analysis, cookies with 12% mulberry pomace had the highest hardness. Total phenol and flavonoid content increased according to the amount of mulberry pomace added. Antioxidant activities, such as DPPH radical scavenging, hydroxyl radical scavenging, ABTS radical scavenging, and FRAP were highest in cookies with 12% mulberry pomace. In the sensory evaluation, sensory scores for color, taste, flavor, texture, and overall preference were highest in cookies with 8% mulberry pomace. Thus, our results suggest that the optimum amount of mulberry pomace to add to cookies is 8%.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.4
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• pp.220-227
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• 2004

Phosphorus desorption study is essential to understanding P behavior in agricultural and environmental soils because phosphorus is considered as two different aspects, a plant nutrient versus an environmental contaminant. This study was conducted to determine soil P buffering power related to P desorption quantity intensity (Q/I) parameters, $Q_{max}$(an index of P release capacity) and $l_0$(an index of the intensity factor), and to investigate the characteristics of relationship between the P desorption Q/I parameters and the soil properties. Soil samples were prepared with treatments of 0 and $100mg\;P\;kg^{-1}$ applied as $KH_2PO_4$ solution. The P desorption Q/I curves were obtained by a procedure using anion exchange resin beads and described by an empirical equation ($Q=aI^{-1}+bln(I+1)+c$). The P desorption Q/I curves for the high available P (${\g}20mg\;kg^{-1}$ of Olsen P) soils were characteristic concave trends with or without soil P enrichment, whereas for the low available P (${\lt}20mg\;kg^{-1}$ of Olsen P) soils, the anticipated Q/I concave curves could not be obtained without a proper amount of P addition. When the soils were enriched in phosphates, the values of desorbed solid phase labile P and solution P, such as $Q_{max}$ and $I_0$ respectively, were increased, but the ratio of $Q_{max}$ versus $I_0$ was decreased. Thus, the slope of desorption Q/I curve represented as phosphorus buffering power, $|BP_0|$, is decreased. The $|BP_0|$ values of the high available P soils ranged between 48 and $61L\;kg^{-1}$ in the P untreated samples and between 18 and $44L\;kg^{-1}$ in the P enriched samples. Overall $|BP_0|$ values of both low and high available P soils treated with $l00mg\;P\;kg^{-1}$ ranged between 14 and $79L\;kg^{-1}$. The $Q_{max}$, values ranged between 71.4 and $173.1mg\;P\;kg^{-1}$, and the lo values ranged between 0.98 and $3.82mg\;P\;L^{-1}$ in the P enriched soils. The $Q_{max}$ and $I_0$ values that control the P buffering power may be not specifically related to a specific soil property, but those values were complicatedly related to soil pH, clay content, soil organic matter content, and lime. Also, phosphorus release activity, however, markedly depended on the desorbability of the applied P as well as the native labile P.

• Journal of Aquaculture
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• v.15 no.3
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• pp.145-155
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• 2002

Effect of density (30, 40, 65, 90 or 120/cage) of lantern and bottom cages on growth of the ark shell, Scapharca satowi was studied in the Korean west coast from April 2000 to October 2001, when the following range of environmental conditions prevailed : temperature : 4.2 -25.5 $^{\circ}C, salinity : 30.23-32.$15\textperthousand, dissolved oxygen : 5.12-7.16 $ml$/l, pH : 7.84-8.17, phosphate : 0.22-0.56 $\mu $M, dissolved inorganic nitrogen : 3.16-9.10 $\mu $M, suspended solid : 7.6-17.9 mg/l, chemical oxygen demand: 0.46-1.61 mg/l and chlorophyll-a : 0.92-5.93 $\mug/l. Daily growth rate of shell length ranged from 0.066 to 0.071 mm/day for the lantern net cages, and from 0.079 to 0.082 mm/day for the bottom cages. Total weight also ranged from 0.067 to 0.082 g/day in the lantern net cages, as against 0.099 to 0.114 g/day in the bottom cages. Hemoglobin content of S. satowi (55 mm shell length), which was about 3.9 g/dl during february, 2001, increased to 6.0 and 7.0 g/dl during October, 2001 in animals culture in the lantern and bottom cages, respectively. ANOVA test of the growth rate showed that the growth rate of S. satowi, was significantly dependent on rearing density and the tested culture methods (P < 0.0001). The daily growth rate of the shell length was more significantly correlated with water temperature; the growth rate of shell length and total weight showed a tendency decrease with decreasing temperature. In cages suspended at the bottom, not only the increase shell weight but also the meat obtainable from comparable sized S. satowi was greater. Survival decreased with increasing density and was optimal at the density of 30 individual/cage.

• Journal of Mushroom
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• v.16 no.1
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• pp.22-30
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• 2018

This study was performed to determine optimal extraction conditions of fermented Polygonum multiflorum root by Lentinula edodes (JMI10079) Pegler mycelials using response surface methodology. The independent factors were extraction temperature (X1: $40-100^{\circ}C$), extraction time (X2: 2-10 hrs.), and the ratio of water to sample (X3: 33-100 mg/mL). Their effects were assessed on dependent variables of the extract properties, which included soluble solid contents (Y1), $^{\circ}Brix$ of sample extract (Y2), total polyphenol content (Y3), total flavonoid content (Y4), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical cation scavenging activity (Y5) and 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (Y6). The experimental data obtained were fit to a second-order polynomial equation. The optimal extraction conditions for fermented P. multiflorum root were: X1: $91.22^{\circ}C$, X2: 7.72 hrs, and X3: 39.71 mg/mL.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.2
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• pp.281-286
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• 2014

This study was carried out to develop Yakju, a new kind of Korean traditional rice wine added with bamboo ethanol extract and characterized by containing various health benefits. The wine with bamboo ethanol extract was fermented by adding ginger and pear to improve flavor and quality. Several quality characteristics and physiological functionalities of Yakju were investigated. When bamboo ethanol extract was added to Yakju, the pH level decreased compared to that of the control. However, total acidity and soluble solid levels were higher than those of the control. The alcohol content of Yakju added with bamboo ethanol extract was slightly higher than that of the control. In examining the colors of Yakju containing bamboo ethanol extract, L value was lower than that of the control, whereas b value and brownness were higher. Various organic acids such as citric acid, malic acid, succinic acid, lactic acid, and acetic acid were determined, and the main organic acid among them was lactic acid. Various free sugars such as sorbitol, glucose, and fructose were detected and glucose was the most abundant. Total polyphenol content of Yakju added with bamboo ethanol extract was lower than that of the control. Further, electron-donating ability ranged from 23.8~40.0%, which was higher than that of the control. Nitrite scavenging ability of Yakju added with bamboo ethanol extract ranged from 15.2~36.4%, which was higher than that of the control at pH 6.0. Sensory evaluation of Yakju showed that bamboo ethanol extract+ginger as well as bamboo ethanol extract+ginger+pear treatment significantly increased flavor, taste, and overall acceptance compared to the others.

• Journal of Bio-Environment Control
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• v.14 no.3
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• pp.203-211
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• 2005

The experiment was conducted to investigate the nutrition absorption pattern in the growth stages and develope the optimal nutrient solution hydroponically grown the tomato in closed substrate culture system with the nutrient solution of National Horticultural Research Station in Japan into 1/2S, 1 S, and 2S. When plant was grown in 1/2 S, the growth and yield were high and the pH and EC in the rooting zone were stable. Suitable composition of nutrient solution for tomato was $NO_3-N$ 7.1, $PO_{4}$-P 2.1, K 4.0, Ca 3.1, Mg 1.2, and $SO_{4}-S\;1.2\;me{\cdot}L^{-1}$ in the early growth stage and $NO_3-N$ 6.5, $PO_4-P$ 2.3, K 3.4, Ca 3.1, Mg 1.1, and $SO_4-S\;1.1\;me{\cdot}L^{-1}$ in the late growth stage by calculating a rate of nutrient and water uptake. To estimate the suitability for the nutrient solution of tomato in a development of optimum nutrient solution of tomato developed by Wonkwang university in korea (WU), plant was grown in perlite substrate supplied with different solution and strengths(S) by research station for greenhouse vegetable and floricultuin in the Netherlands (Proefstation voor tuinbouw onder glas te Naaldwijk; PTG) of 1/2 S, 1 S and 2 S, respectively, The growth was good at the PTG and WU of 2 S in early growth stage, and at the WU 2S in late growth stage. The highest yield of tomato obtained in the WU of 2 S, although blossom-end rot was appeared in all treatments. pH and EC in root zone of WU of 2 S were stable during the early and late growth stage. Therefore when plant was grown in WU of 2 S, N and P content in the nutrient solution need to low, according N and P content of their leaves were high in WU of 2 S.