• Korean journal of applied entomology
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• v.9 no.1
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• pp.15-20
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• 1970

An investigation was carried out to know the relationship between resistance of rice varieties to blast disease and the chemical components, especially total nitrogen and total sugars, in the rice plants. The results sic summarized as follow: 1) The nitrogen contents in the resistant variety were less than those of susceptible one, and sugar contents were reversed. Accordingly, the C/N ratio in the resistant variety was higher than that obtained by susceptible one. 2) The free amino acids contents, especially, Glutamine, Valine, Leusine and Iso-leusine, in the resistant varieties were more than those of the susceptible varieties. 3) The starch synthetic activity of rice leaves in the resistant varieties was higher than that of susceptible one in fructose and glucose solutions, but it was reversed in sucrose solution. 4) When more nitrogen was dressed, the total nitrogen content of rice leaves was increased than the ordinary dressing. The rate of increase in nitrogen content in resistant variety was lower than those of the susceptible. The total sugar content of rice plants dressed more nitrogen was decreased at early tillering stage, but increased at maximum tillering stage. It seemed that the rate of increase of total sugar in the resistant variety was higher than those of the susceptible.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.4
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• pp.437-442
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• 1993

Soybean curds were made from the mixture of soybean milk and cow's milk (raw milk) at the ratio of 10, 20, 30, 40, 50% (v/v), and then the general composition and mineral content, pH, yield, firmness by sensory evaluation and amino acid composition were investigated. As cow's milk addition increased, total sugar crude fat, crude protein, ash content, firmness, weight and volume of the soybean curd were increased. Whereas moisture content decreased, $Ca^{＋＋}$, $K^{＋}$, and Na$^{＋}$ were increased, but $Mg^{＋＋}$ and Fe$^{＋＋}$ decreased. In sensory evaluation, color (white), firmness, flavor, and taste were higher than those of control as cow's milk increased. By adding cow's milk at the ratio of 10, 20, 30, 40%, and 50%, sulfur containing amino acid content such as methionine and cystine were enriched 1.31, 1.58, 1.67, 1.85, and 1.95 times, respectively.

• Korean Journal of Food Science and Technology
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• v.27 no.4
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• pp.439-444
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• 1995

Preparative conditions and characteristics of six-vegetable and fruit juice were studied for the effects of mixing ratio, heat treatment and addition of sugar, salt and organic acid. The vegetables and fruit used were carrot(Ct), cabbage(Cg), pear(Pr), cucumber(Cr), celery(Cy) and dongchimi(Di). From the sensory results of mixing ratio of three of binary mixtures of Cg-Pr(1:3):Ct-Di(1:4):Cr-Cy(3:1), two ratios of 5.0:2.5:2.5(V-6A) and 6.0:2.0:2.0(V-6B) were suggested optimal for six-vegetable and fruit juice. Addition of 2% sucrose and 0.3% NaCl improved the preference significantly. The pH 4.0 for V-6A and pH 3.5 for V-6B were more prefered when pH was adjusted by citric acid. Heating the juice at $100^{\circ}C$ for 100 minutes slightly decreased pH and increased the acidity. Total solids and viscosity were also decreased by heating. All of those changes were more significant in V-6B than V-6A, probably due to lower pH. Heating the juice resulted in a slight decrease in L value and an increase in a and b values. Heating at $100^{\circ}C$ caused an increase in moldy flavor and a decrease in fresh vegetable flavor while heating at $80^{\circ}C$ for 20 minutes changed them little.

• Clean Technology
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• v.20 no.2
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• pp.103-107
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• 2014

Acrylic acid is a commodity chemical which is applicable for various industries such as polymer and textile industry. Currently, it has been produced by chemical synthesis from petroleum. However, due to the high price of petroleum and global $CO_2$ emission, renewable materials such as sugar are interesting alternative carbon sources for the biological production of acrylic acid. For an economic production of acrylic acid from renewable carbon sources, a cost effective separation process for acrylic acid should be needed. In this study, reactive extraction by TOA (tri-n-octylamine) was used for the recovery of acrylic acid from its aqueous solutions. The effects of polarity of diluents and concentration of TOA on extraction equilibrium were investigated. The extraction efficiency was proportional to concentration of TOA and polarity of diluents and its value was more than 95% in the case of sufficient concentration of TOA. From IR spectroscopy, it was concluded that the ratio of (1,1) acid-amine complex was increased and the ratio of acid dimer was decreased with concentration of TOA. Equilibrium model based on IR spectroscopy was well fitted with experimental data.

• The Korean Journal of Food And Nutrition
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• v.37 no.1
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• pp.9-16
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• 2024

To produce super sweet corn sikhye, substituted for sweetener, the ratio of rice and super sweet corn was adjusted and processed with complex enzymes during saccharification, and their physicochemical and sensory properties were analyzed. The soluble solid content of the control and Corn-5 showed significantly high content at 13.50 °Brix, and the reducing sugar content of Corn-5 showed the highest content at 9.45%. The control showed the lowest free sugar content among all the experimental groups, excluding maltose content. In the enzyme-treated corn sikhye group, as the amount of super sweet corn increased, the content of sucrose decreased and the contents of glucose and fructose increased. The content of ascorbic acid and polyphenol compounds increased as the amount of super sweet corn increased. DPPH and ABTS radical scavenging abilities increased with increasing ratio of super sweet corn and enzyme treatment compared to the control. In the case of sensory evaluation, Corn-3, which substituted 30% of super sweet corn for rice and treated with enzymes, showed higher evaluations in taste, sweetness, and overall preference than those of the control.

• Korean Journal of Environmental Agriculture
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• v.4 no.2
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• pp.78-87
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• 1985

To investigate the effects of paper sludge, by-products of paper manufactory, on the chemical properties of paddy soil and growth of paddy rice, paper sludges were applied to the pots at the rates of 300, 600, 900 and 1,200㎏/l0a which were either pread-justed C/N ratio to 30 : 1 or not adjusted. The effects were compared with those of control. Seasonal variations of various forms of soil organic nitrogen, the mineralization of organic nitrogen and the contents of soil minerals were analyzed. The results were summarized as follows: 1) The contents of soil organic nitrogen, especially amino sugar-N and amino acid-N, organic matter, CEC and available $SiO_2$ were increased by application of paper sludge compared with that of control. 2) The mineralizations of organic nitrogen after 6 weeks of incubation at $30^{\circ}C$ were 12. 2, 12.6, 15.1, 9.7 and $15.2^{\circ}C$ in the control, 300㎏/l0a sludge treatment, 300㎏/l0a sludge treatment(C/N ratio adjusted), 600㎏/l0a sludge treatment and 600㎏/l0a sludge treatment(C/N ratio adjusted), respectively. 3) Cu and Pb contents in the soil were in the range of $0{\sim}0.2100$ and $0{\sim}0.0013$ ppm, respectively. Cr and Cu in the soil were not detected at all. There were no differences in the contents of all the heavy metals among all the treatments in the soil.

• The Korean Journal of Food And Nutrition
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• v.26 no.4
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• pp.685-692
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• 2013

Yuza (Citrus junos) has 3 varieties with variable physiochemical properties. This study analyzed these volatile compounds and physiochemical properties according to variety. Three Yuza varieties, native (Citrus junos I), improved I (Citrus junos I+Poncirus trifoliata), improved II (Citrus junos I+C. junos II) were used. The native Yuza weighted more than the improved varieties, but the peel ratio (weight of peel versus pulp) was high in improved one. Protein and ash contents were high in Improved I than native one. Native had 29.6mg% vit. C in pulp and improved I had 57.7mg% vit. C in peel. Free sugar was mainly fructose, and the main organic acid was citric acid in Yuza. Improved I Yuza had high free sugar contents, and the organic acid levels were high in improved II Yuza. Linoleic acid was the most prevalent fatty acid in Yuza; it was distributed in peel or pulp. The most common volatile flavor component was dl-limonene (64~70%); improved II Yuza showed significantly higher contents of dl-limonen and ${\gamma}$-terpinen. Total phenol level of Yuza was identical in all types, but peels had 2.5 times more than pulps.

• Applied Chemistry for Engineering
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• v.34 no.3
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• pp.285-290
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• 2023

Poly-lactic acid (PLA) is the most promising polymer in additive manufacturing as an alternative to acrylonitrile butadiene styrene (ABS). Since it is produced from renewable resources such as corn starch and sugar beets, it is also biocompatible and biodegradable. However, PLA has a couple of issues that limit its use. First, it has a comparatively low glass transition temperature of around 60 ℃, such that it exhibits low thermal resistance. Second, PLA has low impact strength because it is brittle. Due to these problems, scientists have found methods to improve the crystallinity and ductility of PLA. Polyethylene glycol (PEG) is one of the most studied plasticizers for PLA to give it chain mobility. However, the blend of PLA and PEG becomes unstable, and phase separation occurs even at room temperature as PEG is self-crystallized. Thus, it is necessary to investigate the optimal mixing ratio of PLA-PEG at the molecular scale. In this study, molecular dynamics will be conducted with various ratios of L-type PLA (PLLA) or DL-type PLA-PEG (PDLA-PEG) systems by using BIOVIA Materials Studio.

• Food Science and Preservation
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• v.13 no.2
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• pp.144-153
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• 2006

The effects on deacidification of citrus fruits produced at early harvesting season for juice products were examined by heating treatment of raw fruits and electrodialysis of juice. Weight and total acidities were decreased by heating treatment for 40 hr at $25^{\circ}C,\;30^{\circ}C,\;35^{\circ}C\;and\;40^{\circ}C$, but $^{\circ}Brix$ and pH increased Sugar to acid ratio also increased. Total acidities were decreased from 1.25 (Oct30, 2004), 1.24 (Nov.5, 2004), 0.99 (Nov.13, 2004) and 0.98% (Nov.19, 2004) to 0.48 (Oct30, 2004), 0.51 (Nov.05, 2004), 0.37 (Nov.13, 2004) and 0.42% (Nov.19, 2004) by electrodialysis for 100 min respectively, and $^{\circ}Brix$ also slightly decreased, but solid to acid ratio was increased as a result. However pH and color remained almost unchanged by electodialysis. Also, free sugar contents of citrus juice little were changed, but organic acid content were decreased fairly. Narirutin and hesperidin content among flavonoids were slightly decreased by electrodialysis, but they were not significantly different. $K^+,\;PO_4^{2-},\;SO_4^{2-}\;and\;Cl^-$ content were decreased by electrodialysis, and $K^+$ contents decreased by more than 80% However, $Na^+$ consent was increased by about 2 times. Total polyphenol contents and electron donating abilities were decreased a little by electrodialysis but nitrite scavenging abilities were little changed. By acceptability test citrus juice prepared by electrodialysis for 100 min was superior to original citrus juice.

• Applied Biological Chemistry
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• v.42 no.4
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• pp.283-287
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• 1999

This study was carried out to select the most suitable soybean cultivars for the quality kanjang preparation. Six cultivars of soybean, Taekwangkong, Kumjungkong #1, Sinpaldalkong #2, Hwangkeumkong, Danbaegkong and Danyeobkong, were used as the raw materials for kanjang preparations. Grain type meju was prepared by the inoculation of Bacillus subtilis var. globigii seed culture on the cooked soybean of respective cultivar and cultivation at $30^{\circ}C$ for 10 days. Two month matured respective kanjang mash, which was prepared by mixing meju and 20% salt brine in the ratio of 1 : 3, was separated and the liquid portions were used as kanjang samples for this work. The highest crude protein content of 47.5% was obtained from Danbaegkong cultivar among six soybean cultivars tested. High sugar soybean cultivars were found to be Kumjungkong l and Danbaegkong and the content 15.87% and 13.33% respectively. The highest total nitrogen(TN) content of 1.18% was shown from Danbaegkong kanjang. Although the major free organic acid in kanjang was found to be succinic acid, no significant differences in free organic acid and sugars content were observed among cultivars. The highest free total amino acids(TA) and glutamic acid(GA) content in kanjang was observed to be 3365 mg% and 734.44 mg% respectively from Danbaegkong kanjang. Danbaegkong cultivar soybean which was shown to contain the highest crude protein was found to be the most suitable one for the preparation of quality kanjang with high TN, GA content and GA/TA ratio.