• Korean Journal of Food Science and Technology
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• v.23 no.2
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• pp.235-240
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• 1991

Starch phosphates were prepared from the corn starch mixed with 2% sodium tripolyphosphate by twin-screw extruder with a feed rate of 20 kg/hr and an extrusion temperature of $130^{\circ}C$, and the effects of extrusion variables on the physicochemical properties (target parameters) of starch phosphates were investigated. Interrelations of system parameters (specific mechanical energy and extrudate moisture) and rheological properities of starch was analyzed by using the response surface analysis. Degree of substitution (DS) was increased with increasing the feed moisture, and showed the maximum value at the screw of near 250 rpm, Degree of gelatinization was proportionally increased with increasing the screw speed and decreasing the feed moisture. Apparent viscosity of the paste was increased with increasing the feed moisture, but it was not significantly affected by the screw speed. It was found by scanning electron microscopy that the starch microgranules were much more degradaded, and as consequent result, the intrinsic viscosity was decreased, whereas, water solubility index was increased. The rate of retrogradation of the gels was retarded with increasing DS and decreasing viscosity.

• Clean Technology
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• v.20 no.4
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• pp.415-424
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• 2014

In this study, two kinds of polymer (PPQX-2hdPTZ (P1), POPQX-2hdPTZ (P2)) were synthesised by Suzuki coupling reaction based on phenothiazine derivative as electron-donor and quinoxaline derivative as electron-acceptor. Microwave synthesis workstation was used to shorten the polymerization time and increase the degree of polymerization. The physical, thermal stability, optical and electrochemical properties of the synthesized polymer were confirmed. The thermal stability of two polymers was outstanding as the initial decomposition temperature was $323-328^{\circ}C$. And additional substituted alkoxy chain on P2 showed higher degree of polymerization. An analysis of electrochemical properties, all polymer had similar HOMO energy level values. Device was fabricated by ITO/PEDOT:PSS/active layer/$BaF_2$/Al structure and photovoltaic properties were confirmed. Each device has a different film thickness and the resulting change in PCE was confirmed. As a result the thinner thickness of the film showed a high efficiency ($PCE_{max}:P1=1.0%$, P2 = 1.1%).

• Journal of Soil and Groundwater Environment
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• v.13 no.5
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• pp.47-56
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• 2008

Temporal changes of metal solubility have been repeatedly observed in soils equilibrated with metal salt solutions. This phenomenon is known as aging, yet factors that affect the degree of metal aging remain largely unexamined. In this study, we compared the extent of aging on metal partitioning depending on soil, metal, and metal loading. Five soils spiked with four levels of Cd (2.5-20 mg ${kg}^{-1}$), Cu, and Zn (50-400 mg ${kg}^{-1}$) salt solutions were aged in the laboratory up to 1 year. The partitioning coefficient ($K_d$) of each metal was calculated from the ratio of total to dissolved metal concentration in samples collected at times ranging from 1 day to 1 year. The highest $K_d$ values for Cd, Cu and Zn were recorded in a Histosol, Andisol, and fine-textured Alfisol, respectively, whereas the lowest $K_d$ was recorded for an Oxisol and coarsetextured Alfisol. For all soils, a pattern of increasing Kd with aging was evident for Cd and Zn, but not Cu. Rapid Cu sorption was limited when dissolved organic matter was high in soils. In highly-retentive soils, $K_d$ values seemed to be insensitive to metal loading, although a longer period was required for the higher metal loadings to reach the same degree of metal aging as the lower loadings. In soils with low sorption capacity, the $K_d$ values were determined more by metal loading than by aging. Therefore, marked differences can be expected in the degree of metal aging in spiked soils by the soil type, metal and amount of metal added.

• The Korean Journal of Food And Nutrition
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• v.30 no.6
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• pp.1260-1267
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• 2017

The properties of rice were studied on five rice cultivars (Ilpumbyeo, Samkwang, Goami-4, Dodamssal, and Thai rice), and employed two kinds of saccharification treatment methods (treatment I : rice shape, treatment II: grinding rice shape). Thai rice showed differences in width and length when compared to other cultivars of rice, and the Goami 4 had the lowest thousand-grain weight. The Goami4 and Dodamssal each showed high contents of amylose and resistant starch, and the water absorption rate was close to maximum at 90 minutes as well as the highest level of Goami 4 at all times. The qualities of highest water-binding capacity, solubility and swelling power was most significant in Thai rice. The lowest hardness level of wet rice resulted in the lowest hydration-related characteristics. High amylose content rice, in particular, showed low sugar content and slightly increased sugar content as the saccharification process improved (treatment II). On the other hand, high amylose cultivars had the same high degree of hardness as boiled rice. From these results, the Dodamssal was found to have the lowest viscosity at all temperatures but highest viscosity during the saccharification process, suggesting it may be successfully implemented as a thickener in rice beverage processing. The purpose of this study was to attempt to provide basic data on the development of rice beverage manufacturing technology, based upon the quality characteristics related to beverage processing of rice cultivars.

• Korean Journal of Medicinal Crop Science
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• v.22 no.1
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• pp.32-37
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• 2014

To study the cause of physiological disorder in leaf of ginseng cultivated at paddy soil, the degree of brown-colored symptom (BCS) and the contents of inorganic matter in leaf were investigated by irrigating the solution of ferric and ferrous iron of 0.1 ~ 2.0%, and citric acid of 1.0 ~ 4.0% on bed soil, respectively. Ratio of BCS by variety was as high as 85.0% in Yoenpoong, while it was as low as 5.4%, 7.5% in Chunpoong and Hwangsook, respectively. The contents of inorganic matter of leaf in Yoenpoong were lower in $P_2O_5$, Ca, and Mg, while it were higher in K, Fe, and Mn than other variety. Iron solution caused BCS more distinctly when each ferric and ferrous iron were dissolved with 1.0% citric acid than when each iron was dissolved without citric acid. Ferric iron caused BCS more effectively than ferrous iron. BCS occurred in 4.0% citric acid was as same as 2.0% ferric iron mixed with 1.0% citric acid. Low $P_2O_5$ and high Fe content in leaf appeared in both of artificial and natural symptoms. We concluded that excessive Fe uptake caused BCS to leaf because the solubility of iron was increased in condition of low soil pH.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.5
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• pp.478-482
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• 2001

This study was conducted to get a knowledge on food components of cuttle bone (CB) as a food resource. The yields and ash contents of CB were about $7.5\%$ on whole cuttle fish and about $90\%$ on dry basis, respectively, The contents of heavy metal might not invoke health risk in using food resource, The major mineral of CB was calcium as about $22\%$ in content. The yields, proximate compositions, heavy metal and mineral contents were not significantly different between domestic and imported CB. Judging from X-ray diffraction pattern, most of calcium in CB was present as a form of calcium carbonate (CC), and scanning electron micrograph showed irregular form. Buffering capacity of CB showed strongly at pH 7, and its pattern was the same as shown in that of CC, And CB solution showed a very high degree in turbidity comparing to that of CC solution. The solubility of CB was superior to that of CC, but inferior to those of calcium powders on the market, It was concluded from above results that CB could be effectively utilized as a calcium source.

• The Korean Journal of Food And Nutrition
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• v.26 no.3
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• pp.601-607
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• 2013

This study was performed to investigate the changes of total and soluble ${\beta}$-glucan contents, purity and physicochemical characteristics of alkali hydrolyzed barley varieties: Saessalbori (SSB), Saechalssalbori (SCSB) and Hinchalssalbori (HCSB). The barleys were hydrolyzed at different concentrations of sodium hydroxide (0.2~1.0 N) for 12 hours. Total ${\beta}$-glucan contents of raw SSB, SCSB and HCSB were 8.40, 7.77 and 8.28%, and soluble ${\beta}$-glucan contents were 4.80, 4.16 and 4.61%, respectively. The total ${\beta}$-glucan contents after alkali hydrolyzed at 1.0 N NaOH were 7.54, 6.89 and 7.54%, also soluble ${\beta}$-glucan contents were 4.82, 4.30 and 4.55%, respectively. The degree of purity of soluble ${\beta}$-glucan in SSB, SCSB, and HCSB were 35.79, 30.91 and 33.90%, respectively. They were increased to 74.02, 75.28 and 81.41% after hydrolyzed at 1.0 N NaOH, respectively. The molecular weight and viscosity of soluble ${\beta}$-glucan solutions were decreased as sodium hydroxide concentration was increased. The re-solubility of raw barley ${\beta}$-glucan was about 50%; however, it was increased to approximately 87% as sodium hydroxide concentration was increased.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.3
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• pp.342-347
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• 2007

Physicochemical properties of onion powder as influenced by drying methods were investigated. Moisture contents of onion powder were 13.29%, 12.99%, and 10.78% for samples dried using hot-air dryer, freeze dryer, and vacuum dryer, respectively. There were no significant differences in crude fat, crude protein, and crude ash content (p>0.05) depending on the drying methods. Samples prepared by freeze drying showed a significantly higher L-value as compared with those prepared by hot-air and vacuum drying (p<0.05). Scanning electron micrographs showed that freeze drying produced smaller particle-sized sample which in turn resulted in the higher porosity of the sample. Freeze dried samples revealed significantly lower degree of rehydration than other samples (p<0.05) probably due to small particle size of the sample. Water solubility of freeze dried sample appeared to be higher than that of other drying methods while the swelling ratio of the same sample appeared to be lower than that of the others. Browning index was significantly lower in samples prepared by freeze drying (p<0.05) but not significantly different between samples dried by hot-air and vacuum drying. Vitamin C content was higher in freeze dried onion powder due to the lower temperature applied to the sample. Freeze dried onion powder contained significantly lower amount of total polyphenol and higher amount of total sugar as compared to other samples (p<0.05).

• Journal of Environmental Science International
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• v.2 no.1
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• pp.61-72
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• 1993

Result of this study indicate that two criteria must be met in order to have effective macrocycle-mediated transport in these emulsionsystem. First, one must effective extraction of the post transition metals, $Cd^{2+}$. $Pb^{2+}$ and $Hg^{2+}$ , into toluene membrane. The effectiveness of this extraction is greatest if log K values for the metal-macrocycle interaction is large. Second, the ratio of the log K values for the metal ion-receiving phase to the metal ion-macrocycle interaction must be large enough to ensure quantitative stripping of the metal ion at the toluene phase interface. Control of the first step can be obtained by appropriate selection of macrocycle donor atom, substituents, and cavity radius. The second step can be controlled by selecting the proper complexing agent for inclusion in the receiving phase. The order of the transport, when using the several $A^-$ species such as $SCN^-$, $1^-$, $Br^-$ and $Cl^-$ is the order of the changing degree of solvation for $A^-$ and the transport of the metals is also affected by the control of concentration for receiving species because of solubility-differences. In this study, we can seperate each single metal ion from the mixture of $Cd^{2+}$, $Pb^{2+}$, and $Hg^{2+}$ ions by using the toluene membranes controlled by optimized conditions. Transport of the single metal is also very good, and alkaline and alkaline earth metals as interferences ions did not affect the seperation of the metals in this macrocycle-liquid membrances but transition metal ions were partially affected as interferences for the post transition metal ions.

• Korean journal of food and cookery science
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• v.22 no.5 s.95
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• pp.659-665
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• 2006

The effects of resistant starches on the quality characteristics of cookies were investigated by the physicochemical, instrumental and sensory properties of RS-added flours and cookies. Retrograded RS3 by autoclaving-cooling cycle and cross-linked RS4 after annealing treatment were used. The protein content of RS-added flour decreased, but the ash content of RS4-added flour increased slightly with increasing RS content. The RS levels of wheat flour, RS3- and RS4-added flours were 7.0%, 9.6-13.4% and 11.5-17.9%, respectively. The swelling powers of RS-added flours at 80$^{\circ}C$ decreased, but the solubility of RS3-added flour increased by 2-3 fold compared to that of control flour. Initial pasting temperature increased, but peak, holding, and final viscosities decreased with increasing RS content. The retrogradation degree of RS-added flours was lowered, because of the decreased consistency and breakdown viscosity. The yellowness of RS3-added flour increased with increasing RS3 content which induced browning reaction during baking. On the sensory test, RS-added cookies were significantly different in shape, color and overall quality (p<0.05), and their texture also affected. Overall quality was higher in peanut cookies than in AACC standard cookies and RS addition (up to 30%, w/w), regardless of the RS type, improved the cookie quality.