• Korean Journal of Food Science and Technology
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• v.24 no.4
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• pp.387-392
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• 1992

In order to improve the solids and protein concentration and their yields in sea mustard extracts, HCl, sucrose, NaCl, EDTA, and SHMP were added during aqueous extraction and studied their effects on quality characteristics of the extracts. The extracts were prepared by 2 hours of boiling of ground sea mustard and centrifugation. Addition of HCl at $0.1{\sim}0.5N$ level was found that the solids and protein yields was significantly improved along with the ratio of supernatant seperated. The maximum solids and protein yields obtained were 52.48%, 36.73%, respectively, while those values of the aqueous extract without HCl were 23.20%, and 4.87%. Viscosity was reduced from 450 cps to less than 20 cps by HCl addition. When NaCl, sucrose, SHMP, and $Na_2EDTA$ were added in the concentration of range of $0.5{\sim}3.0%$, solid concentration and yields were also significantly improved by the order of $Na_2EDTA-SHMP-sucrose-NaCl$ in their effect. The highest solid yield of 55.0% was obtained from 3% addition of $Na_2EDTA$. Viscosity and turbidity were also reduced by addition of SHMP and $Na_2EDTA$.

• Applied Biological Chemistry
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• v.39 no.5
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• pp.398-402
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• 1996

This study was carried out to compare the fermentation rates of Dongchimi as affected by fermentation temperature and salt concentration of brining solution. The Dongchimi was prepared by fermentation of the radish in salt solutions of 2.0, 3.2 and 5.1% NaCl respectively with addition of garlic, green onion, ginger at $4^{\circ}C,\;10^{\circ}C,\;20^{\circ}C$. The fermentation was classified into 3 steps of initial, intermediate and final stages according to pH changes and the rates of fermentation and color change were calculated from intermediate stage. The time reached equilibrium in hardness of radish and salt concentration and their equilibrated values were also compared. Fermentation rate became more rapid as fermentation temperature and salt concentration increased. The rates of Hunter color change of Dongchimi liquid were increased as the temperature increased. The 'L' values decreased slowly, and 'a' and 'b' values increased rapidly to maximum at the intermediate stage. The time required to reach equilibrium was reduced for both salt concentration and hardness of radish as the fermentation temperature increased. The equilibrated values of salt concentration were increased while those of hardness of radish were decreased as the temperature and salt concentration increased. The data obtained can be used for prediction of some of the major characteristics of Dongchimi during fermentation.

• Korean Journal of Food Science and Technology
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• v.20 no.6
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• pp.840-844
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• 1988

High-protein rice flour (HPRF) was prepared by an enzymatic process using ${\alpha}-amylase$ and g1ucoamylase without cooking Process and the feasibility of HPRF as infants foods was tested. Rice flour slurry was treated with 0.25% ${\alpha}-amylase$ and 0.5% glucoamylase at $55^{\circ}C$ for 24hrs. After saccharification, the digested rice slurry was centrifuged and the precipitated paste, was then heat-dried to obtain HPRF. The protein content of the HPRF was 20.8%. On the other hand, the supernatant of glucose enriched solution was decolourized, deionized and then isomerised to furctose at $60^{\circ}C$ for 100min by using immobilized glucose isomerase column. The high-fructose solution (HFS) contained 56% glucose, 42% fructose and 2% oligosaccharide. The nutritional quality of the HPRF was compared with milk protein and soybean protein in weight gain, feed efficiency ratio (FER), protein efficiency ratio (PER) and liver weight. HPRF was almost the same in all items with milk and soybean protein, but significantly superior to rice flour group.

• 대한공업교육학회지
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• v.36 no.1
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• pp.167-190
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• 2011

The purpose of this study is to identify the effect of problem solving with task-based activities on understanding of major concepts and learning attitude in 'Applications of ICT' subject. In teaching the 4th class of 'Applications of ICT' subject, problem solving with reasoning task-based activities are used for the experimental groups and instructor-oriented teaching for the comparative groups. The results are as follows: First, no meaningful difference was found in the pretest result of concepts of ICT, while posttest found that the students with problem solving with reasoning task-based activities in experimental group marked average 5.87 point higher than the control group and showed meaningful difference at significance level p<.05. Dividing concepts about Information Communication Technology into four domains, there were no meaningful difference between two groups in the concept test about communication principles and methods and network, while the test results about the other two concepts, that is, expressions and patterns of information and compositions and types of communication network, showed the meaningful difference at significance level p<.05. Second, the research proved that the experimental group with problem solving with reasoning task-based activity teaching, compared to the control group with lecture, showed desirable change in learning attitude. From the results, the solving with reasoning task-based activity model is better teaching-learning method compared to lecture, revealing positive change in understanding major concepts of information and communication technology and learning attitude.

• Journal of the Korea Organic Resources Recycling Association
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• v.9 no.1
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• pp.73-78
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• 2001

The biological carbon dioxide fixation using microalgae and photo-bioreactor has been known as an effective carbon dioxide reduction technology. As algae has many other environmental factor for its growth, the desirable cultivation factors were investigated using a green alga, Euglena gracilis Z. In this study, Euglena gracilis Z showed good $CO_2$ fixation ability in high $CO_2$ concentration of 10-20% and it contained the high protein and vitamin E enough to be used as fodder. For the mass cultivation, the continuous and semi-continuous cultivation methods were employed. The optimum hydraulic retention time (HRT) for the continuous cultivation was 4 days at carbon dioxide concentration of 10%. In this condition, the final cell number was $3.57{\times}10^6/m{\ell}$. The growth of Euglena gracilis Z increased according to the light intensity.

• Korean Journal of Food Science and Technology
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• v.29 no.5
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• pp.860-868
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• 1997

The effects of oil unsaponifiables (8 species) and methanolic plant extracts (53 species) on the thermal oxidation of oils during 14 or 16 hour heating at $180^{\circ}C$ were studied by analyzing the fatty acid composition of soybean oil or cottonseed oil. All the unsaponifiables tested did not show any antioxidative activities on the thermal oxidation of soybean oil. However, among the 53 species of methanolic plant extracts, some species (Rheum undulatum L., Chelidonium majus L. var. asiaticum and Eugennia caryopyllata T.) showed very strong antioxidative activities on the thermal oxidation of cottonseed oil. The antioxidative activities of methanolic extracts of these 3 species on thermal oxidation of cottonseed oil during an extended heating period were also studied by heating cottonseed oils for 7 hours a day for 8 days at $180^{\circ}C$. The methanolic extracts of Chelidonium majus L. v. asiaticum and Eugennia caryopyllata T. greatly reduced both polymer formation and linoleic acid decomposition after the 8 day heating at $180^{\circ}C$. However, the methanolic extracts of Rheum undulatum L. was effective for the reduction of polymer formation, but not for the reduction of linoleic acid decomposition.

• 대한공업교육학회지
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• v.41 no.1
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• pp.108-127
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• 2016

We confront incessant choices in life. A person or a group stands at a crossroad continuously and make decisions under limited conditions in each time in order to achieve a goal. These series of processions are referred to as decision making and dominates our actions. Based on this view, the decision making is crucial and it secures its own position in school education as well as in real life. The purpose of this study is to develop decision making skills instructional model that can be applied to improve decision making skills in technological subjects. The components of decision making skills in technological education was problem recognition, problem identification, alternative production, alternative assessment, optimum selection, optimum evaluate. An instructional models for improvement of decision making skills in technology education and examination was designed according to the components of decision making skills in technological education. Depending on the components of decision making skills developed a teaching material to experience each step. And in the teaching material was to verify the improved decision-making skill. Accordingly, a decision making instruction model in technology is expected to contribute to enhance students' decision making skills.

• Applied Biological Chemistry
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• v.30 no.3
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• pp.210-218
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• 1987

In the previous report, we isolated and purified one of tendering enzyme 'ficin' from fig latex. In this study, various crude ficin concentrations and reaction time were employed to investigate the contents of free amino acids and other free nitrogen compounds after the treated with beef round muscle. 1. Free amino acids contents increased with the increase of temperature and time during the aging of beef at $1^{\circ}C$ and $8^{\circ}C$, and the increasing rate was remarkably high when fresh beef was treated with ficin. In the case of ficin treatment after various cooking, steaming showed the highest increase in free amino acid contents among three cooking methods such as boiling, steaming and pan broiling. The increased amounts of free amino acids in three groups-aging beef at $1^{\circ}C$ for 3 days, fresh beef treated with ficin(0.1%, 2hrs) and beef treated with ficin(0.1%, 2hrs) after cooking were 13%, 293% and 137% respectively. In contrast to aging group, the amount of free amino acids in other two groups treated with ficin was superiorly increased. 2. The amounts of total free nitrogen, free non-protein nitrogen and $NH_3-nitrogen$ increased with the increase of temperature and time during the aging of beef at $1^{\circ}C$ and $8^{\circ}C$, and the increasing rate was remarkably high in fresh beef treated with ficin. In the case of ficin treatment after cooking, steaming gave larger amount of total and non-protein nitrogen than other two cooking, e.g. boiling and panbroiling. The increasing rate of nonprotein nitrogen to the total nitrogen of fresh beef treated with ficin(0.1%, 2hrs) was 75 times greater than that of aging fresh beef at $1^{\circ}C$ for 3 days.

• Korean Journal of Agricultural Science
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• v.27 no.1
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• pp.54-62
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• 2000

This study was performed to evaluate the food technological properties according to different emulsion state of carthamus red pigment. For making emulsion, lecithin was used as an emulsifier and polyglycerol monooleate(PGMO) and polyoxyethylene sorbitan monooleate(Tween 80) were used as an assistant, and glycerin, distilled water and soybean oil were used as base materials respectively. Paprika stock solution was used for comparing carthamin on the rheological properties. The results were described as following: 1. Hunter L-value was not drastically increased until passed by 8 hours for glycerin, carthamin, and lecithin mixed sample. 2. Hunter a-value was higher at carthamin added sample than others. and b-value was higher to paprika added sample than others. 3. The viscosity, shear rate and shear stress levels in which glycerin was used as base material were higher than soybean oil or distilled water. 4. In which soybean oil was used as base material. lecithin was not affected on the rheological properties. But, in which glycerin was used. the lecithin was higher affected on carthamin than paprika. 5. The value of shear stress was increased both carthamin and soybean oil. However, that of shear rate was shown similar trends.

• Korean Journal of Food Science and Technology
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• v.45 no.4
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• pp.441-450
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• 2013

The purpose of this study was optimization of the conditions for mixing different amounts of red radish (Raphanus sativus L.) sprout powder, butter, and sugar when baking domestic wheat cookies prepared using red radish sprout powder. Response surface methodology, with a central composite design comprising 5 levels and 3 variables, was used to identify the best possible combination of amounts of red radish sprout powder ($X_1$), butter ($X_2$), and sugar ($X_3$). The physical and mechanical properties of each of the 20 samples analyzed, including color L (p<0.001), color a (p<0.01), color b (p<0.001), spread ratio (p<0.001), and hardness (p<0.01), differed significantly. The results of sensory evaluations, including color (p<0.001), appearance (p<0.001), texture (p<0.001), flavor (p<0.01), taste (p<0.001), and overall quality (p<0.001) also differed significantly among the samples. The optimal compositional ratios were 5.15 g for the red radish sprout powder, 64.84 g for the butter, and 47.18 g for the sugar.