• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2005.05a
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• pp.307-311
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• 2005

본 연구는 동결농축유의 미량성분을 분석하고 관능적 특성을 알아보기 위하여 실시하였다. 농축유의 수용성비타민은 동결농축유가 진공농축유보다 비타민의 감소율이 적었고, 같은 동결농축유의 경우에 17% 고형분인 농축유가 27% 고형분인 농축유보다 비타민의 감소율이 적었다. 지용성비타민도 동결농축유가 진공농축유보다 비타민 감소율이 적었으며, 수용성비타민 보다는 그 감소율이 크지 않았다. 유리아미노산은 진공농축유보다 동결농축유에서 많이 측정되었고 단쇄유리지방산은 진공농축유가 동결농축유보다 생성량이 많았으며 고형분이 많을수록 많이 측정되었다. 지방산화도는 단쇄유리지방산의 결과와 같이 동결농축유보다 진공농축유가 더 높게 측정되었다. 관능검사는 cooked flavor, oxidized flavor, cheesy flavor, fat-taste, oxidized taste, off-taste에서 동결농축유가 진공농축유보다 양호하게 평가되었다. 결과적으로 동결농축유가 진공농축유보다 미량성분의 손실이 적고 관능적으로 양호하게 평가되었기 때문에 영양학적, 관능적으로 우수하다고 사료된다.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2005.05a
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• pp.303-306
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• 2005

본 연구는 개발한 batch type 동결농축장치를 이용하여 제조한 동결농축유의 일반성분 분석 및 이화학적 특성을 분석하고, 진공농축유와 비교하여 동결농축유의 우수성을 입증하기위하여 실시되었다. 동결농축유와 진공농축유는 농축방법에 따라 차이가 나타났으며, 전기영동 실험결과 진공농축유에 비하여 동결농축유의 band가 뚜렷하게 나타나 열처리한 진공농축유가 열변성이 된 것을 확인할 수 있었다. 열처리시에는 Maillard반응이 일어나거나 유효성 lysine함량이 감소되며, 유청내 용해성 칼슘이 인산이나 변성된 단백질과 결합하여 한외여과성칼슘(calcium ions in milk ultrafiltrates)함량이 감소되며, 비타민 손실, 유당의 이성체화, 휘발성 황화합물 생성에 의해 가열취가 발생될 수 있다. 따라서 전기영동 실험결과 batch type 동결농축장치를 이용하여 제조한 동결농축유의 우수성을 확인할 수 있었다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.9
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• pp.1347-1355
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• 2015

In this study, the physicochemical properties, antioxidant capacities, and volatile flavor compounds of oriental melon wine prepared by freeze concentration after heat treatment (HA), ascorbic acid treatment (AAT), and heat and ascorbic acid treatment (HAAT) were investigated. During fermentation period, the melon wine by HAAT showed greater reduction of soluble solids and reducing sugar contents compared to other treatments. In addition, the melon wine treated with HAAT also showed a higher L value and lower browning index compared to other treatments. After aging, free sugar including fructose, and organic acids including citric acid, succinic acid, and malic acid were detected in all samples. For antioxidant activities and contents, HAAT treated wine showed greater antioxidant activities and total phenolic contents than those of others. In GC/MS analysis, a total of 33 volatile flavor compounds were identified. In the principal component analysis of volatile flavor compounds, principal components 1 and 2 represented 88.15% of the whole date distribution and showed opposite tendencies. Taken together, HAAT enhanced the antioxidant activities and sensory properties of oriental melon wine. Moreover, freeze concentration gave the different volatile flavor characteristics in oriental melon wine.

• Journal of the Korea Convergence Society
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• v.12 no.11
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• pp.419-426
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• 2021

Until recently, various studies for the production of high-acidity vinegar have been conducted, but there have been few studies on the concentration process of vinegar. In this study, the possibility of introducing freeze-concentration method was investigated for the production of high-quality, high-acidity vinegar. Acidity, pH, specific gravity, and glucose concentration were measured for frozen concentrated vinegar fractions obtained by freezing and thawing three types of Rubus coreanus vinegar with different acidy (7.53, 5.43, and 3.72). Acidity, specific gravity, and glucose concentration were all highest when 15% of the original vinegar was thawed. pH was the lowest when 15% of the original vinegar was melted. As a result of the measurement of cumulative acidity, when 20% of the original vinegar was melted, it was the highest at 9.32, which was 3.89 higher than that of the original vinegar. In this study, it was confirmed that vinegar can be effectively concentrated using the freeze concentration method and at the same time, the thawing ratio can be controlled to effectively obtain vinegar with the desired acidity. However, it is considered that studies such as organic acid and amino acid analysis are needed to determine whether the freeze-concentration method is introduced into the high-acidity concentrated vinegar manufacturing process.

• Journal of Navigation and Port Research
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• v.37 no.2
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• pp.129-135
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• 2013

Recently, waste water treatment system is developed in small and middle size to get more economic advantage. Freeze concentration system has high thermodynamic efficiency and low energy consumption, can re-use purified water and cold energy obtained from ice. This study was experimentally performed to investigate pollution containment in frozen layer by cooling wall temperature, air-bubble flow methods, initial ice-lining thickness of frozen layer in NaCl aqueous solution and the representative heavy metals, Pb and Cr aqueous solution. As the result, a decrease in the cooling wall temperature bring a higher growth rate of ice front and the more solute was involved in frozen layer. The method to inject directly air-bubble into ice-liquid interface through ring shape nozzle gave high purity of ice compared to indirect method. Ice lining in 5mm thickness resulted in frozen layer with higher purity than 1mm thickness.

• Korean Journal of Food Science and Technology
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• v.41 no.1
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• pp.32-36
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• 2009

The physical properties of freeze-dried Aloe vera gel powders were examined according to the influence of the concentration degrees of the gel solutions as raw materials during freeze-drying. As a pre-treatment prior to freeze-drying, the gel solutions were vacuum-concentrated at three concentration levels (g water/g solids): high (H), 76; medium (M), 119; and low (L), 159. The water contents of the three powder samples were almost the same. For their viscosity measurements, non-Newtonian fluid behavior with shear thinning was observed in samples H and M, whereas Newtonian liquid behavior was found in sample L. In electrical conductivity measurements, sample H showed the highest conductivity upon dissolving the powder in water. For their water sorption isotherms, sample H was analyzed to have the least amount of bound water. Finally, it was determined that the degree of concentration caused only slight differences in the physical properties of freeze-dried Aloe gel powders.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.51-52
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• 2006

This study was progressed on the freezing behavior of waste water in relation to freeze concentration method useful to waste water treatment system of small and middle size and which can re-use purified water. The object of this experiment is comparing a pollutant contain of the frozen layer and of an aqueous solution by cooling wall temperature, a flow field effect and a initial thickness of frozen layer.

• Korean journal of food and cookery science
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• v.18 no.1
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• pp.73-80
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• 2002

The effect of sodium metabisulfite and adipic acid on the color changes of garlic juice was evaluated. The garlic(Uisung variety) juice was extracted and 1% sodium metabisulfite and 1% adipic arid were added to the garlic juice before or after concentration. Garlic juice was concentrated by heating at 90$\^{C}$, by heating using a rotary vacuum evaporator at 45$\^{C}$, or by freeze-drying at -50$\^{C}$ until the volume was reduced to 70% of the original volume. The garlic juice concentrate was kept at 4$\^{C}$ and 25$\^{C}$ for 60 days and evaluated for the color change and the relation between the additives and browning. Browning of the garlic juice concentrate containing adipic acid and sodium metabisulfite was effectively inhibited compared with the control. Inhibition effect of sodium metabisulfite on the browning of the concentrate was stronger than that of adipic acid. The addition of sodium metabisulfite afrer concentration of garlic juice was the most effective on browning inhibition in the 9$\^{C}$-heated concentrate, but the addition of sodium metabisulfite before concentration was the most effective in the 45$\^{C}$-heated concentrate and the -50$\^{C}$-freeze-dried concentrate. In the color change of the garlic juice concentrate during the storage, a and b values of the concentrate with sodium metabisulfite were lower than those of the control, which means that sodium metabisulfite inhibited the browning of the garlic juice concentrate.

• JOURNAL OF ELECTRICAL WORLD
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• no.9 s.14
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• pp.47-50
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• 1977

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.5
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• pp.467-476
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• 2013

Freeze concentration method has advantages of high thermodynamic efficiency, low energy consumption and purified water re-use. In this study, freeze concentration waste-water system which was designed as the small and medium sized capacity was analyzed about the rate of electric power consumption and the daily treatment capacity to suggest the direction of system development. At first, power consumption and operation time of the system with fresh water precooler or without it was calculated by computer modeling and analysis. Subsequently, the change of design treatment capacity was applied to the system with fresh water cooler. As a result, the rate of electric power consumption was higher as 0.6 Wh/kg but daily treatment capacity increased in quantity as 19 % in the system with fresh water precooler. As design treatment capacity increased, the rate of electric power consumption was lower and daily treatment capacity was larger in quantity.