• Korean Journal of Food Science and Technology
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• v.36 no.6
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• pp.937-942
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• 2004

Physicochemical properties and mineral composition of seaweed salts prepared by incineration and osmotic dehydration methods were determined. As the incineration temperature increased, yield of seaweed salts, insoluble solids, pH, alkalinity, and oxidation-reduction potential (ORP) decreased. Alkalinity of salt prepared with sea tangle was higher than that of sea mustard. ORP decreased by incineration above $700^{\circ}C$, and was lower in salt with sea tangle. As incineration temperature increased, amounts of K and Ca in seaweed salt increased, whereas that of Mg decreased. Potassium and Ca contents of seaweed salt increased remarkably compared with those of common salt. Potassium content of sea tangle salt was higher than that of sea mustard. As incineration time increased, yield of seaweed salts, insoluble solid content, and pH decreased, whereas ORP of the salt increased. Potassium content of seaweed salt with incineration time, while Ca and Na contents decreased after incineration of 8 and 4 hr, respectively. Yield of seaweed salt by osmotic dehydration increased as immersion time in sea water increased. pH of salt from sea mustard was higher than that of sea tangle. ORP of seaweed salt dried three times was -128.8 mV, significantly lower than that of salt prepared by incineration method. As sea water immersion time increased, Mg content of seaweed salt increased significantly, while Ca content decreased. Potassium content of seaweed salt was higher in sea tangle salt. In case of salt prepared by incineration of residuals, pH increased with immersion time but ORP decreased.

• The Korean Journal of Food And Nutrition
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• v.19 no.4
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• pp.358-365
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• 2006

To study simultaneous water and solute transport kinetics during soaking in concentrated solution, the influence of the concentration and molecular weight of the solute(polyethylene glycol(PEG) and NaCl) in the soaking solution and the temperature on the water loss and solute gain rates were observed by using a model vegetable tissue(potato). When potato slices$(4cm{\times}4cm{\times}0.1cm)$ soaked in 60% PEG solutions, the water loss rate of the early phase decreased with increasing of the molecular weight of PEG from 200 to 6,000, while the final water loss increased with increasing the molecular weight of PEG and it reached to 80%. The cell wall of potato tissue was permeable to NaCl and PEGs of which average molecular weight is smaller than 400 but it was not permeable to PEG 600 and larger molecules. PEG which has average molecular weight below 600 induced plasmolysis and those above 600 induced cytorrhysis. The water loss rate of potato sample soaked in smaller molecular weight PEG solution was faster than those soaked in higher molecular weight PEG solution before cytorrhysis happened. The water loss rate was reversed after cytorrhysis happened. The volume change of potato within the first 60 minutes was larger in low molecular PEG solution but the final ratio of decreasing volume was larger in high molecular PEG solutions. In PEG 200 solution, the potato tissue was slightly shrinked without shape change. However, in PEG 4,000 solution, volume of potato was reduced significantly and potato tissue was twisted.

• Korean Journal of Food Science and Technology
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• v.28 no.6
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• pp.1126-1134
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• 1996

The physical characteristics changes of carrots during drying were studied to minimize the quality degradation by applying improved drying process and pretreatment method. Physico-chemical properties of the product were analyzed, and then, drying mechanisms were explained by diffusion coefficients and drying models. In hot air drying process, the drying and rehydration efficiencies were high at low relative humidity and high temperature. Browning degree and specific volume also showed similar trend to drying efficiency. Diffusion coefficient, which describes moisture transfer, was also high at low relative humidity and at high temperature. It was verified using. Arrhenius equation that drying process was influenced by temperature. It was also observed during experiment that temperature changes were more effective in drying than relative humidity changes. Quadratic model was the most fittable in explaining the process. As a result of analyzing the experimental data with respect to the drying time, the contents of carotene and moisture could be modeled as a polynomial. As the air velocity increased, drying performance and rehydration efficiency increased.

• Journal of Life Science
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• v.23 no.12
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• pp.1557-1561
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• 2013

Carbonic anhydrase isozymes are a widespread, zinc-containing metalloenzyme family. The enzyme catalyzes the reversible inter-conversion of $CO_2$ and $HCO_3$. This reaction is the main role played by CA enzymes in physiological conditions. This enzyme has been found in virtually all organisms, and at least 16 isozymes have been isolated in mammals. Unlike mammals, there is little information available regarding CA isozymes in the tissues of non-mammalian groups, such as fish. Carbonic anhydrase is very important in the osmotic and acid-base regulation in fish. It is well-known that the gills of fish play the most important role in acid-base relevant ion transfer, the transfer of $H^+$ and/or $HCO_3^-$, for the maintenance of systemic pH. Rainbow trout, Oncorhynchus mykiss, is the most important freshwater fish species in the aquaculture industry of Korea, with annual production increasing each year. In addition, environmental toxicology research has shown that rainbow trout is known to be the species that is most susceptible to environmental toxins. Consequently, carbonic anhydrase was detected in rainbow trout, Oncorhynchus mykiss. The isolated protein showed the specific band with a molecular weight of 30 kDa and pI of 7.0, and it was identified as being carbonic anhydrase. The immunohistochemical result demonstrated that the carbonic anhydrase was located in the epithelial cells of the gills.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.4
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• pp.292-301
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• 2000

To make a better use of the beneficial bacterial inoculants in the agricultural practice, dry forms of bacterial fertilizer or pesticides are prepared with carrier materials. During the drying process of bacterial inoculant, most of the cells face a severe osmotic pressure and dehydration, and die off. Our study describes the effect of osmoprotectants such as trigonelline and trehalose on the survival of bacterial cells in high salt concentration and drying conditions. A fluorescent Pseudomonas, strain SSL3, used in this study, could grow in high salt concentration of upto 5% but the cells could not overcome the growth retardation at over 7% of salt concentration. The addition of trigonelline, even on small amount, in liquid medium containing 4% NaCl was detrimental to the cell. However, the addition of trehalose of upto 10 mM to the liquid medium containing 4% NaCl, enhanced cell growth. The cell growth was retarded when 150mM trehalose was added to the medium. Upon dry formulation of cells, trehalose was added. And the dry cells were inoculated into the soil to determine the effect of osmoprotectants on the survival of the cells. The survival of the cells, both in wet or dry soil, was improved by the addition of trehalose during the dry cell formulation. The positive effect of trehalose on the cell survival at $-20^{\circ}C$ and $-70^{\circ}C$ was oven more pronounced. The FTIR (Fourier transformation infra-red) spectroscopic analysis showed that the change of the 2nd amide group was reduced by adding trehalose to the medium containing 4% NaCl. These results suggest that trehalose can protect the cell membrane from dryness or high concentration of salt, thereby diminishing the sudden change of the protein structure of the cell membrane and, as a consequence, improving the cell survival.

• Korean journal of food and cookery science
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• v.26 no.5
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• pp.636-648
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• 2010

Two types of wild grape extracts(WGE) prepared by different methods were added into butter-top bread at different concentrations(0, 5, 10, 15, 20% of water). Then, the resulting breads were analyzed for their physicochemical and sensory properties in order to identify whether or not the WGE-enriched breads were comparable to control bread in terms of qualities and preferences. Wild grape sugar mixture(WGS), which was prepared by osmotic dehydration of wild grape fruits with the same amounts of sugar, presented significantly lower moisture content and titratable acidity as well as higher pH and sugar content compared to wild grape juice(WGJ), which was produced by boiling the fruits in a vacuum jar and squeezing. The pH of the doughs and breads containing WGE tended to decrease with increasing amounts of WGE, and this phenomenon was more appreciable in those containing WGJ than WGS. This was presumably due to the higher contents of tartaric acid in WGJ. For both types of extracts, hardness, gumminess, and chewiness of the doughs decreased with the addition of WGE, nevertheless, which properties were not remained in the resulting breads. This could be partially attributed to the relatively high degree of baking loss and lower pH of the WGE-enriched breads than those of control bread. Contrary to the mechanical analyses, the sensory properties of the breads were dependent on the WGE type. That is, WGJ-enriched bread showed lower consistency and moistness than control bread, which consequently led to relatively lower overall acceptability. However, WGS addition did not adversely affect the sensory properties of the bread. In particular, addition of 5% WGS somewhat improved the physical and sensory qualities of the bread. Thus, WGE-enriched bread could be produced without loss of bread quality when prepared with 5% WGS.