• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.799-804
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• 2002

Optimum conditions of freeze-dried carrots were determined using response surface methodology. Physicochemical and sensory properties of freeze-dried carrot prepared at different plate temperatures and chamber pressures were evaluated. Drying time increased with decreasing plate temperature and chamber pressure. Rehydration ratio decreased inversely with chamber pressure at low plate temperature, but increased proportionally with chamber pressure at high temperature. Density, color, and sensory off-flavor were not affected by the plate temperature and chamber pressure. Sensory color, tenderness, and carrot flavor increased with decreasing plate temperature, but were not affected by chamber pressure. Based on the drying time, rehydration ratio, and sensory attributes, optimum plate temperature and chamber pressure for the preparation of freeze-dried carrot were determined as $43^{\circ}C$ and 700 micronHg, respectively.

• Journal of the Korean Geotechnical Society
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• v.15 no.6
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• pp.219-238
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• 1999

In the present study, laboratory tests including the seepage-induced consolidation test, suction test, and desiccation shrinkage test are performed to investigate characteristics of the desiccation shrinkage in reclaimed hydraulic fills. Soil samples for laboratory tests are obtained from three sites (districts of Haenam, Kogeum and Koheung in Chunnam area). Desiccation shrinkage settlement caused by three dimensional volume change is numerically evaluated using finite difference technique based on the governing equation proposed by Abu-Hejleh & Znidarcic. Also characteristics of the desiccation shrinkage analyzed from the test results are used as input data for numerical evaluations. Further predicted total settlements including the self-weight consolidation settlement are compared with values measured at the site of Haenam district. Finally, effects of parameters related to the desiccation shrinkage on settlements are examined.

• Food Science and Preservation
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• v.22 no.1
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• pp.56-62
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• 2015

In this study, the quality characteristics of different drying methods of Aronia melanocarpa, which contains large amounts of bioactive substances, were investigated for the improvement of their practical use. During the drying period, the weight reduction was the highest with vacuum freeze drying (81.6%). The water content was reduced to the maximum level when vacuum freeze-drying was used. With regard to the color value measurement results, there were no significant differences in the $L^*$ value. Values of $a^*$ and $b^*$ were increased in vacuum freeze drying and cold air drying, but decreased in hot air drying. The hardness was increased dramatically after 36 hours of hot air drying, while with cold air drying, it increased slowly until 132 hr and increased rapidly after 132 hr. The dried yield was the highest with cold air drying (24.2%). As for the general component analysis results of Aronia melanocarpa, the moisture content was the lowest, and the crude protein and crude fat contents were the highest with vacuum freeze drying. No difference in pH value was shown among the dried Aronia melanocarpa obtained from the different drying methods, but the sugar content was the highest with vacuum freeze drying. The mineral content was the highest with cold air drying, and K, Ca, Mg, and Na were the major minerals. The free sugar content of dried Aronia melanocarpa was found to be 5.92~20.59 g/100 g, and the highest free sugar content was found with vaccum freeze drying.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.9
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• pp.1573-1579
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• 2004

This study was conducted to develop intermediate material for new processed food from sweet pumpkin. Osmotic dehydration was carried out as pretreatment before drying. After the sweet pumpkins were pretreated under optimized osmotic dehydration conditions, they were dried by three drying methods (hot air drying, vacuum drying and cold air drying). The moisture contents of dried sweet pumpkin products by osmosis treatment (sucrose) and hot air drying, vacuum drying, and cold air drying were 14.48, 14.09 and 13.87%, respectively. Cold air drying preserved more vitamin C content and showed lower color difference than hot air drying and vacuum drying. As a result of microscopic analysis, cold air dried sweet pumpkin was observed regular tissue, while hot air and vacuum dried sweet pumpkins were observed a cell collapse following the loss of water.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.6
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• pp.973-980
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• 2000

This study was conducted to evaluate the quality of the cold air dried anchovies (CA), and compared with those of sun-dried anchovies (SA) and hot air dried anchovies (HA). Peroxide value increased, while ratio of percentage of (20:5+22:6) to that of 16:0 decreased during boiling and drying. The extents of change were CA>SA>HA in the order. In the case of CA, lightness was higher, but redness, yellowness and degree of browning was lower than in SA and HA. From the results of lipid properties, color test and sensory evaluation on color and rancidity odor, lipid deterioration was the lowest in CA of all boiled dried anchovy. Favorite properties such as a hot-water soluble nitrogen content and sensory evaluation on color and appearance of CA was superior to that of SA and HA. The nutritional properties (total amino acid contents, mineral contents and fatty acid compositions) of CA was similar to that of SA, but was superior to that of HA. Consequently, CA was recognized as a boiled dried anchovy with the most quality.

• Korean Journal of Food Science and Technology
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• v.38 no.5
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• pp.635-641
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• 2006

In an attempt to find ways of improving the quality and sanitary state of dried squid, this study compared artificial drying methods i.e. hot air drying and cold air drying with natural drying method. The drying rates of squid were in the order of hot air, cold air and natural drying. However, cold-air drying was slower than natural drying at $7^{\circ}C$. The drying rates increased with increasing drying temperature. When drying temperature was close to the dew point on a dehumidifier surface, which was the case with cold air drying at $7^{\circ}C$, the driving force for dehumidification was lower than under other drying conditions, which resulted in a lower drying rate. There were little color differences between the drying methods and temperature. Squid dried by cold air-drying had better mechanical texture and sensory qualities than with other drying methods. In addition, the cold air drying method maintained superior quality in terms of the contents of amino acids, taurine, EPA, DHA, other fatty acids and a low TBA value than the other drying methods.

• Nuclear Engineering and Technology
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• v.24 no.3
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• pp.219-227
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• 1992

An experiment was conducted to determine the reaction of boric acid with lime and the drying of its product using a reactor-dryer. no characteristics of dried products were observed. The major chemical species of dried Products was calcium borate of 2CaO.B$_2$O$_3$. From the particle size distribution of the dried products, it was found that quick lime was better than slaked lime as an additive. The Ca/B mole ratio of reaction was determined to be 3/4 considering the cohesion and agglomeration properties of dried products. The flowability of dried products up to 8 wt% of water content was acceptable for transport process and to reduce drying time.

• Food Science and Preservation
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• v.10 no.4
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• pp.470-475
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• 2003

The response surface methodology was performed by central composite design for moisture content, titratable acidity, hunter's color value and organoleptic properties based on drying temperature and time of Citrus, to apply basic data to preparation of dried Citrus. Moisture content, b value and organoleptic color were affected by drying temperature ; That decreased with increase of drying temperature. Titratable acidity was affected by drying time. Organoleptic flavor and taste were affected by drying temperature and time. The optimum drying conditons for organoleptic taste were 67.56$^{\circ}C$ in drying temperature and 8.06 hr in drying time.

• Food Science and Preservation
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• v.12 no.5
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• pp.436-441
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• 2005

This study was observed the effects of drying methods on the extraction characteristics of Rubi fructus (fruits of Rubus coreanus). Extraction yields of soluble solids and total sugar were high in the Rubi fructus dried by freeze drying, followed by infrared drying and sun drying. Extraction yield of phenolic compounds and DPPH radical-scavenging activity of extracts were in the following order; the Rubi fructus dried by freeze drying, the Rubi fructus dried by infrared drying, the Rubi fructus dried by sun drying. L value was the highest in the Rubi fructus dried by freeze drying, and a and b value were lowest in the fruit dried by freeze drying. These results suggest that freeze drying has an beneficial effect to enhance the quality of Rubi fructus. Water and ethanol extractions was more effective in the extraction of soluble solids and the antioxidative components.

• Analytical Science and Technology
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• v.10 no.6
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• pp.418-426
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• 1997

Dewatered digested sewage sludge were heated with microwave and their drying characteristics were investigated on the effect of their surface area, shape, diameter and thickness. The drying characteristics of identical samples in a conventional drying oven were studied. In conventional drying, constant rate period was not found and moisture was evaporated with capillary action. Moisture in the sludge was a bound water and free water was not exist. In microwave drying, the falling rate period was divided into two zones. In falling rate drying period, moisture movement occured by diffusion. The evaporation surface area was a significant variable, the greater heating surface area promoted water removal rate over wide region of water content. Drying rate was slow and constant rate drying period was found in wide moisture content region with increasing diameter. Drying characteristics appeared differently in various shape. In microwave heating, first of all temperature of sludge center was increased and was the highest. Temperature in the constant rate drying period was remained constantly at $80{\sim}100^{\circ}C$.