• Food Science and Preservation
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• v.18 no.4
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• pp.488-496
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• 2011

Cold-air drying was conducted for a steamed pumpkin-sweet potato slab to improve its quality, convenience, and preference as a snack. A steamed pumpkin-sweet potato slab was dried from 10 to $25^{\circ}C$ for 48 h, and its moisture content, color, texture, and taste at different drying temperatures and drying times were evaluated. The lowest moisture content was 4.98%, at $25^{\circ}C$. The lightness decreased, but the other color values (a, b, and ${\Delta}E$) increased with the increasing drying temperature and drying time. The reducing sugar and soluble solid ranged from 98.7 to 194.75 mg/g and 19-70 $^{\circ}Brix$, respectively. The highest hardness of the steamed pumpkin-sweet potato slab was 23.88 $kg_f/cm^2$, and the springiness and cohesiveness were 91.15 and 98.36% when it was dried at $25^{\circ}C$ for 48 h. The sensory evaluation score was high at $10^{\circ}C$, 40 h and at $25^{\circ}C$, 24 h. The optimum drying condition was predicted at $19^{\circ}C$, 32 h via response surface methodology (RSM).

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.1321-1326
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• 2008

A study on the heat and mass transfer for the drying time in spray freezing drying process was experimentally presented in this paper. A spray freezing dryer for the production of an inhalable powder medicine is developed and an albumin solution as protein specimen is adopted. The freeze-drying for the albumin solution is tested in three different height of the particles piled up in a tray such as 2 mm, 5 mm, 7 mm, and the drying time is estimated as 10 h, 15 h, 22 h. From this results, the correlation is suggested and the drying time with various height of the particles piled up in a tray can be estimated. The assessment on the drying time is conducted thought a microbalance and the rate of water content is measured. The results based on temperature and weight are compared. The difference of the results happens due to the heat transfer from the lateral side of the vial. It is thought that the better estimation in drying time can be predicted by considering the heat transfer effect.

• Textile Coloration and Finishing
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• v.9 no.6
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• pp.74-78
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• 1997

This study was performed to obtain the basic data of the effect of antimicrobic finishing on chrome-tanned leather for apparel. This study was to examine the effect of conditions of antimicrobic finishing on content of antimicrobic agents in the specimen by analysis and on the antimicrobic activity of specimens by means of shake flask test. The optimum conditions of antimicrobic finishing were found to be ; the concentration of Si-QAC-0.5%(o.w.f.), treating time-30minute, and drying method-air drying.

• Journal of the East Asian Society of Dietary Life
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• v.25 no.6
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• pp.1029-1040
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• 2015

Effects of punching and drying process on quality of Yukwa were determined. Lightness (L) of Yukwa dough with punching was higher than that with no punching. Air cell distribution of Yukwa dough was fine with higher punching. Microstructure of Yukwa dough showed a broken surface structure with increasing punching. Hardness and adhesiveness of Yukwa dough decreased after 5 min of punching and then increased with higher punching. Expansion ratio of Yukwa base with punching at 155 rpm for 5 min was highest among the samples. Appearance of Yukwa base with no punching showed a poor shape and cross section, whereas Yukwa base with punching at 95 rpm for 10 min showed the best appearance and cross section and Yukwa base with punching at 155 rpm for 5 min also showed good appearance. The moisture content of Yukwa Bandegi after 24 hr of drying was 14.93%. Microstructure of Yukwa Bandegi showed a broken surface structure and empty spaces with increased drying time. Expansion ratio of Yukwa base with 24 hr of drying at $40^{\circ}C$ was highest among the samples. Overall, optimum punching conditions were 10 min of punching at 95 rpm or 5 min of punching at 155 rpm and optimum drying condition was 24 hr of drying at $40^{\circ}C$.

• Journal of Environmental Science International
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• v.10 no.1
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• pp.59-64
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• 2001

The effect of major operating parameters in spray drying sorber(=SDS) for automatic control for the simultaneous removal of acidic and organic gaseous pollutants from solid waste incinerator was performed. The field experiment was carried out in pilot scale test for the quantification of major operating parameters of hydrophilic and the hydrophobic pollutants. The removal efficiencies of $SO_2$and HCI in the 5wt% slurry condition were being increased with the increase of the stoichiometric ration which is the molecular ratio of lime to the pollutant concentration, and with the decrease of inflow flue gas temperature in the pilot SDS reactor. The removal efficiency along the height of spray drying sorber was closely related to the temperature profile, and more than 90% of total removal efficiency was achieved in an absorption region. For the removal of acidic gas the optimum operating condition considering the economics and a stable operation is the 5wt% of slurry concentration, 1.2 of stoichiometric ratio and 25$0^{\circ}C$ of inflow flue gas temperature. For the organic gases of benzene and toluene the removal efficiencies were 20-60% which is much lower than that of acidic gas. The best removal efficiency was obtained at 1.5 of stoichiometric ratio and 25$0^{\circ}C$ of inflow flue gas temperature. The organic\`s removal efficiency along the height of spray drying sorber was quite different from that of acidic gas, that is, more than 60% of the total removal efficiency for benzene and 90% of the total removal for toluene were achieved in the dried adsorption region, which was formed at the lower or exit part of the reactor.

• Magazine of the Korean Society of Agricultural Engineers
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• v.17 no.1
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• pp.3677-3684
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• 1975

A newly devised dryer with heated air for the farm products, especially suited for high water content materials such as red pepper, Beer ground, each Vegetables, and Low water content materials such as Rough rice was tested for its thermal efficiency and drying mechanism, and the optimum conditions for each sample were established. In order to improve the present rural situation of drying farm products which entirely dependent upon natural solar radiation, a study upon an economic multi-parpose dryer was conducted. A series of drying tests were run first with red pepper which is one of the important cash crop in Korean farm. And successive series of tests were also run with such proaucts as garlic, sweet potatoes, green onion, radish, Beer ground and Rough rice. The results from the above experiment in drying system with heat dryer can be summarized as follows. 1. Drying duration could be shortened by the tempering effect in high water content crop such as red pepper and beer ground. 2. The color changes occured in around 20% water content in red pepper. The degree of color change was heavily affected by high temperature and short drying duration. 3. The drying condition of red pepper was most favourable at the temperature of 85$^{\circ}C$ in early stage and 80$^{\circ}C$ in middle stage and 75$^{\circ}C$ at the final stage, and with the air rate of 0.81㎥/sec and with sample amount of 200kg. 4. The drying condition of Rough rice(I.R.667) was most favourable at the templature of 40$^{\circ}C$ in early stage and 35$^{\circ}C$ in middle stage and final stage and with the air rate of 0.2㎥/sec and with sample amount of 75kg. 5. In order to prevent the color change of red pepper and to assure high efficiency in drying mechanism, it was necessary to lower the temperature as the time passes in drying process. 6. For vege tables, the drying rate were short in early stage and there was also tempering effect. However, for garlics, Constant drying rates through the early and final stages were observed and there were no tempering effects. 7. The drying condition or capability were as follows; Sample drying temp($^{\circ}C$) amount of material(kg) drying time(hr) Red pepper 85 200 9 Garlic 85 150 7 Sweet potato 85 200 6 Green Onion 85 200 4 Carrot 85 200 4 Radish 90 250 4 Rough rice(I.R.667) 35 75 4 Beer ground 90 320 3 Considering the above result of experiments, if this kind of dryers were distributed Korean farm and the optimun process were practiced in rural area, it would certainly help them improving the qualites of their product preventing their undue losses, and thus assuring an increase of Korean farm income and promotion of their living standards.

• Journal of Sensor Science and Technology
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• v.15 no.5
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• pp.371-377
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• 2006

Nano porous, transparent silica aerogels monoliths were prepared under ambient drying (1 atm, $270^{\circ}C$) condition by the combination of sol-gel process and surface modification with subsequent heat treatment. Three kinds of solvent, n-hexane, n-heptane and xylene, were selected in the point view of low surface tension and vapor pressure in order to restrain a formation of cracks during drying. Crack-free silica aerogels with over 93 % of porosity and below $0.14g/cm^3$ of density were obtained by solvent exchange and surface modification under atmosphere condition. Optimum solvent was confirmed n-heptane among these solvents through estimation of FT-IR, TGA, BET and SEM. Modified silica aerogel exhibited a higher porosity and pore size compare to unmodified aerogels. Hydrophobicity was also controled by C-H and H-OH bonding state in the gel structure and heat treatment over $400^{\circ}C$ effects to the hydrophobicity due to oxidation of C-H radicals.

• Korean Journal of Environmental Agriculture
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• v.25 no.4
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• pp.289-296
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• 2006

Various drying conditions, temperatures (40 to $80^{\circ}C$) and durations (overnight to 72 hrs), for the particulate organic matter (POM) fraction after wet-sieving size fractionation have been applied for determination of POM contents in the weight loss-on-ignition method. In this study, we investigated the optimum drying condition for POM fraction in quantification of POM and/or mineral-associated organic matter (MOM; usually indirectly estimated). The influence of the drying conditions on quantifying POM was dependent upon soil properties, especially the amount of soil organic components. In relatively high organic soils (total carbon > 40 g/kg in this study), the POM values were significantly higher (overestimated) with drying at $55^{\circ}C$ than those values at $105^{\circ}C$, which were, for example, 173.2 and 137.3 mg/kg, respectively, in a soil studied. However, drying at $55^{\circ}C$ for longer than 48 hrs of periods produced consistent POM values even though the values were much higher than those at $105^{\circ}C$. Thus, indirect estimates of MOM (MOM = SOM-POM) also tended to be significantly impacted by the dry conditions. Therefore, we suggest POM fractions should be dried at $105^{\circ}C$ for 24 hrs as determining POM and MOM contents. If the POM traction is needed to be dried at a lower temperature (e.g. $55^{\circ}C$) with a specific reason, at least 48 hrs of drying period is necessary to obtain consistent POM values, and a moisture correction factor should be determined to adjust the values back to a $105^{\circ}C$ weight basis.

• Food Science of Animal Resources
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• v.32 no.3
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• pp.285-292
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• 2012

This study was conducted in order to evaluate the effects of brine pre-soaking at different concentrations and drying time on the quality characteristics of pork jerky. The physicochemical properties of pork jerky including final moisture content, water activity ($a_w$), shear force, microstructure, and thiobarbituric acid reactive substance (TBARS) values were investigated. The sensory attributes of pork jerky were evaluated and used as parameters for determining the optimum drying condition. The sliced pork samples were pre-soaked at salt concentrations ranging from 0 to 10% for 3 h and then dried at $70^{\circ}C$ for up to 10 h. The pre-soaked samples in the salt solution showed higher final moisture content than the control sample after drying for 10 h. The final moisture content of pork jerky increased with increasing salt concentrations. On the other hand, the water activity with regards to the pre-soaked samples in a 10% salt solution showed the lowest value for up to 8 h drying. The shear force values of pork jerky decreased with increasing salt concentration while the TBARS values of the samples increased with increasing salt concentrations. Sensory evaluation suggested that the color, flavor, juiciness, and tenderness of the pork jerky samples were improved by pre-soaking in a 2% salt solution and the highest likeability score of pork jerky among the samples were obtained by pre-soaking in a 2% salt solution prior to drying.

• Food Science and Preservation
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• v.24 no.3
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• pp.361-366
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• 2017

This study investigated quality change of ginseng depending on far-infrared (FIR) drying methods. The ginseng was cut into 2 mm slices and measured moisture content (MC), color, total polyphenol content (TPC), total flavonoid content (TFC) and DPPH radical scavenging activity (DPPH). The color values (L, a, and b) were decreased after far-infrared (FIR) drying. As increase in drying time, color was changed. Considering quality parameters including MC, TPC, TFC, and DPPH, the optimum condition for drying was set at $65^{\circ}C$ for 60 min. Furthermore, we compared color and functional compounds depending on drying process including FIR, freeze-, vacuum, and hot-air drying. The color values of ginseng were decreased when dried using vacuum and hot-air. While the color values of ginseng were increased after freeze drying. Comparison with another drying method, FIR drying presented the highest color difference. FIR and vacuum-dried ginseng indicate higher contents of TPC and TFC than freeze- and hot air-dried ginseng. And hot-air-dried ginseng present the highest DPPH when compared to another drying methods. On the other hand, freeze dried ginseng show the lowest TPC, TFC, and DPPH.