• Journal of Advanced Marine Engineering and Technology
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• v.34 no.4
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• pp.460-469
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• 2010

In spite of the global-class aquaculture and fishing technology of our country, the processing technologies are lags behind the other nations relatively. The processed marine products are mainly frozen foods, canned goods, salty food (fermented fish products), fish paste products (boiled fish paste), and we can see that the high-value dehydrated foods by drying are very few. These problems are considered to be caused directly by the lack of drying technologies. This paper is concerned to the experimental results of drying heat transfer characteristics for the green energy type vacuum dryer for the high quality sea foods production.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.6
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• pp.839-848
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• 2015

This study examined the optimal salting drying method and processing conditions (salt concentration, curing time, dry temperature, and drying time) for preparing salted semi-dried common gray mullet (SSD-CGM) Mugil cephalus based on the moisture content, salinity, and overall acceptance using response surface methodology (RSM). The moisture content, salinity, and overall acceptance of SSD-CGM prepared with different salting methods revealed that dry salting was the optimal salting method for preparing high-quality SSD-CGM. The optimal drying method for preparing high-quality SSD-CGM based on the drying velocity and sensory color was hot air-blast drying. The results of the RSM program indicated that the optimal independent variables ($X_1$, salt concentration; $X_2$, curing time; $X_3$, dry temperature; $X_4$, drying time) based on the dependent variables ($Y_1$, moisture content; $Y_2$, salinity; $Y_3$, overall acceptance) for high-quality SSD-CGM were 5.6% for $X_1$, 2.7 h for $X_2$, $47.0^{\circ}C$ for $X_3$, and 8.5 h for $X_4$ for uncoded values. The predicted values of $Y_1$, $Y_2$, and $Y_3$ for SSD-CGM prepared under optimal conditions were 54.4%, 4.2%, and 6.3, respectively, while the experimental values were $55.2{\pm}1.0%$, $4.1{\pm}0.3%$ and $6.7{\pm}0.8$. The actual and predicted values did not differ.

• Korean Journal of Medicinal Crop Science
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• v.19 no.6
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• pp.501-507
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• 2011

This experiment was carried out in order to collect the basic data on the standardization of the manufacturing process of Rehmannia glutinosa Libosch. var. purpurea Makino drying. By the drying methods of R. glutinosa, the content of water, inorganic components, reducing sugar, catalpol and benzo[${\alpha}$]pyrene were investigated. The water content was 15.6~17.2% when R. glutinosa was dried by cold-warm air moisture absorption drying method (CAMAD) at $60^{\circ}C$ during 6 days. Among of the inorganic components of R. glutinosa the K content was the most followed by P, Na, Ca and Mg. The reducing sugar content of R. glutinosa by the hot air drying method (HAD) was much more than that by the CAMAD. The catalpol content of R. glutinosa was not different by the drying temperature when it was dried by the CAMAD. The catalpol content of the large size tuber (about 50.0 g/unit) showed a tendency to increase from $60^{\circ}C$ until $70^{\circ}C$ drying temperature, but that of the small size tuber(about 4.0 g/unit) was decreased as being a trend as the drying temperature high when R. glutinosa was dried by the HAD, But the catalpol content R. glutinosa had a tendency to drop significantly at drying temperature above $80^{\circ}C$. The benzo[${\alpha}$]pyrene content was little detected when R. glutinosa was dried by both the SLD and the CAMAD, and the sampling by the HAD indicated within the scope of 5 ${\mu}g/kg$ which was the scope to regulate by Korean food and drug administration. In conclusion, it seemed that an appropriate drying temperature of R. glutinosa by the CAMAD and the HAD was about $60^{\circ}C$ and about $70^{\circ}C$, respectively, when we consider the catalpol content and benzo[${\alpha}$]pyrene detection in the manufacturing process of drying R. glutinosa.

• Food Science of Animal Resources
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• v.21 no.3
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• pp.265-271
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• 2001

We investigated changes of immunoglobulin G (IgG) concentrations by heating and drying condition. Also it is performed to group for commercial product by promoting of IgG preservation and reducing of protein denaturation. The result was that content of IgG in colostrum was higher than normal milk. Especially, IgG content of colostrum within 12 hrs after parturition was over 44.67mg/ml and it is 60 times of normal milk. IgG contents was reduced rapidly according as passage of the time. IgG content of the sample heating at 30min at 65$^{\circ}C$ was still a little higher that heating for 10sec at 72$^{\circ}C$. IgG denaturation of heat treatment at 100$^{\circ}C$ for 10sec was lower than at 85$^{\circ}C$ for 30min. We investigated the changes of IgG concentrations of kinds of market milk different with heating processing. This result showed that IgG denaturation ratio by ultra high temperature pasteurization (UHT) was higher than long time low temperature pasteurization (LTLT). On the other hands, IgG content by spray drying was 14.5mg/g and freezing drying was 10.8mg/g. It showed that denaturation of protein content by freezing drying was more than spray drying.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.5
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• pp.908-913
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• 1998

Chemical components and some physical proeprties of fresh, defrosted and dried yams(Dioscoreab batatas) were determined to obtain basic data for high quality yam processing. Fresh yam showed 81.79% moisture and 15.24% N-free extract. The cohesiveness and adhesiveness of defrosted yam homogenate were significantly higher than those of fresh yam homogenate. Free sugars of yam were mainly composed of sucrose, rhamnose, fructose and glucose, and the contents of fructose and glucose were apparently decreased by hot air drying. Linoleic(45.64%), oleic(8.32%), and arachidic acids(7.40%) were major fatty acids of yam. Hot air drying caused a decrease in unsaturated fatty acids and an increase in saturated acids. Hot air-dried yam powder showed higher gelatinization properties than freeze-dryed yam powder, such asinitial pasting temperature, temperature at maximum viscosity, and viscosity at different parameters. Hot air-dried yam powder showed higher Hunter parameter b and ΔE values and lower L value than freeze-dried one.

• Korean Journal of Food Science and Technology
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• v.40 no.4
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• pp.466-469
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• 2008

This study examined the effect of drying temperature on the qualitative properties of Chrysanthemum boreale M. flowers. The flower samples were dried in a hot air dryer at $40^{\circ}C$, $50^{\circ}C$, and $60^{\circ}C$, respectively, to attain a $23{\pm}1%$ moisture content. The time required to reach the target moisture content was 8.5-69 hr, and there was a very high negative correlation between log (spending time) and temperature. The Hunter color L- and b-values of the flowers were decreased with increasing drying temperature, whereas the a-value was increased. The volatile compounds contained in the dried flowers were determined by a solid-phase microextraction method. Twelve primary volatile compounds were detected and then quantified based on the GC chromatograms of the samples. The total contents of volatile compounds were increased with increasing drying temperature, and germacrene D and camphor were the main compounds in all samples.

• Journal of Biosystems Engineering
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• v.9 no.2
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• pp.65-73
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• 1984

While most of researches on the performance of high temperature grain dryer have dealt mainly with improving dryer capacity and drying speed during the last twenty years, energy efficiency, in fact, has not been emphasized. Current fuel supplies and energy cost have shifted the emphasis to reducing the energy consumption for grain drying while maintaining dryer capacity and grain quality. Since the energy input for drying is relatively large, the recovery and reuse of at least part of the exhaust energy can significantly reduce the total energy consumption in existing drying systems. Unilization of exhaust heat in grain dryer either through direct recycling or by a thermal coupling in heat exchanger have been subject of a number of investigators. However, very seldom research in Korea has been done in this area. Three drying tests(non-recycling, 0.22 recycle ratio, and 0.76 recycle ratio)were performed to investigate the thermal efficiency and heat loss factors of continuous flow type dryer, and to analyze the effect of recycle ratio (weight of exhaust air recycled/total weight of input air) on the energy requriements for rough rice drying. The test results showed that when the exhaust air was not recycled, the energy lost from furnace was 15.3 percent of input fuel energy, and latent and sensible heat of exhaust air were 61.4 percent and 11.2 percent respectively. The heat which was required in raising grain temperature and stored in dryer was relatively small. As the recycle ratio of exhaust air was increased, the drying rate was suddenly decreased, and thermal efficiency of the kerosene burner was also decreased. Drying test with 0.76 recycle ratio resulted in 12.4% increase in fuel consumption, and 38.4% increase in electric power consumption as compared to the non-recycled drying test. Drying test of 0.22 recycle ratio resulted in 6.8% saving in total energy consumption, 8.0% reduction in fuel consumption, and 2.5% increase in electric power consumption as compared to the non-recycled drying test.

• Applied Biological Chemistry
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• v.34 no.3
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• pp.258-261
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• 1991

In order to establish the optimum drying temperature of the heated air blast-grain circulation dryer, a 2 ton scale of paddy was used in this experiment. The temperatures of heated air used were 45, 50, 55, 60, 65 and $70^{\circ}C$. Moisture content of the paddy was reduced to 15% from 24% by drying. The higher air temperature, the shorter drying time and the less fuel consumed. The portion of cracked kernels was found to be low as $3{\sim}10%\;at\;40{\sim}55^{\circ}C$, but was very high to $28{\sim}30%\;at\;60{\sim}70^{\circ}C$. The germination percent was very high as 98 and 93% at 40 and $45^{\circ}C$, but it was decreased to 86 and 30% at 50 and $70^{\circ}C$, respectively. The recovery yield of milled rice from paddy was decreased by 1.76, 2.63 and 7.52% at 60, 65 and $70^{\circ}C$, respectively, compared with 75.86% as drying at $40^{\circ}C$. The higher heated air temperature, the less head rice of milled rice was recovered, and the decreased ratio was increased $60^{\circ}C$. The higher heated air temperature, the less alkali disintergation value and gel consistency of milled rice and the more water up take, expanded vlume, total solid in residual liquid and intensity of starch iodine blue value of residual liquid, and those tendency was found clear from $60^{\circ}C$ temperature of heated air.

• Korean Journal of Food Science and Technology
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• v.46 no.6
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• pp.769-772
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• 2014

This study was conducted to provide basic information on the effects of drying temperatures (45, 65, and $85^{\circ}C$) on saponins and free sugar contents of a 5-year-old Platycodon grandiflorum Radix. Platycodin D levels decreased with increase in drying temperature (956, 334, and 197 mg% at 45, 65, and $85^{\circ}C$, respectively). Polygalacin D levels were the highest at $45^{\circ}C$ (577 mg%), while platycodin $D_3$ and deapioplatycodin D were high at $65^{\circ}C$ (304 and 272 mg%, respectively). Sucrose levels were 3,825 mg% at $85^{\circ}C$ and 1,226 mg% at $45^{\circ}C$, and decreased when the drying temperature was decreased. The sucrose content showed significant negative correlation with saponin levels in dried P. grandiflorum ($-0.987^{**}$, p<0.01). These results suggested that drying P. grandiflorum at low temperatures is more economically viable.

• Food Science and Biotechnology
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• v.16 no.2
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• pp.187-192
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• 2007

The objectives of this study were to examine changes in the color and antioxidant compounds of paprika powder under various conditions, as well as to establish the suitable conditions for drying and storage. Paprika was dried using the following methods: freeze-drying, vacuum drying, far infrared-ray drying, and hot-air drying. Measurements of the moisture content, color pigments, and antioxidant compounds (total carotenoids, capsanthin, ascorbic acid, and total polyphenols) were completed during 120 days of storage at 4 and $30^{\circ}C$. We found that drying methods, storage temperatures, and packaging materials affected the American Spice Trade Association (ASTA) and Hunter color values, as well as the antioxidant content of paprika powder. There was a high correlation (r=0.87, p<0.01) between the ASTA color and the $a^*/b^*$ value. The loss of red color was closely related to the reduction of moisture content (r=0.81, p<0.01) during storage. Drying paprika with a low temperature in the absence of air resulted in better retention of the carotenoids and ascorbic acid. Also, as the retention of the carotenoids and ascorbic acid increased, the stability of the red pigment increased. Freeze-drying was found to be the most suitable drying method for the stability of the antioxidant compounds and red pigment.