• Food Science and Preservation
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• v.6 no.3
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• pp.319-323
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• 1999

This study was conducted to minimize the deterioration of dried kiwifruit quality. Osmotic dehydration was carried out as pretreatment before drying. After the kiwifruits were pretreated under optimized osmotic dehydration conditions, they were dried by three drying methods(hot air drying, vacuum drying, freeze drying). Hot air drying and vacuum drying were superior to freeze drying in the drying speed. But vacuum and freeze drying preserved more vitamin C than hot air drying. Also, osmotic dehydrated kiwifruit kept better quality than nontreated kiwifruit. Diffusion coefficient which describes moisture transfer, was high in drying process pretreated with osmosis. The changes of vitamin-C followed the second-order reaction rate equation with high RE, respectively.

• 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 Food Hygiene and Safety
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• v.18 no.4
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• pp.243-250
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• 2003

S-methylmethionine, vitamin U levels were affected by cultivars, parts fo Korean Chinese cabbages, and drying methods. Among drying conditions, freeze drying method appeared the best condition to maintain bitamin U content compared to oven and air drying methods. In the case of KOrean Chinese cabbages, outward leaves have high levels of chlorphyll and fiber. From this study, the outward parts contained high levels of vitamin U in two cultivars. Leaf parts were 1.1-21.2 times higher in vitamin U levels than midribs in both cultivars. This difference was shown most distinctively in freeze dried outward parts of Winter Pride cultivar. Like vitmnin U, fee amino acids also showed much higher levels in leaves. Levels of amino acids showed irregulatoy changing patterns at different parts and cultivar of Korean Chinese cabbages with various drying methods, Alanine and threonie appeared relatively aboundant amino acids in most parts of samples. Since no distinctive trends were observed in this rsult, it seems no relationship exists between amon oacids and bitamin U levels. Levels of methionine in differnent parts and cultivars of Korean Chinese cabbages dried with various methods did no show clear relationship with tlevel of vitamin U. Moreover, emthionine was not detected in freeze dired outward leaf parts which were the hithest parts of vitamin U levels in Winter Pride and 55 days cultivar. There were simila levels of methionine between overn and freeze drying. Samples prepared by air drying showed significatly lower levels than those by oven and freeze dryting. Methionine as aprecursor of vitamin U, may play a role in an increase of vitamin U during drying of KOrean Chinese cabbages.

• Korean Journal of Veterinary Research
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• v.47 no.1
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• pp.117-125
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• 2007

Bone graft had been investigated previously to restore bone defects in orthopedics. The purpose of this study was to investigate the efficacy on new bone formation in bone autografts by treatment of implants. Cortical bone autografts were transplanted to midshaft of diaphyseal fibulae of 9 rabbits which were divided in 3 groups according to the treatment method of implants. Cortical bone implants for graft were treated with 3 different methods; freezing, freeze-drying, defat-freezing. Autografts were achieved by cross-transplantation method to bilateral fibulae of the presented rabbits after implant treatment procedures. The grafted regions of fibulae of all groups had been radiographed biweekly for 16 weeks to observe new bone formation and union between donor and recipient bone in the grafted region. Bone alkaline phosphatase (BALP) in all groups was evaluated biweekly till the end of the experiment to determine osteoblast activities. Unions of the experimental grafted regions were observed at 83% (5 of 6 cases) of freezing, 17% (1 of 6 cases) of freeze-drying and 67% (4 of 6 cases) of defat-freezing autografts, respectively. BALP was increased over 100% after 2 weeks of graft procedures in all union cases (all cases in freezing group and in defat-freezing group, and 1 of 3 in freeze-drying group, respectively), then gradually decreased from 4 th week of graft to 16 th week. In non-union cases, there is no significant variation in BALP value until the end of experiment. It is speculated that defat-freezing method of treatments of implants is more safe to preserve the osteogenic ability in autograft than freeze-drying method.

• Food Science and Preservation
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• v.6 no.1
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• pp.87-91
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• 1999

In an attempt to test experimental condition of preparing grape powder, grapes having less commercial value was used and tried. With drying method, spray and freeze drying were satisfactory to produce power. Moisture content and odor retention were better by the latter method. Three grape strains stored for 40 days contained more odors than those stored for 5 days. Maltose 90% plus dextrin 10% was suitable for drying support. To increase odror sense, citric acid and vitamin C can be added up to 0.1 and 0.2%, respectively. Considering these conditions, grape complex powder prapared from grape powder 20% comprising drying support, glucose 79.7%, citric acid 0.1%, vitamin C 0.2% with freeze drying was the best by overall evaluation including sensory test. When campbell and neomuscut were mixed by 15:5 or 10:10, sensory evaluation was also ameliorated.

• Journal of the Korean Ceramic Society
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• v.40 no.8
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• pp.798-803
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• 2003

In synthesis of nano powders, the hard agglomeration for the synthesized powders occurred during the drying processing. In order to avoid hard agglomeration in particles the freeze drying process was used in this experiment. e fabricated the Yttira-Doped Ceria(YDC) nano powder by co-precipitation. Starting materials used in experiments were the cerium(III) nitrate and yttrium(III) nitrate solution with 야-water, which two solutions were mixed and then the precipitated hydroxides were prepared for adding sodium hydroxide. The co-precipitated powders were dried by the thermal drying at 8$0^{\circ}C$ for 24 h and by freeze drying at -4$0^{\circ}C$, 30 mtorr for 72 h. The lattice parameter and crystallite size as a function of calcination temperature was characterized by XRD analysis. The lattice parameter of YDC was decreased with addition amount of yttrium and was estimated as 5.401683 $\AA$ at $700^{\circ}C$. Crystallite size were calculated by XRD-LB method, and morphologies were confirmed with the observation of TEM and SEM. The freeze dried YDC powders had medium diameter of 17 nm with more uniform size distribution than the thermal dried YDC posers, which were mainly ascribed to the difference of agglomerates formation during drying stage.

• Journal of Pharmaceutical Investigation
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• v.15 no.1
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• pp.15-21
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• 1985

The inclusion of ${\alpha}-cyclodextrin$ and ${\beta}-cyclodextrin$ with flurbiprofen in aqueous phase was investigated by UV absorption and circular dichroism spectroscopies. The inclusion complex in solid powder form were made by the freeze-drying and coprecipitation methods in molar ratio 1:1. The inclusion complex formation was confirmed by infrared absorption spectroscopy. The freeze-drying method was successful in obtaining the inclusion compounds compared with the coprecipitation method. The dissolution of solid flurbiprofen inclusion complex was examined in comparison with those of flurbiprofen alone. The inclusion complex obtained by freeze-drying method increased the dissolution rate.

• Korean Journal of Food Science and Technology
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• v.40 no.6
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• pp.721-725
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• 2008

Changes in the physicochemical and sensory characteristics of the uncooked food, Codonopsis lanceolata saengsik, were investigated to determine an efficient drying method, one of the most important manufacturing processes in the preparation of C. lanceolata saengsik. No changes in the proximate compositions of all samples were observed during hot-air drying at 50 and $60^{\circ}C$ and freeze-drying. The L value in the freeze-dried sample was higher than that in the hot-air dried samples, whereas the b value in the freeze-dried sample was reduced. Dietary fiber content in the hotair dried samples were higher than that in the freeze-dried sample, whereas the total phenolic compounds and crude saponin contents were lower than those in the freeze-dried sample. The highest overall acceptability values in the sensory test for color, flavor, taste, and overall acceptability were 5.63, 5.45, 5.75, and 5.85, respectively. In conclusion, the freezedrying method was the most favorable of the tested method for the manufacture of C. lanceolata saengsik.

• 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.

• The Korean Journal of Food And Nutrition
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• v.31 no.6
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• pp.933-939
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• 2018

The objective of this study was to determine the effects of drying methods on the quality characteristics and antioxidant activities of pumpkin (Cucurbita moschata Duch.). Pumpkins were dried naturally ($25^{\circ}C$), hot-air drying ($60^{\circ}C$), and throgh freeze drying ($-40^{\circ}C$) methods. The moisture activities were highest in the freeze dried group. The soluble solid showed no significant differences among all groups. The pH was highest in the freeze dried group. The L values were increasing in freeze dried group, whereas the b values were increased in hot-air dried group. The free sugar was highest in freeze dried group. The DPPH radical scavenging activity of hot-air dried group was higher than those of the other groups. The ABTS radical scavenging activities were highest with hot-air dried group and freeze dried group. It was established that hot-air dried group is the most effective drying method for the production of high quality dried pumpkin.