• 보존과학연구
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• s.35
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• pp.45-55
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• 2014

The small dining tables which are made of bamboo were deteriorated condition when those were excavated from Mado shipwreck No.1. Therefore, preliminary test was conducted for consolidation (Sucrose, Dammar gum, Cetyl alcohol and Polyethylene glycol 4000) then impregnated and vacuum freeze dried. After the test, since the treatment with vacuum freeze drying using an aqueous solution of PEG 4000 keep the shape well the most and present bright colour, waterlogged archaeological bamboo conserved with vacuum freeze drying using an aqueous solution of PEG 4000. One bamboo table consolidated with soluble PEG 4000 from 10% to 40%, then vacuum freeze dried. Another impregnated with soluble PEG 4000 from 10% to 70%. After that, it was separated and held in polycarbonate sheet for preventing bending during dry. The small dining tables are the three dimensional shapes and have some loss. Therefore the mounting for support tables were necessary which are made of acrylic sheet. It keep the table shape and make it convenient for storage and handling.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.3
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• pp.572-578
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• 1999

This study was conducted to investigate processing condition and characteristics of chestnut paste. The kinds of chestnut powder processed with blanching and drying of raw material were four named RH(not blanched, hot air dried), RF(not blanched, freeze dried), BH(blanched, hot air dried) and BF(blanched, freeze dried). Blanching affected the reduction of drying time in chestnut. Water absorption index of the blanched samples were higher than the nonblanched. Blanching affected the viscosity of pastes when water was added to process paste also, but drying methods did not affected to it. The proper ratio of water to the powder to process paste was 1.3 to 1.5 times in RH and RF, whereas 2.7 times in BH and BF by sensory evaluation. Soluble tannin content of paste was higher in RF and RH paste than BF and BH. Vitamin C content was the highest(88.49mg/100g) in RF paste and reducing sugar content was the highest in RF paste. Hunter's L and a values were the highest in BF and RH pastes, respectively, among the all paste samples. Volatile compounds detected from chestnutpastes were hydrocarbons, alcohols, phenols, ketones. The major volatile compound in all the pastes was 2,6 bis(1,1 dimethylethyl) 4 methyl phenol.

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.2
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• pp.168-178
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• 1983

Influence of several dehydration treatments on original structure and water behavior in the process of drying were investigated employing three hawaiian volcanic ash soils and four synthetic minerals. These three soils were developed under different rainfall condition and contained three different amount of amorphous materials in them. Measurement of water losses by oven drying at $105^{\circ}C$, $P_2O_5$ drying, freeze drying, and critical point drying revealed that more water losses were noted by oven drying than by three other drying techniques and the differences of water losses between oven and $P_2O_5$-drying were closely related to amoun: of amorphous materials in them, showing the order of Kaiwiki > Hilo > Kawaihae. This indicates that dehydration of amorphous materials by elevated temperature ($105^{\circ}C$) excluded water beyond that in the adsorbed (hygroscopic) state. The effect of dehydration treatments on initial structure was visualized by scanning electron microscopy. The micrographs showed that oven-and $P_2O_5$-dried samples formed into large mass of sub-angular blocky, dense, and closed crumbs, while the freeze dried and critical point dried samples resulted in less shrinkage, and small, fluffy and open spongy structure. However, critical point drying technique produced bulkier, softer, and greater open structure samples than even freeze drying. Additional Index Words: original structure, synthetic minerals, critical point drying, $P_2O_5$ drying. 1. This is a part of author's Ph.D. dissertation submitted to the University of Hawaii, Honolulu, Hawaii 96822 in 1979. 2. Professor of Agricultural Chemistry, Korea University.

• Journal of Pharmaceutical Investigation
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• v.25 no.3
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• pp.249-264
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• 1995

Although liposome has many advantages as a pharmaceutical dosage form, its application in the industrial field has been limited because of some problems such as preparation method, reproducibility, scale-up, stability and sterilization etc. Liposomes prepared by microemulsification method had defined size, narrow size distribution, reproducibility and high entrapment efficiency. For enhancing the stability, the dry form of liposome was recommended. These types of liposome are proliposome and freeze-dried liposome. The liposome must have some properties for preparing of freeze-dried liposome; small size $(50{\sim}200\;nm)$, narrow size distribution and cryoprotectant. In this experiment, the liposomes containing 5-Fluorouracil(5-FU) and its prodrug(pentyl-5-FU-1-acetate; PFA, hexyl-5-FU-1-acetate; HFA) were made with soybean phosphatidylcholine, cholesterol, stearylamine(SA) and dicetyl phosphate(DCP) employing hydration method or microemulsification method using $Microfluidizer^{TM}$. Both or liposome types were MLV and MEL. After preparation, freeze drying and rehydration were performed. In the process of freezing, trehalose(Tr) was added as a cryoprotectant. Their evaluation methods were as follows; entrapment efficiency, mean particle size and size distribution, dissolution test, retain of entrapment efficiency and turbidity after freeze-drying. The results are summarized as belows. The entrapment efficiency of 5-FU was dependent on total lipid concentration and cholesterol content but that of PFA and HFA was decreased when cholesterol was added. When DCP and SA were added, entrapment efficiency was decreased. As the partition coefficient of drug was increased, entrapment efficiency was increased. Under the same condition, entrapment efficiency of MEL is similar to that of MLV. The mean particle size and size distribution of MEL were smaller than those of MLV. Dissolution rates of drug from both liposome types were comparatively similar. Dissolution rates of drugs with serum and liver homogenate were faster than without these material. After preparation of liposome, free drug was removed efficiency by Dowex 50W-X4. When liposome was freeze-dried and then rehydrated in the presence of Tr, characteristics of liposome were maintained well in MEL than MLV. Tr Was used successfully as a cryoprotectant in the process of freeze drying and the optimal ratio of Tr:Lipid was 4:1(g/g).

• Journal of Conservation Science
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• v.16 s.16
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• pp.110-118
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• 2004

In order to evaluate two-step treatment of PEG-freeze drying for highly-degraded waterlogged ash woods (Fraxinus PP.; ca. 5,700 BP), which were excavated from peat lands in western Korea, dimension stability was examined during 45 months after complete treatment. The samples pre-treated with PEG in water solution showed better dimensional stabilities than the ones with PEG in t-butanol(TBA) solution. It suggests that TBA reduced the flexibility of wood cells and overflying by TBA induced micro-checks during freeze drying. Micro-checks results in fragile wood structures and consequently, large shrinkage by moisture absorbances of high PEG contents during exposure in humid condition. The results suggest that PEG in water-solution treatment is better than PEG in t-butanol as pretreament for freeze drying of highly-degraded waterlogged ash woods.

• YAKHAK HOEJI
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• v.42 no.3
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• pp.284-289
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• 1998

The effect of reaction condition, solvent addition and thermal treatment on the bulk density, crystallinity and chemical properties of the freeze-dried cefazohn sodium was inves tigated to prepare the cefazolin sodium powder for injection with good flowability. Crystalline cefazolin sodium powder with high untapped-bulk density (about 45%) and low compressibility (about 40%) was obtained by solvent addition to the very highly concentrated cefazohn sodium solution followed by subsequent thermal treatment before freeze-drying. The desirable solvent was low substituted alcohol such as isopropyl alcohol and anhydrous ethanol with the final concentration of about 9%. The pH adjustment and nitrogen gas purging during the reaction did not give significant effect on the chemical properties such as content, color, transmittance and pH of the reconstituted cefazolin sodium aqueous solution.

• Korean Journal of Medicinal Crop Science
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• v.8 no.1
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• pp.49-57
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• 2000

To understand the effects of drying conditions on changes of volatile compounds in fruits of Schizandra chinensis, we analyzed SDE (steam distillation and extraction) extract and Headspace vapor of fresh and dried samples using GC/MS (Gas chromatograph/Mass spectrometer). Contents of essential oils from samples with different drying conditions were 0.58% in fresh ones, 0.60% in freeze dried ones, and 0.30% in hot-air dried ones. In SDE extract, major volatile compounds in fresh samples were terpinen-4-ol(9.01%), ${\gamma}-terpinene(7.02%),\;{\beta}-myrcene(7.55%)$, unidentified sesquiterpenes(28.48%), showing almost the same composition as that in freeze-dried ones, but those in hot-air dried samples at $60^{\circ}C$ were ${\gamma}-terpinene(5.40%),\;{\alpha}-elemene(8.28%)$, unidentified sesquiterpenes(50.38%), indicating the chemical changes during drying procedure. In Headspace vapor, major compounds in fresh samples were ${\beta}-myrcene(22.05%),\;{\gamma}-terpinene(9.47%),\;{\alpha}-pinene(8.91%)$, sabinene(8.48%), which were different from those in SDE extract. In chemical compositions of volatile compounds in dried samples, ${\beta}-myrcene,\;{\alpha}-terpinene$ decreased in the order of freeze-drying > hot-air drying at $60^{\circ}C$ > hot-air drying at $60^{\circ}C$, and ${\alpha}-ylangene,\;{\alpha}-pinene$, camphene increased in the reverse order of the former. We observed the changes of the contents and compositions of essential oils compounds during drying procedure, especially a decrease in monoterpenes and alcohols and an increase in sesquiterpenes with relatively weak volatility.

• Journal of Mushroom
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• v.21 no.4
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• pp.222-227
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• 2023

Mushrooms have a unique taste and aroma, so in the processing of mushroom products with other ingredients, a separate pre-processing step is often taken to eliminate the mushroom aroma. In this study, we analyzed the changes in the concentration of volatile compounds according to drying conditions to promote the activation of processing using the fruiting bodies of yellow oyster mushrooms(Pleurotus citrinopileatus) and pink oyster mushrooms(P. djamor). The caps and stipes of yellow oyster and pink oyster mushrooms were separated and freeze-dried at -70℃ for 120 hours. Subsequently, they were hot air-dried at temperatures of 40, 50, 60, and 70℃ for 24, 24, 16, and 12 hours, respectively. The dried samples were pulverized and quantitatively analyzed by SPME-GC-MS. In the case of yellow oyster mushrooms, the concentration of t-2-nonenal in caps and stipes during freeze-drying was 164.43 ㎍/g d.w. and 174.80 ㎍/g d.w., respectively, whereas during hot air-drying, it significantly decreased to 0.35~3.41 ㎍/g d.w. and 0.98~59.88 ㎍/g d.w. In a similar manner, for pink oyster mushrooms, the concentration of 1-octen-3-ol during freeze-drying in caps and stipes was 31.05 ㎍/g d.w. and 176.17 ㎍/g d.w., respectively, whereas during hot air-drying, it significantly decreased to 1.59~9.66 ㎍/g d.w. and 1.96~15.77 ㎍/g d.w. Furthermore, most volatile compounds showed a tendency to decrease in concentration as the temperature during hot air-drying increased.

• Food Science of Animal Resources
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• v.28 no.3
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• pp.312-318
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• 2008

The objective of this study was to investigate the changes in ice dendrite size during freezing process in gelatin matrix as a model food system in order to provide mathematical relation between freezing condition and ice dendrite size. Gelatin gel as a model matrix was frozen in unidirectional Neumann's type of heat transfer. The thermograms' analysis allowed to determine the freezing temperature of the sample, the position of the freezing front versus time, and thus, freezing front rate. The morphology of ice dendrites was observed by scanning electron microscopy after freeze-drying. We observed that the means size of ice dendrite increased with the distance to the cooling plate; however, it decreased with the cooling rate and the cooling temperature. In addition, the shorter durations of the freeze-drying process was shorter decreeing the decreased the freezing front rate, resulted in their resulting in a larger pore size of the ice dendrite pores for the sublimation channel of that operate as water vapor sublimation channels. From these results, we could derive a linear regression as an empirical mathematical model equation between the ice dendrite size and the inverse of freezing front rate.

• Korean journal of food and cookery science
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• v.20 no.3
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• pp.310-316
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• 2004

This study was conducted to investigate quality characteristics of Aster scaber to increase the value of functional food resources. To examine quality characteristics of Aster scaber, various factors such as color, texture, fiber, minerals, tannin, crude proteins, crude lipids and sensory quality were determined using physiochemical methods. The contents of dietary fiber were 0.68 g in each 100 g of Aster scaber (freeze drying base). In mineral contents, iron was the highest value in Aster scaber (freeze drying base). The contents of tannin were 35.6 ppm of Aster scaber (fresh base). Aster scaber was shown significant difference in tannin from freeze drying leaf. From the results of sensory evaluation, the age of 30's and 40's showed a better acceptability in blanching. Functional healthy drinks were made from extracts of Aster scaber for relieving thirst and promoting health. The recipe of drinks were decided to establish manufacture condition through the sensory evaluation, color, flavor, taste, and overall acceptability. The shelf-life was established in 18 months through quality was analyzed such as soluble solids, optical density 480, pH, acidity and microorganisms.