• Title/Summary/Keyword: vacuum freeze-drying

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The Quality Properties of Dried Carrots as Affected by Blanching and Drying Methods during Storage (건조 방법에 따른 예비열처리 당근의 저장 중 품질 특성)

  • Lee, Kyoung-Sook;Park, Kwan-Hwa;Lee, Sang-Hwa;Choe, Eun-Ok;Lee, Hyeon-Gyu
    • Korean Journal of Food Science and Technology
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    • v.35 no.6
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    • pp.1086-1092
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    • 2003
  • This study was carried out to investigate the effectiveness of blanching on the different drying methods and to examine the quality properties of carrots dried by freeze., vacuum- or hot air-drying during storage. Blanched carrots (BC) dried faster than raw carrots (RC), while RC showed more effective rehydration than BC by hot air- and vacuum-drying methods. There was more stability for BC on carotene retention and browning degree than RC in all drying methods during storage. Moreover, firmness of RC and BC by vacuum-drying was slightly lower than that of hot air-drying, but higher than freeze-drying. In firmness, BC and RC showed similar trends with different drying methods (decreasing with increased storage periods), while BC showed about 3 time firmer texture than RC in all cases during storage. The dried carrots prepared with blanching treatment showed more fine structures than those not treated. These results showed that the blanching treatment of carrots was good for maintaining quality by various drying methods.

Comparison of Cosmetical Activities of Curcuma longa L. Leaf Extracts Using Different Extraction Methods (추출 방법에 따른 강황 잎 추출물의 향장 활성 비교)

  • Kim, Nam Young;Lim, Hye Won;Lee, Hyeon Yong
    • Korean Journal of Medicinal Crop Science
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    • v.22 no.4
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    • pp.255-261
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    • 2014
  • Cosmetic activities of the leaves of Curcuma longa L. were compared according to different drying methods, to expand the use of the by-products of Curcuma longa L. The highest extraction yield of 29.4% was obtained from vacuum drying process (VD), whose value was very close to 29.2% from freeze drying process (FD). Relatively lower extraction yield were observed as 24.5% and 25.3% from the raw leaf (RL) as control and hot air drying process (HD). The cytotoxicity was observed lower FD and VD than RL and HD. It shows that cytotoxicity was closely related to cosmetic activities such as tyrosinase and melanin inhibition activities by showing much better cosmetic activities of the extracts from both FD and VD than those from the RL and HD. It was interesting that was differences of the cosmetic activities and cytotoxicity between FD and VD, which implies that VD method should be a more efficient process than FD method in terms of drying time and operation costs: 6 hours vs 24 hours and 3-5 times higher extraction costs in drying. It was observed that VD is more excellent dry method than others. This result could be utilized to effectively dry other soft plant biomass.

Manufactureing Conditions and Quality of Dried Meat on the Snow Crab II. Change of Weight Loss Yield on the Steaming and Various Drying Method (건조게육의 가공조건과 품질 II. 증자 및 건조방법에 따른 감량 수율 및 유리 아미노산의 변화)

  • 양철영
    • The Korean Journal of Food And Nutrition
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    • v.12 no.3
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    • pp.258-264
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    • 1999
  • This study was carried out to investigate the status in weight loss yield of edible meat quality and free amino acid contents of the snow crab(Chionoectes japonicus) by steaming and various drying treat-ment. Change of body weight loss in steaming treatment sample were 20.48∼26.72% and yield of edible meat of steaming sample was higher than raw sample(p<0.05) The pH value was increased with steam-ing and drying and pH of trunk meat was more increased than leg meat. Volatile basic nitrogen(VBN) content of vacuum dried sample was highest and VBN of hot-air and freezing dried sample were about 10mg%. Content of vaccum dried sample wre 41.33 and 48,56mg%. Thirty kind of free amino acids dectected in the snow crab and changes of free amino acid in leg meat were markedly reduced by vacuum drying and the reducing ratio of leg meat by freeze drying was little. The major free amino acid of leg and trunk meat were 39.94% 46.78% respectively. The formation of flavor free amino acid in freezing dried sample were high but its hot-air aried sample were small.

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Adsorption Characteristics of Soybean Curd Powder Prepared with Various Drying Methods during Storage (건조방법을 달리한 두부분말의 저장 중 수분흡습 특성)

  • Lee Sang-Duck;Kim Jin-Sung;Kim Jun-Han;Ha Young-Sun
    • Journal of the East Asian Society of Dietary Life
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    • v.14 no.5
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    • pp.457-462
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    • 2004
  • Physical properties of soybean curd powder prepared with hot air, vacuum and freeze drying methods were investigated. Adsorption characteristics were studied under various water activities (such as 0.11, 0.33, 0.44, 0.55, 0.66, 0.75, 0.85, and 0.93) at 5℃, and prediction models were developed. Equilibrium moisture and monolayer moisture contents were the highest when freeze dried. due to the porous structure. In this result, Oswin model was the best fit for the isotherm of soybean curd. Sorption enthalpy indicated that high moisture content of powder showed lower sorption than that of low moisture content.

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Conservation of Straw Sandals Excavated at Goongnamji in Buyeo (부여 궁남지 출토 짚신의 보존처리)

  • Na, Mi-Sun;Kim, Ik-Joo;Kim, Kyeong-Hee
    • Journal of Conservation Science
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    • v.17 s.17
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    • pp.65-72
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    • 2005
  • To preserve straw sandals excavated at Goongnamji site, this study examined the weight change rate by applying the methods of Primal MC-76 and vacuum freeze-drying used mostly as a earth-layer hardening material among PEG and acrylic resin, which are applied widely for preservation of waterlogged archaeological wood, as a means to preserve plant-based cultural properties along with the examination of the subject material. An experiment was also performed on moisture absorption after treatment. The materials of sandals were identified as Typha spp. The weight change experiment revealed that the vacuum freeze-drying after being treated with PEG 2-Step showed the most stabilized changes in weight, while it offered the smallest change in color as well.

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Conservation for Wooden Objects excavated from Isong Sansung Fortress in Hanam, Korea (하남 이성산성 출토 목제품의 보존 처리)

  • Kim, Soochul;Son, Junhyuk
    • Conservation Science in Museum
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    • v.12
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    • pp.47-52
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    • 2011
  • The authors did conservation treatment of wooden objects excavated from Isong Sanung Fortress upon request of the Museum of Hanyang University. The authors investigated types of the trees prior to conservation treatment to find out 1 Pinus spp. and 11 Querus spp. The authors investigated paint coating of 1 wooden ware to find out No.4 of the exterior and No.3 of the interior and about 100㎛ thickness of the lacquer layer. The. conservation treatment was done to immerse wooden ware into high molecular PEG#3,350 in water solution (10 ~ 45%) and to give physical strength and to do vacuum freeze drying.

Comparison of the Physicochemical Properties of Meat and Viscera of Dried Abalone (Haliotis discus hannai) Prepared using Different Drying Methods (건조방법에 따른 건조 전복 (Haliotis discus hannai)의 이화학적 특성 비교)

  • Park, Jeong-Wook;Lee, Young-Jae;Park, In-Bae;Shin, Gung-Won;Jo, Yeong-Cheol;Koh, So-Mi;Kang, Seong-Gook;Kim, Jeong-Mok;Kim, Hae-Seop
    • Food Science and Preservation
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    • v.16 no.5
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    • pp.686-698
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    • 2009
  • We sought basic data for product development and storage improvement of abalone. We explored drying methodologies, such as shade drying, cold air drying, and vacuum freeze drying. We also examined various physicochemical features of both meat and viscera. Raw abalone meat had $78.88{\pm}1.01%$ moisture, $9.24{\pm}0.27%$ crude protein, and $10.05{\pm}0.81%$ carbohydrate (all w/w). The moisture level of dried abalone meat was highest after cold air drying, at $18.38{\pm}0.91%$, and lowest after vacuum freeze drying, at $1.05{\pm}0.05%$. The total amino acid content of raw abalone meat was $17,124.05{\pm}493.18\;mg%$, and fell after shade-drying to $12,969.92{\pm}583.65\;mg%$, and to $13,328.78{\pm}653.11\;mg%$ after cold air drying. The total free amino acid content of raw abalone meat was $4,261.99{\pm}106.55\;mg%$, and rose after shade-drying to $6,336.50{\pm}285.15\;mg%$, to $5,072.04{\pm}248.53\;mg%$ after cold air drying, and to $4,638.85{\pm}218.03\;mg%$ after vacuum freeze drying. The fatty acid proportions in raw abalone meat were $47.00{\pm}0.99%$ saturated, $22.18{\pm}1.05%$ monounsaturated, and $30.82{\pm}1.45%$ polyunsaturated. In the viscera, however, the proportions were $36.72{\pm}0.74%$ saturated, $25.44{\pm}1.12%$ monounsaturated, and $37.84{\pm}1.67%$ polyunsaturated. The contents of chondroitin sulfate in raw abalone were $11.95{\pm}0.35%$ in meat and $7.71{\pm}0.19%$ in viscera (both w/w). After shade-drying, the chondroitin sulfate content was $16.57{\pm}0.90%$ in meat and $9.24{\pm}0.50%$ in viscera. The figures after cold air drying were $16.17{\pm}0.79%$ and $12.44{\pm}0.61%$, and those after vacuum freeze drying $25.17{\pm}1.16%$ and $15.22{\pm}0.70%$ (thus including the highest meat content). The level of collagen in raw abalone was $69.80{\pm}3.07\;mg/g$ in meat and $40.62{\pm}1.79\;mg/g$ in viscera. Meat and viscera dried in the shade had $144.05{\pm}7.78\;mg/g$ and $44.16{\pm}2.39\;mg/g$ collagen, respectively, whereas the figures after cold air drying were $133.29{\pm}6.53\;mg/g$ and $69.20{\pm}3.39\;mg/g$, and after vacuum freeze drying $137.51{\pm}6.33\;mg/g$ and $60.61{\pm}2.79\;mg/g$. Volatile basic nitrogen values of raw abalone showed a higher content in viscera, at $19.01{\pm}0.84\;mg%$, compared to meat ($10.10{\pm}0.44\;mg%$). The value for shade-dried abalone meat was $136.77{\pm}7.37\;mg%$ and that of viscera $197.97{\pm}10.69\;mg%$. After cold air drying the meat and visceral values were $27.32{\pm}1.34\;mg%$ and $71.37{\pm}3.50\;mg%$, respectively.

Development and Quality of Dried Cherry-Tomatoes (건조방울토마토 제조와 품질 특성)

  • 윤경영;김미현;이광희;신승렬
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.28 no.6
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    • pp.1283-1287
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    • 1999
  • This study was carried out to develop new processed food from cherry tomatoes. The dried cherry tomatoes were prepared by using a sequence of osmotic dehydration, air drying, vacuum drying and freeze drying. The moisture contents of dried cherry tomato products by nontreatment and osmosis treatment were about 11~13% and 7.5~ 10%, respectively. The vitamin C contents of the dried product after osmotic dehydration were higher than those of the dried products by nontreatment. The vitamin C content of the freezing dried product was the highest of the others. The vacuum dried product by nontreatment was retained color of fresh fruit in the change of color. The ΔE value of the air dried product was lower than those of the others. As a result to microscopic analysis, fresh cherry tomato was observed regular tissue, while cherry tomato treated by osmosis was observed a cell collapse following the loss of water. The dried product had cell shrinkage and dense tissue. And the cell wall of dried products after osmotic dehydration were much more damage than those of nontreatment dried product. The palatability of the air dried product was the best of three drying methods. The dried cherry tomatoes treated by osmosis were superior to the dried cherry tomatoes by nontreatment.

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Absorption Characteristics of Persimmon Powder Depending on Temperature Changes and Drying Methods (건조방법과 온도변화에 따른 감 분말의 흡습특성)

  • 이원영;김종국
    • Journal of the East Asian Society of Dietary Life
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    • v.11 no.6
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    • pp.479-484
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    • 2001
  • The absorption characteristics of persimmon powder related to different drying methods and various storage temperatures was investigated. The physical properties of persimmon powder by different drying methods displayed the largest amount of porosity in the freeze-dried sample, and the smallest in hot air dried sample. Equilibrium moisture was reached in 6 days. Monolayer moisture contents were predicted to 0.09687~0.19712(freeze drying), 0.07820~0.18617(vacuum drying) and 0.07715~0.18056(hot air drying) g H2O/g solid respectively using the BET equation. BET equation for isothermal absorption curve showed over 0.95 R-square for all dried methods. Monolayer moisture contents were increased as storage temperature was incremented because water molecular movement was more active and there was a greater chance to clash with the absorption surface area.

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Several Functional Properties of Freeze-dried Powder of Pre-concentrated Aloe vera gel (농축 전처리된 Aloe vera gel의 동결건조분말의 기능성)

  • Lee, Nam Jae;Lee, Seung Ju
    • Food Engineering Progress
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    • v.13 no.3
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    • pp.216-220
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    • 2009
  • The several functional properties of freeze-dried powder of Aloe vera gel was examined as influenced by pre-concentration degrees of the gel solution. As a pre-treatment prior to freeze drying, the gel solution was vacuum-concentrated by three levels (unit: g-water/g-solids) - high (H), 76; medium (M), 119; low (L), 159. In FT-IR spectra, the sample H showed the highest absorbance in the range of 1600-1550 $cm^{-1}$ and 1450-1400 $cm^{-1}$, which corresponded to level of the acetyl group in glucomannan. The sample H of freeze-dried powder was the highest in polysaccharide content, jack bean urease inhibition rate, and FAC (fat adsorption capacity). It could be inferred that the sample H had an effect on Helicobacter pylori inhibition and fat adsorption suppression according to urease inhibition rate and FAC, respectively.