• Title/Summary/Keyword: freeze drying process

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Drying Characteristics of Mango Powder according to Foam-Mat Drying Conditions (포말건조 조건에 따른 애플망고 분말의 건조 가공 특성)

  • Hyeonbin Oh;Chae-wan Baek;Taeho Kwak;Hyun-Wook Jang;Ha-Yun Kim;Yong Sik Cho
    • The Korean Journal of Food And Nutrition
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    • v.36 no.6
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    • pp.496-505
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    • 2023
  • This study explored a method to enhance the drying process usability of local mangoes by producing foam-mat dried powder under varying drying temperatures (50, 60, 70℃) and foam thicknesses (3, 6, 9 mm). The drying process period ranged from 60 to 390 minutes based on the set conditions, with higher temperatures and thinner foams accelerating drying. Powder chromaticity (L*,(L*, a*, and b*) demonstrated a declining trend with increasing drying temperature and foam thickness, exhibiting notable variance in chroma values. The water absorption index varied significantly, between 3.08 to 4.24, under different drying conditions, although the water solubility index remained consistent across foam-dried samples. Powder moisture content ranged from 2.53% to 3.83%, with hygroscopicity escalating with temperature and foam thickness. Vitamin C structure was compromised during the hot air drying process, especially at temperatures above 60℃. Electronic nose analysis distinguished foam-dried powder from freeze-dried powder; however, a thicker foam yielded a scent profile closer to that of freeze-dried powder. The findings provide fundamental data on mango foam drying, which is expected to improve processing and storage tech for local mangoes.

Change of Physicochemical Characteristics and Functional Components in the Raw Materials of Saengsik, Uncooked Food by Drying Methods (건조방법에 따른 생식 원료의 이화학적 특성 및 기능성 성분의 변화)

  • Jin, Tie-Yan;Oh, Deog-Hwan;Eun, Jong-Bang
    • Korean Journal of Food Science and Technology
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    • v.38 no.2
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    • pp.188-196
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    • 2006
  • Changes in physicochemical characteristics and functional components content of saengsik, uncooked food, were investigated to find efficient drying methods, one of important manufacturing process of saengsik. No changes in proximate compositions of all samples were observed during hot-air drying at 50, 55, and $60^{\circ}C$ and freeze-drying. Colors of carrot, Lentinus edodes, and sea mustard did not change, while a value of cabbage, L, a, and b values of Agaricus bisporos, and a value of laver changed slightly by hot-air drying at all temperatures and freeze-drying. Dietary fiber content increased by hot-air drying but not by freeze-drying. Reductions in vitamin C and ${\beta}-carotene$ contents of carrot, cabbage, sea mustard, and laver were higher by hot-air drying than by freeze-drying. Contents of total phenolics and lectin of L. edodes and A. bisporos were not affected by hot-air drying and freeze-drying. Contents of pectin, alginic acid, and porphyran in sea mustard and laver increased by hot-air drying.

The Stability of Color and Antioxidant Compounds in Paprika (Capsicum annuum L.) Powder During the Drying and Storing Process

  • Park, Jae-Hee;Kim, Chang-Soon
    • 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.

Study on Major Korean Protein Sources Before and After Freeze Drying Processing (한국인 주요 단백질 급원식품 10종에 대한 동결건조 전후의 특성 연구)

  • Son, Yang-Ju;Choi, Soo-Young;Lee, Keum-Yang;Huang, Ying;Yoo, Kyung-Mi;Hwang, In-Kyeong
    • Korean journal of food and cookery science
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    • v.30 no.1
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    • pp.64-75
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    • 2014
  • Freeze-drying process was used for 10 major protein foods referred by the Korea Health Statistics 2011 as follows; chicken, pork, beef, eggs, tofu, squid, soybean, mackerel, anchovy, and pollack/frozen pollack. Boiled samples and re-hydrated samples after freeze-drying were prepared for analysis. The weight variation, the chromaticity, the mechanical texture and sensory properties by eight trained panelists were measured. In the ratio of re-hydration, the anchovy showed the highest value(89.40%), followed by eggs, and squid showed the lowest value(35.51%). Changes of Hunter color value were observed among all samples. For rates on changes of hardness, every sample was increased except for eggs(p<.05). Among the 9 samples, except for eggs, chicken showed the lowest rate of increase in hardness(125.44%) while squid showed the highest rate of increase in hardness(1335.1%). Except for eggs and pork, eight samples represented differences in sensory properties, especially in juiciness and tenderness(p<.05). As a result, we found that egg is the most suitable for freeze-drying among 10 protein sources followed by pork and chicken.

Effect of Solidification Condition of Sublimable Vehicles on the Pore Characteristics in Freeze Drying Process (동결건조 공정에서 동결제의 응고조건이 기공특성에 미치는 영향)

  • Suk, Myung-Jin;Kim, Ji Soon;Oh, Sung-Tag
    • Journal of Powder Materials
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    • v.21 no.5
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    • pp.366-370
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    • 2014
  • The present study demonstrates the effect of solidification condition on the pore structure in freeze drying process using the slurries of CuO/sublimable vehicles. Camphene and Camphor-45 wt% naphthalene based slurries with 14 vol% CuO powder were frozen into a mold at $-25^{\circ}C$, followed by sublimation at room temperature. The green bodies were hydrogen-reduced and sintered at $500^{\circ}C$ for 1 h. The porous Cu specimen, frozen the CuO/camphene slurry into the heated mold of the upper part, showed large pores with unidirectional pore channels and small pores in their internal wall. Also, it was observed that the size of large pores was decreasing near the bottom part of specimen. The change of pore structure depending on the freezing condition was explained by the nucleation behavior of camphene crystals and rearrangement of solid powders during solidification. In case of porous Cu prepared from CuO/Camphor-naphthalene system, the pore structure exhibited plate shape as a replica of the original structure of crystallized vehicles with hypereutectic composition.

Effect of Powder Characteristic and Freeze Condition on the Pore Characteristics of Porous W (텅스텐 다공체의 기공특성에 미치는 분말특성 및 동결조건의 영향)

  • Kwon, Na-Yeon;Oh, Sung-Tag
    • Journal of Powder Materials
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    • v.19 no.4
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    • pp.259-263
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    • 2012
  • Dependence of the freeze-drying process condition on microstructure of porous W and pore formation mechanism were studied. Camphene slurries with $WO_3$ contents of 10 vol% were prepared by milling at $50^{\circ}C$ with a small amount of dispersant. Freezing of a slurry was done in Teflon cylinder attached to a copper bottom plate cooled at $-25^{\circ}C$. Pores were generated subsequently by sublimation of the camphene during drying in air for 48 h. The green body was hydrogen-reduced at $800^{\circ}C$ for 30 min, and sintered in the furnace at $900^{\circ}C$ for 1 h. After heat treatment in hydrogen atmosphere, $WO_3$ powders were completely converted to metallic W without any reaction phases. The sintered samples showed large pores with the size of about $70{\mu}m$ which were aligned parallel to the camphene growth direction. Also, the internal wall of large pores and near bottom part of specimen had relatively small pores with dendritic structure due to the growth of camphene dendrite depending on the degree of nucleation and powder rearrangement in the slurry.

Optimization of Preparation Variables for Trimyristin Solid Lipid Nanoparticles

  • Choi, Mi-Hee;Lee, Mi-Kyung
    • Journal of Pharmaceutical Investigation
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    • v.37 no.1
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    • pp.51-55
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    • 2007
  • Solid lipid nanoparticles (SLNs) have been regarded to behave similar to the vegetable oil emulsions because emulsions of lipid melts are formed before lipid droplets being solidified to turn into SLNs. Compared to lipid emulsion, however, it has been more difficult to obtain stable SLNs and needs more extensive considerations on stabilizer and manufacturing process. In the present study, we tried to prepare phosphatidylcholine-based trymyristin (TM) SLNs using high pressure homogenization method and optimize the manufacturing variables such as homogenization pressure, number of homogenization cycles, cooling temperature, co-stabilizer and freeze-drying with cryoprotectants. Nano-sized TM particles could be Prepared using egg Phosphatidylcholine and pegylated phospholipids ($PEG_{2000}$PE) as stabilizers. Based on the optimization study, the dispersion was manufactured by homogenization under the pressure of 100 MPa for more than 5 cycles, and solidifying the intermediately formed lipid melt droplets by dipping in liquid nitrogen followed by thawing at room temperature. In addition, TM SLNs could be freeze-dried and then redispersed easily without significant particle size changes after freeze drying with 10% and 12.5% sucrose or trehalose. The TM SLNs established in this study can be used as delivery system for drugs and cosmetics.

Fabrication of Porous Cu-Ni by Freeze Drying and Hydrogen Reduction of CuO-NiO Powder Mixture (CuO-NiO 혼합분말의 동결건조 및 수소환원에 의한 Cu-Ni 다공체 제조)

  • Seo, Han Gil;Oh, Sung-Tag
    • Journal of Powder Materials
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    • v.21 no.1
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    • pp.34-38
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    • 2014
  • Cu-Ni alloys with unidirectionally aligned pores were prepared by freeze-drying process of CuO-NiO/camphene slurry. Camphene slurries with dispersion stability by the addition of oligomeric polyester were frozen at $-25^{\circ}C$, and pores in the frozen specimens were generated by sublimation of the camphene during drying in air. The green bodies were hydrogen-reduced at $300^{\circ}C$ and sintered at $850^{\circ}C$ for 1 h. X-ray diffraction analysis revealed that CuO-NiO composite powders were completely converted to Cu-Ni alloy without any reaction phases by hydrogen reduction. The sintered samples showed large and aligned parallel pores to the camphene growth direction, and small pores in the internal wall of large pores. The pore size and porosity decreased with increase in CuO-NiO content from 5 to 10 vol%. The change of pore characteristics was explained by the degree of powder rearrangement in slurry and the accumulation behavior of powders in the interdendritic spaces of solidified camphene.

Fabrication of Porous Cu by Freeze-drying Process of Camphene Slurry with CuO-coated Cu Powders (CuO가 코팅된 Cu 분말을 혼합한 Camphene 슬러리의 동결건조에 의한 Cu 다공체 제조)

  • Bang, Su-Ryong;Oh, Sung-Tag
    • Journal of Powder Materials
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    • v.21 no.3
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    • pp.191-195
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    • 2014
  • This study reports a simple way of fabricating the porous Cu with unidirectional pore channels by freeze drying camphene slurry with Cu oxide coated Cu powders. The coated powders were prepared by calcination of ball-milled powder mixture of Cu and Cu-nitrate. Improved dispersion stability of camphene slurry could be achieved using the Cu oxide coated Cu powders instead of pure Cu powders. Pores in the frozen specimen at $-25^{\circ}C$ were generated by sublimation of the camphene during drying in air, and the green bodies were sintered at $750^{\circ}C$ for 1 h in $H_2$ atmosphere. XRD analysis revealed that the coated layer of Cu oxide was completely converted to Cu phase without any reaction phases by hydrogen heat treatment. The porous Cu specimen prepared from pure Cu powders showed partly large pores with unidirectional pore channels, but most of pores were randomly distributed. In contrast, large and aligned parallel pores to the camphene growth direction were clearly observed in the sample using Cu oxide coated Cu powders. Pore formation behavior depending on the initial powders was discussed based on the degree of powder rearrangement and dispersion stability in slurry.

Fabrication of Porous W-Ti by Freeze-Drying and Hydrogen Reduction of WO3-TiH2 Powder Mixtures (WO3-TiH2 혼합분말의 동결건조 및 수소환원에 의한 W-Ti 다공체 제조)

  • Kang, Hyunji;Park, Sung Hyun;Oh, Sung-Tag
    • Journal of Powder Materials
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    • v.24 no.6
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    • pp.472-476
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    • 2017
  • Porous W-10 wt% Ti alloys are prepared by freeze-drying a $WO_3-TiH_2$/camphene slurry, using a sintering process. X-ray diffraction analysis of the heat-treated powder in an argon atmosphere shows the $WO_3$ peak of the starting powder and reaction-phase peaks such as $WO_{2.9}$, $WO_2$, and $TiO_2$ peaks. In contrast, a powder mixture heated in a hydrogen atmosphere is composed of the W and TiW phases. The formation of reaction phases that are dependent on the atmosphere is explained by a thermodynamic consideration of the reduction behavior of $WO_3$ and the dehydrogenation reaction of $TiH_2$. To fabricate a porous W-Ti alloy, the camphene slurry is frozen at $-30^{\circ}C$, and pores are generated in the frozen specimens by the sublimation of camphene while drying in air. The green body is hydrogen-reduced and sintered at $1000^{\circ}C$ for 1 h. The sintered sample prepared by freeze-drying the camphene slurry shows large and aligned parallel pores in the camphene growth direction, and small pores in the internal walls of the large pores. The strut between large pores consists of very fine particles with partial necking between them.