• Food Science and Biotechnology
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• v.15 no.1
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• pp.13-18
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• 2006

Mandarin juice was processed using a continuous high pressure $CO_2$ system. Response surface methodology was used to investigate the effects of the processing parameters such as temperature, pressure, residence time, and %(w/w) ratio of $CO_2$ to juice on total aerobic count (TAC), pectinesterase (PE) activity, cloud level, $^{\circ}Brix$, pH, and titratable acidity (TA) of the juices. Maximum log reduction (3.47) of TAC was observed at $35^{\circ}C$, 41.1 MPa, 9 min residence time, and 7% $CO_2$. PE was inactivated by 7-51%. The cloud was not only retained but was also enhanced by 38%. Lightness and yellowness increased, and redness decreased. The processing temperature and % $CO_2$/juice ratio significantly affected high pressure $CO_2$ processing of the juice in terms of pasteurization, PE inactivation, cloud increase, and color change. The $^{\circ}Brix$, pH, and TA before and after treatment remained unchanged.

• The Korean Journal of Food And Nutrition
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• v.24 no.4
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• pp.746-752
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• 2011

In the manufacture of baby food in the form of semi-solid to give the most suitable rheological properties to select thickener, 4% of rice flour, modified starch 1 and modified starch or 0.3% pectin added to baby food. After 3 minutes at a pressure 550 MPa high pressure processing(HPP), sensory evaluation conducted to measure the viscosity results, the addition of rice flour, baby food bananas and apples all the color, texture, flow properties and high affinity for most commercial baby food as well as the most likely to show the viscosity of semi-solid state in the manufacture of baby food there were rice flower most suitable. The baby food that 4%, 6% and 8% of rice flower added as thickener were high pressure processing at 450 MPa and 550 MPa pressure and 1, 3 and 5 min conditions. In results, the higher added percentage of rice flower, the viscosity and lightness were increased, pH and sugar content were not significantly different from. In addition, ultra-high pressure processing conditions and the processing time for a change in pressure due to the increase is not significantly different. Because of high-pressure processing does not significantly affect the physical properties of the baby food, consideration of the economy and gelatinization degree, high-voltage processing conditions for the manufacture of baby food 550 MPa, 3 min was considered the most suitable processing conditions.

• Korean Journal of Materials Research
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• v.28 no.6
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• pp.337-342
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• 2018

Using a high pressure homonizer, we report on the electrochemical performance of $Li_4Ti_5O_{12}(LTO)$ particles manufactured as anode active material for lithium ion battery. High-pressure synthesis processing is performed under conditions in which the mole fraction of Li/Ti is 0.9, the synthesis pressure is 2,000 bar and the numbers of passings-through are 5, 7 and 10. The observed X-ray diffraction patterns show that pure LTO is manufactured when the number of passings-through is 10. It is found from scanning electron microscopy analysis that the average size of synthesized particles decreases as the number of passings-through increases. $LiCoO_2-based$ active cathode materials are used to fabricate several coin half/full cells and their battery characteristics such as lifetime, rate capability and charge transfer resistance are then estimated, revealing quite good electrochemical performance of the LTO particles as an effective anode active material for lithium secondary batteries.

• The Korean Journal of Food And Nutrition
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• v.24 no.4
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• pp.777-785
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• 2011

For the purpose of develop semi-solid baby food, we investigated ingredients, processing aids as a thickener, processing suitability test, natural antibrowning agent, packing method, novel preservation technology, storage test and quality evaluation. In results, semi-solid baby food was developed. It's formulation is eco-friendly apple as a main ingredients, natural rhubarb extract 5% and thickener 4%. Thickener was used brown rice puffing powder and sweet pumpkin puffing powder. High pressure processing(HPP) and pouch packaging was used as processing and novel preservation technology. In results of storage test and quality evaluation, shelf-life of semi-solid baby food was 15 days in $5^{\circ}C$ cold storage and hedonic score of sensory evaluation was 4.3/5.0. Taste of them was fresh and sweet.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.3
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• pp.424-431
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• 2017

Objective: Study on the application of high pressure processing (HPP) for dark-firm-dry (DFD) beef was conducted to observe whether HPP has any impact on physical properties and to evaluate oxidative deterioration during refrigerated storage under vacuum. Methods: The longissimus lumborum muscles obtained from Friesian Holstein steers ($33{\pm}0.5$ months old) with 24-h postmortem pH higher than 6.0 were vacuum-packed and subjected to pressurization at 200, 400, and 600 MPa for 180 s at $15^{\circ}C{\pm}2^{\circ}C$; the samples were then stored for 9 days at $4^{\circ}C{\pm}1^{\circ}C$ and compared with control (0.1 MPa). Results: HPP increased meat pH by 0.1 to 0.2 units and the tenderness of cooked DFD beef significantly with no significant effects on meat texture profile. The stability of meat pH was well maintained during refrigerated storage under vacuum. No clear effects were found on the activity of catalase and superoxide dismutase, however, glutathione peroxidase activity was significantly reduced by high pressure. HPP and storage time resulted in aroma changes and the increasing amount of malondialdehyde and metmyoglobin relative composition. Conclusion: Although the increasing amount of malondialdehyde content, metmyoglobin formation and aroma changes in HPP-treated samples could not be avoided, HPP at 200 MPa increased $L^*$ and $a^*$ values with less discoloration and oxidative deterioration during storage.

• Transactions of Materials Processing
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• v.23 no.2
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• pp.116-121
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• 2014

Low pressure die casting and flow forming have been successfully used to produce sound road wheels from magnesium alloy AM80. In the current study, high speed compression testing was initially conducted to simulate the flow forming of a Mg wheel. Subsequently the flow forming was simulated with "Forge$^{TM}$", an FEM software package. On the basis of flow forming simulations, the flow forming of the Mg wheel was performed under different conditions. For the flow forming experiments, the preform castings were made by low pressure die casting from AM80, a commercial magnesium alloy. In flow forming of the magnesium preform wheel, the flow forming of the Mg wheel was successfully accomplished when the feed rate was less than half that for the forming of an aluminum road wheel. The reduction in feed rate was 52%. Finally, a comparison with the flow forming simulations was made.

• Journal of Technologic Dentistry
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• v.40 no.3
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• pp.125-131
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• 2018

Purpose: Automatic dental prosthesis manufacturing process was accelerated by the spread of dental CAD / CAM system. The CAD / CAM system with milling alloys were needed supplement. So, sintered alloy blocks were introduced. In this study, we want to study sintered alloy block. And to evaluate the alloy block manufacture and alloy properties. Methods: The alloy powders were prepared by high pressure water dispersion method. The sintered alloy blocks were prepared by low temperature pressing method. Their components observation were EDX, and the alloy structure was observed by XRD. Results: Co-Cr alloy powders were observed to have a circle shape with an average diameter of about $100{\mu}m$ and a Ni-Cr alloy powder had a circle shape with an average diameter of about $50{\mu}m$. The Co-Cr alloy block is composed of Co (34.62 wt%), Cr (17.33 wt%), Mo (2.98 wt%), Si (0.36 wt%) and C (44.17 wt%). The Ni-Cr alloy powder was composed of Ni (40.29 wt%), Cr (19.37 wt%), Mo (3.53 wt%), Si (0.52 wt%) and C (33.18 wt%). The peak of the Co and CoCr peaks were observed in the CoCr alloy body by the means of XRD study. Cr2Ni3 of the peak was observed in the Ni-Cr alloy material. Conclusion : As a result, the following conclusions were obtained. 1. Prepared by high-pressure water-law Co-Cr alloy powder has an average diameter $100{\mu}m$, Ni-Cr alloy powder was found to have the form of sphere having an average diameter $50{\mu}m$. 2. Co-Cr alloy and Ni-Cr alloy block produced by low-temperature processing showed a certain ratio. 3. In the XRD study, Co phase appeared in Co-Cr alloy block after sintering. and Cr2Ni3 phase appeared in Ni-Cr alloy block after sintering.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.6
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• pp.889-893
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• 2016

This study was carried out to investigate the physicochemical and fermentation properties of yogurt made from high pressure processing (HPP) treated milk. Raw milk and commercial yogurt starter were used to make yogurt. Raw milk was HPP treated at 350 or 450 MPa (HPP 350 or 450) for 15 min or heat treated at $80^{\circ}C$ for 10 min. The numbers of lactic acid bacteria of the HPP treated group (HPP yogurt) rapidly increased during 2~4 h, whereas there was not significant difference from control (P<0.05). Titratable acidity of all samples increased, and pH decreased during storage from 0.99 to 1.24%, as well as from 4.59 to 4.20, respectively. It is confirmed that these values are in general ranges for yogurt. Control showed higher viscosity than HPP 350. Syneresis was significantly lower than that of the control (P<0.05). Based on the data obtained from the present study, HPP treatment was effective to enhance the quality of yogurt.

• Food Engineering Progress
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• v.15 no.3
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• pp.203-208
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• 2011

Effects of particle size and high pressure processing on the extraction rate of oil compounds from soybean powder were evaluated by Soxhlet method using hexane and supercritical fluid extraction (SFE) using $CO_{2}$. SFE was carried out at 4,000 psi and $50^{\circ}C$ for 4 hr. The mean particle sizes were varied from 26.7 to 862.0 ${\mu}m$ by controlling milling time. Saturation solubility increased as the particle size decreased. At large particle size, high pressure processing (HPP) showed higher extraction yield in both hexane extraction and SFE, but, as the particle size decreased, the HPP was irrelevant to the extraction yield in SFE. The higher extraction rate obtained from the smaller particle size. The scanning electronic microscopy of soybean powder treated by HPP showed pores on the surface of the particle. The higher extraction rate and yield from HPP treatment might be due to the less internal resistance of transferring the solvent and miscellar in the solid matrix by collapsing of tissues.

• Korean Journal of Food Science and Technology
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• v.35 no.6
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• pp.1104-1109
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• 2003

Response surface methodology (RSM) was used to investigate the effects of the processing parameters on supercritical $CO_2\;(SC-CO_2)$. extraction of total carotenoids and ${\beta}$-cyptoxanthin from Citrus unshiu press cake. The parameters tested were $SC-CO_2$ pressure, dynamic extraction time, and concentration of ethanol added as the modifier to $CO_2$. Experimental data correlated well with the processing parameters (p<0.01), and there was a high statistically significant multiple regression relationship for the extraction of total carotenoids and ${\beta}-cyrptoxanthin$ ($R^2=0.9789$ and 0.9796, respectively). The optimal processing conditions were extraction pressure 33.4 and 37.3 MPa, extraction time 39.6 and 41.0 min, ethanol concentration 18.6 and 17.0% for total carotenoids and ${\beta}-cryptozanthin$, respectively. Maximum extraction yields predicted by RSM were 61.1 and 95.8% ppm, respectively. The extraction yield of total carotenoids increased asymptotically with the increase of the extraction pressure. It increased in proportion to extraction time and concentration of the cosolvent. The extraction yield of ${\beta}-cryptoxanthin$ increased with extraction pressure, extraction time, and concentration of the cosolvent. The extraction time and the concentration of the cosolvent, and the interaction between extraction time and the concentration of the cosolvent significantly affected the extraction yields of carotenoids from C. unshiu press cake.