• Title/Summary/Keyword: high hydrostatic pressure

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Comparative Study on Pore Closing in Open Die Forging by Conventional Forging Press and Radial Forging Machine (일반자유단조 프레스와 방사형 단조 프레스의 기공 압착에 관한 비교 연구)

  • Kim, S.H.;Lee, M.C.;Jang, S.M.;Eom, J.G.;Joun, M.S.
    • Transactions of Materials Processing
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    • v.19 no.7
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    • pp.399-404
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    • 2010
  • We propose an analysis model for simulating the detailed procedure of pore closing in open die forging of shafts. In the analysis model, an artificial symmetric plane is used, on which initial pores are located to be traced. The analysis model is employed to carry out three-dimensional simulation of pore closing in shaft free forging by both conventional free forging press and radial forging machine. With this result, two typical types of free forging equipment for manufacture of shafts are compared in detail. It has shown that the radial forging machine is much superior to the conventional open die forging press especially in pore closing under high hydrostatic pressure with sound strain.

Changes in Microbial Counts, Enzyme Activity and Quality of Foxtail Millet Yakju Treated with High Hydrostatic Pressure During Storage (초고압 처리한 좁쌀약주의 저장 중 미생물수, 효소활성 및 품질변화)

  • 임상빈;좌미경;목철균;박영서
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.33 no.3
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    • pp.576-581
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    • 2004
  • Foxtail Millet Yakju were treated with heat ($65^{\circ}C$/15 min) or high hydrostatic pressure ($25^{\circ}C$ (RT) and $65^{\circ}C$ (HT)/400 MPa/10 min), and stored for 64 days at l$0^{\circ}C$, $25^{\circ}C$ and 37$^{\circ}C$. Changes in microbial counts, enzyme activity and quality of Yakju during storage were measured. Total viable cells were about 10$^2$ CFU/mL, and remained almost constant during storage at l$0^{\circ}C$ and $25^{\circ}C$, while decreased significantly at 37$^{\circ}C$, and undetected after 55 days of storage in heat- and pressure(RT)-treated, but after 25 days in pressure(HT)-treated Yakju. Lactic acid bacteria and yeast in heat- and pressure-treated Yakju were not detected during storage. The relative activities of a -amylase in heat- and pressure(RT)-treated were more than 100%, while those in pressure(HT)-treated were less than 40% during storage of 64 days at l$0^{\circ}C$. However, at $25^{\circ}C$ and 37$^{\circ}C$ the relative activities in untreated and pressure(RT)-treated were decreased greatly and then reached at the point of the activities of heat- and pressure(HT)-treated. The relative activities of glucoamylase in untreated and pressure(RT)-treated were decreased as the increase of the storage temperature during storage, while those in heat- and pressure(HT)-treated increased slightly as the increase of storage period at 1$0^{\circ}C$ and $25^{\circ}C$, and had no change at 37$^{\circ}C$. pH in heat- and pressure-treated had almost no change. Turbidity and reducing sugar in heat- and pressure-treated increased as the increase of storage temperature during storage.

Changes in Quality Characteristics of Seasoned Soy Sauce Treated with Superheated Steam and High Hydrostatic Pressure during Cold Storage (과열증기와 초고압 처리법을 적용한 간장 소스의 냉장저장 중 품질 특성 변화)

  • Choi, Yoon;Oh, Ji-Hye;Bae, In-Young;Cho, Eun-Kyoung;Kwon, Dae-Joong;Park, Hae-Won;Yoon, Sun
    • Korean journal of food and cookery science
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    • v.29 no.4
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    • pp.387-398
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    • 2013
  • Seasoned soy sauce is one of the popular seasoning sauces added to the Korean traditional foods such as Bulgogi, Galbi. However, industrially processed sauces have poor sensory quality because of heating treatment for sterilization. The purpose of this study was to develop seasoned soy sauce having fresh taste and good quality by applying superheated steam (SHS) and high hydrostatic pressure (HHP) technologies. To maintenance the sauce qualities, food materials such as apple, onion, and garlic were pretreated with SHS (heater $100^{\circ}C$, steam $280^{\circ}C$, 30 s~1 min 30 s) before mixing with other ingredients. During storage of 7 days, color, pH, and browning potential of SHS treated samples (apple, onion and garlic) did not change and also polyphenol oxidase was inactivated (p<0.05). The seasoned soy sauce including SHS treated materials was sterilized by thermal process ($85^{\circ}C$, 30min) or non-thermal process, HHP (550 MPa, $5{\sim}10^{\circ}C$, 3 min). In SHS+HHP treated sauce, salinity, sugar contents, lightness, viscosity did not change (p<0.05), and total viable cell counts were detected below 4 log cycle at $5^{\circ}C$ for 30 days. E.coli and B.cereus are not determined in all samples. In sensory evaluation, Bulgogi prepared with SHS+HHP treated sauce was more acceptable than others.

Quality Changes in Kochujang treated with High Hydrostatic Pressure (초고압처리에 따른 고추장의 품질 변화)

  • Lim, Sang-Bin;Jwa, Mi-Kyung;Mok, Chul-Kyoon;Park, Young-Seo
    • Korean Journal of Food Science and Technology
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    • v.33 no.4
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    • pp.444-450
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    • 2001
  • Kochujang, fermented hot pepper paste, was treated with combined high hydrostatic pressure and heat. Viable cell counts and chemical compositions of Kochujang were determined as a function of high pressure processing conditions such as temperature, pressure and time, and during storage for 120 days at $37^{\circ}C$. Viable cell counts were decreased with the increase of temperature, pressure and time. Viable cell counts in the treated Kochujang were decreased up to $0{\sim}3$ log cycle with the temperature of $49{\sim}73^{\circ}C$, $0{\sim}3$ log cycle with the pressure of $380{\sim}680\;MPa$, and $2{\sim}5$ log cycle with the time of $10{\sim}70\;min$, compared with the untreated. pH, titratable acidity, amino nitrogen, reducing sugar and ethanol content in the treated Kochujang were comparable to the untreated regardless of the treatment condition. Hunter L, a and b values in the treated Kochujang were higher than those of the untreated. Viable cell counts were decreased with the increase of the storage period at $37^{\circ}C$. Viable cell counts in Kochujang treated at 380 MPa/30 min were decreased up to 2 log cycle from $1.8{\times}10^6\;to\;1.94{\times}10^4\;CFU/g$ after 120 days of storage, while those at 680 MPa/70 min were not detected after 60 days from the initial stage of $4.00{\times}10^1\;CFU/g$. pH, amino nitrogen and ethanol content were decreased, and titratable acidity were increased significantly as the increase of the storage period. Hunter L, a and b values also decreased significantly. The changes in physicochemical properties of Kochujang treated at 680 MPa/70 min were greater than those at 380 MPa/30 min.

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Microbial and Quality Changes during Storage of Raw Oyster Treated with High Hydrostatic Pressure (초고압 처리한 생굴의 저장 중 미생물수 및 품질 변화)

  • Park, Whan-Jun;Jwa, Mi-Kyung;Hyun, Sun-Hee;Lim, Sang-Bin;Song, Dae-Jin
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.10
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    • pp.1449-1455
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    • 2006
  • Raw oysters were treated at $10^{\circ}C$ and $22^{\circ}C/350$ Mpa/15 min, and microbial counts and quality were measured during storage of 14 days at $10^{\circ}C$. Total viable cell count (TVCC) in untreated oyster increased greatly during storage from starting inoculum of $1.6\times10^2\;CFU/mL$, and reached to $5.6\times10^2\;CFU/mL$ after 4 days of storage. TVCC of the pressure-treated was about $10^1\;CFU/mL$ right after high hydrostatic pressure treatment and increased slowly during storage, and about $10^3\;CFU/mL$ even after 7 days of storage. Lactic acid bacteria count (LABC) in the untreated was increased greatly during storage from starting inoculum of $3.3\times10^3\;CFU/mL$ at 3 days of storage and $7.2\times10^4\;CFU/mL$ after 4 days of storage. LABC in the pressure-treated was detected only after 5 days of storage, and about $10^2\;CFU/mL$ after 8 days of storage. The pH of the untreated was 6.19 and decreased gradually during storage, and 5.83 after 4 days of storage. The pH of the pressure-treated showed little change during storage, and 6.07, 6.03 and 5.82 after storage of 4, 8 and 14 days, respectively. Volatile basic nitrogen (VBN) in the untreated was 16.8 mg%, and maintained almost constant until 1 day of storage, and then increased suddenly, and 30.1 mg% after 4 days of storage. VBN of the pressure-treated stayed unchanged during storage, and about 20 and 23 mg% even after 4 and 8 days of storage, respectively. Hunter $L^*,\;a^*\;and\;b^*$ values were increased until 2 days of storage and then showed no change during storage. Demerit score was the lowest in the thawed raw oyster, and then in the increasing order of the pressure-treated (4 day and 8 day storage) and the untreated (4 day storage).

Changes in Microbial Counts, Enzyme Activity and Quality of Foxtail Millet Takju Treated with High Hydrostatic Pressure during Storage (초고압 처리한 좁쌀탁주의 저장 중 미생물수, 효소활성 및 품질변화)

  • Lim, Sang-Bin;Jwa, Mi-Kyung;Mok, Chul-Kyoon;Park, Young-Seo;Woo, Gun-Jo
    • Korean Journal of Food Science and Technology
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    • v.36 no.2
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    • pp.233-238
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    • 2004
  • Foxtail Millet Takju was treated with heat ($65^{\circ}C/30\;min$) (HT) or high hydrostatic pressure ($27^{\circ}C/400\;MPa/10\;min$) (PT), and changes in microbial count, enzyme activity, and quality were determined during 30-day storage at 10 and $25^{\circ}C$. Total viable cellcount remained constant, while lactic acid bacteria and yeast were not detected in HT and PT Takjus. Relative activities of ${\alpha}-amylase$ in PT Takju significantly increased by 169.7% at 3 days storage, then decreased to 137.7 and 68.7% at 10 and $25^{\circ}C$, respectively, at 30 days. Relative activities of glucoamylase in HT Takju showed reversible change, and were 36.5 and 54.3% at $10\;and\;25^{\circ}C$, respectively, at 30 days storage. Activities in PT Takju increased with storage period, 158.2% at 30 days storage at $10^{\circ}C$. Titratable acidity in untreated Takju increased, while those in HT and PT Takjus remained almost constant during 30 days storage. Reducing sugar content in untreated Takju showed no change, while that in HT Takju increased gradually, reaching 2.9% at 30 days, whereas that in PT increased sharply after 3 days, reaching 4.8% at 30 days. Sensory evaluation showed sourness and bitterness were low, and sweetness and overall acceptance were high in PT Takju after 30 days storage at $10^{\circ}C$.

High Hydrostatic Pressure Sterilization of Vibrio parahaemolyticus and Escherichia coli in Raw Oyster (생굴 중 Vibrio parahaemolyticus와 Escherichia coli의 초고압 살균)

  • Park, Whan-Jun;Jwa, Mi-Kyung;Hyun, Sun-Hee;Lim, Sang-Bin;Song, Dae-Jin
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.7
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    • pp.935-939
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    • 2006
  • Raw oyster (Crassostrea gigas) was inoculated with Vibrio parahaemolyticus and Escherichia coli, treated with high hydrostatic pressure and evaluated for microbial counts. Cell death of V. parahaemolyticus (Vp) increased with the increase of applied pressure. Vp starting inoculum of $3.8{\times}10^5\;CFU/mL$ was totally eliminated after exposure to 200 MPa for 10 min at $22^{\circ}C$ Viable cell of Vp decreased with the increase in treatment time and dropped below the detection limit with treament of 25 min at $22^{\circ}C/150\;MPa$. The number of Vp by treatment of $0^{\circ}C$ and $10^{\circ}C$ for 20 and 25 mon at 100 MPa, respectively. For E. coli, there was an initial lag up to 250 MPa gollowed by a rapid decline. Treatment at 325 MPa/$22^{\circ}C$ for 15 min caused 5-log reduction, while that at 375 MPa resulted in total reduction of starting inoculum of $4.0{\times}10^7\;CFU/mL$. Lower treatment temperature showed higher killing effect of E. coli at the same treatment pressure and time. Viable cell of E. coli decreased with the increase in treatment time, and 4-log reduction was achieved with treatment of 5 min at $10^{\circ}C$/350 MPa and then total reduction was achieved after treatment of 15 mon. Higher pressure, lower temperature and longer time were more effective in sterilizing V. parahaemolyticus and E. coli.

Effects of Immersion Liquids Containing Citrus junos and Prunus mume Concentrate and High Hydrostatic Pressure on Shelf-life and Quality of Scomber japonicus during Refrigerated Storage (유자(Citrus junos), 매실(Prunus mume) 농축액을 첨가한 침지액과 초정수압의 병행처리가 고등어(Scomber japonicus)의 냉장 저장 중 저장성 및 품질에 미치는 영향)

  • Kang, Bo-Kyeong;Kim, Koth-Bong-Woo-Ri;Kim, Min-Ji;Bark, Si-Woo;Pak, Won-Min;Kim, Bo-Ram;Ahn, Na-Kyung;Choi, Yeon-Uk;Byun, Myung-Woo;Ahn, Dong-Hyun
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.43 no.10
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    • pp.1555-1564
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    • 2014
  • This study investigated the effects of combined treatment of immersion liquids (adjusted pH 4.5 with Citrus junos concentrate (CL), pH 5.5 with Prunus mume concentrate (PL), or no pH adjustment, pH 6.5, control) and high hydrostatic pressure (HHP, 450 MPa) on shelf-life and quality of mackerel. In this study, we measured changes in viable cell counts, pH level, volatile basic nitrogen, thiobarbituric acid reactive substances, color analysis, volatile organic compounds, and sensory evaluation of mackerel at $4^{\circ}C$ for 20 days. CL/HHP and PL/HHP treatments reduced viable cell counts by 3 log cycles during storage compared to the control. Mackerel treated with CL/HHP and PL/HHP showed significantly lower TBARS and VBN levels as compared to the control. After combined treatment, lightness and whiteness increased but redness decreased. VOCs tests showed that contents of alcohol, acid, and ketones in mackerel fillet treated with CL/HHP and PL/HHP were relatively reduced. Especially, CL/HHP and PL/HHP suppressed production of sulfur. In the sensory evaluation, aroma, taste, salinity, hardness, and springiness of mackerel treated with combined HHP showed higher scores than the control. These results suggest that immersion liquids and HHP treatments may increase shelf-life of mackerel and maintain quality during storage at $4^{\circ}C$.

Effect of Various Sterilization Methods on Growth of Microorganism Contaminated in Ginseng Powder (여러 가지 살균방법이 인삼분말에 오염된 미생물의 성장에 미치는 영향)

  • 곽이성;장진규
    • Journal of Food Hygiene and Safety
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    • v.16 no.3
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    • pp.221-226
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    • 2001
  • Various sterilization methods were applied to the powder of ginseng for the improving hygienic quality. Ultra-violet (UV) and Infrared ray (IR) treatments could not inhibit highly growth of bacteria in ginseng powder. However, high hydrostatic pressure treatment showed high inhibition rate against bacterial growth in ginseng powder. Changes of viable cell count by the pressure showed positive relationship between growth inhibition rates and the pressures applied. When powder was treated with 2,000 kg/$\textrm{cm}^2$ for 10 min at $25^{\circ}C$, initial viable cell count of the powder, 2.0$\times$10$^4$CFU/g, was decreased to 1.0$\times$10$^4$CFU/g. When it treated with 3,000, 4,000 and 5,000 kg/$\textrm{cm}^2$ of pressures under the same condition, viable cell counts were 8.0$\times$10$^3$, 7.0$\times$10$^3$and 1.8$\times$ 10$^3$CFU/g, respectively. Ginseng saponins of the powders were all detected when analyzed by TLC chromatography after treatment with the Pressures. Therefore, it was considered that saponin of ginseng powder was stable under the condition of 5,000 kg/$\textrm{cm}^2$ of pressure, even though the treatment induced coagulation of the powder.

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Process Parameters on Quality Characteristics of Jacopever (Sebastes schlegeli Hilgendorf) under Treatment of Hydrostatic Pressure (고압처리 공정변수가 조피볼락의 초기 품질특성에 미치는 영향)

  • Kim, Min-Ji;Lee, Soo-Jeong;Kim, Chong-Tai
    • The Korean Journal of Food And Nutrition
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    • v.29 no.3
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    • pp.371-381
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    • 2016
  • The present study investigated the effects of processing parameters such as time (10, 20, 30, 40 min), pressure (25, 50, 75, 100 MPa), and the salinity of brine (0~10%(w/v)) on jacopever (Sebastes schlegeli Hilgendorf) in order to establish optimization of the three factors using a high hydrostatic pressure (HHP) machine. To do so, it analyzed the quality characteristics of volatile basic nitrogen (VBN), trimethylamine (TMA), total bacterial counts, dynamic viscoelasticities, and differential scanning calorimetry (DSC) properties. First, when the time increased to 40 mins, by 10 min intervals, the total bacterial counts in HHP groups under $25^{\circ}C$, 100 MPa, and 4%(w/v) brine were significantly decreased except for the first 10 min in comparison to the control group. In regards to DSC properties, the onset temperature ($T_O$) of the first endothermal curve was significantly reduced. Second, when the pressure level increased up to 100 MPa by 25 MPa increments, the total bacterial counts in the HHP samples significantly decreased for 20 min at 50 MPa or higher. As the pressure increased, G', G" and the slope of tan ${\delta}$ decreased (except for 50 MPa). Third, in regards to the salinities of brine, when the HHP processing was treated at 100 MPa, $25^{\circ}C$ for 20 min, the total bacterial counts of all the HHP groups significantly decreased in comparison to those of the control group. A significant difference was found in the enthalpy of the second endothermic curve in the 6~10%(w/v) (except 7%(w/v)) HHP groups. Therefore, the salinity of the immersion water under the HHP condition was appropriate when it was lower than 6%(w/v). The present study demonstrated that the optimum parameter condition according to/under the condition of the microbial inhibition and economic effects using an HHP would be the reaction time for 20 min, reaction pressure at 100 MPa, and the salinity of 4%(w/v) brine.