• Title/Summary/Keyword: heat treatment

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Effects of Heat Treatment on the Dietary Fiber Contents of Soybean sprout and Spinach (가열처리에 의한 콩나물과 시금치의 식이섬유 함량변화)

  • Lee, Eun-Young;Kim, Young-A
    • Korean journal of food and cookery science
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    • v.10 no.4
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    • pp.381-385
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    • 1994
  • The dietary fiber contents of soybean sprout and spinach were changed by heat treatment. Before heat treatment, soybean sprout and spinach had larger amount of insoluble dietary fiber than soluble, and similar proportions of insoluble v/s soluble dietary fibers. After heat treatment, the value of insoluble dietary fiber of soybean sprout and spinach was increased significantly, except for microwave heating short time treatment. It is believed that the increment of insoluble dietary fiber is due to Maillard reaction products and resistant starch after heat treatment. The change of soluble dietary fiber contents of soybean sprout and spinach were not consistent in heat treatment. It is supposed that some soluble dietary fiber was destroyed by heat treatment, and some insoluble dietary fiber was hydrolysed or destroyed to be soluble. Total dietary fiber of soybean sprout and spinach was significantly incereased by all heat treatment, except for microwave heating short time of spinach.

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A Study on Slide Way Deformation from High Frequency Heat Treatment by Finite Element Method (유한요소법을 이용한 고주파 열처리시 안내면 변형에 관한 연구)

  • 홍성오;조규재
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.11 no.3
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    • pp.57-64
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    • 2002
  • Finite element program(ANSYS) estimated thermal deformation quantity in high frequency heat treatment process of a machine tool fred drive system slideway and apply deformation quantity in roughing process. Having processed the heat treatment minimizing methods of the quantity of deformation heat treatment process. Having done heat treatment with high frequency after taper processing with considering the existed heat treatment generating the quantity of deformation, existed quantity of deformation can be reduced down to 80%, consequently productivity and material saving can be achieved. When high frequency heat treatment finite element method estimated deformation quantity at difference temperature and time, it is progress at cost don and saved time.

A Study on Mechanical Properties and Microstructure of Local-Hardening Heat-Treated Automotive Panel (국부 경화 열처리된 차체 부품의 기계적 성질과 미세조직에 관한 연구)

  • Lee, Jae Ho;Jeong, Woo Chang
    • Journal of the Korean Society for Heat Treatment
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    • v.23 no.6
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    • pp.301-308
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    • 2010
  • A steel with chemical composition, 0.22% C, 0.25% Si, 1.26% Mn, 0.22% Cr, 0.04% Ti, 0.0042% B, and a microstructure of ferrite and spheroidized cementite has been press-formed to automotive center pillar followed by local-hardening heat-treatment. Hardness, tensile properties, fractography, microstructure and surface roughness of local-hardening heat-treated automotive center pillar have been examined. The directly heated and quenched area had fully martensitic structure with Vickers hardenss in the range of 500 to 510. The heat affected area close to the directly heated area showed dual-phase structure of ferrite and martensite. The width of the heat-treated and heat-affected areas after the local-hardening heat treatment was ranging from 32 mm to 50 mm. The surface of the local-hardening heat-treated center pillar revealed some temper color as a consequence of the oxidation during the heat treatment, but the surface roughness was not affected by the local-hardening heat treatment.

Studies on Heat Sensitivity of Egg Albumen III. Effects of Egg Albumen Concentration and Addition of Sugars on Heat Sensitivity of Egg Albumen (난백의 열감수성에 관한 연구 III. 난백의 농도와 당류의 첨가가 난백의 열감수성에 미치는 영향)

  • 유익종;김기성;송계원
    • Korean Journal of Poultry Science
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    • v.16 no.1
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    • pp.23-28
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    • 1989
  • This study was undertaken to find out the effect of eeg albumen concentration and addition of sugars on the functional properties of egg albumen before and after heat treatment at $60^{\circ}C$ for 5 minutes. The turbidity was decreased until 8.3% protein concentration but increased as diluted and decreased again below 3.32% protein concentration before and after the heat treatment. The foaming power was peak at 8.3% protein concentration but decreased as diluted before and after the heat treatment. The foam stability was decreased as diluted before and after the heat treatment. The turbidity was not changed by addition of sucrose before the heat treatment and decreased after the heat treatment. The foaming power was decreased by addition of over 5% sucrose before the heat treatment and decreased by addition of over 2.5% sucrose after the heat treatment . The foam stability was increased by addition of over 5% sucrose before the heat treatment and increased by addition of sucrose after the heat treatment. The turbidity was increased by addition of glucose before the heat treatment and not changed after the heat treatment. The foaming power was decreased by the addition of glucose before the heat treatment and decreased by the addition of over 5% glucose after the heat treatment. The foam stability was decreased by the addition of glucose before and after the heat treatment.

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A Study on SCr420HB Helical Gear Deformative Simulation by Heat Treatment Quenching Method (열처리 냉각방식 변화에 따른 SCr420HB 헬리컬 기어 시뮬레이션 적용에 관한 연구)

  • Byun, J.H.;Byun, S.D.;Yi, C.H.
    • Journal of the Korean Society for Heat Treatment
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    • v.28 no.1
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    • pp.24-31
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    • 2015
  • In this study, a simulation was used to derive an optimal process of heat treatment with carburizing, and compared the derived result with SCr420HB helical gear in heat treatment with carburized quenching process about a change of the quenching method. The optimal carburizing process time is derived by the simulation with the theoretical time. The process has been performed by oil quenching and salt quenching method. Through the comparison of the results from the simulation(Hardness, effective case depth hardened by carburizing treatment and deformation) and the actual process, analyzed the error value of each quenching. And it verified the applicability of the simulation.

Heat source control intelligent system for heat treatment process

  • Lee, JeongHoon;Cho, InHee
    • International journal of advanced smart convergence
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    • v.11 no.4
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    • pp.28-40
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    • 2022
  • Although precise temperature control in the heat treatment process is a key factor in process reliability, there are many cases where there is no separate heat source control optimization system in the field. To solve this problem, the program monitors the temperature data according to the heat source change through sensor communication in a recursive method based on multiple variables that affect the process, and the target heat source value and the actual heat treatment heat source to match the internal air temperature and material temperature. A control optimization system was constructed. Through this study, the error rate between the target temperature and the atmosphere (material surface) temperature of around 10.7% with the existing heat source control method was improved to an improved result of around 0.1% using a process optimization algorithm and system.

Effects of Heat Treatment on the Nutritional Quality of Milk. IV. Effects of Heat Treatment on the Physical and Nutritional Properties of Milk Protein (우유의 열처리가 우유품질과 영양가에 미치는 영향: IV. 우유의 열처리가 우유단백질의 이화학적 성질과 영양에 미치는 영향)

  • Jung, Jong-Wook;Jung, Jiyoon;Mim, Tae Sun;Oh, Sejong
    • Journal of Dairy Science and Biotechnology
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    • v.35 no.4
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    • pp.270-285
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    • 2017
  • Among milk proteins, caseins are not subjected to chemical changes during heat treatment of milk; however, whey proteins are partially denatured following heat treatment. The degree of whey protein denaturation by heat treatment is decreased in the order of high temperature short time (HTST) > low temperature long time (LTLT) > direct-ultra-high temperature (UHT) > indirect-UHT. As a result of heat treatment, several changes, including variations in milk nitrogen, interactions between beta-lactoglobulin and k-casein, variations in calcium sulfate and casein micelle size, and delay of milk coagulation by chymosin action, were observed. Lysine, an important essential amino acid found in milk, was partially inactivated during heat treatment. Therefore, the available amount of lysine decreased slightly (1~4% decrease) after heat treatment, However, the influence of heat treatment on the nutritional value of milk was negligible. Nutritional value and nitrogen balance did not differ significantly between UHT and LTLT in milk. In conclusion, our results showed that heat treatment of milk did not alter protein quality. Whey proteins denatured to a limited extent during the heat treatment process, and the nutritional value and protein quality were unaffected by heat treatment.