• 제목/요약/키워드: Heat treatments

검색결과 1,079건 처리시간 0.038초

열처리 및 유기산처리가 신선편이 연근의 품질에 미치는 영향 (Effect of Mild Heat and Organic Acid Treatments on the Quality of Fresh-Cut Lotus Roots)

  • 박주현;홍석인;정문철;김동만
    • 한국식품저장유통학회지
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    • 제20권1호
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    • pp.23-29
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    • 2013
  • 박피 연근절편의 선도연장을 위한 연구로 연근절편을 $50^{\circ}C$ 물에 열수 처리하였고, 아울러 시너지 효과를 조사하기 위해 열처리와 ascorbic acid 1%와 citric acid 1%를 각각 병행 처리한 후 $5^{\circ}C$에서 12일 동안 저장하면서 미생물수, 색상 및 관능적 품질변화를 조사하였다. 일반세균수는 열수 및 citric acid 병행 처리구의 경우 저장 9일후 그 값이 가장 낮았으며, 이를 제외한 다른 처리구들은 유의적 차이가 없었다. 곰팡이 수의 경우 대조구가 6.81 log CFU/g을 나타낸 반면, 열수 처리구는 12일 후 3.89 log CFU/g으로 유의적으로 낮았다. 연근절편 색도의 L값은 시간이 지남에 따라 점차 감소하는 경향을 나타낸 반면, ${\Delta}E$값은 점차 증가하는 경향을 보였다. 대조구가 급격히 색 변화가 일어나는데 비해 열수 처리구는 완만한 변화를 보였고 열처리 후 각각 ascorbic acid와 citric acid를 병행한 처리구는 색 변화가 거의 일어나지 않았다. 관능적 품질평가 결과, 상품성은 대조구가 3일간 유지되었던 반면 열수 처리 구는 9일간, 열수 및 유기산 병행 처리구는 12일간 상품성이 유지되었다. 전반적인 품질, 색, 조직감 등은 열처리를 한 처리구들이 열처리를 하지 않은 처리구에 비해 기호도가 유의적으로 높았으며, 그 중 열수 및 유기산 병행 처리구가 관능적으로 가장 높은 값을 나타내었다. 본 실험을 통해, 연근 절편의 열처리는 미생물과 갈변을 억제시킴으로써 연근의 관능적 품질유지에 효과적이었고, 특히 citric acid 1%를 열처리와 함께 병행하는 것이 연근의 품질유지와 갈변억제에 가장 효과적인 것으로 판단되었다.

Variations in total phenols, total anthocyanins, and antioxidant activity levels in black chokeberry (Aronia melanocarpa) fruits subjected to dry and moist heat treatments

  • Kim, Hekap;Mai, Thu Thi Hoai
    • 한국식품과학회지
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    • 제52권5호
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    • pp.503-509
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    • 2020
  • The present study investigated the effects of dry and moist heat treatments on total phenols, total anthocyanins, and antioxidant activity levels in black chokeberry (Aronia melanocarpa) fruits. Lyophilized chokeberry powder samples were heated in a drying oven at 60, 100, 160, 180, and 200℃ for 20, 40, or 60 min. Finely ground fresh chokeberry fruits were heated in water at 60, 80, and 100℃ for 20 min, and bioactive compound and antioxidant activity levels were measured. The bioactive compounds and antioxidant activity decreased with increasing temperature and treatment duration. Antioxidant activity was preserved at 160℃ or lower without significant loss for dry heating, whereas moist heat treatment increased both bioactive compounds and antioxidant activity with increasing temperature.

낙엽송 열기건조재의 수지삼출예방을 위한 처리기술 (Treatments to Prevent Kiln-dried Larch Boards from Resin Exudation)

  • 강호양;김수원
    • 농업과학연구
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    • 제31권1호
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    • pp.9-14
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    • 2004
  • This study was carried out for deresinning the larch boards dried in a conventional kiln. Prior to heat treatment they were steamed in an autoclave for 5 hours or frozen for 24 hours at a temperature of $-35^{\circ}C$. The velocities of ultrasound transmitted through the specimens were measured to examine the correlation with their resin contents. It was found that the specimens heated at $100^{\circ}C$ for 5 hours contained less resin that those heated at $200^{\circ}C$ for an hour. Both treatments of steaming and freezing were effective for deresinning and the former was better than the latter. The ultrasonic velocities measured before the heat treatment showed a negative correlation to the resin contents of the specimens, but those measured after the heat treatment a positive correlation. This difference may be attributed to the viscosity of resin.

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외감열병(外感熱病)의 원인(原因)과 치법(治法)에 대한 통시적(通時的) 고찰(考察) (A Study on the Pathogenic Factors and Treatments of Exogenous Febrile Disease with Time)

  • 양광열
    • 대한한의학원전학회지
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    • 제21권1호
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    • pp.295-302
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    • 2008
  • Until the middle of the 20th century, exogenous febrile disease was the most common disease that threatened the human health. For a long time, oriental medicine doctors developed many ways to cure this disease by studying pathogenic factors. The phthogenic factors and treatments of exogenous febrile disease with time are as followings. "Naegyeong(內經)" : Cold pathogen. Diaphoretic therapy, purgation therapy. Hwata : Cold pathogen. Diaphoretic therapy, emetic therapy, purgation therapy. Jangjunggyeong(張仲景) : Cold pathogen. Eight principal therapeutic methods except diaphoretic therapy with pungent and cool properties. Yuhagan(劉河間) : Fire pathogen. Diaphoretic therapy with pungent and cool properties. Idongwon(李東垣) : Improper diet and overstrain. Reinforcing therapy. Ouga(吳又可) : Epidemic pathogenic factors. Diaphoretic therapy with pungent and cool properties, Heat-reducing therapy. purgation therapy Seopcheonsa(葉天士) : Warm pathogen. diaphoretic therapy, Heat-reducing therapy, expel Heat therapy, cooling the blood and eliminating stagnation of blood. Oguktong(吳鞠通) : Six pathogenic factors. Eight principal therapeutic methods including diaphoretic therapy with pungent and cool properties.

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전기화학적 방법을 이용한 Ti(Grade 2)재의 최적 어닐링 열처리에 대한 연구 (A Study of Annealing Heat-treatment for Ti(Grade 2) by Electrochemical Methods)

  • 백신영
    • Journal of Advanced Marine Engineering and Technology
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    • 제26권1호
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    • pp.90-98
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    • 2002
  • In this paper, the annealing heat treatments for the best corrosion resistant of Ti(Grade 2) were studied in a 3.5% NaCl solution by electrochemical methods. The annealing heat treatments were accomplished at 650, 700 and $750^{\circ}C$ with different time of 30min., 1hour and 2 hours in a vacuum condition. The obtained results are: 1) in the case of solution heat treated $930^{\circ}C$ for 2 hours in a vacuum and air, the corrosion potentials were -348.7 and -567. 1mV, and current densities 2.32 and $22.62\mu\textrm{A}$, respectively, 2) as increase both annealing heat treatment temperature 650, 700, $750^{\circ}C$ and time 30min., 1 hour, 2 hours, the corrosion potential were decreased, whereas corrosion current density increased, 3) in the case of cyclic polarization, the measured charges were increased as increasing solution heat treatment temperature and time, 4) on the bases of corrosion potential, current density and charge, the best annealing temperature and time were measured as $700^{\circ}C$ and 30min. for Ti(Grade 2) material.

고온 환경 조건에서 액상 라스베라트롤의 급여가 육계의 생산성, 육질 및 회장 형태에 미치는 영향 (Effect of Dietary-Liquid Resveratrol on Growth Performance, Meat Quality Traits, and Ileum Morphology of Broiler Chickens under Moderate Heat Stress)

  • 이영주;유재홍;사미루;김은주;구본진;허정민
    • 한국가금학회지
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    • 제43권1호
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    • pp.21-29
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    • 2016
  • A total of 144 one-day-old male broilers (ROSS ${\times}$ Ross 308) ($42{\pm}0.1g$) were used in a completely randomized design and allotted to one of three dietary treatments to give 6 replicates per treatment (8 birds per cage). The three watery dietary treatments were 1) a corn-soybean meal-based relation [Negative control (NC); no antimicrobial compounds added] with tab water, 2) 8 ppm liquid-alpha-lipoic acid [Positive control (PC)] or 3) 100 ppm liquid-resveratrol. All dietary treatments were continuously provided as a liquid form. Birds were housed in a battery cage (n=48), and were offered liquid dietary treatments at all times. The ambient temperature was maintained at $32{\pm}1^{\circ}C$ for the first 3 weeks and decreased gradually to $28{\pm}1^{\circ}C$ by the end of the experiment (d 35) to induce moderate heat stress. One bird per pen (n=6) was euthanized via cervical dislocation at day 21 to obtain terminal ileum to measure villous height and crypt depth, while another bird per pen (n=6) was similarly euthanized at day 35 and used to harvest breast meat and drumsticks to evaluate meat quality traits. Birds fed liquid-resveratrol did not improve (P>0.05) body weight and average daily gain compared with those fed other dietary treatments from day 1 to day 35. Birds fed liquid-resveratrol had no effect (P>0.05) on villous height compared with birds were in other dietary treatments at day 21. Liquid-resveratrol had no effect (P>0.05) on thiobarbituric acid reactive substance (TBARS) in drumsticks compared with other dietary treatments at day 35. Furthermore, birds fed liquid-resveratrol had no effect (P>0.05) on DPPH radical scavenging activity both in breast meat and drumsticks compared with those fed other dietary treatments at day 35. Morphological changes of ileum were not observed by immunofluorescence, and the level of occludin protein from ileum extracts also did not differ among groups. Our results suggested that liquid form of antioxidant compounds used in the current study such as alpha-lipoic acid (8 ppm) or resveratrol (100 ppm) did not improve growth performance, meat quality traits and histology of terminal ileum compared with those fed negative control in broiler chickens under moderate heat stress for 35 days.

열처리에 의한 굴(Crassostrea gigas)의 영양성분 변화 (Effect of Heat Treatment on Biochemical Characteristics of Pacific Oyster Crassostrea gigas)

  • 심길보;김민아;박큰바위;손광태;임치원
    • 한국수산과학회지
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    • 제48권6호
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    • pp.876-882
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    • 2015
  • The aim of this study was to investigate changes in the biochemical characteristics of the Pacific oyster Crassostrea gigas in response to boiling water bath ($85^{\circ}C$, $100^{\circ}C$) and autoclaving ($100^{\circ}C$) heat treatments for 5, 10, 15, and 20 min. The weight loss (7.6-9.5%) of oysters exposed to a $100^{\circ}C$ boiling water bath for 15 min was lower compared to those receiving no treatment. Oysters exposed to the $100^{\circ}C$ boiling water bath for 20 min lost 27.8% of their total weight. The $100^{\circ}C$ autoclaving treatment resulted in weight loss of 13.0-26.1%, with the highest weight loss occurring after 10 min of treatment (26.1%). Heat-treated oysters had significantly higher levels of crude lipid and crude protein relative to untreated oysters (P<0.05). In the heat-treated oysters, total amino acids (including proline and glutamic acid) were increased, but they were decreased by the 20-min $100^{\circ}C$ boiling water bath and autoclaving treatments. The fatty acid composition of oysters was not significantly affected by the water bath heat treatment, but oysters treated with $100^{\circ}C$ autoclaving for 20 min had decreased polyunsaturated fatty acids. Oysters exposed to the water bath heat treatment had significantly increased vitamin A content, but $100^{\circ}C$ autoclaving for 20 min was associated with reduced vitamin A content, as compared to all of the other heat treatments. Therefore, oysters were affected by heat treatment, undergoing metamorphosis and weight loss, but nutrient quality did not change significantly compared to controls, except with the 20-min $100^{\circ}C$ boiling water bath and autoclaving treatments.

열처리가 알루미나 나노기공의 배열에 미치는 영향 (Effects of Heat Treatments of Aluminum Substrate on Nanopore Arrays in Anodic Alumina)

  • 조수행;오한준;김성수;주은균;유창우;지충수
    • 한국재료학회지
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    • 제12권11호
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    • pp.856-859
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    • 2002
  • To investigate effects of heat treatments including grain size control in substrate aluminum on nanopore arrays in anodic alumina template, aluminum was heat treated at $500^{\circ}C$ for 1h. The heat treated aluminum was anodized by two successive anodization processes in oxalic solution and the nanopore arrays in anodic alumina layer were studied using TEM and FE-SEM. The highly ordered porous alumina templates with 110 nm interpore distance and 40 nm pore diameter have been observed and the pore array of the anodic alumina has a uniform and closely-packed honeycomb structure. In the case of alumina template obtained from heat treated aluminum substrate, the well- ordered nanopore region in anodic alumina increased and became more homogeneous compared with that from non-heattreated one.

고출력 다이오드 레이저를 이용한 프레스 전단금형의 경화특성 (Heat Treatment Characteristics of Press Blanking Die by Using High Power Diode Laser)

  • 황현태;소상우;황재현;김종도
    • 열처리공학회지
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    • 제23권5호
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    • pp.257-262
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    • 2010
  • Recently, metal molding has become essential not only for automobile parts, but also mass production, and has greatly influenced production costs as well as the quality of products. Its surface has been treated by carburizing, nitriding and induction hardening, but these existing treatments cause considerable deformation and increase the expense of postprocessing after treatment; furthermore, these treatments cannot be easily applied to parts that requiring the hardening of only a certain section. This is because the treatment cannot heat the material homogeneously, nor can it heat all of it. Laser surface treatment was developed to overcome these disadvantages, and, when the laser beam is irradiated on the surface and laser speed is appropriate, the laser focal position is rapidly heated and the thermal energy of surface penetrates the material after irradiation, finally imbuing it with a new mechanical characteristic by the process of self-quenching. This research estimates the material characteristic after efficient and functional surface treatment using HPDL, which is more efficient than the existing CW Nd:YAG laser heat source.