• 제목/요약/키워드: cooking and drying

검색결과 81건 처리시간 0.029초

Finite Element Prediction of Temperature Distribution in a Solar Grain Dryer

  • Uluko, H.;Mailutha, J.T.;Kanali, C.L.;Shitanda, D.;Murase, H
    • Agricultural and Biosystems Engineering
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    • 제7권1호
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    • pp.1-7
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    • 2006
  • A need exists to monitor and control the localized high temperatures often experienced in solar grain dryers, which result in grain cracking, reduced germination and loss of cooking quality. A verified finite element model would be a useful to monitor and control the drying process. This study examined the feasibility of the finite element method (FEM) to predict temperature distribution in solar grain dryers. To achieve this, an indirect solar grain dryer system was developed. It consisted of a solar collector, plenum and drying chambers, and an electric fan. The system was used to acquire the necessary input and output data for the finite element model. The input data comprised ambient and plenum chamber temperatures, prevailing wind velocities, thermal conductivities of air, grain and dryer wall, and node locations in the xy-plane. The outputs were temperature at the different nodes, and these were compared with measured values. The ${\pm}5%$ residual error interval employed in the analysis yielded an overall prediction performance level of 83.3% for temperature distribution in the dryer. Satisfactory prediction levels were also attained for the lateral (61.5-96.2%) and vertical (73.1-92.3%) directions of grain drying. These results demonstrate that it is feasible to use a two-dimensional (2-D) finite element model to predict temperature distribution in a grain solar dryer. Consequently, the method offers considerable advantage over experimental approaches as it reduces time requirements and the need for expensive measuring equipment, and it also yields relatively accurate results.

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쌀의 품질평가 현황과 금후 연구방향 (Trend and Further Research of Rice Quality Evaluation)

  • 손종록;김재현;이정일;윤영환;김제규;황흥구;문헌팔
    • 한국작물학회지
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    • 제47권
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    • pp.33-54
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    • 2002
  • Rice quality is much dependent on the pre-and post harvest management. There are many parameters which influence rice or cooked rice qualitys such as cultivars, climate, soil, harvest time, drying, milling, storage, safety, nutritive value, taste, marketing, eating, cooking conditions, and each nations' food culture. Thus, vice evaluation might not be carried out by only some parameters. Physicochemical evaluation of rice deals with amy-lose content, gelatinizing property, and its relation with taste. The amylose content of good vice in Korea is defined at 17 to 20%. Other parameters considered are as follows; ratio of protein body-1 per total protein amount in relation to taste, and oleic/linoleic acid ratio in relation to storage safety. The rice higher Mg/K ratio is considered as high quality. The optimum value is over 1.5 to 1.6. It was reported that the contents of oligosaccharide, glutamic acid or its derivatives and its proportionalities have high corelation with the taste of rice. Major aromatic compounds in rice have been known as hexanal, acetone, pentanal, butanal, octanal, and heptanal. Recently, it was found that muco-polysaccharides are solubilized during cooking. Cooked rice surface is coated by the muco-polysaccharide. The muco-polysaccharide aye contributing to the consistency and collecting free amino acids and vitamins. Thus, these parameters might be regarded as important items for quality and taste evaluation of rice. Ingredients of rice related with the taste are not confined to the total rice grain. In the internal kernel, starch is main component but nitrogen and mineral compounds are localized at the external kernel. The ingredients related with taste are contained in 91 to 86% part of the outside kernel. For safety that is considered an important evaluation item of rice quality, each residual tolerance limit for agricultural chemicals must be adopted in our country. During drying, rice quality can decline by the reasons of high drying temperature, overdrying, and rapid drying. These result in cracked grain or decolored kernel. Intrinsic enzymes react partially during the rice storage. Because of these enzymes, starch, lipid, or protein can be slowly degraded, resulting in the decline of appearance quality, occurrence of aging aroma, and increased hardness of cooked rice. Milling conditions concerned with quality are paddy quality, milling method, and milling machines. To produce high quality rice, head rice must contain over three fourths of the normal rice kernels, and broken, damaged, colored, and immature kernels must be eliminated. In addition to milling equipment, color sorter and length grader must be installed for the production of such rice. Head rice was examined using the 45 brand rices circulating in Korea, Japan, America, Australia, and China. It was found that the head rice rate of brand rice in our country was approximately 57.4% and 80-86% in foreign countries. In order to develop a rice quality evaluation system, evaluation of technics must be further developed : more detailed measure of qualities, search for taste-related components, creation and grade classification of quality evaluation factors at each management stage of treatment after harvest, evaluation of rice as food material as well as for rice cooking, and method development for simple evaluation and establishment of equation for palatability. On policy concerns, the following must be conducted : development of price discrimination in conformity to rice cultivar and grade under the basis of quality evaluation method, fixation of head rice branding, and introduction of low temperature circulation.

사료 중의 곰팡이와 곰팡이 독소에 대한 문제점과 가능한 대책 (Problems and Possible Solutions about Feed Fungi and Mycotoxins)

  • 남기홍
    • 한국가금학회지
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    • 제21권2호
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    • pp.113-117
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    • 1994
  • Of the 200, 000 known species of molds, only 50 or 60 are known to be harmful to humans or livestock. Certain fungi that grow on grains and grasses can produce chemical substances called mycotoxins that adversely affect performance in poultry. There are several methods of preserving feed ingredients. The list includes: drying, antioxidants, mold inhibitors, organic acids, phosphates, cooking or toasting, fat extraction, blending and fermenting. Mold inhibitors are manufactured to inhibit mold growth and prevent the production of toxic substances. They are fungistats and not fungicides, that is, they only stop the growth of molds. Practical and cost-effective methods to detoxify mycotoxin containing feedstuffs are in great demand. 0.5% hydrated sodium calcium aluminosilicate added to the diet protected chicks from the deleterious effects of aflatoxin-contaminated feed. The dietary addition of antioxidants and methionine also significantly diminished the negative effects on body weight in chicks toxicated with 3.0 ppm aflatoxin B1.

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곰취가루를 첨가한 설기떡의 품질 특성 (Quality Characteristics of Sulgidduk Supplemented with Ligularia fischeri Powder)

  • 강양선;김정수
    • 동아시아식생활학회지
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    • 제21권2호
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    • pp.277-283
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    • 2011
  • The goal of this study was to make more efficient use of Ligularia fischeri which has both medical and cooking applications after freezing and drying. We manufactured Sulgidduk containing 0, 2, 4, 6 and 8% of Ligularia fischeri powder. Chemical analysis showed that Ligularia fischeri powder contained, 5.77% water, 19.97% crude protein, 1.89% crude fat, 13.12% crude ash, and 9.73% crude fiber. The water content of Sulgidduk to which Ligularia fischeri was added ranged from 37.72~40.20%. As more Ligularia fischeri was added, the L value and 'a' value increased, while the 'b' value did not significantly change. Optimal preference was for a 4% content of added Ligularia fischeri powder. Based on the results of this experiment, Sulgidduk manufactured with added Ligularia fischeri powder showed less hardness than the control group throughout a period of storage, and adequate addition of Ligularia fischeri powder can effectively enhance the storability of Sulgidduk containing Ligularia fischeri.

전분 분무기술을 통한 다층지의 물성개선 (Improvement of Multiply Board Properties with Starch Spraying)

  • 이학래;류정용
    • 펄프종이기술
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    • 제39권3호
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    • pp.12-23
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    • 2007
  • Frequently spraying of natural starch slurry onto the formed wet web has been adopted to improve properties of paperboards. This conventional starch spraying technique, however, becomes less effective in strength improvement. In this study the effects of various factors including wet web dryness, quantity of starch slurry sprayed, and drying temperature on paperboard properties were investigated. Migration of starch granules into the webs appeared to cause a reduction in plybond strength when the web dryness was lower than this level. Wet webs should contain enough water to swell the starch granules, and at the same time they should be heated to a temperature high enough for complete cooking of the sprayed starches to occur. This suggested that preheating of the wet web can be employed to improve the plybond strength.

Effect of Different Preservation Methods on Physicochemical Quality of Beef

  • Akter, H.;Akhter, S.;Rahman, S.M.E.;Rahman, M.M.;Hossain, M.M.;Ra, C.S.;Kim, Jai-Moung;Oh, Deog-Hwan
    • 한국식품위생안전성학회지
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    • 제24권3호
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    • pp.217-225
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    • 2009
  • 본 연구는 쇠고기의 품질에 있어서 건조, 절임, 냉동의 효과를 평가하기 위해 수행되었다. 건조의 3가지 타입(소금 비처리 = $T_1$, 소금 처리 = $T_2$, 소금 및 향료 처리 = $T_3$), 절임의 3가지 타입(소금 절임 = $T_4$, 설탕 처리 = $T_5$, 소금물 처리 = $T_6$)과 냉동의 3가지 타입($0^{\circ}C$ = T7, $-10^{\circ}C$ = T8, $-20^{\circ}C$ = T9)으로 180일 동안 시간 간격을 두고 쇠고기의 단백질, 지방, 회분, 색도와 조리 영양손실을 분석하였다. 모든 화학적 구성요소들(단백질, 지방과 회분)은 120일 까지 점차적으로 감소하였으며 감소 경향은 저장 120일이 지난 후 180일까지 빠르게 진행되는 것으로 관찰되었다. 180일 저장 기간 동안 $T_7$에서 단백질 손실이 11.1%로 가장 높았으며 $T_6$는 3.85%로 가장 낮은 단백질 손실을 나타냈고 다른 처리구들에서도 유의적 차이(p < 0.01)가 나타났다. $T_6$에서 지방 손실이 7.52%로 가장 높았으며 $T_2$에서 3.18%로 가장 낮았다. 또한 다른 처리구들에서도 서로 유의적인 차이(p < 0.05)를 나타내었다. 향료가 처리된 건조 쇠고기가 가장 밝은 색을 나타냈으며 절임 쇠고기는 갈색으로 나타났다 색의 명암은 저장 기간이 증가함에 따라 점차적으로 감소하였다. 3가지 벙동 타입 중 $T_9$ 쇠고기가 가장 낮은 조리 영양손실을 나타냈으며 다른 처리구들 또한 유의적 차이(p < 0.01)를 나타냈다 설탕 절임($T_5$)과 향료처리 건조($T_3$)방법은 농촌 지역에서 육류 저장기술로 유용할 것이며 냉동($T_9$)방법은 도시 지역에서 큰 규모의 저장에 사용되면 좋을것으로 사료된다.

율무 flake 제조시 가열정도에 따른 특성 (Functional Characteristics of Job's-tears Flakes Subjected to Varying Degree of Heating)

  • 이영택;석호문;김성수;홍희도;김경탁
    • 한국식품과학회지
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    • 제27권5호
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    • pp.640-645
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    • 1995
  • 율무쌀을 이용하여 간편식인 flaked cereal을 제조하기 위하여 율무를 수침, 가열처리, 중간수분$(25{\sim}30%)$건조, flaking, 건조 및 cooking하였다. 율무는 가열처리시 가열시간이 $5{\sim}30$분으로 증가함에 따라 호화도가 증가하였으며 가열정도에 따른 호화도는 율무의 flaking roll 통과 적성에 변수로 작용하여 최종 flake 제품의 특성에 영향을 미쳤다. 율무는 flaking하기에 적합한 물성을 제공한 가열조건($5{\sim}10$분 증자처리)에서 호화도가 증가함에 따라 율무 flake의 specific volume이 증가하고 절단 강도는 감소하였다. 그러나 가열시간이 20분 이상으로 길어 호화도가 높아진 경우 flake 성형에 부정적 영향을 미쳐 specific volume이 감소하고 절단강도는 증가하는 경향을 보였다. 율무는 가열시간이 길어짐에 따라 율무 flake의 수분흡수지수와 수분용해도지수가 증가하였다. 율무 flake를 분쇄한 분말의 점도를 측정한 결과 전분의 호화도가 높아짐에 따라 점도는 현저히 증가하였고 amylograph에 의한 초기점도는 높은 반면 온도상승에 따라 최고점도는 낮아지는 경향을 나타냈다.

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양생방법 변화가 혼화재 다량치환 고강도 모르타르의 압축강도 및 수축변화에 미치는 영향 (Influence of Curing Methods on Compressive Strength and Shrinkage of High Strength Mortar with High Volume SCMs)

  • 한천구;백철
    • 한국건축시공학회지
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    • 제18권1호
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    • pp.33-40
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    • 2018
  • 우리나라의 많은 건설 공사에서는 건축물이 고층화 되면서, 공기단축 및 물의 처리 곤란 등의 이유로 고강도 콘크리트일지라도 습윤양생을 실시하지 않고 공사를 진행하는 경우가 존재한다. 이와 같이 건조 상태로 양생하게 되면 압축강도 감소, 건조수축 및 자기수축 등 수축변화가 크게 증가할 것으로 예상된다. 또한 본 연구팀에서는 기존의 연구로서 유지류를 콘크리트에 혼합할 경우 비누화 반응을 이용하여 콘크리트의 자기수축 저감 및 내구성 향상에 대한 연구를 진행한바 있다. 그러므로 본 연구에서는 양생방법을 비양생 건조, 유화처리정제식용유(ERCO) 도포 후 건조, 7일 수중양생 후 건조 및 28일 수중양생 후 건조 등 양생 방법 변화에 따른 혼화재 다량치환 모르타르의 압축강도 특성, 수분증발에 따른 수축변화 특성에 대하여 분석하였다. 실험결과는 양생방법으로 비양생 건조를 실시하게 되면 28일 수중양생을 실시하였을 경우보다 약 50% 전후의 강도저하와 1.9배의 수축 길이변화율 증가로 나타나, 혼화재 다량치환 고강도 모르타르에 있어 습윤양생이 매우 중요하게 영향을 미치는 것을 알 수 있었다. 단, ERCO 도포의 경우는 강도 및 수축변화측면에서 무양생인 건조보다는 우수하지만 7일 수중양생 후 건조보다는 성능이 저하하는 것으로 나타났다.

"역잡록"의 조리가공에 대한 분석적 고찰 (A Study on the Cooking in 'The Ryuk-Jab-Rok')

  • 김성미;이성우
    • 동아시아식생활학회지
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    • 제3권1호
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    • pp.12-17
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    • 1993
  • This book is named 'The Ryuk-Jab-Rok' because it was written in the last page of 1820's almanac. This book is written purely in Korean and has not been published yet. This book comprises twenty eight items, among which there are eight items of vegetable preserving method, ten items of Jook preparation methods(a kind of cereal soup), nine items of Pyun-Myun methods(a kind of rice cakes and noodles) and Yak-Bab(a kind of spiced rice). In vegetable preserving method, the eggplant, the cucumber and a songi mushroom were preserved with the drying method., A radish, a sorojangii, and the root of white cabbage were used with the cold temperature preservation. A garlic was dried after salting. The sprouts of DooRub, which were coming in the hot room, were used. In the Jook preparations, there were five animal materials which were lamb, chick, crudian, oyster and abalone. In nine Pyun-Myun methods, Jap-Gua-Sil was illegible because the letters were not clear. Among eight items, the stick rice was used in four cases, the regular rice in two cases. The ground pine nuts, honey and the Chinese date were used most ofter. And the sesame salt and the chestnut were next. The analysis of the terms I this book revealed that 26 items were used for cooking processes. And it also showed us that there were seven kind of cutting procedure and eight kinds of heating procedure. The shapes and size of foods were revealed at only three places in all items. The one-chi(chi ; abut three cm) and three-Ja(Ja ; about thirty cm) which the terms represent the length were revealed twice and once respectively in this book. In the taste description, 'the good', the most common word, was used in seven times, and which was the most frequently introduce case. The measuring unit is hard to revive since the measurements were taken by the container, which were Jong-Ja, Sabal and Tang-gii, then in use. Fifteen kinds of containers and cookers were used for preparing foods. And all of them are now I use.

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건조방법에 따른 복분자 분말의 갈변 및 흡습 특성 (Browning and Moisture Sorption Characteristics of Rubus coreanus Prepared by Different Drying Methods)

  • 정헌식;성종환;이영근;김한수;이주백;윤광섭
    • 한국식품저장유통학회지
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    • 제16권6호
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    • pp.797-803
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    • 2009
  • 건조방법이 복분자 분말의 갈변 및 흡습 특성에 미치는 영향을 조사하기 위하여, 신선 복분자를 천일, 적외선 및 동결 건조한 다음 분쇄하고 이 분말의 색도와 수분활성도 ($a_w$) 0.11-0.90 범위에서 평형수분함량(EMC)을 각각 측정하였다. 갈변지표인 $L^*$값과 $a^*$값은 동결 건조한 복분자 분말이 다른 방법으로 건조한 분말보다 높고 낮은 값을 나타내었고, 황색도인 $b^*$값은 동결 건조 분말에서 가장 높은 수준을 보였다. EMC는 $a_w$의 증가와 함께 증가하는 경향을 보였으며 특히, 0.75 $a_w$ 이상에서 급격하게 증가하였다. 동일한 $a_w$에서 분말의 EMC는 동결건조품이 천일과 적외선 건조품 보다 유의적으로 높게 나타났다. 복분자 분말의 흡습곡선은 전형적인 sigmoid 형태를 보였고, 천일건조 분말은 Halsey model, 적외선 건조 분말은 Kuhn model, 그리고 동결 건조 분말은 Oswin model이 적합도가 가장 높았다. 단분자층 수분함량은 GAB 방정식으로 설명 할 수 있었으며, 적외선 건조 분말에서 0.005 g $H_2O/g$ dry solid, 천일 및 동결 건조 분말에서 0.019 g $H_2O/g$ dry solid를 각각 나타내었다. 이로써 건조방법은 복분자 분말의 갈변과 흡습 특성에 영향을 미치는 것으로 확인되었다.