• Title/Summary/Keyword: boiling time

Search Result 395, Processing Time 0.075 seconds

A Study on the Impulse Breakdown Characteristics of Epoxy Composites due to Water Absorption Aging (흡수열화에 따른 에폭시 복합체의 임펄스 절연파괴특성에 관한 연구)

  • 이덕진;손인환;신성권;김명호;김경환;홍진웅;김재환
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2000.07a
    • /
    • pp.156-159
    • /
    • 2000
  • In this paper, the physical and electrical properties of epoxy composites are investigated at boiling absorption condition to observe the influences of moisture. Also, in order to improve water resistance of matrix resin, IPN method was introduced and the influence was investigated. In order to analyze the basic physical properties of samples, scanning electron microscopy method was utilized, and impulse voltage dielectric strength was measured. As a result, it was verified that, in case of IPN samples, the ratio of moisture absorption was decreased due to the improvement of adhesion strength, and impulse voltage dielectric strength of SN sample was degraded abruptly as boiling time and filler content were increasing, while IPN samples were slowly degraded due to the improvement of adhesion strength.

  • PDF

Changes in the Riboflavin Content of Spinach Salad and Sesame Leaf Salad with Various Cooking and Holding Process in Foodservice Institutions (단체급식소에서 제공되는 시금치 나물과 깻잎 나물의 생산단계 및 보관단계에 따른 리보플라빈 함량 변화(II))

  • 김혜영;박화연
    • Korean journal of food and cookery science
    • /
    • v.20 no.1
    • /
    • pp.34-41
    • /
    • 2004
  • The retention rate of riboflavin in two cooked vegetable salads (spinach salad and sesame leaf salad) were examined at every cooking stage, holding temperature and holding time, with various cooking methods, and a better food preparation method developed. The riboflavin contents of the samples were analyzed by HPLC, with fluoresence detection. The changes in the pH and water contents of the samples were measured during the holding stage at various temperatures and times. There were significant differences in the riboflavin contents during the various preparation and cooking processes, such as trimming, washing, boiling and parching etc. The retention rates of the riboflavin with the various holding methods and cooking temperature were also significantly different. The boiling process caused large losses of riboflavin: in the cases of spinach salad and sesame leaf salad these were 78% and 52% respectively. The pH and water contents showed faster change during 0-6 hours than during 6-12 hours.

Effects of Beef Bone Extracts on Quality of Baeck Kimchi (사골 국물이 백김치의 품질에 미치는 영향)

  • 박영희;박소희;이종호;조재선
    • Korean journal of food and cookery science
    • /
    • v.19 no.2
    • /
    • pp.188-194
    • /
    • 2003
  • This study was conducted to investigate the effect of beef bone extracts on the organoleptic quality and fermentation of Baeck Kimchi. For this study, the organoleptic characteristics of Baeck Kimchi, with addition beef bone extracts were tested, and the changes in the fermentation factors, such as pH, acidity, reducing sugar and total microbial count, were observed during fermentation at 10$^{\circ}C$ and 20$^{\circ}C$. Greater amounts of lipids and soluble nitrogen were extracted to increasing the boiling time for the preparation of the beef bone extracts. However, 1% of the mixed beef bone extracts, prepared by boiling for 5, 7 and 9 hours, was the most acceptable for the Baeck Kimchi fermentation, as assessed from the results of sensory consumer tests. The beef bone extracts enhanced the umami taste of the unfermented Baeck Kimchi. The carbonated taste, sourness and fresh flavor of the fermented Baeck Kimchi were also enhanced. The fermentation rate was increased by the addition of beef bone extracts to Baeck Kimchi.

Palatability Evaluation and Physical Characteristics of Cooked Rice (쌀의 물리적 특성과 식미와의 상관)

  • Kim Young Doo;Ha Un Gu;Song You Chun;Cho Jun Hyeon;Yang Eun In;Lee Jae Kil
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.50 no.spc1
    • /
    • pp.24-28
    • /
    • 2005
  • Many parameters such as textural, cooking and pasting properties and chemical components aye the main reasons of tardy progress in evaluation of cooked rice. To increase the evaluation effect of cooked rice, physical properties and palatability of cooked rice were studied with five varieties. The highest palatability was observed in Kosihikari while Hoan showed the lowest value. The cooked rice of Kosihikari showed a high values of waxiness (0.12) and boiling time (21.1 min.) while the porosity and expansibility were as low as 19.0 and $28.6\%$, respectively. The water absorption time of Kosihikari and Sindongin was a little bit slow compare to the other varieties. A negative correlations were observed between palatability and expansibility (-0.390), porosity (-0.874**) and water absorption time (-0.960**) while a positive correlations were observed between palatability and boiling time (0.861**), waxiness (0.920**) and hardness (0.478). The path coefficient of water absorption time, porosity, boiling time and waxiness contributed to the palatability were 35.9, 22.7, 17.0 and $8.2\%$, respectively, Thus, the results obtained in this study suggested that the physical characteristics of vice grains could be effectively utilized in high quality of cooked rice breeding programs.

Study on the most effective Yinqiao San by the GC(Gas Chromatography) (Gas-Chromatography를 이용한 은교산 전탕시간에 대한 연구)

  • Lee, Yong-Bum;Kook, Yoon-Bum;Choi, Sung-Mo
    • Journal of Korean Medical classics
    • /
    • v.19 no.1 s.32
    • /
    • pp.202-206
    • /
    • 2006
  • Yinqiao San is the medicine for the outer part disease of the human body. In ${\ulcorner}$Wenbingtiobian${\lrcorner}$, this medicine is the most useful when it is used within short time after the starting boiling it. In this study, the volatile ingredients of the Yinqiao San were observed by GC and compared with each other in time scale. Most of the ingredients were observed about 5 min after the starting boiling it, after10 min., the GC peaks were smaller and smaller, and after 2 hours and 30 min. the GC peaks were almost gone. It is confirmed that was written about the Yinqiao San in ${\ulcorner}$Wenbingtiobian${\lrcorner}$.

  • PDF

The Effects of Blanching Temperature and Cooking Methods on the Changes in Vitamin C of Potato (감자의 Vitamin C의 변화에 대한 Blanching 온도 및 조리 방법의 영향)

  • Chung, Hyoun-Mi;Lee, Gui-Ju
    • Korean Journal of Food Science and Technology
    • /
    • v.21 no.6
    • /
    • pp.788-794
    • /
    • 1989
  • This study was attempted to investigate the effects of blanching temperature and cooking methods on the changes in the proportions of vitamin C of fresh potato and potatoes with different storage time. Sensory evaluation of fresh potato by different cooking methods was also conducted. The contents of residual ascorbic acid(AA) and total ascorbic acid(TAA) of fresh potato were maximum at $40^{\circ}C$ followed by rapid decrease at $50-65^{\circ}C$ while leached AA and TAA showed steady increase as the blanching temperature increased. Oxidized AA and dehydroascorbic acid(DHA) hydrolyzed increased at $50-65^{\circ}C$. From these results, it was considered that AA was lost mainly by oxidation up to $65^{\circ}C$ and leaching of AA was the major mode of loss above $65^{\circ}C$. In the case of potatoes stored for 1-4 weeks, they showed similar changes in the proportions of vitamin C as that of fresh potato. However, at $40^{\circ}C$ the content of residual TAA decreased and those of leached TAA and DHA hydrolyzed increased redundant during storage. At $65^{\circ}C$, the content of DHA hydrolyzed decreased The residual TAA of fresh potato by different cooking methods decreased in the order of pressure cooking (PC) > microwave cooking (MC)>boiling. Leached TAA were 49.5% and 36.4%, during boiling and MC, respectively. While DHA hydrolyzed were 22.3% and 4.2%, respectively Leached TAA and DHA hydrolyzed during PC were not determined. From these results, it was considered that AA was lost mainly by leaching during cooking. Residual TAA of stored potatoes by different cooking methods decreased during storage. But leached TAA and DHA hydrolyzed did not show any steady increase or decrease. Overall eating quality of fresh potato by different cooking methods decreased in the order of PC>MC>boiling(p<0.05).

  • PDF

Quality Characteristics of Ginseng Jung Kwa and Jung Kwa Solution on Jung Kwa Process (인삼정과 제조과정에 따른 품질학적 특성)

  • Lee, Ka-Soon;Kim, Gwan-Hou;Kim, Hyun-Ho;Song, Mi-Ran;Kim, Mee-Ree
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.38 no.5
    • /
    • pp.587-593
    • /
    • 2009
  • This study was carried out to investigate the quality characteristics of ginseng Jung Kwa and Jung Kwa solution prepared according to boiling frequency on Jung Kwa process. Ginseng Jung Kwa was made as follows: washed ginseng 8 kg was boiled 5 min with water 16 kg and then boiling water 8 kg was removed. Sucrose 10 kg was added to boiled ginseng soaking in hot water. Jung Kwa was boiled down for 60 min in sugar syrup and soaked for 24 hrs. According to the above process, Jung Kwa was boiled down 5 times. Moisture and pH of Jung Kwa and Jung Kwa solution decreased as the number of boiling time increased and $^{\circ}Brix$ of Jung Kwa solution increased. Crude saponin content of last Jung Kwa (GJ 6) increased to 4 times of raw ginseng. Content of Rf and Rd, component of ginsenosides, increased 77 and 16 times on Jung Kwa, respectively and content of crude saponin on last Jung Kwa solution (GJS 5) was 61.88 mg/g. The other ginsenosides on Jung Kwa decreased. As the number of boiling time increased, concentration of total sugar, glucose and fructose of Jung Kwa and Jung Kwa solution increased. Content of total organic acid on Jung Kwa decreased, especially, succinic acid, main organic acid of ginseng, decreased rapidly. L value of Jung Kwa decreased whereas a and b values increased.

The Changes of $Vit.D_2$ and $Vit.B_2$ Contents according to Ultraviolet rays and Cooking Methods of Mushrooms (버섯의 자외선조사와 조리조건에 따른 $Vit.D_2$$Vit.B_2$ 함량의 변화)

  • Oh, Hae-Sook;Yoon, Sun;Park, Hee-Ok
    • Journal of the Korean Society of Food Culture
    • /
    • v.16 no.5
    • /
    • pp.463-469
    • /
    • 2001
  • This study was to investigate the effect of ultraviolet rays, soaking, boiling and baking to ergocalciferol ($Vit.D_2$) and riboflavin($Vit.B_2$) contents of mushrooms, Lentinus edodes, Pleurotus ostreatus and Agaricus bisporus. The results were as follow: 1. Mushrooms were exposed to ultraviolet rays Lentinus edodes : $10J/cm^2$, Pleurotus ostratus : $2J/cm^2$ and Agaricus bisporus : $2J/cm^2$. 2. Before exposing to ultraviolet rays, the ergocalciferol contents of mushrooms were all $0{\mu}g/g$ dry base, but after exposing to it , those of Lentinus edodes, Pleurotus ostreatus and Agaricus bisporus were $222.50{\pm}5.30{\mu}g/g$ dry base, $150.90{\pm}6.60{\mu}g/g$ dry base and $23.98{\pm}1.20{\mu}g/g$ dry base, respectively 3. Before and after exposing to ultraviolet rays, the riboflavin contents of Lentinus edoes, Pleurotus ostreatus and Agaricus bisporus were $18.22{\pm}0.71{\mu}g/g$ dry base and $11.72{\pm}0.50{\mu}g/g$ dry base, $4.57{\pm}0.20{\mu}g/g$ dery base and $3.26{\pm}0.15{\mu}g/g$ dry base, and $37.42{\pm}1.20{\mu}g/g$ dry base and $27.33{\pm}2.10{\mu}g/g$ dry base, respectively. 4. The ergocalciferol contents of mushrooms according to boiling time were not significantly different but the riboflavin contents of them were decreased according to the increase of boiling time. 5. The ergocalciferol and riboflavin contents of mushrooms were decreased according to the increase of NaCl concentration and baking temperature. 6. The ergocalciferol content of Lentinus edodes after a short time soaking at $80^{\circ}C$ was higher than a long time soaking at $20^{\circ}C,\;40^{\circ}C$ and $60^{\circ}C$.

  • PDF

A Study on the Evaporation and Ignition of Single Fuel Droplet on the Hot Surface (고온벽면에서의 액적연료의 증발 및 착화에 관한 연구)

  • 송규근
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.26 no.1
    • /
    • pp.132-137
    • /
    • 2002
  • Recently, impinging spray is used for atomization of diesel engine, but it bring on adhesion of fuel. Therefore, we studied about droplet behavior on high temperature plate changing the size of droplet, surface temperatures, and surface roughness of plate. In this study, We studied to confirm experimentally about mechanism of evaporation and ignition process of single fuel droplet. We observed evaporation time, evaporation appearance and ignition delay time by the photopraphs of 8mm video camera. Experimental results are summarized as follows: 1. The boiling point of fuel affect a evaporation and ignition process. 2. The surface roughness affect a evaporation time. 3. The ignition delay time relate to evaporation characteristic.

A Study on the variations of mechanical and electrical property of epoxy composites due to boiling absorption (비등흡수에 의한 에폭시 복합재료의 기계적 특성 및 전기적 특성 변화에 관한 연구)

  • 이덕진;신성권;김재환
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.14 no.1
    • /
    • pp.53-58
    • /
    • 2000
  • In this paper, the variable mechanical strength and dielectric breakdown strength of epoxy composites were measured at boiling absorption condition in order to observe the influences of moisture in out door use. Also, in order to improve water resistance of matrix resin, IPN(interpenetrating polymer network) method which had been already reported, was introduced and the influence was investigated. As Adding filter(SiO2) classified by o[phr], 50[phr] and 100[phr] to two kinds of matrix resin, six kinds of specimens were manufactured. As a result, it was confirmed that the moisture absorption rate was increased and mechanical strength and dielectric breakdown strength were degraded with boiling time and filler content increasing. On the other hand, it was confirmed that moisture absorption rates were decreased and the degrading rates of mechanical strength and dielectric breakdown strength were lowered according to improvement of adhesion strength in case of IPN specimens.

  • PDF