• Title/Summary/Keyword: Sour

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Effect of $H_2S$ Partial Pressure and pH of Test Solution on Hydrogen Induced Cracking of High Strength Low Alloy Steels

  • Kim, Wan Keun;Koh, Seong Ung;Kim, Kyoo Young;Yang, Boo Young;Jung, Hwan Kyo
    • Corrosion Science and Technology
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    • v.4 no.6
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    • pp.236-241
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    • 2005
  • Hydrogen induced cracking (HIC) is one of the hydrogen degradation phenomena of linepipe steels caused by $H_2S$ gas in the crude oil or natural gas. However, NACE TM0284-96 standard HIC test method is hard to satisfy the steel requirements for sour service application since it uses more severe environmental conditions than actual conditions. Therefore, in order to use steels effectively, it is required to evaluate HIC resistance of steels in the practical range of environmental severity. In this study, HIC resistance of two high strength low alloy (HSLA) steels being used as line pipe steels was evaluated in various test solutions with different $H_2S$ pressures and pH values. The results showed that the key parameter affecting crack area ratio (CAR) is $H_2S$ partial pressure of test solution when the pH value of test solution is not over 4. Hydrogen diffusivity was not a constant value, but it was rather affected by the hydrogen ion concentration (pH value) in the solution.

The Physiochemical Characteristic and Descriptive Sensory Evaluation of the Blackberry Fruit Beverage (복분자 음료의 이화학적 특성 및 묘사적 관능평가)

  • Yang, Hyang-Sook;Rho, Jeong-Ok
    • Korean Journal of Human Ecology
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    • v.21 no.2
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    • pp.363-375
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    • 2012
  • The purpose of this study was to analyze the physiochemical properties of blackberry fruit beverage(BFB) and to develop a descriptive analysis procedure for evaluating the sensory characteristics of BFB. The amount of soluble solid, free sugar, pH, acidity, chromaticity, flavonoid, and anthocyanin of BFB were determined. All BFB samples demonstrated significantly different physicochemical properties(p<.01). Ten highly trained panelists identified the following eleven sensory attributes in the BFB and defined by standardized terminology for each attribute; turbidity, chromaticity for appearance characteristics, berry, grass, fermented, sweet, astringent, and sour for flavor characteristics, throat hit, refreshing, as well as astringent grade for textural characteristics. There were significant differences in all the eleven sensory attributes of the BFB samples(p<.001). Descriptive terminology used in the BFB analysis was capable of classifying the sensory attributes of the BFB. Based on these results, the analysis method and sensory evaluation techniques used in this study could be reasonably applied to other fruit beverages for establishing similar physiochemical characteristic and descriptive sensory attributes.

Sensory Characteristics of the Brewed Coffee Roast Based on the Elapsed Time after Grinding (커피의 배전 후 경과 시간에 따른 관능적 특성)

  • Kim, Hyun-Ah;Lee, Kyung-Hee
    • Journal of the East Asian Society of Dietary Life
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    • v.23 no.3
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    • pp.382-390
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    • 2013
  • The purpose of this study is to provide the basic findings concerning a quality evaluation. The first conclusion is the coffee's $CO_2$ gas production between a roast brewed at 0 hour and 72 hours after grinding. The espresso, 48 hours after its grind, emits a small amount of $CO_2$ gas, whereas 72 hours after being grinded there is no discharge. In the sensory evaluation, the overall preference is the 72 hours later grind, in accordance to the decrease of the bitter, acid, and sour taste with the increase of the sweet, nutty, and chocolaty flavors. The foam index indicates a significant reduction between the roasts brewed at 0 hour and 72 hours after grinding. A persistence of crema in the Colombian Colombia and Ethiopian Yirgacheffe decline for the 72 hours after its grind coffee. The Tanzanian Kilimanjaro and Brazilian Cerrado roasts show no difference. The pH is decreased in the 72 hours after its grind roast. Moreover, sugar contents in the Colombian Excelso and Brazilian Cerrado are increased, whereas the Tanzanian Kilimanjaro sugar contents are decreased, along with its density.

Recognition and Buying Practices of Street-vended Foods among College Students (대학생의 길거리 음식에 대한 인식 및 이용실태)

  • Kim, Gi-Nam;U, Jeong-In;Choe, Mi-Hyeon;Han, Hyo-Mi
    • Journal of the Korean Dietetic Association
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    • v.9 no.3
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    • pp.259-268
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    • 2003
  • The purpose of this study was to investigate recognition and buying practices of street-vended foods among college students in Chungbuk Area. A general dietary practices including snacks, related factors of buying street-vended foods were analyzed. The results showed that many students had irregular dietary habit, especially more than eighty percent of them skipped breakfast. More than sixty percent of students had frequent snacks. It was investigated that college students ate street-vended foods two or three times per week. The order of frequent choice of street-vended foods was rice cake with pasted red pepper(51.9%), sweet and sour pork(19.7%), sundae(5.7%). In microbiological examination, MPN of Coliform and CFU of standard plate count was over a standard value respectively, and acid value of frying oil revealed over value for maximum limitation point. Therefore, food and equipment in street-vended food store was evaluated as poor sanitation status. Most of college students have opinion that street-vended food store must be kept the line. In conclusion, nutrition education for college students should be required to protect them from unsafe street-vended foods.

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The Medicinal Effects of Seafoods in ${\ulcorner}$Lim-Won-Sib-Rheuk-Ji${\lrcorner}$ ("임원십육지(林園十六誌)"에 수록된 어패류의 향약성(鄕藥性)에 관한 연구)

  • 최영진;백숙은
    • Journal of the East Asian Society of Dietary Life
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    • v.14 no.3
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    • pp.187-195
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    • 2004
  • This study was conducted to figure out the nutritional nature of seafoods categorized according to the medicinal effects and the usages introduced in Lim-Won-Sib-Rheuk.-Ji, one of the well-known encyclopedias published during the Chosun Dynasty. They were compared with those introduced in other cooking books in order to find out how they were used in the diet of real-life. The seafoods of the book were first categorized into the fish 20, the mollusk 5, the crustacea 4, and the shellfish 7, and reptile according to the biological taxonomy, and then each one was reviewed in terms of the taste and the food-nature. Generally, the fishes had the sweet taste; the crustacea and the shellfish the salty or sour in addition to the sweet taste; none of them were bitter or hot. Most of them had the mild nature; seven of them were regarded as warm; four as cool; one as cold from the standpoint of the traditional medicine. The food-nature of seafoods was closely related with the medicinal effects on the human body. These seafoods were characteristically used in daily dietary life as well as the medical applications; used as the side-dishes rather than the main-dishes. The cooking methods of boiling, steaming, and baking were preferred to drying and stewing. The preservation methods favored were the fermentation, drying and salting. These cooking and preservation methods were believed to reflect the nature of the seafoods to manifest the medicinal effects.

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Quality Characteristics of Gochujang Dressing Containing Various Amounts of Maesil(Prunus mune) Concentrate (매실 농축액 첨가 고추장 소스의 품질 특성)

  • Lee, Min-Soo;Park, Mi-Lan;Jung, Hyeon-A;Choi, Soo-Keun
    • Journal of the East Asian Society of Dietary Life
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    • v.21 no.1
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    • pp.38-45
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    • 2011
  • This study aimed to determine the sensory acceptability of Gochujang dressing containing added Maesil (Prunus mune) concentrate. Gochujang dressing was blended with different concentrations of Maesil concentrate (0%, 1%, 2%, 3%, 4%). Moisture contents, L, a, b values, pH level, and sugar contents decreased, whereas acidity and viscosity increased with increasing Maesil contents. Salinity did not change significantly. For attribute difference test, as Maesil concentration increased, color intensity, savory flavor, sour flavor, hot taste, and mouthfeel decreased, whereas glossiness decreased. The acceptance test showed that 2% Maesil concentrate was the most preferable for appearance, taste, texture, and overall quality. In conclusion, the results indicate that addition of 2% Maesil concentrate to Gochujang dressing is optimal and provides good properties as well as reasonably high overall acceptability.

A Study on the Recognition and the Ways of Consuming Mushrooms by Elementary and Middle School Students and School Dietitian (초, 중학생 및 급식 담당 영양사를 대상으로 한 버섯의 인식 및 이용형태에 관한 연구)

  • Lee, Jong-Suk;Lee, Kyung-A;Ju, Young-Cheoul;Lim, Gab-June;Lee, Jae-Sung
    • Journal of the Korean Society of Food Culture
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    • v.19 no.3
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    • pp.259-266
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    • 2004
  • A study on the recognition on the mushrooms by elementary school pupils, middle school students and school dietitians were-carried out. The ways of cooking mushrooms by school dietitians were also investigated. Most students and dietitians highly recognized mushrooms as good food. The most favorite mushroom was Flammulina velutipes, the cooking of mushrooms with meat and the hot mushroom soup with meat(Jungol) being the most preferred cooking methods. School ditetitians like to use mushrooms in school lunch and generally use medium or high duality mushrooms. Students, however, do not tend to prefer mushrooms compared to other vegetables. Mushroom dishes that can promote the consumption by students are mushroom bulgogi, mushroom pizza, sweet and sour mushroom in the order.

Determination of Malodor-causing Chemicals Produced by Microorganisms Inside Automobile (차량 내 미생물에 의해 생성되는 악취유발 화학물질의 분석)

  • Park, SangJun;Kim, EuiYong
    • KSBB Journal
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    • v.29 no.2
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    • pp.118-123
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    • 2014
  • It was confirmed that malodor connected with an air-conditioner in an automobile is caused by microbial volatile organic compounds (MVOCs) produced by microorganisms getting into an air-conditioner when it is operating. Chemicals such as hydrogen sulfide, dimethyl sulfide, nbutyric acid, n-valeric acid, iso-valeric acid, n-octanol and toluene were detected above the odor threshold inside the automobile. The characteristics of a funky odor in the air blown into the automobile were due to detected sulfur compounds (hydrogen sulfide and dimethyl sulfide). Dimethyl sulfide was produced by microorganisms such as Aspergillus versicolor, Methylobacterium aquaticum, Herbaspirillum sp. and Acidovorax sp. In addition, the characteristics of a sour odor in the air blown into the automobile were due to detected organic acids (n-butyric acid, n-valeric acid and iso-valeric acid). N-valeric acid and iso-valeric acid were generated from Aspergillus versicolor, while iso-valeric acid was produced by Methylobacterium aquaticum. In addition, the odor intensity of the air blown into the automobile was affected by the concentration of detected sulfur compounds and organic acids. On the other hand, it is estimated that chemicals such as hydrogen sulfide, n-octanol and n-butyric acid detected in the air blown into the automobile were produced by non-identified species of microorganisms.

A Study on the Quality Characteristics of Makpyeon Prepared with Dry Milled Rice Powder (건식 쌀가루를 이용한 막편의 품질특성)

  • Jo, Yun Ju;Yoon, Hye Hyun
    • Journal of the Korean Society of Food Culture
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    • v.31 no.3
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    • pp.235-242
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    • 2016
  • The purpose of this study was to investigate the quality characteristics of makpyeon prepared with dry milled rice powder. The makpyeon samples prepared with dry milled rice powder and various amount makgeolli (0% (CON), 25% (M25), 50% (M50), 75% (M75), 100% (M100)), and analyzed for moisture content, pH, Hunter's color value, TPA and sensory evaluation. The moisture content did not showed significant difference among makpyeon samples. The L-value, a-value resulted in that CON showed the highest and decreased with the amount of makgeolli. The b-value of makpyeon samples showed that CON was the lowest and increased with the amount of makgeolli. TPA resulted in that M100 showed the highest hardness and the lowest adhesiveness, cohesiveness. Chewiness and gumminess of makpyeon samples were higher than those of CON. Based on quantitative descriptive analysis, the score of brightness, moistness, particle size and gloss of showed higher in CON that in makpyeon samples, firmness increased with the amount of makgeolli. Flavor attributes of liquor odor, sour odor, fermentation odor of makpyeon was stronger in makpyeon samples that in CON with the amount of makgeolli. Acceptance test resulted in makpyeon made with CON, 100% of makgeolli (M100) showed the significantly highest score in taste and overall acceptance.

Consumption Pattern of Kimchi in Seoul Area (서울지역의 김치섭취에 관한 실태조사)

  • 강선이;한명주
    • Korean journal of food and cookery science
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    • v.18 no.6
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    • pp.684-691
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    • 2002
  • The objectives of this study were to determine the consumption pattern and importance of Kimchi in our meals, and the preference of Kimchi. The 77.0% of the housewife respondents were preparing Kimchi at home. The reasons for not making Kimchi were ‘don't have time’(39.4%), ‘don't know how to make Kimchi’(18.2%) and ‘don't eat much’(18.2%). The amounts of daily Kimchi intake of the respondents were ‘less than 50g’(42.3%) or ‘50-100g’(29.8%). They are Kimchi because it was ‘delicious’(48.4%) or ‘habitual’(39.5%). The 70.0% of the respondents answered that Kimchi was important in each meal. The most respondents favored ‘moderate’ in the degree of fermentation(48.1%), hot taste(65.0%) and salty taste(72.4%). As the age of the respondents increased, they favored less sour, less hot and less salty taste. Baechu Kimchi(4.15), Chonggak Kimchi(3.89), Dongchimi(3.85), Kkaktugi(3.74), water Kimchi(3.67) were preferred by the respondents. The 73.97% of the respondents preferred Kimchi Jjigye. The 10- to 19-years old respondents preferred Kimchi Jjigye(52.8%), Kimchi pan cake(24.5%) and fried rice with Kimchi(17.0%).