• Title, Summary, Keyword: roasting

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Changes in Methyl Pyrazines of Cocoa Beans during Microwave Roasting (Microwave Roasting에 의한 Cocoa Bean의 Methyl Pyrazine류의 변화)

  • Lee, Joo-Hee;Kim, Suk-Shin
    • Korean Journal of Food Science and Technology
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    • v.32 no.3
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    • pp.654-658
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    • 2000
  • Flavor components focused on the methyl pyrazines(2,3-dimethyl pyrazine, 2,3,5-trimethyl pyrazine, tetramethyl pyrazine) of microwave-roasted cocoa beans were determined and compared with those of conventionally-roasted cocoa beans. Domestic microwave oven was modified to design the microwave roasting system. Temperature measurement technique using thermocouple probes was developed to determine the center temperature of cocoa beans during microwave roasting. Microwave roasting was carried out under two different conditions. Under the first condition, roasting time was fixed to 30 min, while roasting temperature was varied to $110^{\circ}C,\;120^{\circ}C,\;130^{\circ}C,\;140^{\circ}C,\;and\;150^{\circ}C$ Under the second condition, roasting temperature was fixed to $130^{\circ}C$, while roasting time was varied to 5 min, 10 min, 20 min, and 30 min. Conventional roasting was done at $120^{\circ}C$ for 15 min as a reference. Amount of methyl pyrazines and their ratios were influenced by microwave roasting temperature and roasting time. The most suitable methyl pyrazine ratio of cocoa beans was obtained at $140^{\circ}C$ for 30 min of microwave roasting.

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Changes in Chemical Components of Cocoa Beans during Microwave Roasting (마이크로웨이브 Roasting 중 Cocoa Bean의 이화학적 성분 변화)

  • Kim, Suk-Shin;Lee, Joo-Hee;Chang, Kyu-Seob
    • Korean Journal of Food Science and Technology
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    • v.32 no.4
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    • pp.814-821
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    • 2000
  • The physicochemical properties of microwave-roasted cocoa beans such as color, degree of browning, pH, titrable acidity, organic acid, and sugar content were determined and compared with those of conventionally-roasted beans. Microwave roasting temperatures were 110, 120, 130, 140 and $150^{\circ}C$. Roasting times were 0, 5, 10, 20, and 30 min. Conventional roasting was done at $120^{\circ}C$ and 15 min as a reference. The pH had no relations with roasting temperature or roasting time. As roasting time and roasting temperature were increased, the titrable acidity values of roasted cocoa beans became higher than those of raw bean. But there were no differences among each condition. Color, degree of browning, and sugar content changed as roasting temperature and roasting time increased. The organic acid content of roasted beans increased but the degree of increase was different from organic acid to organic acid. Roasting by microwaves resulted in higher inner temperature of samples than the surface temperature. To increase roasting efficiency, the other heat sources should be used together with microwave.

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Change in Flavor Components during Microwave Roasting of Cocoa Mass (Cocoa Mass의 마이크로파 Roasting 중 향기성분의 변화)

  • 이은정;윤상현;노희진;박덕철;김상용;정명섭;오상석;김석신
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.29 no.3
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    • pp.384-388
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    • 2000
  • 본 연구는 cocoa mass를 마이크로파 roasting하여 그 향기성분의 변화를 pyrazine류를 중심으로 살펴보는 한편 상법으로 roasting한 경우와 비교하고자 하였다. 마이크로파 roasting은 110,120,130,140,15$0^{\circ}C$의 온도에서 20분 및 30분 동안 행하였고 상법의 경우는 14$0^{\circ}C$에서 30분간 roasting하였다. Roasting한 시료를 연속수증기증류추출법으로 추출하고 농축한 후 GC와 GC/MS로 향기 성분을 분석하였다. 마이크로파 roasting의 경우 5분만에 14$0^{\circ}C$에 도달한 후 그 온도를 잘 유지하였으나, 상법의 경우 25분이 경과되어서야 14$0^{\circ}C$에 도달되었다. Roasting 한 시료의 향기성분으로 2,6-dimethyl pyrazine, 2,3,5-trimethyl pyrazine, 2,3,5,6-teramethyl pyrazine, 5-methyl fufural, 2-methyl-6-propyl pyrazine 등이 확인되었다. Roasting 온도가 증가함에 따라 dimethyl-, trimethyl-, tetramethyl pyrazine류가 증가하였고, tetramethyl pyrazine은 15$0^{\circ}C$ 20분 roasting의 경우 현저하게 증가하였으나, 30분 동안 roasting한 경우 14$0^{\circ}C$에서 증가하였다가 15$0^{\circ}C$일 때는 감소하였다. 그러나 적정 roasting 지표인 di/tri, di/tetra pyrazine의 비율은 1 이하를 보임으로써 마이크로파 roasting이 cocoa mass의 향기 발현에는 부족한 것으로 나타났다.

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Analyses of Organic Acids and Phenolic Compounds in Columbia Coffee Bean in Roasting Process

  • Park, Jongsun;Kim, Yongsung;Yeon, Jihun;Woo, Jongwook;Seo, Youmi;Mun, Jeong-Yun;Choi, Ji-Soo;Park, Min-Jeong;Im, Jong-Yun;Jang, Tae-Won;Park, Jae-Ho
    • Proceedings of the Plant Resources Society of Korea Conference
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    • pp.88-88
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    • 2018
  • Coffee is one of the most popular drinks in the world. Roasting process of coffee bean is one of major steps to make coffee, however, there are few studies which analyzed chemical compounds in intermediate state of roasting coffee beans due to technical limitations to get coffee beans with the same roasting condition. We utilized Stronghold S7 pro roasting machine which guarantees the saming roasting conditions repletively with the aid of precise computer to control heat sources to get 20 steps (every 30 seconds) of roasted coffee beans during roasting process (10 min in total). Along with roasting process, phenolic compounds were decreased, which can be explained that roasting process cause phenolic compounds degradation. Caffeine is almost constant during roasting, reflecting that caffeine is not affected in roasting process. These samples presents that organic acids significantly increase along with the roasting process by HPLC analysis. With additional analysis of coffee beans, such as moisture contents, pH, as well as coffee tastes, our analysis will show detailed process of chemical compounds of coffee beans during roasting process.

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Roasting Conditions for Improvement of Viscosity and Sensory Properties of Sea Tangle Extracts (다시마 추출액의 점성과 향미 개선을 위한 볶음처리 조건)

  • 박명한
    • The Korean Journal of Food And Nutrition
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    • v.12 no.5
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    • pp.484-489
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    • 1999
  • Rosting conditions for improvement of viscosity and sensory properties of sea tangle extracts were investigated. The supernatant % solid yield and crude protein yield were increased by increasing of roasting temperature and times. The highest contents of algin was obtained in roasting temperature of 175$^{\circ}C$ ash contents were increased by roasting temperature increasing. Viscosities of sea tangle extract were significantly decreased by increasing of roasting temperature and time upto 175$^{\circ}C$ and 10 mins more than further roasting conditions. The pH of sea tangle extracts slightly decreased from 5.94 to 5.83 in the roasting of 15$0^{\circ}C$ however at temperature more than 175$^{\circ}C$ its pH was increased by increasing of temperature and time. According to increase of roasting temperature and time Lightness (L value) were significantly decreased and redness (a value) and yellowness (b value) reached the highest value in the roasting of 20$0^{\circ}C$ 15 min. or 175$^{\circ}C$ 30 min and after that its value were decreased. The odor characteristics showed that sea tangle extract prepared by roasting of 175$^{\circ}C$ 10mins was slightly reduced in intensity of savory and seaweed taste but significantly low in intensity of nauseous taste and high in intensity of roasted taste and accetability. Overall data suggested 175$^{\circ}C$ 10min was the most effective roasting conditions for improvement of viscosity and sensory properties of sea tangle extract.

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Color Changes and Optimization of Orgsnoleptic Properties of Roasted Polygonatum odoratum Tea (둥굴레의 볶음처리에 따른 차의 색도 변화와 관능적 특성의 최적화)

  • 류기철;정형욱;이기동;권중호
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.26 no.5
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    • pp.831-837
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    • 1997
  • Response surface methodology(RSM) was applied in roasting processes of Polygonatum odoratum roots in order to monitor Hunter color parameters and to optimize organoleptic properties of the tea. In roasting processing based on the central composite design with variations in roasting temperature (110~19$0^{\circ}C$) and roasting time(15~75min), coefficients of determinations($R^{2}$) of the models were above 0.9827(p<0.01) in Hunter color parameters and above 0.7748 in organoleptic properties. Hunter color L and $\Delta$E values of the powdered samples decreased with the roasting processes, whereas Hunter color a and b values increased up to around 59 min at 136$^{\circ}C$ and thereafter showed a decreased tendency. Organoleptic qualities on color, taste and aroma of Polygonatum odoratum tea were improved along with roasting processes, thereby estimating the optimum roasting conditions by RSM for the maximized qualities of organoleptic properties as a range from 127$^{\circ}C$ to 135$^{\circ}C$ and from 60min to 66 min. Hunter color a value(redness) was found to generate a similar response surface to that of organoleptic properties, showing the possibility of quality index in roasting processes of Polygonatum odoratum roots.

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Influence of Roasting Treatment on the Antioxidant Activities and Color of Burdock Root Tea

  • Lee, Darye;Kim, Choon Young
    • Preventive Nutrition and Food Science
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    • v.22 no.1
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    • pp.21-29
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    • 2017
  • The major trend in the antioxidant market is the growing consumer demand for natural antioxidants. Tea, one of the most widely consumed beverages in the world, is an easy way to obtain antioxidant components from a natural source. Our objective was to develop burdock root tea (BRT) with potent antioxidant activity and good color quality. In order to obtain maximum antioxidant activity and quality, the effect of roasting was determined. The antioxidant capacities and total phenolic contents of BRT increased as roasting increased. The color of BRT became darker with increased roasting, extraction time, and amount of burdock roots. Color of BRT was also positively correlated with total antioxidant capacity. Roasting significantly enhanced the total antioxidant activities and color quality of BRT. These results suggest that roasting BRT increases beneficial antioxidant components from burdock roots.

Changes in Physicochemical Components of Cocoa Mass during Microwave Roasting (마이크로파 Roasting 중 Cocoa Mass의 이화학적 성분 변화)

  • Kim, Suk-Shin;Lee, Eun-Jung;Yoon, Sang-Hyun;Roh, Hoe-Jin;Park, Duck-Chul;Kim, Sang-Yong;Chung, Myung-Sub;Oh, Sang-Suk
    • Korean Journal of Food Science and Technology
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    • v.32 no.3
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    • pp.634-639
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    • 2000
  • This study was done to determine the changes in physicochemical components focused on the general compositions, pH, titratable acidity, organic acids, color and sugars during the microwave roasting of cocoa mass and to compare the changes with those during a conventional roasting. The cocoa mass was microwave-roasted at 110 to $150^{circ}C$ and for 10 to 40 min or conventionally roasted at $140^{circ}C$ for 30 min. General compositions of microwave-roasted cocoa mass were not different from those of raw cocoa mass or conventionally-roasted one. The pH changes did not affect the changes in titratable acidity or organic acids. Titratable acidity was different among the three samples. Microwave-roasted cocoa mass showed less sufficient effects on removing organic acids and less changes in color. Fructose, glucose and maltose decreased during a roasting but sucrose showed little changes.

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Changes in Properties of Dandelion Tea Induced by Roasting Conditions (볶음조건에 따른 민들레 잎차의 특성 변화)

  • 오상룡;양진무;차원섭;조영제;강우원;강미정;김광수
    • Journal of the East Asian Society of Dietary Life
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    • v.10 no.2
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    • pp.129-135
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    • 2000
  • This study was attempted to develop dandelion tea under various roasting conditions. The quality properties of tea were evaluated by measuring soluble solid. total yield, pH, color value, turbidity, browning degree, and sensory evaluation induced by various roasting time and temperature. The total yield and soluble solid content were the highest at the roasting process at 23$0^{\circ}C$ for 10 min. pH value was higher in non-treatment than pre-drying treatment and was not different among the roasting times. L value was reduced with increasing roasting time. Turbidity and browning degree of dandelion tea were the highest at the roasting condition at 23$0^{\circ}C$ for 10 min. Palatability was the highest at the roasting condition at 23$0^{\circ}C$ for 5 min without pre-drying. The higher solid yield was obtained with an increase in roasting temperature. Turbidity and browning degree increased under the roasting conditions at 230 and 26$0^{\circ}C$, respectively. Palatability in sensory evaluation increased at the roasting condition at 26$0^{\circ}C$ for 10 min. The higher savory taste value was obtained with an increase in roasting temperature.

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Effects of Dry Roasting on the Vitamin E Content and Microstructure of Peanut (Arachis hypogaea)

  • Eitenmiller, Ronald R;Choi, Sung-Gil;Chun, Jiyeon
    • Journal of agriculture & life science
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    • v.45 no.4
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    • pp.121-133
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    • 2011
  • Effects of roasting on vitamin E content, color, microstructure and moisture of peanuts, and vitamin E content in peanut oils prepared from the roasted peanuts were investigated. Runner-type peanuts were roasted at 140, 150, and $160^{\circ}C$ for 10-20 min. As roasting temperature and time increased, the CIELAB $L^*$ value of peanuts decreased while $a^*$ and $b^*$ values increased, resulting in formation of the golden brown color of roasted peanuts. Moisture ratio (M/Mo) and color $b^*$ value of peanuts roasted at 140 to $160^{\circ}C$ showed a correlation of $b^*=21.61\;(M/Mo)^2-40.62\;(M/Mo)+34.12$ ($R^2=0.9123$). Overall changes in the tocopherol contents of peanuts and peanut oils were significantly affected by roasting temperature and time (p<0.05). Roasting at $140^{\circ}C$ caused a slight increase in the levels of tocopherols of peanuts over roasting time up to 20 min (p<0.05). There was no significant change in the tocopherol levels of peanuts during roasting at $150^{\circ}C$ for 20 min (p>0.05). At $160^{\circ}C$, the levels of tocopherols significantly decreased during the initial 10 min of roasting (p<0.05) while there was no extended loss after 10 min, resulting in about 5, 12, 20, and 10% losses of ${\alpha}$-, ${\beta}$-, ${\gamma}$- and ${\delta}$-T, respectively. After 20 min, total tocopherols decreased by 18%. However, tocopherol contents of pressed peanut oils significantly decreased at all roasting temperatures (p<0.05). After roasting peanuts at $160^{\circ}C$ for 20 min, about 84% of initial ${\alpha}$-T in peanut oils was retained. ${\alpha}$-T was the most stable to roasting while ${\gamma}$-T was the least. Swollen epidermal cells on the inner surface and broken cell walls of parenchyma tissue of peanut cotyledon were observed in peanuts after roasting at $160^{\circ}C$ for 15 min. Severe changes in microstructure of peanut by roasting would contribute to vitamin E stability because of exposure of oil droplets in peanuts to oxygen.