• Title, Summary, Keyword: roasting process

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Characteristic of Iron Oxide and the Magnetic Properties of Sr-ferrite by Roasting Temperature of Iron Oxide (산화철 배소에 따른 분체 특성 및 Sr-ferrite 자석의 소결 특성)

  • Jang Se-Dong
    • Resources Recycling
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    • v.12 no.6
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    • pp.19-25
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    • 2003
  • This experiment was carried out to examine the effect of iron oxide roasting for Sr-ferrite magnet. Chloride content was decreased with raising the 2 nd roasting temperature of iron oxide for ruthner process iron oxide. The optimization temperature for roasting of ruthner process iron oxide was around $800^{\circ}C$ as average particle size 1.5∼1.9 $\mu\textrm{m}$, apparent bulk density 1.4 g/$m\ell$ and chloride content 0.05%. The relation between Br and HcJ by sintering temperature for Sr-ferrite magnet was found to be Br≒-0.258HcJ+494. In case of having a vibrating disk mill for the ruthner process iron oxide, the magnetic properties were Br 421 mT and HcJ 251 kA/m.

Changes in Physicochemical Characteristics of Immature Barley Kernels during Roasting (미숙보리곡립의 볶음중 이화학적 특성변화)

  • Lee, Young-Tack;Seog, Ho-Moon;Kim, Sung-Soo;Kim, Kyung-Tack;Hong, Hee-Do
    • Korean Journal of Food Science and Technology
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    • v.26 no.3
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    • pp.336-342
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    • 1994
  • Changes in physicochemical characteristics were investigated for immature barley kernels roasted at $160{\sim}220^{\circ}C$ for $1{\sim}12$ min. Only small differences in chemical constituents including starch, protein, fat, ash, total dietary fiber, and ${\beta}-glucan were observed between immature and mature barley kernels. The amounts of 75% ethanol-soluble sugars and amino acids present in immature barley kernels were considerably higher than those in mature kernels, and gradually decreased in the process of roasting. Of free sugars, sucrose, raffinose, glucodifructose($GF_{2}$) and maltose were reduced by roasting. Glucose and fructose, simple reducing sugars, decreased at the early stage of roasting, followed by a slight increase at the later stage. Starch and nitrogen contents decreased slowly, while TDF(total dietary fiber) had a tendency to increase slightly. Stacking volume of immature barley kernels increased markedly, especially at the higher temperatures. L value of immature barley decreased throughout roasting, and a, b values increased at the early stage of roasting but b value decreased with continued roasting. The degree of roasting was strongly affected by the roasting temperature. Darkness of immature barley kernel, depending on the degree of roasting, was highly associated with concentrations of brown pigments extracted from roasted immature barley kernels.

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Effect of Heat Pretreatment on the Functional Constituents of Rice Germ

  • Kwon, Yun-Ju;Lee, Ki-Teak;Yun, Tae-Moon;Choi, Sang-Won
    • Preventive Nutrition and Food Science
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    • v.9 no.4
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    • pp.330-335
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    • 2004
  • Changes in functional constituents of rice germ prepared using three different heat pretreatments: roasting, steaming and microwave heating, were determined and compared with those of non-treated rice germ. The yield of rice germ oil increased generally and then decreased with increasing time for all three heat pretreatments, although the yields of rice germ oil varied among the three heat pretreatments. There were no major differences in fatty acid compositions among the rice germ oils subjected to the three different heat pretreatments. Levels of $\alpha$-tocopherol in rice germ oil increased up to about 1.5 times at 3 min of roasting and microwave heating, compared to control, and then decreased with increasing treatment time, but $\alpha$­tocopherol concentrations in rice germ oil gradually decreased with increasing steaming time. The contents of three phytosterols ($\beta$-sitosterol, stigmasterol and ergosterol) decreased progressively with increases in roasting and steaming time, while concentrations of the three phytosterols increased up to - 15$\%$ with 3 min of microwave process as compared to control, and then decreased thereafter. Levels of $\gamma$-oryzanol in rice germ oil decreased gradually with increasing time during all three different heat pretreatments. However, levels of $\gamma$ -aminobutyric acid (GABA) in rice germ decreased gradually with increasing roasting time, while those of GABA increased greatly up to about 2 times after 10 min of steaming process, and then decreased slowly thereafter. During microwave heating, the contents of GABA increased at 3 min of treatment time and then decreased. These results suggest that microwave heating may be the most suitable processing method to preserve functional constituents in rice germ.

Changes in Chemical Composition and Biological Activities of Oriental Crude Drugs by Food Processing Techniques IV - Increase in 5-HMF Content of Aurantii nobilis Pericarpium During Roasting Process - (식품학적 가공에 의한 생약의 성분 및 활성 변화 IV - Roasting처리에 의한 진피 중 5-HMF 함량증가 -)

  • Ni, Qinxue;Hur, Jong-Moon;Choi, Sun-Ha;Yang, Eun-Ju;Lee, Yu-Mi;Kang, Young-Hwa;Song, Kyung-Sik
    • Korean Journal of Pharmacognosy
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    • v.38 no.2
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    • pp.133-138
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    • 2007
  • Regarding chemical changes in oriental drugs after food processing such as roasting, fermentation, and extrusion, fifty commonly-used medicinal plants were investigated. As a result, Aurantii nobilis Pericarpium (a tangerine peel from Citrus unshu Markovich) showed remarkably different HPLC profiles after being roasted. An increased peak was isolated by repeated chromatography and identified as 5-hydroxymethyl furfral (5-HMF) by means of instrumental analyses. The 5-HMF content of Aurantii nobilis Pericarpoum reached its maximum level after being roasted for 30 min at 225$^{\circ}C$ (49.2 mg/g extract, ca 42 times of increase over untreated control). Although there were no significant changes in in vitro biological activity such as antioxidative, anti-dementia, anti-hypertension, anti-coagulation, or cytotoxicity, before and after roasting process, our results suggested that simple heat treatment might improve the value of the above oriental drug since 5-HMF has been known to possess inhibitory activities toward nitric oxide formation, tyrosinase, and sickling of red blood cells.

Optimization of Roasting Process for Preparation of Water Extracts from Job's tears (Coicis lachryma-jobi) (고품질 율무추출액 제조를 위한 볶음공정의 최적화)

  • Chung Hun-Sik;Youn Kwang-Sup
    • Korean Journal of Food Preservation
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    • v.13 no.2
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    • pp.119-124
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    • 2006
  • This study was conducted to optimize roasting process of Job's tears for utilization as food Optimal condition for masting was investigated with changes in temperature and time by response surface methodology. The qualities of water extract such as browning degree, polyphenol and DPPH radical scavenging ability were affected more by roasting temperature than time. The values increased with temperature and time proportionally. The response variables were more significant with temperature than time and the established polynomial model was suitable (P>0.05) model by Lack-of-Fit analysis. Optimal roasting conditions with the limit of $0.2{\sim}0.3$ browning degree, $2.0{\sim}2.5{\mu}g/mL$ polyphenol, $30{\sim}40%$ scavenging ability and $0{\sim}100$ hue angle were $215^{\circ}C$ and 32 min.

Quantitative Changes in Phenolic Compounds of Safflower (Carthamus tinctorius L.) Seeds during Growth and Processing

  • Kim, Eun-Ok;Lee, Jun-Young;Choi, Sang-Won
    • Preventive Nutrition and Food Science
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    • v.11 no.4
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    • pp.311-317
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    • 2006
  • Phenolic compounds in safflower seeds were recently found to stimulate bone formation and increase plasma HDL cholesterol levels in estrogen deficient rats, and to inhibit melanin synthesis. Nine phenolic compounds: $N-feruloylserotonin-5-O-{\beta}-D-glucoside,\;8'-hydroxyarctigenin-4'-O-{\beta}-D-glucoside,\;luteolin-7-O-{\beta}-D-glucoside$, N-(p-coumaroyl)serotonin, N-feruloylserotonin, 8'-hydroxy arctigenin (HAG), luteolin (LT), $acacetin-7-O-{\beta}-D-glucuronide$ (ATG) and acacetin (AT), were quantified by HPLC in safflower (Carthamus tinctorius L.) seeds during growth and processing. During growth, levels of the nine phenolic compounds in the seeds increased progressively with increasing growth stages, reached a maximum on July 30 (42nd day after flowering), and then remained relatively constant. During the roasting process, levels of phenolic compounds, except HAG, LT and AT, generally decreased with increased roasting temperature and time, whereas those of HAG, LT and AT increased progressively with increased roasting temperature and time. During the steaming process, levels of other phenolic compounds except HAG and AT generally tended to increase with increased steaming time, whereas those of HAG and AT were scarcely changed. During the microwave treatment, quantitative changes of phenolic compounds were similar to the roasting process, although there were some differences in levels of phenolic compounds between two heat treatments. These results suggest that the steamed safflower seeds after harvesting on late July may be useful as potential dietary supplement source of phenolic compounds for prevention of several pathological disorders, such as atherosclerosis and osteoporosis and aging.

Optimization of Roasting Process as Pre-treatment for Extraction of Omija(Schizandra chinensis Baillon) (오미자 추출을 위한 전처리로서의 볶음공정 최적화)

  • Mok, Chul-Kyoon;Song, Ki-Tae;Lee, Sang-Ki;Na, Young-Jin;Park, Jong-Hyun;Kwon, Young-An;Lee, Seung-Ju
    • Korean Journal of Food Science and Technology
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    • v.33 no.3
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    • pp.333-337
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    • 2001
  • The effect of roasting of Omija (Schizandra chinensis Baillon) on the physicochemical properties and the sensory quality of the extract was investigated in order to improve the quality of Omija beverage. The response surface methodology was introduced to optimize the roasting condition of Omija based on the sensory quality of the extract. The titratable acidity, the soluble solid content and the reducing sugar content of the extract increased with a mild roasting, but decreased with an excessive roasting. Prolonged roasting at high temperature decomposed red pigment making the color of the extract lighter, less red and less yellow. A mild roasting of Omija improved the sensory quality of the extract, and the highest sensory quality of the extract was provided with the roasting at $180^{\circ}C$ for 10 min, indicating the optimum roasting condition of Omija. The extract of the roasted Omija was superior in sensory properties to that of the unroasted one.

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Evaluation of bioactive compounds and antioxidant activity of roasted oats in different extraction solvents (볶음귀리의 추출물 종류에 따른 생리활성 성분 및 항산화 효능 분석)

  • Lee, Ji Hae;Lee, Byoung-kyu;Lee, Byong Won;Kim, Hyun-Joo;Park, Ji-Young;Han, Sangik;Lee, Yu Young
    • Korean Journal of Food Science and Technology
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    • v.50 no.1
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    • pp.111-116
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    • 2018
  • Roasting process of grains modifies their physicochemical characteristics that affect flavor, color, taste, and textures, as well as composition of bioactive compounds. We roasted oats at different temperatures (150, 200, and $250^{\circ}C$) and for different time periods (15 and 30 min). The polyphenol and flavonoid contents in different solvent extracts (methanol, fermented ethanol, and water) were also investigated. The total polyphenol and flavonoid contents were highest in the methanolic extract (135 mg gallic acid equivalent/g and 29 mg catechin equivalent/g, respectively, at $250^{\circ}C/30min$ roasting) and increased with roasting time and temperature. In addition, the avenanthramides were most abundant as accessed ($266{\mu}g/g$) in the methanolic extract upon roasting at $200^{\circ}C$ for 15 min. The radical scavenging activities, using 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid scavenging, increased with roasting temperature and time. The roasting process may modify the physicochemical structure of oats, thereby, improving polyphenol extraction and antioxidant activity. The results of this study could be used for the manufacture of foods using roasted oats.

Changes in Physicochemical and Sensory Characteristics of Dandelion (Taraxacum officinale) Leaves by Roasting Treatment (덖음처리에 의한 민들레 잎의 이화학적 및 관능적 특성 변화)

  • Choi, Hee-Don;Koh, Yoon-Jeoung;Kim, Yun-Sook;Choi, In-Wook;Cha, Dong-Su
    • Korean Journal of Food Science and Technology
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    • v.39 no.5
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    • pp.515-520
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    • 2007
  • To establish the roasting conditions of dandelion leaves for the manufacture of processed foods such as beverages and tea, we investigated the physicochemical and sensory characteristics of dandelion leaves and their hot water extracts by roasting treatment. As the number of roasting times increased, the free sugar content of the roasted dandelion leaves decreased, and in particular, free amino acid and total polyphenol content decreased greatly after only 1 roasting treatment. The amino nitrogen and total polyphenol contents of the roasted dandelion leaf hot water extracts also decreased greatly, and their L-, a-, and b-values showed much lower values than those of the raw leaf extracts. However, a greater amount of reducing sugars was extracted in the roasted leaves than in the raw leaves, suggesting that the roasting process allows for easier extraction of the compounds in dandelion leaves. Five sensory characteristics, including astringent taste, bitter taste, peen flavor, burnt taste, and sweet odor, were deduced through quantitative descriptive analysis of the hot water extracts. Among them, astringent taste, bitter taste, and green flavor showed significant differences between roasting treatments. The sensory evaluation results show that as the number of roasting times increased, the palatability of the hot water extracts increased greatly, in terms of color and taste.

The Sensory Charactateristics of Korean Green Tea Produced by Kujeungkupo′s Method (구증구포(九蒸九)에 의한 녹차의 제조 II. 관능적 품질특성 및 기호도)

  • 박금순;전정례;이선주
    • Korean journal of food and cookery science
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    • v.15 no.5
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    • pp.475-482
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    • 1999
  • This study was carried out to prepare green tea by traditional roasting process, Kujeungkupo, and to determine its sensory characteristics. The carotenoid content in green tea was increased by roasting and reached 1,317 mg/100 g by Kujeungkupo. Of all carotenoids, the contents of lutein and $\beta$-carotene were 1,170 mg/100 g and 111.1 mg/100 g, respectively. The total cathechin content in green tea was 14.57 g/100 g after 9th roasting. The more the number of roasting the little contents of cathechin in green teas. Of all cathechin, epigallocathechingallate was the highest(6.80g/100 g) followed by epicathechingallte and epicathechin. total cholrophyll content was 141 mg/100 g of green tea. The free sugar content in Kujeungkupo green tea wet 2.18 g/100 g, of which sucrose comprised 46% (1.01 g/100 g). The color value ($\Delta$E) of Kujeungkupo green tea was 16.25. In sensory evaluation, sweet taste was the highest in green tea roasted 3 times and the flavor was best in that roasted 5 times. The sweet and astringent tastes of green tea had negative relationships with a and b values. The content of cathechin in green tea had a negative relationship with sweet taste and a positive relationship with astringent taste.

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