• Title/Summary/Keyword: gelatinization

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Varietal Variation in Gelatinization and Adaptability to Rice Bread Processing and Their Interrelation (쌀의 호화 및 제빵적성의 품종 변이와 관련특성간 상관)

  • 강미영;손현미;최해춘
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.42 no.3
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    • pp.344-351
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    • 1997
  • The experiment was conducted to examine the varietal variation in gelatinization of rice flour and adaptability to rice bread processing, and the interrelation among the relevant properties. IR 44 showed the lowest temperature of gelatinization onset(T$_{o}$ ) and the highest gelatinization enthalphy(ㅿH) measured by differential scanning calorimetry (DSC). The following lower T$_{o}$ was found with the order of Suweon 230<Pusa-33-30<T(N) 1, Daeribbyeo 1 and the next higher ㅿ.H was followed by the order of Pusa-33-30>Suweon 230. IRAT 177 revealed the highest temperature of gelatinization onset and conclusion(T$_{c}$) and the following higher T$_{c}$ was found with the order of Pusa-33-30>AC 27>Nonganbyeo. The varietal range of T$_{o}$ and T$_{c}$ was 50.0~72.5$^{\circ}C$ and 70.2~87.4$^{\circ}C$, respectively. The rice materials tested can be classified by scatter diagram on the plane of upper two principal components contracted from DSC thermogram and various characteristics relevant to processing and sensory preference of rice bread by principal component analysis. AC27, Suweonjo and IR 44 among high-amylose rices showed better suitability to rice bread processing. The temperatures of gelatinization peak and conclusion of rice flour checked by DSC were significantly negatively associated with springiness of rice bread. The most properties relevant to processing and sensory preference of rice bread such as hardness, moistness, springiness, cohesiveness, specific loaf volume and distribution or size of air cell revealed the close correlation between each other.other.

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Effects of Soaking on Pasting Gelatinization of Acorn Flour (수침이 도토리 앙금의 호화에 미치는 영향)

  • Na, Hwan-Sik;Oh, Geom-Soon;Park, Jong-Hun;Kim, Kwan;Kim, Sung-Kon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.29 no.5
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    • pp.770-776
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    • 2000
  • Pasting gelatinization of acorn flours which were prepared with soaked nut and sediment at 7.8$^{\circ}C$ for 0, 1, 2, 3 and 4 days were investigated. The peak temperature of gelatinization of untreated acorn flour (0-0) by Rapid Visco Analyzer was 73.1$^{\circ}C$, respectively, but those of flours were decreased by soaking. Peak viscosity, setback and breakdown of acorn flours were increased by soaking. In addition, consistency was increased by soaking treatment. From the result of the pasting properties, gel formation ability of acorn flour was increased with increasing soaking days of acorn nut and soaking times of sediment. The gelatinization temperature examined by X-ray diffractometry was lowered with increasing of soaking days. The observation of microstructure through a scanning electron microscope revealed that gelatinized acorn flour showed loser their original shape and structure than that of with out soaking treatment (0-0). The degree of gelatinization under the fixed temperature increased with increasing soaking days. From these results, it might be concluded that the increase of soaking days and soaking times is the factor affecting the gelatinization of acorn flour.

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Degree of Gelatinization of Cooked Sweet Potatoes by Different Cooking Methods (가열방법에 따른 고구마의 호화도 측정)

  • Shin, Mal-Shick;Ahn, Seung-Yo
    • Applied Biological Chemistry
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    • v.29 no.4
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    • pp.372-374
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    • 1986
  • Changes in moisture content and degrees of gelatinization during cooking of sweet potatoes by different cooking methods were studied. The samples were cooked by boiling, steaming, gas oven or microwave oven baking. Changes in the moisture content of sweet potato during cooking were +30.0% by boiling, +4.4% by steaming, -5.8% by gas oven baking, and -46.6% by microwave oven baking. The degrees of gelatinization of sweet potatoes were 83.8%, 75.7%, 73.0% and 67.7%, respectively.

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The Effects of Blending Starches on the Development of Plybond Strength of Two-ply Linerboard (삼성분 전분혼합에 의한 이겹지의 층간결합강도 개선)

  • Lee, Hak-Lae;Ryu, Jeong-Yong
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.39 no.4
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    • pp.14-20
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    • 2007
  • The effects of blending starches with different gelatinization temperatures on the development of ply-bond strength were systematically investigated using a three component mixture design technique. Oxidized corn starches with different gelatinization temperatures were blended with natural corn starch and sprayed for plybonding. Optimum blend ratio for maximizing plybond strength improvement for the starch blends was 40% of natural starch, 27% of oxidized starch with low gelatinization temperature and 33% of oxidized starch with high gelatinization temperature. Starch granules with the lowest gelatinization temperature gelatinizes at the lowest temperature, while the natural corn starch gelatinizes at later stage of drying. The improvement of plybond strength with starch blends were verified on machine trial as well. Plybond strength improvement obtained from the machine trial was lower than that achievable with handsheets, which was attributed to the lower internal bond strength of the linerboards made from recycled fibers.

Gelatinization Properties of Cowpea Flour (동부 앙금의 호화성질)

  • 이애랑;김성곤
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.22 no.1
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    • pp.40-47
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    • 1993
  • Gelatinization properties of the air-dried sediment of cowpea were investigated. The water-binding capacity of cowpea flour was drastically increased over the temperature range of 52~55$^{\circ}C$. The percent transmittance of flour suspension was linearly increased at temperature between $65^{\circ}C$ to 75$^{\circ}C$. The gelatinization temperature determined by differential scanning calorimetry was 63.4~76.$0^{\circ}C$. Cowpea flour showed a single-stage of swelling and a low solubility pattern. The minimum moisture content required for the gelatinization was 37.0% . The amylograph peak viscosity was greatly influenced by concentration of the flour, but was not affected by heating temperatures (85~94$^{\circ}C$) at a given concentration. The 20 min height and cold viscosity at 3$0^{\circ}C$ at a fixed concentration was negatively correlated (p<0.05) with heating temperatures.

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Effect of Phosphate on Gelatinization of Rice Starch (인산염이 쌀전분의 호화에 미치는 영향)

  • Kim, Il-Hwan;Kim, Sung-Kon;Lee, Kyu-Han
    • Korean Journal of Food Science and Technology
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    • v.17 no.1
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    • pp.5-7
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    • 1985
  • Effect of phosphate (sodium polyphosphate 85%, sodium hexametaphosphate 7% and potassium phosphate 7%) on gelatinization of nonwaxy and waxy rice starches was investigated with X-ray diffractometry. The minimum moisture content for the gelatinization of nonwaxy starches was lowered in the presence of phosphate. The minimum temperature for the gelatinization of 5% starch suspensions was not altered by phosphate. However, the degree of gelatinigation of rice starches at the same temperature was higher in the presence of phosphate, except waxy rice starch.

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Production of Alcohol from Starch without cooking: A chemical gelatinization method (무증자(無蒸煮)전분법에 의한 알코올생산(生産): 화학적(化學的) 호화법(糊化法))

  • Park, Kwan-Hwa;Oh, Byung-Ha;Lee, Ke-Ho
    • Applied Biological Chemistry
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    • v.27 no.1
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    • pp.52-54
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    • 1984
  • Ethanol fermentation from the chemically gelatinized starchy material was examined. The critical concentration of sodium hydroxide solution for gelatinization was dependent on the species of starch; 0.4M for potato and 0.6M for tapioca at room temperature. For alcohol fermention the starchy material was gelatinized by addition of sodium hydroxide solution, neutralized by sulfuric acid, and then yeast was added. The amount of $CO_2$ evolved during ethanol fermentation indicates that non-fermentable material was not produced from the starch by chemical gelatinization. In ethanol fermentation of potato and tapioca starch no significant difference was observed between the thermal and the chemical gelatinization.

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Improvement of Gelatinization, Saccharification and Panfrying Processes of Nochi, a Traditional Korean Rice Cake (노치 제조방법의 공정개선에 관한 연구)

  • 이영춘;이종미;윤희정
    • Korean journal of food and cookery science
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    • v.13 no.4
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    • pp.384-389
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    • 1997
  • Attempts were made to improve gelatinization, saccharification and panfrying processes for mass production of Nochi, a kind of traditional Korean rice cake. Gelatinization of waxy rice powder with 20-55% of moisture content were completed within a minute at 120$^{\circ}C$ or above by using the extrusion cooker. Among enzymes tested for liquefaction and saccharification of the gelatinized rice, in place of malt, BAN (0.53%)+${\beta}$-amlyase (4.27%) was the most suitable enzymes for the production of Nochi. Panfrying process of Nochi was drastically shortened by heating Nochi dough for 1 minute in a microwave oven and subsequently panfrying at 150$^{\circ}C$ for 7 minutes.

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Effect of Ohmic Heating on Thermal and Water Holding Property of Starches (옴가열이 전분의 열적 특성과 흡수력에 미치는 영향)

  • Cha, Yun-Hwan
    • The Korean Journal of Food And Nutrition
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    • v.27 no.1
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    • pp.112-119
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    • 2014
  • Ohmic heating uses electric resistance heat which occurs equally and rapidly inside food when the electrical current is transmitted into. Prior to the study, we have researched the potato starch's thermal property changes during ohmic heating. Comparing with conventional heating, the gelatinization temperature and the range of potato starch treated by ohmic heating are increased and narrowed respectively. Herein, we have studied thermal property changes of wheat, corn, potato and sweet potato starch by ohmic heating as well as conventional heating. And then we measure the water holding capacity of starches. Annealing of starch is a heat treatment method heated at 3~4% below the gelatinization point. This treatment changes the starch's thermal property. In the DSC analysis of this study, the $T_o$, $T_p$, $T_c$ of all starch levels have increased, and the $T_c$-$T_o$ narrowed. In the ohmic heating, the treatment sample is extensively changed but not with the conventional heating. From the ohmic treatment, increases from gelatinization temperature are potato ($8.3^{\circ}C$) > wheat ($5.3^{\circ}C$) > corn ($4.9^{\circ}C$) > sweet potato ($4.5^{\circ}C$), and gelatinization ranges are potato ($7.9^{\circ}C$), wheat ($7.5^{\circ}C$), corn ($6.1^{\circ}C$) and sweet potato ($6.8^{\circ}C$). In the case of conventional treatment, water holding capacity is not changed with increasing temperature but the ohmic heating is increased. Water holding capacity is related to the degree of gelatinization for starch. This result show that when treated with below gelatinization temperature, the starches are partly gelatined by ohmic treatment. When viewing the results of the above, ohmic treatment is enhanced by heating and generating electric currents to the starch structure.

Physicochemical Properties of Extruded Rice Flour and Gelatinization Popped Rice Flour (제조 방법이 다른 팽화미 분말의 이화학적 특성)

  • Lee, Jung-Eun;Kim, Yu-Jin;Cho, Mun-Gyeong;Park, Shin-Young;Kim, Eun-Mi;Cho, Yong-Sik;Choi, Yoon-Hee
    • The Korean Journal of Food And Nutrition
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    • v.25 no.4
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    • pp.850-854
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    • 2012
  • This study is carried out in order to develop food materials for the promotion of rice consumption. In this study, we researched the physicochemical properties of extruded rice flour (ER) and gelatinization popped rice flour (GPR) by the extrusion process and by the popped method with milled rice and brown rice. The extrusion process used a couple of screw extruders. The extrusion parameter was kept constant at a feed moisture content of 25%, barrel temperature of $120^{\circ}C$ and screw speed of 400 rpm. GPR was prepared by batch popping machine after gelatinization of rice. In order to evaluate the physicochemical properties of ER and GPR, as well as the gelatinization rate, water soluble index (WSI), water adsorption index (WAI), DPPH radical scavenging activity and total dietary fiber content, the color value was carried out. The gelatinization rate was similar to 71.1~73.8%. Further, the results of WSI and WAI were increased at ER and GPR compared to the raw materials; ER was also higher than GPR. DPPH radical scavenging activity and total dietary fiber content showed a tendency to reduce after extrution and popping. As a result of the color value, the L value of ER decreased more than the raw materials, whereas GPR increased at a and b values.