• Title, Summary, Keyword: gelatinization

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Studies on Gelatinization Characteristics of Some Starches by Differential Scanning Calorimetry (DSC에 의한 전분의 호화 특성에 관한 연구)

  • Kong, Jai-Yul;Kim, Min-Yong
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.17 no.2
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    • pp.144-148
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    • 1988
  • Differential scanning calorimerty(DSC) was used to study gelatinization phenomena of defatted rice, corn, wheat, potato starch and nondefatted rice and wheat starch at heating rate $5{\sim}15^{\circ}C/min$. Gelatinization temperature of defatted rice and wheat starch indicated $4{\sim}5^{\circ}C$ lower temperature than nondefatted starch. More rapid heating rate resulted in a increasing of the gelatinization enthalpy for various starches. A linear relation was observed between water content, heating rate and gelatinization temperature. From the linear relationship existing between water content and gelatinization enthalpy, minimum water content for the gelatinization were 41, 38, 33 and 30% of rice, potato, wheat and corn starch, respectively.

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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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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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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.

Microstructural Changes of Starch Aqueous Solutions during Gelatinization and Retrogradation Studied through X-ray Scattering (X-선 산란을 이용한 전분의 호화와 노화 과정중의 미세구조 변화)

  • Kang, Min Kwan;Jeon, Hye-Jin;Song, Hyun Hoon
    • Textile Science and Engineering
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    • v.51 no.1
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    • pp.7-13
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    • 2014
  • Microstructural changes of potato and corn starch aqueous solutions associated with their gelatinization and retrogradation processes were examined through the use of small- and wide-angle X-ray scattering. It was found that the structural changes during these two processes were dominantly affected by the amount of phospholipids and phosphates contained in the starch. The phosphates contained in the amylopectin of the starch granule allow easy penetration of water into the structure, thus causing easy swelling or high solubility. This simultaneously allows greater freedom of chains, thus causing the recrystallization of the chains during the retrogradation process. On the other hand, in corn starch, which contains a lower amount of phosphates and a complex structure formed between phospholipid and amylose, the chain movements are much reduced, resulting in a higher gelatinization temperature and a reduction of recrystallization during retrogradation and a broad distribution of crystal size. In both starches, a micro-phase separated inhomogeneous structure was suggested in the amorphous state above the gelatinization temperature, which appears to be associated with the presence of highly branched amylopectin units.

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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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 ${\beta}-Glucan$ on Gelatinization of Barley Starch (${\beta}-Glucan$이 보리 전분의 호화에 미치는 영향)

  • Choi, Hee-Don;Seog, Ho-Moon;Kim, Sung-Ran;Park, Yong-Kon;Lee, Cherl-Ho
    • Korean Journal of Food Science and Technology
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    • v.35 no.4
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    • pp.545-550
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    • 2003
  • The effect of ${\beta}-glucan$ on gelatinization of barley starch was studied. By the rapid visco-analyzer measurement, gelatinization of starch became rapid and viscosity increased largely on the RVA pattern by addition of ${\beta}-glucan$ to starch. The results of differential scanning calorimeter showed that molecular structure of starch was getting stabilized through shifting up of gelatinization temperature and increase in enthalpy by addition of ${\beta}$-glucan. X-ray diffraction pattern also showed the same results as differential scanning calorimeter. But it was revealed that addition of ${\beta}$-glucan to starch didn't affect characteristics such as microscopic observation, solubility, swelling power, and iodine binding properties during gelatinization of starch.