• Title, Summary, Keyword: gelatinization

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Comparison of Gelatinization Properties of Japonica and Tongil Brown Rice Starches (일반계와 통일계 현미전분의 호화성질 비교)

  • 변기원
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.21 no.4
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    • pp.428-435
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    • 1992
  • Intrinsic viscosity and gelatinization properties of brown rice starches of Japonica and Tonsil type cultivars were investigated. The intrinsic viscosity was similar between the two cultivars. The gelatinization temperature of Japonica brown rice starch determined by differential scanning calorimetry was higher than that of Tonsil brown rice starch. However, the range of gelatinization temperature, gelatinization enthalpy and the water content for gelatinization were similar between the two starches. The treatment of starch at 6$0^{\circ}C$ for 24hr increased the gelatinization temperature and gelatinization enthalpy and decreased the range of geltinization temperature. The water content for gelatinization was negatively correlated with the range of gelatinization temperature in case of Japonica starch and with the intrinsic viscosity in case of Tonsil one. The in-trinsic viscosities of both Japonica and Tonsil starches were positively correlated with gelatinization enthalpy.

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Changes in Gelatinization Properties of Potato Starch by Microwave Heating Methods (마이크로파 가열방법에 따른 감자전분의 호화특성 변화)

  • Choi, Ock-Ja;Koh, Moo-Seok;Shin, Mal-Shick
    • Korean Journal of Food Science and Technology
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    • v.26 no.6
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    • pp.696-703
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    • 1994
  • The purpose of this study was to investigate the gelatinization properties of potato starch heated with microwave. Two types of potato starches were prepared; In group A raw potato starch was heated with microwave and in group B potato starch was isolated from potato heated with microwave. Both groups were exposed to the microwave energy in a 560W, 2,450 MHz oven for 60, 120, 180 and 300 seconds. Gelatinization behaviour by DSC made a few differences according to the ratio of starch to water. As the microwave heating time took longer, gelatinization temperature and gelatinization $enthalpy({\bigtriangleup}H_1)$ were decreased in and melting $enthalpy({\bigtriangleup}H_2)$ was increased in group A. Whereas they were increased in group B. In both groups, maximum viscosity in gelatinization by Brabender amylogram was decreased by microwave heating. Then the peak of the maximum viscosity was shifted to higher temperature and cold viscosity was slightly increased. In group A, viscosity in gelatinization and light transmittance by NaOH was increased in initial stage and gel volume in gelatinization by KSCN was decreased. On the other hand, in group B, viscosity by alkali was slightly decreased, but light transmittance by NaOH was almost never changed. Gel volume is decreased like group A.

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Bran structure and gelatinization properties of upland waxy rice starch (밭벼 찹쌀의 겨층 구조와 전분의 호화 성질)

  • Kim, Sung-Kon
    • Applied Biological Chemistry
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    • v.34 no.1
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    • pp.75-76
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    • 1991
  • Bran structure and gelatinization property of upland and lowland japonica waxy brown rice were compared. Dimension, weight and number of aleurone layer were similar between upland(Nonglimna 1) and lowland(Shinsunchalbyeo) rices, but the aleurone layer and pericarp of upland rice were thicker. Water uptake rate of upland rice at $60^{\circ}C$ was lower than that of lowland one. There was no difference in intrinsic viscosity between two rice starches. Upland rice starch had lower onset temperature, narrower gelatinization temperature and lower water content lot gelatinization compared with lowland rice starch.

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Gelatinization Characteristics of Glutinous Rice Varieties

  • Kim, Kwang-Ho;Park, Hong-Sook;Kim, Jae-Sung
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.44 no.1
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    • pp.64-69
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    • 1999
  • Gelatinization characteristics of 111 glutinous rice varieties were evaluated by Rapid Visco Analyzer. Gelatinization viscosity of glutinous rice tested varied with ecotypes or varietal groups: indica, japonica, and Tongil type. Indica rice showed the highest average value of initial pasting temperature. The average values for peak, hot, and cool viscosities were highest in Tongil-type rice, and lowest in japonica rice. Japonica showed the lowest breakdown and consistency, but the highest setback value. Indica was lower in alkali digestion value (ADV), and shorter in gel length after gelatinization thanjaponica and Tongil-type. Glutinous rices tested could be divided into six groups by cluster analysis based on their gelatinization characteristics. Group I-A was mostly early maturing japonica varieties while I-B was mostly indica and Tongil-type rices. Groups II-A and II-B were consisted of very early maturingjaponica, and III-A and III-B included medium or medium late maturingjaponica varieties. Group III-A showed the lowest average values of peak, hot, cool, and consistency viscosities, and also in breakdown and setback ratios. Group I-B revealed the highest values in peak, hot, cool, breakdown, and consistency viscosities. ADV was low in groups I-A, I-B, and II-B, and gel consistency was not different among the six varietal groups. Principal component analysis using seven traits related with gelatinization produced four effective components, and the first and second components were highly correlated with all the gelatinization characters evaluated.

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Physiochemical Characteristics of Corn Starch during the Alkali Gelatinization (알칼리 호화에 따른 옥수수전분의 특성)

  • Cho, Seok-Cheol;Shin, Hae-Hun
    • Korean Journal of Food Science and Technology
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    • v.39 no.6
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    • pp.637-643
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    • 2007
  • In this report, we discussed the physiochemical characteristics of corn starch during the alkali gelatinization process. Here, solubility and the amounts of eluted polysaccharides and amyloses increased in proportion to the amount of alkali added. The X-ray diffraction patterns and DSC thermogram showed that in the early stage of alkali gelatinization, crystallinity of the starch granules was disrupted as compared with heat gelatinization. This resulted in the eluted amylose content, while granule sizes were hardly changed in the alkali treated corn starch. The endotherm peak in the DSC thermogram shifted toward a higher temperature region as the degree of gelatinization increased, suggesting that the retained starch granules were more compactly crystallized during alkali gelatinization than during the heat process. Thus, we concluded that during the alkali gelatinization of corn starch, the disruption of weak particles would occur first, before swelling of the granules.

Alkali Gelatinization of Corn Starch Suspension (옥수수전분 현탁액의 알칼리 호화)

  • Shin, Hae-Hun;Cha, Yun-Hwan;Pyun, Yu-Ryang;Cho, Seok-Cheol
    • Korean Journal of Food Science and Technology
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    • v.39 no.2
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    • pp.169-174
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    • 2007
  • In this study, we examined the characteristics of alkali gelatinization of corn starch. Here, the degree of corn starch gelatinization increased exponentially with the NaOH concentration of the starch slurry. The alkali gelatinization initiation point (AGIP) was obtained from the intersection point of gelatinization slope line, which resulted from the regression of the logarithmic degree of gelatinization, and was markedly changed. The effects of temperature and corn starch concentration on alkali gelatinization were studied with a 10%(w/w) corn starch suspension. We found that this corn starch suspension gelatinized in 24.1 meq/g starch of NaOH at $40^{\circ}C$, and in 9.8 meq NaOH/g starch at $60^{\circ}C$. Moreover, a 40%(w/w) corn starch suspension gelatinized with 9.5 meq NaOH/g starch, even at $40^{\circ}C$. These results indicate that the amount of alkali added for the gelatinization of corn starch has an inverse relationship with the temperature and concentration of corn starch.

Effects of Amylose Contents and Degree of Gelatinization of Rice Flour on In Vitro Starch Digestibility, Physical Characteristics, and Morphological Properties

  • Park, Ji Eun;Bae, In Young;Oh, Im Kyung;Lee, Hyeon Gyu
    • Food Engineering Progress
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    • v.21 no.4
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    • pp.341-350
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    • 2017
  • The relationship of in vitro starch digestibility and gel strength was investigated at various concentrations (10-30%) of rice cultivars with different amylose contents (27.9, 17.9, and 5.2%). As the rice flour concentration increased, predicted glycemic index decreased, but gel strength increased regardless of amylose contents. Gel strength correlated strongly with amylose content, whereas in vitro starch digestibility was more highly affected by rice flour concentration than by amylose contents. Moreover, the impact of degree of gelatinization on in vitro starch digestibility of high amylose rice was also examined in terms of structural features and rheological properties. The digestion rate of fully gelatinized flour was 1.7 times higher than that of native flour, while the disrupted structure with a different gelatinization degree during starch digestion was visually demonstrated through the X-ray diffraction and molecular distribution analysis. The rice flour changed from an A-type to a V-type pattern and showed difference in crystalline melting. The low molecular weight distribution increased with increasing degree of gelatinization during starch digestion. The apparent viscosity also increased with degree of gelatinization. These results demonstrated that the starch digestibility of rice was more affected by concentration than by amylose content, as well as by the degree of gelatinization due to structural difference.

Antioxidative Activities and Gelatinization Characteristics of Sponge Cake added with Purple Sweet Potato (자색고구마를 첨가한 스펀지케이크의 항산화성 및 호화 특성)

  • Kim, Jong-Hee;Lee, Kun Jong
    • Journal of the East Asian Society of Dietary Life
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    • v.23 no.6
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    • pp.750-759
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    • 2013
  • In the study, purple sweet potato sponge cake was prepared with different ratios of purple sweet potato powder in order to examine the antioxidative activities and gelatinization characteristics. For DPPH radical scavenging effect, content of $IC_{50}$ came out with (+) control group of BHA. Sponge cake with purple sweet potato powder of 0% showed a range of 49.7 mg/mL, The treatment groups with purple sweet potato powder of 5~30% showed a range of 25.0 mg/mL~6.0 mg/mL. That was, the higher the added quantity of purple sweet potato powder was, antioxidative activities increased. With the higher quantity of purple sweet potato, the content of phenols and flavonoids also increased. As a result of examining the gelatinization activity with DSC, the group with purple sweet potato powder showed a faster progress in temperature for starting gelatinization compared to the control group. Gelatinization activity increased in proportion to the content of purple sweet potato powder. Based on the above study results, it was proved that there is a possibility to produce baking processed foods using purple sweet potato with stable gelatinization and excellent antioxidative activities.

Alkali Gelatinization of Rice, Corn, Arrow Root and Ginger Root Starches (쌀, 옥수수, 칡 및 생강 전분의 알카리 호화)

  • Kim, Sung-Kon;Chung, Hye-Min;Cho, Man-Hee
    • Applied Biological Chemistry
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    • v.27 no.3
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    • pp.214-216
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    • 1984
  • Alkali gelatinization of rice, corn, arrow root and ginger root starches at various sodium hydroxide concentrations was investigated. Critical concentrations of alkali for starch gelatinization ranged from 2.33 to 3.17 meq NaOH per gram of starch. Ginger root starch was most resistant to alkali gelatinization and arrow root starch was least stable to alkali.

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