• 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.

• 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.

• 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.

• The Korean Journal of Food And Nutrition
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• v.25 no.4
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• pp.1068-1074
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• 2012

Ohmic heating uses electric resistance heat which occurs equally and rapidly inside of food when electrical current is flown into. In other study, we researched about soybean protein's characteristic changes by ohmic heating. Nevertheless treated same temperature, denaturation of soybean protein were accelerated by ohmic heating than conventional heating. In this time, we studied thermal property change of potato starch by ohmic heating besides conventional heating. For this purpose, potato starch was heated at same subgelatinization temperature by ohmic and conventional heating. And thermal properties were tested using DSC. Annealing of starch is heat treatment method that heated at 3~4% below the gelatinization point. DSC analysis results of this study, the $T_o$, $T_p$, $T_c$ of potato starch levels were increased, whereas $T_c{\sim}T_o$ was narrowed. This thermal property changes appear similar to annealing's result. It is thought the results shown in this study, because the heating from below the gelatinization point. 6, 12, 24, 72, and 120 hours heating at $55^{\circ}C$ for potato starch, $T_o$, $T_p$, $T_c$ values continue to increased with heating time increase. The gelatinization temperature of raw potato starch was $65.9^{\circ}C$ and the treated starch by conventional heating at $55^{\circ}C$ for 120 hr was $72^{\circ}C$, ohmic was $76^{\circ}C$. The gelatinization range of conventional (72 hr) was $10^{\circ}C$, ohmic was $8^{\circ}C$. In case of 24 hours heating at 45, 50, 55, 60, $65^{\circ}C$ for potato starch, the result was similar to before. $T_o$, $T_p$, $T_c$ values continue to increased and gelatinization range narrowed with heating temperature increase. In case of conventional heating at $60^{\circ}C$, the results of gelatinization temperature and range were $70.1^{\circ}C$ and $9.1^{\circ}C$. And ohmic were $74.4^{\circ}C$ and $7.5^{\circ}C$. When viewed through the results of the above, the internal structure of starch heated by ohmic heating was found that the shift to a more stable form and to increase the homology of the starch internal structure.

• Food Science and Biotechnology
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• v.16 no.5
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• pp.663-674
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• 2007

Starches from different botanical sources differ in the ratio of amylose to amylopectin contents, molecular structures of amylose and amylopectin, granule morphology, and minor-component contents. These structural features result in different gelatinization, pasting, retrogradation properties, and enzyme digestibility of starch granules. In this review, compositions and molecular structures of starches and their effects on the physicochemical properties are summarized and discussed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.1
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• pp.17-24
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• 1997

The effects of steeping on the physicochemical and gelatinization characteristics of glutinous rice flour and its starch were studied. Steeping conditions were 1 day at 25"C,7 days at 2iC and 7 days at 35"C. Crude protein, lipid and ash content were decreased br steeping. It was observed with scanning electron microscopy that endosperm cell wall of glutinous rice flour was diminished by steeping. Although morphology of the glutinous rice starch granules was not affected, the size was decreased by steeping. Density and water binding capacity(WBC) of glutinous rice flour and its starch were changed by steeping. X-ray diffraction pattern of glutinous rice starch was A type and was not affected by steeping. Swelling power of glutinous rice flour and its starch was increased but solubility was decreased by steeping. In Brabender amylographic examination, peak viscosity of untreated glutinous rice flour was very low and increased enormously by steeping resulting in the similar Brabender viscosity pattern to its starch. The gelatinization temperature examined by X-ray diffractometry was lowered by steeping. And the degree of gelatinization under the conclusion temperature increased with increasing of steeping Period and temperature.mperature.

• The Korean Journal of Food And Nutrition
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• v.23 no.2
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• pp.147-153
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• 2010

Sulgidduk samples containing 1, 2, and 4% Adenophora remotiflora powder and a control were examined for moisture content, gelatinization property, color, textural characteristics, and sensory qualities to determine the optimal ratio of Adenophora remotiflora powder in the formulation. The highest viscosity, lowest viscosity, final viscosity, setback and breakdown decreased as the contents of Adenophora remotiflora powder increased in the gelatinization property of flour blends of rice cake made with Adenophora remotiflora powder. The water content of rice cake with Adenophora remotiflora powder was 40.54~41.30% and there was no significant difference between samples with Adenophora remotiflora powder. L values indicating brightness were highest in the control group and all of the a values displayed green color indicating that they were negative. The b values were lowest in the control group and the values increased as the level of Adenophora remotiflora powder increased. Evaluation of the mechanical characteristics of rice cake with Adenophora remotiflora powder, hardness, cohesion, adhesion and chewiness were all higher in the control group and as its contents were rich, such properties were reduced. In addition, there was no significant difference between adhesion and chewiness. Adhesion and elasticity were low in the control group and as its contents were rich, such properties increased. The results of the sensory test revealed that the, control group containing 1% Adenophora remotiflora powder had the highest color, flavor, taste and overall preference.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.38 no.2 s.115
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• pp.43-51
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• 2006

Starch is widely used as an adhesive material in the paper and corrugated board industry. The adhesion problem of corrugated board is categorized by two main parts called zipper board and white glue line. The object of this research is to investigate the factors affecting the adhesion problem by the gelatinization of various starch solutions and dynamic penetration properties measurements of various commercial base paper and handsheets. Flow property of starch solution is affected by sodium hydroxide addition and reaction level. Absorption property of commercial base papers and handsheets is affected by sizing and stock composition. Optimum bonding between top/bottom liners and corrugated medium is accomplished by acceptable flow viscosity of mixed starch solution and proper adsorption characteristic of base paper.

• Korean journal of food and cookery science
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• v.18 no.2
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• pp.179-184
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• 2002

This study was carried out to investigate the effects of adding prickly pear (Opuntia ficus-india var. Sabolen) on the quality characteristics of Jeung-Pyun, a traditional fermented Korean rice cake, and to find out an appropriate ratio of prickly pear powder to give a favorable color. Changes in the quality characteristics of prickly pear-added Jeung-Pyun during storage period were also studied. As the addition of prickly pear powder was increased from 1 to 3%, the degrees of expansion and gelatinization of Jeung-Pyun were increased. The degree of gelatinization and hardness were changed slowly during storage at room temperature (20$^{\circ}C$). In sensory evaluation, control Jeung-Pyun samples without prickly pear powder was preferred to that with prickly pear powder, but it was not significant up to 2% prickly pear powder. In the case of Jeung-Pyun containing 2% prickly pear powder, those stored for 12 hr received higher sensory scores than those right after being manufactured. In general, Jeung-Pyun samples with 2% prickly pear powder was favored. The addition of prickly pear powder was likely to improve the preservation property of Jeung-Pyun.

• Korean Journal of Food Science and Technology
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• v.31 no.2
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• pp.564-567
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• 1999

Gelatinization characteristics of pigmented rice varieties were determined in terms of amylose contents, amylograph, gel consistency, water absorption index (WAI) and water soluble index (WSI). Amylose contents of black and red rice were lower than those of brown rice, especially Sanghaehyanghyulla exhibited the lowest amylose contents among the pigmented rice varieties tested. There was no significant difference in WAI among the pigmented rice varieties, but WSI was lower in red rice than the others. Peak viscosity of black rice measured in a Brabender amylograph was lower than those of red and brown rice.