• Current Research on Agriculture and Life Sciences
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• v.29
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• pp.1-10
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• 2011

This study was conducted to determine the agronomic characteristics of low amylose lines which were derived from induced mutants by T-DNA insertion. The agronomic and physicochemical properties of the low amylose mutants were analyzed and compared with a donor cultivar 'Dongjin' and a low amylose cultivar 'Baekjinju'. The heading date of the low amylose mutants was similar to the donor cultivar 'Dongjin' and yield index of the mutants was 78~92% compared with 'Dongjin'. The amylose content of four mutants in brown rice was ranged from 16.1 to 16.7%. Among low amylose mutants, 'P50-4-4-5' was lower 3.6%(13.3%) than those of 'Dongjin'(16.9%) in amylose content of milled rice. The grain length of 'P50-4-4-5' was similar to the donor cultivar, however, thousand grain weight(18.9g) was lighter than those of 'Dongjin'. The score of alkali digestion in brown rice of 'P50-4-4-5'(5.5) was lower than that of 'Dongjin'(6.8) and similar to 'Baekjinju'(5.8). The gel consistency of 'P50-4-4-5'(84mm) in milled rice exhibited that was longer than 'Dongjin'(76mm) and 'Baekjinju'(81mm). The result of eating quality showed that 'P50-4-4-5'(78.8) was higher than those of 'Dongjin'(60.3) and 'Baekjinju'(67.2). Thus our data suggest that 'P50-4-4-5' will facilitate the development of a new cultivar with low amylose rice.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.20
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• pp.142-147
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• 1975

The varietal variations of protein and amylose content of rice grown at field and green house were studied. The protein content was negatively correlated with growth duration, and the amylose content was positively correlated with heading date. The environmental variation of the amylose content by cultural season and year was greater in the low amylose varieties than in the high amylose one.

• Korean journal of food and cookery science
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• v.33 no.1
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• pp.87-93
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• 2017

Purpose: Rice starch is known not to be suitable to Mook. Its gel is not hard and elastic enough and too sticky. This study investigated the effects of agar, carrageenan, and gelatin addition on low amylose rice flour paste and gel properties for making Mook. Methods: Angemi, low amylose rice, and Goamibyeo, intermediate amylose rice, were dry milled. The properties of Mook were determined by texture profile analysis (TPA), cold storage stability, and sensory acceptance. Results: Addition of agar and carrageenan increased cold paste viscosity, whereas addition of gelatin decreased cold paste viscosity while improving breakdown and setback viscosity. When 30% of gelling agents such as agar, carrageenan, and gelatin were added to low amylose rice, Angemi, Mook-like gels were formed. The hardness, adhesiveness, and springiness of gelling reagent-added Angemi Mook increased, whereas cohesiveness decreased, and fracturability was not observed. The addition of gelling agent decreased lightness and increased yellowness. Angemi Mook added with gelatin showed the best freeze-thaw stability while addition of agar and carrageenan increased syneresis. The carrageenan-added Angemi Mook was equal to Goamibyeo 100% Mook in all sensory acceptance properties without significant difference. Conclusion: Above results suggest that addition of carrageenan and gelatin to low amylose rice can be used to produce Mook with improved physical properties.

• Korean Journal of Food Science and Technology
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• v.25 no.3
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• pp.264-269
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• 1993

Molecular structural properties of legume starches were investigated. In intrinsic viscosity and degree of Polymerization of amylose and amylopectins, cow pea and mung bean were high, but kidney bean was low. Low molecular weight fractions for kidney bean starch were much eluted by gel chromatography. In the elution profiles of their amylose by Sepharose 2B-CL, molecular weight of kidney bean amylose was smaller than that of other amylose Molecular weights of cow pea and mung bean amyloses were large, but that of kidney bean amylose was small and red bean amylose was medium. The elution profiles by Sephadex G-50 after debranching amylopectins with pullulanase showed similar patterns.

• Korean Journal of Food Science and Technology
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• v.21 no.6
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• pp.766-771
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• 1989

physicochemical properties of rice starch isolated from eight varieties were examined to evaluate the rice processing suitability The amylose contents of rice starch were varied with 16.7-29.7%, and IR 30, Godael, Aguja and Lengkwang varieties showed higher amylose content than the other varieties. The water binding capacity and blue value were in the range of 87.0 103.0 and 0.178-0.305, respectively. As the amylose content increased, the amylogram pasting temperature and the break down ratio increased, while the peak viscosity did not show any significant difference. The transmittance of 0.1% starch suspension slowly increased at $50^{\circ}C$ in the low-amylose content rice group, and rapidly increased at $65^{\circ}C$ in the high-amylose content rice group, but there were no differences above $75^{\circ}C$ among varieties. Also the low-amylose rice starch showed higher values in the swelling power and solubility. The hardness of the 30% rice starch gels was low in low-amylose one. During storage at $20^{\circ}C$ for 14 days, the increment of hardness was more slow in high-amylose one. The retrogradation velocity constant of rice starch gel by Avrami equation was the highest as 0.219 in Aguja variety.

• 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.

• 한국전자현미경학회:학술대회논문집
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• 2005.05a
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• pp.26-26
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• 2005

• The Korean Journal of Community Living Science
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• v.17 no.2
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• pp.61-68
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• 2006

This Study was conducted to investigate the processing quality of high-amylose content rice(goami) flour for noodle. The potassium and magnesium contents of rice flour were negatively associated with gross score of noodle making mixed with wheat flour. The high-amylose content of rice flour was closed associated with gel consistency negatively and with hardness of rice noodle positively, Setback viscosity of rice flour measured in a rapid visco-analyser(RVA) was significantly affected by amylose content as well as gel consistency. Also the amylose content decreased, the amylogram pasting temperature and the breakdown ratio increased. The low-amylose content rice(Chucheong) flour showed higher values in solubility. Cooking quality and texture were measured, and sensory evaluation was performed with the noodles prepared. Texture measurement showed that the noodles of composite flour containing 40% goami rice flour were superior to those wheat flour alone. Water binding capacity of the composite flour containing 40% goami rice flour was lower than that of 40% chucheong rice flour. In sensory evaluation, chewiness, overall acceptability of noodle with 40% goami ricer was evaluated as the best.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.2
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• pp.86-97
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• 2018

The objective of this study was to determine the effects of low temperature on starch accumulation in rice grains. We used four major Japonica-type Korean rice cultivars as materials: Jinbu (JB), Junamjosaeng (JJ), Geumyoung (GY), and Hwawang (HW). Rice plants were moved into two phytotrons the day after heading. Temperatures in the two phytotrons were maintained at $19/29^{\circ}C$ (night/day) as the control, and $13/23^{\circ}C$ as the low temperature condition, both under natural daylight with a relative humidity of 65%. The ripening rates of JB and JJ showed no significant difference between the low temperature and control conditions at 45 days after heading (DAH). In contrast, the ripening rates of GY and HW were 86% and 57% lower than those of JB and JJ under the low temperature condition at 45 DAH, respectively. However, the ripening rates of these four varieties at 61 DAH (when accumulated temperature reached $1,100^{\circ}C$) under the low temperature condition were similar to those at 45 DAH under the control condition (JB, 94%; JJ, 97%; GY, 97%; HW, 88%). The total starch contents showed no significant difference between the control and low temperature conditions. However, the amylose contents in the cultivars were higher under the low temperature than under the control condition. The enzyme activities of starch biosynthesis were about 5-10 days slower in cultivars under the low temperature than under the control. The grain-filling rate showed significant correlations with the enzyme activities of SuSase ($r^2=0.70^{***}$), AGPase ($r^2=0.63^{***}$), UDPase ($r^2=0.36^{***}$), StSase ($r^2=0.51^{***}$), and SBE ($r^2=0.59^{***}$). In conclusion, although StSase activity was increased at $13/23^{\circ}C$ up to 20 DAH, there might not be enough time for SBE to synthesize amylopectin, thus affecting the amylose content of HW, which had the slowest grain filling rate. Notably, the decreased activity of SuSase and SBE and late increase in AGPase activity under the low temperature during the ripening stage are considered to be disadvantageous, as they delay ripening and increase the amylose content.

• Korean Journal of Food Science and Technology
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• v.30 no.3
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• pp.590-595
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• 1998

Seven varieties (Suweonjo, Suweon232, BG276-5, IR44, IR41999-139, Suweon230 and Yongjubyeo) of rice were used to study for making rice bread by amylose content. Suweonjo had the highest amylose content (27.07%) and Yongjubyeo had the lowest one (17.17%). Suweonjo showed the highest volume after baking, while Yongjubyeo the lowest volume one. Volume and hardness of the rice bread decreased as amylose content decreased. The amylose content was not associated with hardness and color values of rice bread after baking. Sensory evaluation for internal parts of rice bread showed that score of air cell, color of crumb, aroma, taste, chewability and texture decreased as amylose content increased, while volume of rice bread increased. The low-amylose rice cultivar revealeded better suitability for rice bread.