• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.1
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• pp.87-92
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• 2005

This study was investigated to examine gelatinization properties of waxy black rice starches. X-ray diffraction patterns in raw starches showed traditional A type of cereals. The crystalline regions of both black rice and Shinsunchalbyeo starches disappeared when temperature increased to $65^{\circ}C$ where the crystalline regions of two starches changed to amorphous ones. Scanning Electron Microscope showed that granule type of Shinsunchalbyeo starch was more collapsed compared to that of black rice starch heated at 6$0^{\circ}C$. Gelatinization in both samples completed when samples were heated at 63$^{\circ}C$. The results by Differential Scanning Calorimetry (DSC) revealed that gelatinization patterns were similar in both samples. In Rapid Visco Analyzer examination, there was no difference in peak viscosity, breakdown, final viscosity and setback between Shinsunchalbyeo and waxy black rice starches.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.3
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• pp.226-232
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• 2012

Through the sampling four rice cultivars with differing amylose contents, the relationship between the structural and gelatinization properties of endosperm starches was analyzed. These rice varieties exhibited different chain length distribution ratio within the amylopectin cluster as well as varing amylose levels. The proportion of amylopectin short chains of in Goami cutlivars was higher than the other varieties, whereas the Goami 2 which shows amylose extender mutant properties in the endosperm showed the highest proportion of long chains. In X-ray diffraction analysis of rice starches, the Goami 2 variety displayed a B-type pattern whereas the other varieties were all A-type. Among the cultivars with high and normal rice starch levels, those with the higher amylose contents showed distinctly lower swelling. Goami 2 rice was found to have the highest onset and peak gelatinization temperature from the differential scanning calorimetry results. The four rice cultivars under analysis also showed different rates of hydrolysis by amyloglucosidase. These findings suggest that the composition and chemical structure of the starch content is a major determinant of both the gelatinization and functional properties of rice.

• Korean Journal of Food Science and Technology
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• v.36 no.2
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• pp.288-293
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• 2004

Differential scanning calorimetry (DSC) was used to study effects of sucrose and gluten on wheat starch glass transition, gelatinization, and retrogradation. Glass transition temperature ($T_{g}$) of wheat starch decreased as the ratio of sucrose or gluten to starch increased. Both peak temperature ($T_{G}$) and enthalpy values of gelatinization endotherm increased or decreased with increasing ratio of sucrose or gluten, respectively. Wheat starch gel with no sucrose and gluten recrystallized up to 4 weeks of storage at $4^{\circ}C$, whereas those with sucrose and gluten completed recrystallization within 1 week. Both wheat starch gels with no sucrose and gluten, and those with sucrose and gluten at storage temperature of $32^{\circ}C$ recrystallized up to 4 weeks, with wheat starch-sucrose-gluten (1 : 0.5 : 0.12) system, which had highest ratios of gluten and sucrose to starch, showing lowest recrystallization. Nucleation and propagation rates of starch gel recrystallization based on polymer crystallization principles can be converted into peak width (${\delta}T$) and peak temperature ($T_{R}$) of retrogradative endotherm by DSC, because higher nucleation rate at storage temperature of $4^{\circ}C$ close to $T_{g}$ showed higher ${\delta}T$, whereas higher propagation rate at $32^{\circ}C$ (close to $T_{G}$) had higher $T_{R}$.

• Korean journal of food and cookery science
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• v.21 no.6 s.90
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• pp.877-887
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• 2005

This study determined the effects of soybean oil$2\%$) and chitosan($1\%$) on the quality characteristics of Omija Jelly made of various starches (mungbean starch, cowpea starch and corn starch). RVA(Rapid Visco Analyzer) viscosity was measured for starches suspended in Omija aextract with $2\%$ soybean oil and $1\%$ chitosan. The color value, syneresis, texture(rupture test and TPA test) and sensory properties of the samples were measured. Gelatinization of cowpea starch was expedited by adding soybean oil and chitosan. Otherwise, gelatinization of mungbean starch and com starch was retarded by adding chitosan. The lightness(L) and the syneresis of Omija Jelly with soybean oil and chitosan were decreased, indicating the increased transparency and stability of Omija Jelly. Rupture stress and rupture energy of Omija Jelly were decreased by adding soybean oil. Rupture stress was increased and rupture energy was decreased by adding chitosan. The addition of soybean oil improved texture of Omija Jelly, indicating that the springiness, cohesiveness and chewiness of Omija Jelly were increased and adhesiveness was decreased. By adding chitosan, the springiness and hardness of Omija Jelly were increased and the cohesiveness and adhesiveness were decreased. The overall acceptability of Omija Jelly made of $6%$ or $7\%$ cowpea starch and com starch was increased by adding soybean oil and chitosan, but the quality characteristics of Omija Jelly made of mungbean starch were not influenced by additives such as soybean oil and chitosan.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.6
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• pp.738-747
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• 1992

The important legumes in Korea are mungbean, red bean, kidney bean and cowpea. Mungbean has traditionally been used for mook (jelly-like starch gel) preparation. Cowpea has recently been utillized for substitution of mungbean. The major use of sediment of red bean is for the sweet paste. The studies related to legume starches and flours (air-dried sediment) in Korea are concentrated on the understanding of the properties of mook. The structure of starch, gelatinization and gelling properties of legume starches and flours are reviewed with emphasis of Korean literatures.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.2
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• pp.35-46
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• 2023

The transplanting period limit considering the rice yield in the Dague region, the inland plains of Gyeongsangbuk-do, was estimated to be July 15^th for early and mid-maturing rice and July 5^th for mid-late maturing rice. However, as the transplanting time was delayed, the characteristics of rice starch changed significantly. In the case of early and mid-maturing rice varieties, the starch granule size increased as the transplanting time was delayed; the opposite tendency was observed for mid-late maturing varieties. In all mature rice types, the late transplanting resulted in a longer pasting time and a higher pasting temperature. In addition, the peak viscosity, breakdown, and gelatinization temperature were significantly lowered, the relative crystallinity degree decreased, and the setback was significantly increased. In the case of Ilpum, a mid-late maturing rice variety, the distribution of amylopectin short chains tended to increase when rice was transplanted on June 30^th.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.3
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• pp.99-105
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• 2023

Starch characteristics and pasting properties of Tongil-type rice varieties with different amylose content were analyzed. Three different Tongil-type rice varieties and one Japonica-type rice variety were examined for their properties. Tongil-type rice varieties have longer panicles and higher rice yield (721-765 kg per 10a) than Boramchan, a Japonica-type high-yield rice variety. The protein content of the Tongil-type rice variety was higher than that of Boramchan. Japonica-type rice varieties had lower amylose content than Japonica-type rice varieties, except for Amimyeon (Milyang355). Amimyeon had higher protein content than the other varieties, and its amylose content was particularly high at 39.2%. The distribution of starch granule sizes of the four varieties was similar, and the particle size corresponding to D50 was approximately 87.8-81.9 ㎛. The pasting properties of rice flour varied among varieties. The Dasanbyeo and Hanarum2 amylogram patterns were similar. These two varieties had a higher peak viscosity (PV) and lower setback (SB) than Boramchan. In the case of Amimyeon, the hot paste viscosity (HPV), cool paste viscosity (CPV), and SB were significantly higher than those of the other Toingil-type varieties, and the breakdown (BD) was very low, showing pasting properties significantly different from that of the other varieties. The onset (T_o), peak (T_p), and conclusion temperature (Tc) of gelatinization of rice flour from Amimyeon were lower than those of the other tested varieties. In addition, the gelatinization temperature, measured using differnetial scanning calorimetry (DSC), and BD, measured using al rapid visco analyzer (RVA) were low in Amimyeon. Amylose content showed a high positive correlation with pasting time (PTi), HPV, and SB and a negative correlation with PV and BD.

• Applied Biological Chemistry
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• v.34 no.4
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• pp.360-365
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• 1991

Rheological properties of Shinsunchalbyeo(Japonica) and $Hangangchalbyeo(J{\times}Indica)$ waxy-rice starches gelatinized with thermal or alkali solutions were investigated with rotational viscometer(Brabender Viscotron). The two starches showed Bingham pseudoplastics behavior in $4{\sim}8%$ thermal or alkali gelatinized starch solutions. The shear stress of Hangangchalbyeo starch solution gelatinized with thermal or alkali showed higher values than that of Shinsunchalbyeo starch and the difference of the two varieties gelatinized with alkali showed higher values than that gelatinized with thermal. Consistency index and yield stress values of Hangangchalbyeo starch showed higher than that of Shinsunchalbyeo starch in the two gelatinized methods and the difference of the two varieties gelatinized with alkali showed higher values. And it was higher that the deffendence of consistency index on starch concentration and initial starch concentration of yield stress in the alkali gelatinized samples than those of in the thermal gelatinized ones.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.3
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• pp.436-442
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• 1997

Corn starch was extruded under relatively low shear, high moisture, and low temperature. Puffing of corn starch dough was induced by injecting $CO_2$gas in the range from 0MPa to 0.09MPa. Piece density and compressive modulus for puffed corn starch were decreased by increasing the injection pressure to 0.07MPa, and increased above 0.07MPa. the microstructure of corn starch puffed with $CO_2$gas showed thick cell size, compared with those puffed with steam. RVA paste viscosity curves of corn starch puffed with $CO_2$had different patterns from those puffed with steam, probably resulted from partial gelatinization of starch. Water absorption and solubility were not significantly changed by $CO_2$injection pressure, but the average degree of polymerization was reduced by higher $CO_2$injection. The water absorption, water solubility, and the average degree of polymerization for corn starch puffed with $CO_2$were significantly lower than those puffed with steam.

• Korean Journal of Food Science and Technology
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• v.25 no.4
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• pp.334-339
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• 1993

Physicochemical properties such as amylose content, swelling power, gelatinization and DSC of legume starches were investigated. The granule shape of legume starches was oval. The size of cowpea and mung bean were smaller than kidney bean and red bean. The amylose content of mung bean and kidney bean was larger and were $25{\sim}29%$. Swelling power of kidney bean starch was much lower than other starches in all temperature range. In gelatinization temperature by Brabender amylogram, red bean starch was low, but kidney bean starch was rather high. Amylographic hot-paste viscosity and set back of cow pea, mung bean and red bean starches were high. But those of kidney bean starch were very low. DSC results Indicated kidney bean starch gelatinized in higher temperature. From above results, row pea and mung bean starches were similar in granule size and shape, solubility and swelling power, amylogram, and DSC thermogram. But kidney bean starch was very different and red bean starch was slightly different with the physicochemical properties of cow pea and mung bean starches.