• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.2
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• pp.179-186
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• 2008

This study was carried out to investigate the changes of brown rice, and cooking properties after milling of brown rice according to storage temperature and varieties. Brown rices were stored at $15^{\circ}C$ and $35^{\circ}C$ for 10 weeks. Tz values of brown rice stored at $35^{\circ}C$ were higher in Hwaseongbyeo, Koshihikari, Hitomebore, than the other varieties. The increasing rate of hardness of cooked rice in Odaebyeo, Junghwabyeo, Sangmibyeo stored at $35^{\circ}C$ were lower than those of other varieties. In stored brown rice at $15^{\circ}C$ and $35^{\circ}C$, correlations between pH of brown rice and fat acidity, hardness, b value of cooked milled rice and head rice rate of milled rice were significant $0.743^{**}$, $0.539^*$, $-0.693^{**}$, 0.250, respectively. At $15^{\circ}C$ and $35^{\circ}C$, correlations between L value and b value of cooked milled rice, head rice rate of milled rice were significant $-0.772^{**}$, $0.638^*$, and those between fat acidity of brown rice and consistency of milled rice were $0.604^*$. In brown rice stored at $15^{\circ}C$, It was higher quality of milled rice and cooked rice than those at $35^{\circ}C$ that increased head rice rates of milled rice and glossy value of cooked milled rice but lower color b value and hardness of cooked rice.

• Korean Journal of Food Science and Technology
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• v.19 no.5
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• pp.451-452
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• 1987

The effect of cook temperatures, 100-$120^{\circ}C$, on firming rate of cooked rice stored at $4^{\circ}C$ for 72 hours was studied. The cook temperatures had a definite effect in retarding the firming rate of cooked rice. The time constants, reciprocal of firming rate constants, of cooked rice cooked at $110^{\circ}C$ and $120^{\circ}C$ were 1.2 and 1.5 times greater, respectively, than that at $100^{\circ}C$. The total material available for crystallization and the Portion of material that durings storage were decreased as the cook temperature increased.

• Korean Journal of Food Science and Technology
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• v.29 no.1
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• pp.90-95
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• 1997

A study was conducted to investigate the effects of rice bran dietary fiber on wheat flour rheology and wet noodle quality. More than 99% of rice bran dietary fiber contained smaller particle size than $250\;{\mu}m$. The initial pasting temperature, peak and final viscosities in amylograph, and the water absorption and dough stability in farinograph increased with the increase of rice bran dietary fiber concentration. The lightness values decreased with the increase of rice bran dietary fiber concentration in raw noodles as well as cooked noodles. The addition of rice bran dietary fiber was not effective on the cooked weight and volume of cooked noodles. However, the cooking loss of cooked noodles was the highest in control, and increased with the increase of rice bran dietary fiber concentration. Most of texture parameters (hardness, adhesiveness, gumminess and chewiness) of cooked noodles increased, but the cohesiveness decreased with the increase of rice bran dietary fiber concentration. There were no significant differences in appearance, taste and acceptability of cooked noodles between control and noodles containing 3% and 6% rice bran dietary fiber.

• Korean Journal of Food Science and Technology
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• v.27 no.1
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• pp.105-111
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• 1995

The relationship betwwen the molecular structure of amylopectin and the texture of cooked rice was investigated using Korean rice [3 varieties of Japonica type and 3 varieties of Tongil type(Japonica-Indica breeding type)]. The molecular structure of rice amylopectin was polymodal and distributed A chain of $\overline{DP}$ 12.4, short B chain of $\overline{DP}$ 20.6, B chain of $\overline{DP}$ 26.3, long B chain of $\overline{DP}$ 45 and super long chain of above $\overline{DP}$ 55. The super long chain of amylopectin was composed of long linear chain with poorly branched chain. Also, the super long chain of amylopectin showed positive correlated with average chain length, inherent viscosity and ${\beta}-amyloysis$ limit$({\%})$, but negative correlated with ${\lambda}max$ of iodine reaction of amylopectin. The structural properties of amylopectin in Japonica type were different from those of amylopectin in Tongil type. In relationship between molecular structure of amylopectin and texture of cooked rice, the average chain length, inherent viscosity, ${\beta}-amyloysis$ limit and super long chain of amylopectin was showed a positive correlation with hardness, but a negative correlation with adhesiveness of cooked rice. The long chain of rice amylopectin is the less, the eating quality of cooled rice was the better. These results suggest that the molecular structure of rice amylopectin could be responsible for the texture of cooked rice.

• Journal of the Korean Society of Food Culture
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• v.24 no.1
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• pp.69-76
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• 2009

This study was conducted to determine the optimal cooking conditions for brown rice using an electric pressure rice cooker. The effects of steeping conditions and cooking pressure on the hydration, gelatinization, texture and palatable properties of cooked brown rice were evaluated. Based on water uptake and DSC data, the optimal steeping time and temperature for brown rice were determined to be 25 minutes and ${\sim}60^{\circ}C$, respectively. The cooking conditions for brown rice were then divided into the following 6 categories: steeping at $25^{\circ}C$ for 25 minutes and cooking at an atmospheric pressure of 1.7 (25P) or 1.9 (25HP), steeping at $57^{\circ}C$ for 25 minutes and cooking at an atmospheric pressure of 1.7 (57P) or 1.9 (57HP), steeping at $85^{\circ}C$ for 15 minutes and cooking at an atmospheric pressure of 1.7 (85P) or 1.9 (85HP). The susceptibility of cooked brown rice starch to degradation into maltose by ${\alpha}$-amylase, which is related to the degree of gelatinization and in vitro digestibility, were then determined. The amount of maltose produced by cooked brown rice samples was highest in the 57HP group, followed by the 57P and 85HP groups. Storing cooked brown rice at $73^{\circ}C$ for 24 hours resulted in significantly higher amounts of starch being degraded into maltose in the 57P, 57HP and 85HP groups than in the other groups. Textural analysis demonstrated that the 57P, 57HP and 85HP groups had significantly lower gumminess and chewiness values when compared to the other groups, and that 57HP received had the lowest hardness of all treatments. These results were confirmed by the results of the sensory evaluations. Furthermore, the 57P and 57HP groups were found to have a higher glossiness, stickiness aroma and taste score than the other groups. These findings were taken to indicate that steeping conditions and pressure exerted a positive synergistic effect on the cooking quality of brown rice. The texture analyzer also revealed that storing the cooked rice at $73^{\circ}C$ for 24 hours only led to significantly lower scores in gumminess, hardness and chewiness in the 57P and 57HP groups, which indicates that these groups underwent a lesser degree of retrogradation than other groups. Taken together, the results of the present study demonstrate that steeping brown rice at $57^{\circ}C$ for 25 minutes and a higher cooking pressure improved the palatability and in vitro digestibility of brown rice significantly.

• Culinary science and hospitality research
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• v.8 no.3
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• pp.267-278
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• 2002

To promote the consumption of race, comparative study was performed on characteristics of wheat flour noodle mixed with brown rice flour and colored rice flour. Protein content of colored rice was higher than that of the brown rice, but lipid and ash contents were similar to those of brown rice. Colored rice flour had significantly lower peak viscosity, holding viscosity, breakdown viscosity, final viscosity and setback viscosity than those of wheat flour, while brown rice had significantly higher peak viscosity, breakdown viscosity and setback viscosity than those of colored rice flour and wheat flour. Colored rice and brown rice had 5.3~6.4% total dietary fiber, and the proportions of soluble fiber in total dietary fiber were quite low, ranging from 9.4% to 18.8%. L(brightness), a(redness) and b(yellowness) of raw noodles were measured using a colorimeter. L(brightness) and b(yellowness) values of Asian raw noodles made from colored rice and brown rice significantly decreased. Addition of colored rice flour and brown rice flour to Asian noodle reduces cutting forces of dry and cooked noodles. The cooked noodle with 10% chalheukmi waxy rice flour was the highest in the cutting force of cooked noodle. Addition of 20% chalheukini waxy rice flour and 20% brown rice flour to wheat flour was got to a relatively high score for appearance, color, texture, taste and overall eating quality from sensory evaluation of cooked noodles.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.2
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• pp.96-104
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• 2017

This study was carried out to compare the cooking and antioxidant characteristics of rice containing varying amounts of glutinous rice and cooked by two methods. Rice containing glutinous rice was cooked by general and high-pressure cooking methods with and without fermented alcohol. Pasting characteristics of cooked rice were decreased with increasing amounts of glutinous rice. The water binding capacity and swelling power were significantly decreased with increasing amounts of glutinous rice; however, water solubility indices were significantly increased. Palatability characteristics of cooked rice containing glutinous rice were similar to those of cooked rice without glutinous rice. Total polyphenol contents of cooked rice containing glutinous rice and fermented alcohol were quite different, but this difference was not significant. Total flavonoid contents were increased with increasing amounts of glutinous rice. Total flavonoid content by general cooking method for rice containing 20% glutinous rice and fermented alcohol was $23.20{\pm}0.61{\mu}g\;CE/g$. DPPH radical-scavenging activities for samples with and without glutinous rice were 2.97-5.19 and 3.19-5.45 mg TE/100 g, respectively. ABTS radical-scavenging activity by high-pressure cooking method for rice containing 20% glutinous rice and fermented alcohol was $19.48{\pm}0.63mg\;TE/100g$. In this study, cooking and antioxidant characteristics of cooked rice containing glutinous rice generated data useful for manufacturing processed products.

• Korean Journal of Food Science and Technology
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• v.28 no.5
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• pp.877-881
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• 1996

The firming rate of cooked rice stored at $4^{\circ},\;20^{\circ}$ and $30^{\circ}C$ were analyzed. The initial and limiting firmness of cooked rice were decreased as the moisture content increased from 57.5 to 69.5%. The firming rate was inversely related to the storage temperature, but was fairly constant at moisture content between $60.5{\sim}65.9%$. The activation energy and $Q_{10}$ value for firming of cooked rice was $-4.07{\times}10^3\;cal/mole$ and 1.26, respectively. No significant difference in firming rate was observed among rice cultivars.

• Korean Journal of Food Science and Technology
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• v.24 no.5
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• pp.511-514
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• 1992

The effects of soaking conditions (time and temperature) of rice on the water absorption behaviors and the consequent textural properties after cooking were investigated. Water absorption during soaking was completed in 30 min at $23^{\circ}C$, while the hydration continued up to 60 min at $4^{\circ}C$. The hardness (H) of the cooked rice decreased, while the stickiness (S) and S/H ratio increased with increased soaking time. Soaking at $23^{\circ}C$ gave higher values of S and S/H of cooked rice than soaking at $4^{\circ}C$. Soaking for $10{\sim}40\;min$ at $4^{\circ}C$ or for $10{\sim}20\;min$ at $23^{\circ}C$ resulted the value of S/H between 0.15 and 0.20, which had been found at acceptable textural parameters of the cooked rice.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.2
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• pp.137-145
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• 1990

Six commercial rice varieties were cultivated at different locations in 1987 and 1988. Rice samples harvested from 8 to 20 locations for a variety each year were used to measure or observe grain appearance, amylose content and alkali digestibility, cooked rice texture using rheometer, gelatinization and viscosity of rice flour using amylograph, and eating Quality of cooked rice by sensory evaluation. Relationship between Quality characteristics showing large locational variation were analized to approach the long-term objective, rice grain Quality standardization. Percent white-center and white-belly grain of the same variety showed great variation between locations, but did not affect on 1000-grain weight, amylose content and alkali digestibility, amylogram and rheogram characteristics, and eating Quality of cooked rice. Positive correlationship were obtained between maximum viscosity and break down, and maximum viscosity and alkali digestibility. Set back was correlated negatively with maximum viscosity, break down and alkali digestibility. Rice samples having significantly lower values of maximum viscosity and break down and higher set back value at the same time showed higher ADV and lower texture palatability index (TPI) and viscousness/hardness ratio (Vi/H), and lower sensory evaluation score of cooked rice compared with those of rices having typically higher values of maximum viscosity and break down and lower set back value. When TPI, Vi/H and overall sensory eating score of cooked rices measured were divided into three categories, high, medium and low using deviation from locational mean value of a variety, many of rice samples having high TPI or high Vi/H showed medium or high in overall sensory eating score of cooked rice.