• The Korean Journal of Food And Nutrition
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• v.30 no.3
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• pp.464-472
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• 2017

The qualities of rice cooked on heat plate, induction heat and heat plate with pressure, were investigated. The weight, volume, water soluble index (WSI), hydration by SEM (Scanning Electron Microscope), and gelatinization by DSC (Differential Scanning Calorimetry), as well as the consumer acceptability of cooked rice were analyzed. The weight, volume and WSI of rice cooked on heat plate with pressure were higher than those of rice cooked on heat plate and induction heat. The rice cooked on heat plate with pressure also showed higher degree of hydration and gelatinization, and lower degree of enthalpy of gelatinization than the rice cooked on heat plate and induction heat for 5~15 min. The consumer acceptability revealed that the odor, appearance, taste, texture and overall acceptance of rice cooked on induction heat were better than those of rice cooked on heat plate and heat plate with pressure. During storage in a cooker for 0~12 h, there was a decrease in the consumer acceptability of cooked rice. Overall results indicate that the qualities of rice cooked on induction heat and heat plate with pressure were higher than those of rice cooked on heat plate.

• Korean Journal of Food Science and Technology
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• v.21 no.5
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• pp.613-618
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• 1989

Tirteen rice varieties of Japonica-Indica briefing type (J-I breeding type) and ten of Japonica type produced in Korea in 1985 were studied on cooking quality of milled rice and texture of cooked rice. The results are as follows: in the Looking quality, water uptake ratio of cooked rice and total solid in residual liquid showed significant $(p<2.172^*\;and\;2.419^*,\;respectively)$ between J-I breeding type and Japonica type The water uptake ratio of cooked rice was higher J-I breeding type than Japonica type but the total solid and intensity of iodine blue value in residual liquid were lower J-I breeding type than Japonica type. Minimum cooking time of milled rice showed significant $(p<2.375^*)$ between J-I breeding type and Japonica type for texture of cooked rice. The cooking time of J-I breeding type shorter than Japonica type. Hardness and cohesiveness in texture of cooked rice appeared to be significant cant $(p<4.370^{***}\;and\;2.371^*,\;respectively)$ between J-I breeding type and Japonica type, and then hardness was higher Japonica type than J-I breeding type, but cohesiveness was lower Japonica type than J-I breeding type. The correlation coefficients between amylose content and adhesiveness of varieties in the same type was $-0.922^{**}$ in J-I breeding type and $-0.915^**}$ in Japonica type. The correlation coefficients between protein content and hardness of the varieties in the same type was $0.954^{**}$ in Japonica type and so denoted as positive correlation. And the scatter diagram between protein and hardness could be divided into J-I breeding type and Japonica type.

• Korean journal of food and cookery science
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• v.9 no.1
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• pp.25-29
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• 1993

This study was attempted to enhance taste and quality value of cooked rice by adding fat, vinegar, cellulose in cooking water. Cooked rice with five different levels of material in cooking water (100% water A: 10% vinegar B: 10% fat C: 10% fat and 10% vinegar D: 10% fat, 10% vinegar and 10% celloulose) was tested for rheology, fine structural changes, sensory evaluation, in vitro digestion. 1) Cooked rice by adding 10% fat rate was higher than A, B, D, E samples for softness, Jelly and increased in vitro digestion. 2) sensory evaluation conducted by tweenty university students a panelists showed that B, D sample were low value in flavour, texture and taste, but higher than A sample for softness, Jelly and in Vitro digestion. 3) E sample (l0% fat, 10%s vinegar, 10% cellulose) was more significant for taste, texture, and digestion than A sample. From these results, it was concluded that rice cooked with 10% of fat in cooking water was quite acceptable, in terms of practical food value consisting of palatability rheology and digestibility.

• The Korean Journal of Food And Nutrition
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• v.29 no.5
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• pp.605-609
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• 2016

This study aimed to find the optimum instrumental test conditions for the Texture Profile Analysis (TPA) of cooked rice in order to predict the sensory texture attributes (hardness, adhesiveness, chewiness). Sensory evaluation was performed for three kinds of instant cooked rice with university students in their twenties and the results of the sensory evaluation were compared to instrumental TPA patterns. Using partial least squares regression, the instrumental TPA results at a cross-head speed of 1.0 mm/sec and a compression ratio of 70% proved to be an excellent predictor of the sensory attributes of hardness ($R^2=0.99$) and chewiness ($R^2=0.99$). The results at a cross-head speed of 0.5 mm/sec and compression ratio of 30% provided an excellent model for the prediction of sensory adhesiveness ($R^2=0.83$). In this experimental range, sensory hardness and chewiness showed a high correlation with instrumental TPA parameters (hardness, cohesiveness, adhesiveness, springiness, chewiness) with a high cross-head speed and compression ratio, while sensory adhesiveness showed a high correlation with the TPA parameters with a low cross-head speed and compression ratio.

• Culinary science and hospitality research
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• v.20 no.3
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• pp.161-170
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• 2014

Making jungkwa, a traditional Korean snack, is difficult and complicated. In this study, a rice cooker was used to simplify the process of making jungkwa made with ginseng. Comparing ginseng jungkwa cooked in a rice cooker with the control group cooked in a traditional way, their chewiness, browness, glossy and overall preference were similar when cooked for 160 minutes, 175 minutes, 190 minutes, 205 minutes, and 220 minutes. The moisture content of ginseng jungkwa cooked in a rice cooker decreased, while its sugar content increased with increased cooking time. Also, the ginseng jungkwa had lower lightness and higher redness and yellowness as its cooking time got longer. The ginseng jungkwa cooked for 205 minutes was most similar to the one cooked in a traditional way. In the measurement of texture, the ginseng jungkwa had higher hardness with increased cooking time, and, when cooked for 205 minutes, it was most similar to the one cooked in a traditional way in chewiness. The sensory evaluation showed that the one cooked for 205 minutes was most preferred in appearance, smell, taste, texture and overall preference. Based on these results, this study revealed that using a rice cooker can be substituted for the traditional way of making jungkwa.

• Korean Journal of Food Science and Technology
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• v.52 no.3
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• pp.310-315
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• 2020

The aim of this study was to investigate the texture change of cooked rice within a short time after cooking. Using four instant rice brands, the texture change within 30 min after cooking was measured by the texture profile analysis (TPA) method for hardness, adhesiveness, cohesiveness, chewiness, and springiness with different compression ratios (30, 70%) and cross-head speeds (0.5, 1.0 mm/s). In the case of cohesiveness, adhesiveness, and chewiness, there were significant differences in the rice textures at 20 to 30 min after cooking compared to that in the sample immediately after cooking. In particular, adhesiveness showed significant differences at 10 min after cooking. However, there were little significant differences within 30 min for springiness. In conclusion, when measuring cooked rice texture, it is desirable to measure it, if possible, within 10 to 20 min after cooking.

• The Korean Journal of Food And Nutrition
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• v.23 no.4
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• pp.600-606
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• 2010

The objective of this study was to develop functional rice coated with yacon roots extracts and to evaluate the antioxidant properties and physiological activity of rice coated with yacon extract. The washed rice was coated by spraying yacon extract at 10, 20, 30, and $40^{\circ}Brix$ and dried at room temperature. The moisture contents, color changes, antioxidant properties as total polyphenolics and DPPH radical scavenging activity and instrumental texture property and sensory evaluation change in the yacon root extracts coated rice and uncoated cooked rice were observed during 3 days of storage. Increasing the coating concentration was associated with lower color values(L value) and moisture contents. Total phenolics and DPPH radical scavenging properties generally increased in the cooked rice coated with yacon root extract more than the control (non-coated rice). However, D-20($20^{\circ}Brix$ of the yacon root concentration) resulted in better textural properties and sensory overall acceptability in cooked rice on 0 and 3 storage days. It was concluded that the optimum coating ration of rice and added functional yacon rice were $20^{\circ}Brix$ and 7% respectively, in proportion to the total weight of raw rice.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.3
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• pp.504-512
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• 1996

Changes in quality of cooked rice after microwave reheating were evaluated. Ceramic coated microwave oven reduced a reheating time(1 min). Storage temperature, storage time and microwave reheating did not affect the color value of cooked rice after microwave reheating. Hardness of cooked rice after microwave reheating decreased in frozen storage treatment. Photomicrographs of cross-section of cooked rice after microwave reheating showed restoration of starch. Effect of storage temperature and time were not significant in appearance, aroma, taste and texture of cooked rice after microwave reheating for sensory evaluation test.

• Korean Journal of Food Science and Technology
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• v.34 no.2
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• pp.213-219
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• 2002

This study was investigated cooking conditions of cooked milled rice added 5%, 7%, 9% and 11% ratios of waxy black and glutinous rices. The L value (lightness) of cooked milled rice added waxy black and glutionus rices were decreased according to increase added ratios, the a value (redness) of waxy black rice was decreased and b value (yellowness) of glutinous rice was increased while waxy black rice was decreased. In case of cooked milled rice added 9% glutinous rice, it was showed the highest values for springiness, cohesiveness, chewiness, adhesiveness and adhesiveness/hardness ratio except gumminess and hardness and all parameters of waxy black rice in texture analyser was showed the highest values at 9%, but the other parameters except cohesiveness were no significant difference at p<0.05 level. In sensory evaluation, the cooked milled rice added 9% glutinous rice was showed the highest values for flavor, clumpiness and taste and 11% glutinous rice was showed the highest values for color, glossiness, cohesiveness, hardness, adhesiveness and acceptability. Also the cooked milled rice added 9% waxy black rice was showed the highest values for cohesiveness, taste and acceptability and 11% waxy black rice was showed the highest values for flavor, color, glossiness, clumpiness, hardness and adhesiveness. Correlations between sensory parameters of cooked milled rice added waxy black rice and glutinous rice were found a significant relationship between taste and acceptability and the correlation coefficients of cooked milled rice added waxy black rice and glutinous rice were r=0.7153 and r=0.5760, respectively.

• 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.