• The Korean Journal of Food And Nutrition
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• v.6 no.3
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• pp.189-198
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• 1993

This study was carried out to investigate the effect of medium-cooked rice on brewing of yakju which was a traditional rice wine in Korea. The influences of cooking temperature of rice on hydrolysis of rice starch and rice protein were tested, and experimental brewings were done according to the traditional brewing method of Bangmunju in which some medium-cooked rice was used. The results obtained were as follows The hydrolysis of starch and protein in medium-cooked rice at 60~$65^{\circ}C$ was easier than that of full-cooked rice at 80~10$0^{\circ}C$. The amounts of saccharides, total amino acids and extracts In Yakju brewed with the combined use of medium-cooked rice and full-cooked rice were twice as much as those brewed with full-cooked rice only. The results of sensory test of Yakju brewed with the combined use of medium-cooked rice and full-cooked rice were better in taste, color and flavor than those brewed with full-cooked rice only. It was thought that our ancestor's traditional brewing method of Yakju in which medium cooked rice and full-cooked rice were used combinedly was excellent Judging from zymological point of views.

• Korean Journal of Food Science and Technology
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• v.26 no.1
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• pp.98-101
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• 1994

The amount of added water for rice cooking was determined by extrusion test and sensory evaluation of cooked rice. The extrusion force was positively correlated with hardness and negatively correlated with moisture content and wetness of cooked rice. The extrusion force and moisture content of cooked rice were 57.9 kg and 62.3% respectively at the 'medium' wetness (neither too hard and dry nor too soft and watery) of cooked rice. The optimum water to rice ratio for the cooked rice haying 'medium' wetness was 1.46.

• The Korean Journal of Food And Nutrition
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• v.21 no.4
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• pp.463-469
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• 2008

To make of basic date for the progressive global brand of Korean rice, we compared with characteristics of Calrose and two Korean rice cultivar, Chucheongbyeo(medium-late maturing cultivar) and Odaebyeo(early-maturing cultivar). General characteristics of rice, pasting property of rice flour by Rapid visco Analyser, determination of optimal ratio of water to rice for cooking by electric and pressure cooker and eating quality(sensory evaluation) of Calrose with that of Korean rice cooked at the optimal cooking conditions were measured. One kernel length of Calrose, Chucheongbyeo and Odaebyeo were 6.00, 4.73 and 5.22 mm, respectively. Calrose showed higher viscosity(195 RVU) in all parameters than Korean rices(Chucheongbyeo 176 RVU, Odaebyeo 178 RVU), of which the values were similar. These data imply that the properties of starch of Calrose may be different from that of Korean rice. In general, it is agreed, in Korea and Japan, that the balance of hardness and stickiness of cooked rice is very important. However, stickiness and overall eating quality for cooked Calrose was significantly poorer than Korean rices. Cooked Calrose did not significantly different in hardness, stickiness and overall eating quality compared with those of Korean rices. Calrose cooked with the ratio of water to rice of 1.4 with electric cooker was less sticky than Korean rices and thus was poorer in eating quality compared with Korean counterparts. Calrose cooked with the ratio of water to rice of 1.3 with pressure cooker had the same eating quality with Korean rices.

• Korean Journal of Food Science and Technology
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• v.21 no.4
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• pp.486-491
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• 1989

The textural properties of cooked rice and the molecular weight distribution of amyloses of three rice cultivars different in cooking quality were investigated by the method involving rheometry and gel chromatography he tested rice cultivals were Chunmabyeo (short grain), Yongmunbyeo (medium grain) and Mahatma (long grain) The cooked rice prepared with Mahatma was higher in hardness and lower in adhesiveness than those prepared with the other two cultivars. The molecular wright distribution of amylose from Mahatma was found to be higher than those from the other cultivars.

• 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.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.1
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• pp.72-84
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• 1993

This study was carried out to understand the varietal variation in physicochemical properties of rice grain and those environmental changes by different transplanting time, and to elucidate the interrelationships among the factors related with eating quality of cooked rice. Fifty three rice samples, among which fifty samples were harvested at ordinary or late transplanted plots of the Crop Experiment Station in Suwon and three samples were harvested orpurchased from Niigata prefecture in Japan, were tested for various physicochemical components of rice grain and some physical factors of cooked rice. All of twenty seven rice cultivars tested were the recent-bred Korean japonica rice showing the wide range of maturity from early to medium-late heading and considerable difference in palatability of cooked rice. Amylose content, taste value by Nireco palatability tester (TVN), iodine blue color of cooking extracts(IB), and the ratio of IB /extracted solid amounts (ES) increased significantly by late transplanting, while viscosity (VN) and Mg / K. N value by Nireco tester, hot-water absorption of milled rice (HA), loss tangent of cooked rice by Rheolograph-Micro(LT), and most viscogram characteristics except setback viscosity (C-P) decreased drastically by late transplanting as compared with ordinary transplanting. Most of physicochemical properties of milled rice revealed narrower varietal variation in lately transplanted plot than in ordinary transplanted one. Protein content (PRO), volume expansion rate of cooked rice(VE), C-P and all physical factors of cooked rice by Rheolograph-Micro showed almost negligible seasonal variation, while amylose content (AM), VN, HA, IB/ES, peak viscosity(P), hot viscosity(H) and breakdown(P-H) viscosity exhibited considerably large seasonal variation. The early-headed varieties revealed lower amylose content and smaller seasonal variation of IB/ES compared with medium or medium-late headed rice varieties. AM was closely associatied with IB and IB / ES and VN was highly correlated with Mg/K. N and TVN in both ordinary and late transplanted plots. VN also was highly negatively correlated with cooking characteristics and highly positively correlated with viscogram properties in ordinary culture. PRO was closely connected with moisture content of milled rice and L T in ordinary transplanted plot. IB, which was closely connected with ES, was also singificantly associated LT, P and P-H in ordinary seasonal culture. IB/ES was highly negatively correlated with P, P-Hand P-H / C-P in ordinary culture but with LT and dynamic viscosity of cooked rice in late seasonal culture. The thirty rice cultivars were largely classified into two varietal groups by cluster analysis with physicochemical properties related with eating quality of cooked rice. Korean and Japanese high-quality rice cultivars were separately distributed in two respective varietal group.

• Journal of Nutrition and Health
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• v.27 no.8
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• pp.856-863
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• 1994

To develop a optimized method for educing the errors associated with the estimation of portion size of foods, fuzzy-dta processing of portion size was performed. Cooked-rice was chosen as a food item. The experiment was conducted in two parts. First, to study the conceptions of respondents to bowl size(large, medium, small), 11 bowls of different size and shape were used and measured the actual weights of cooked-rice. Second, to study the conceptions of respondents to volume(1, 1/2, 1/3, 1/4), 16 different volumes of cooked-rice in bowls of same size and shape were used. Respondents for this study were 31 graduate students. After collecting the data of respondents to size and volume, fuzzy sets of size and volume were produced. The critical values were calculated by defuzzification(mean of maximum method, center of area method). The differences of the weights of cooked-rice in various bowl size and volume between the critical values and the calculated values by average portion size using in conventional methods were compared. The results hows large inter-subject variation in conception to bowl size, especially in large size. However, conception of respondents to volume is relatively accurate. Conception to bowl size seems to be influenced by bowl shape. Considering that the new fuzzy set was calculated by cartesian product(bowl size and volume), bowl shape should be considered in estimation of bowl size to make more accurate fuzzy set for cooked-rice portion size. The limitations of this study were discussed. If more accurate data for size and volume of many other food items are collected by the increased number of respondents, reducing the errors associated with the estimation of portion size of foods and rapid processing will be possible by constructing computer processing systems.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.16 no.1
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• pp.37-43
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• 1983

The effects of pH, sodium chloride and potassium sorbate on the germination of Bacillus cereus spores in the medium of cooked rice homogenate were studied. At the range of pH $4.5{\sim}10.0$, the germination of spores were observed. Germinated spores were reached to the number of $10^7/ml$ within 5 hours at $32^{\circ}C$ under the condition of pH 7.0, which was found as optimum pH of germination. In the range of sodium chloride $2{\sim}10\%$, the maximum growth were exhibited under $2\%$ concentration, while it proportionally decreased under the salinity condition higher than $5\%$. The growth of Bacillus cereus were inversely related to the concentration of potassium sorbate within the range of $0{\sim}0.2\%$. Maximum sporulation ratio was observed under the culturing condition: $10\%$ NaCl and $0.2\%$ potassium sorbate in the medium of cooked rice homogenate.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.325-325
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• 2022

In order to developing high-quality rice varieties and processing varieties, systematic and stable evaluation of physicochemical properties is required for breeding lines. In this study, we compared the quality characteristics evaluation results of rice breeding lines for cooked rice, special rice, and whole crop silage rice adapted to central plain region (Suwon) in order to use as basic data for future rice variety development. Brown rice length/width ratio, head rice ratio, protein content, amylose content, alkali digestion value(ADV) and Toyo value were analyzed to evaluate the quality characteristics of yield trial lines cultivated in Suwon for four years (2017-2020). Brown rice length/width ratio, head rice ratio, protein content, ADV and Toyo values showed significant differences by year, but there was no significant difference in amylose content (p<0.05), which showed little environmental variation. The head rice ratio and Toyo value showed an increasing trend, while the protein content showed a decreasing trend. However, the protein content was the highest in 2020, which is thought to be owing to little sunlight hours due to heavy rainfall in 2020. The protein content of whole crop silage rice was 8.1%, which was significantly higher than that of other lines (p<0.05). Toyo value of medium-maturing and early-maturing lines were 67.6 and 73.7%, respectively, and the Toyo value of medium-maturing lines was higher than that of the early-maturing lines (p<0.05). In correlation analysis among the quality characteristics of the rice lines for cooked rice, significant positive correlations were detected between Toyo value and head rice ratio, amylose content, ADV, and a negative correlation was observed between Toyo value and protein content (p<0.05).

• Korean Journal of Food Science and Technology
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• v.42 no.3
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• pp.361-367
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• 2010

Bacterial contamination of cooked rice was analyzed to evaluate the microbial safety. Thirty raw rice samples were collected in Korea and cooked in an electric rice cooker. Mesophilic aerobe, food-poisoning Bacillus cereus group, and their toxin genes were determined on cooked rice. The percentage of total mesophilic aerobe based on 1-3 log CFU/g was 27% among the samples. Bacillus spp. in MYP selective medium was similar to the number of mesophilic aerobe, whileas Bacillus spp. was detected in most samples after enrichment. Thirty-seven isolates from 30 cooked rices were identified as B. thuringiensis, B. cereus, B. valismortis, B. pumilus, B. coagulans, B. licheniformis, Geobacillus stearothermophilus, and Brevibacillus laterosporus. Twenty isolates (54%), more than half of the isolates, were B. thuringiensis while nine (27%) were identified as B. cereus. All B. thuringiensis isolates possessed non-hemolytic toxin genes and interestingly, seven B. cereus among nine isolates possessed emetic toxin genes. More B. thuringiensis was present on the cooked rice than B. cereus and most B. cereus possessed emetic toxin genes rather than diarrheal toxin genes. Therefore, food-borne outbreak due to B.cereus on the cooked rice kept at room temperature might be examples of emetic food-poisoning.