• Proceedings of the Korean Journal of Food and Nutrition Conference
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• 2001.12a
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• pp.39-74
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• 2001

The endeavors enhancing the grain quality of high-yielding japonica rice were steadily continued during 1980s∼1990s along with the self-sufficiency of rice production and the increasing demands of high-quality rices. During this time, considerably great, progress and success was obtained in development of high-quality japonica cultivars and qualify evaluation techniques including the elucidation of interrelationship between the physicochemical properties of rice grain and the physical or palatability components of cooked rice. In 1990s, some high-quality japonica rice caltivars and special rices adaptable for food processing such as large kernel, chalky endosperm aromatic and colored rices were developed and its objective preference and utility was also examined by a palatability meter, rapid-visco analyzer and texture analyzer. The water uptake rate and the maximum water absorption ratio showed significantly negative correlations with the K/Mg ratio and alkali digestion value(ADV) of milled rice. The rice materials showing the higher amount of hot water absorption exhibited the larger volume expansion of cooked rice. The harder rices with lower moisture content revealed the higher rate of water uptake at twenty minutes after soaking and the higher ratio of maximum water uptake under the room temperature condition. These water uptake characteristics were not associated with the protein and amylose contents of milled rice and the palatability of cooked rice. The water/rice ratio (in w/w basis) for optimum cooking was averaged to 1.52 in dry milled rices (12% wet basis) with varietal range from 1.45 to 1.61 and the expansion ratio of milled rice after proper boiling was average to 2.63(in v/v basis). The major physicochemical components of rice grain associated with the palatability of cooked rice were examined using japonica rice materials showing narrow varietal variation in grain size and shape, alkali digestibility, gel consistency, amylose and protein contents, but considerable difference in appearance and torture of cooked rice. The glossiness or gross palatability score of cooked rice were closely associated with the peak. hot paste and consistency viscosities of viscogram with year difference. The high-quality rice variety “Ilpumbyeo” showed less portion of amylose on the outer layer of milled rice grain and less and slower change in iodine blue value of extracted paste during twenty minutes of boiling. This highly palatable rice also exhibited very fine net structure in outer layer and fine-spongy and well-swollen shape of gelatinized starch granules in inner layer and core of cooked rice kernel compared with the poor palatable rice through image of scanning electronic mcroscope. Gross sensory score of cooked rice could be estimated by multiple linear regression formula, deduced from relationship between rice quality components mentioned above and eating quality of cooked rice, with high Probability of determination. The ${\alpha}$ -amylose-iodine method was adopted for checking the varietal difference in retrogradation of cooked rice. The rice cultivars revealing the relatively slow retrogradation in aged cooked rice were Ilpumbyeo, Chucheongbyeo, Sasanishiki, Jinbubyeo and Koshihikari. A Tongil-type rice, Taebaegbyeo, and a japonica cultivar, Seomjinbyeo, shelved the relatively fast deterioration of cooked rice. Generally, the better rice cultivars in eating quality of cooked rice showed less retrogiadation and much sponginess in cooled cooked rice. Also, the rice varieties exhibiting less retrogradation in cooled cooked rice revealed higher hot viscosity and lower cool viscosity of rice flour in amylogram. The sponginess of cooled cooked rice was closely associated with magnesium content and volume expansion of cooked rice. The hardness-changed ratio of cooked rice by cooling was negatively correlated with solids amount extracted during boiling and volume expansion of cooked rice. The major physicochemical properties of rice grain closely related to the palatability of cooked rice may be directly or indirectly associated with the retrogradation characteristics of cooked rice. The softer gel consistency and lower amylose content in milled rice revealed the higher ratio of popped rice and larger bulk density of popping. The stronger hardness of rice grain showed relatively higher ratio of popping and the more chalky or less translucent rice exhibited the lower ratio of intact popped brown rice. The potassium and magnesium contents of milled rice were negatively associated with gross score of noodle making mixed with wheat flour in half and the better rice for noodle making revealed relatively less amount of solid extraction during boiling. The more volume expansion of batters for making brown rice bread resulted the better loaf formation and more springiness in rice bread. The higher protein rices produced relatively the more moist white rice bread. The springiness of rice bread was also significantly correlated with high amylose content and hard gel consistency. The completely chalky and large gram rices showed better suitability for fermentation and brewing. Our breeding efforts on rice quality improvement for the future should focus on enhancement of palatability of cooked rice and marketing qualify as well as the diversification in morphological and physicochemical characteristics of rice grain for various value-added rice food processings.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.3
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• pp.276-280
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• 1991

The quality changes of brown rice during storage were determined by the method of quantitative analysis of n-hexanal, amylogram, texture and volume expansion. The qualities of stored brown rice were also analyzed with sensory evaluation of cooked milled rice obtained from brown rice, n-Hexanal content, peak viscosity and total setback of brown rice flour pastes increased substantially with the increased of storage period at 35$^{\circ}C$. Up to 10 months of storage at 35$^{\circ}C$, stale flavor obtained by a sensory method markedly increased, but stickiness decreased. The scores of overall preference were in good agreement with those of stale flavor (r=-0.98) and sticky texture (r=0.98). The correlation coefficient between stale flavor obtained by a sensory method and instrumetal analysis for stored brown rice was r=0.97.

• The Korean Journal of Food And Nutrition
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• v.27 no.2
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• pp.294-301
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• 2014

Rice (Oryza sativa L.) is one of the most important staple foods in Korea and the consumption of brown rice is increasing annually. The objective of this study is to investigate the physicochemical, hydration and textural properties related to eating quality of cooked brown rice by using glutinous, semi-glutinous, four non-glutinous and four colored varieties. The moisture, protein and total dietary fiber contents of brown rice are shown in the range of 11.1~12.6%, 6.6~8.7% and 6.28~12.40%, respectively. The amount of water uptakes for brown rice during the hydration has shown significant differences. The glutinous variety of Boseogchal indicate the highest water absorption levels by reaching $0.38gH_2O/g$. The hardness of hydration for Seolgaeng is distinctively lower than those of the other brown rice varieties. According to the textural characteristics of cooked brown rice when using the Tensipresser, the hardness of Boseogchal, Baegjinju and Seolgaeng all exhibit the lowest values out of ten varieties and the highest levels of adhesiveness.

• Journal of Plant Biotechnology
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• v.43 no.1
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• pp.76-81
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• 2016

We performed a molecular marker-based analysis of quantitative trait loci for traits that determine the quality of appearance of grains using 120 doubled haploid lines developed by anther culture from the F1 cross between 'Cheongcheong' (Oryza sativa L. ssp. Indica) and 'Nagdong' (Oryza sativa L. ssp. Japonica). We therefore calculated the alkali digestion value (ADV), used to indirectly measure gelatinization temperature, to evaluate the quality of cooked rice in 2013 and 2014. The ADV score of frequency distribution was higher milled rice than brown rice. In total, nine different quantitative trait loci (QTLs) were found on 5 chromosomes in 2013 and 2014. Also, chromosome 5, 8 were detected over two years. We conclude that selected molecular markers from this QTL analysis could be exploited in future rice quality. In conclusion, we investigated ADV of brown and milled rice in CNDH population. This study found nine QTLs related to the ADV of brown and milled rice. The detected one marker can be used to select lines with desirable eating-quality traits because ADV is closely associated with the eating quality of cooked rice. Therefore, it will be useful to collect resources and distinguishable in many varieties for rice breeding program.

• Korean journal of food and cookery science
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• v.28 no.5
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• pp.549-557
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• 2012

In this study, the FFQ-50 questionnaire which composed of 50 food items frequently eaten as sources of dietary fiber, was developed and used to estimate the dietary fiber intake of middle school students in the Chungbuk province. According to the survey, the average daily intakes of dietary fiber for the boys and girls were $23.3{\pm}12.3$ g (93.2%) and $20.8{\pm}11.5$ g (104.0%), respectively, showing a significant difference between the gender. The proportions of boys and girls who did not reach to the sufficient dietary fiber intake were 66.2% and 53.9% respectively. The major sources of dietary fiber were grain foods and vegetables, which measured at 77.24%, followed by fruits, seaweeds, tofu and tofu products, potato and starch, and mushrooms. The cooked white rice contributed the highest (17.81%), followed by baechu-kimchi, cooked brown rice, ramyeon (instant noodle), tangerine, sesame leaf jangajji (pickled sesame leaf), topokki (spicy rice cake stir-fry), blanched and seasoned bean sprouts, bread, and radish kimchi. The study showed that the cooked white rice was the major source of dietary fiber in the boys' diet followed by baechu-kimchi, ramyeon, cooked brown rice, tangerine, bread, strawberry, blanched and seasoned bean sprouts, sesame leaf jangajji, radish kimchi. Girls were taking in dietary fiber mostly from boiled white rice followed by baechu-kimchi, boiled brown rice, tangerine, ramyeon, sesame leaf jangajji, topokki, blanched and seasoned bean sprouts, radish kimchi, and boiled barley.

• Korean Journal of Food Science and Technology
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• v.49 no.3
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• pp.311-317
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• 2017

In this study, the phenolic content and antioxidant activity of rice cooked using different methods with different amounts of germinated brown rice (10, 20, 30, and 50%) were compared. Germinated brown rice was cooked using general and high-pressure cooking methods with and without fermented alcohol. Pasting characteristics decreased, and total polyphenol and flavonoid contents, and DPPH and ABTS radical scavenging activities increased with increasing amounts of germinated brown rice. Moreover, germinated brown rice cooked by general cooking method with fermented alcohol showed higher antioxidant activity than that showed by rice cooked by other cooking methods. The results obtained in this study are expected to serve as basic data for manufacturing of processed products.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.3
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• pp.223-229
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• 2014

The objective of this study was to evaluate quality properties including amylose, alkali digestion value (ADV), texture and GABA (Gamma Amino-Butyric Acid) of brown rice and 1~5 mm germinated brown rice of Keunnun and Samkwang culitvars. The protein content of germinated brown rice showed increasing tendency according to shoot length, however, the difference was not statistically significant. The amylose content of all samples ranged from 15.0% to 16.0% in Keunnun and 17.0% to 18.0% in Samkwang, without significant differences. Compared to regular brown rice, germinated brown rice from both cultivars demonstrated reduced gel consistency, which contributed to the improved cooked rice texture. Especially, germinated brown rice had significantly lower setback values, which is correlated with high palatability of cooked rice. However, there was no significant difference in gel consistency between 1 mm and 2~5 mm germinated brown rice. GABA content in Keunnun increased by 3~5 times after germination process. In Samkwang, GABA content increased by 50 times (from $0.005{\mu}g/g$ to $0.243{\sim}0.247{\mu}g/g$) after germination. The hardness of germinated brown rice was significantly lower than that of brown rice. However, there was no significant difference in hardness according to shoot length. Consequently, when processing germinate brown rice, it is recommended to maximize functional ingredients by germination while maintaining shoot length less than 2 mm.

• Journal of Life Science
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• v.22 no.10
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• pp.1378-1383
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• 2012

To address the limitations of manufacturing noodle products using rice, brown rice noodles were created by the fermentation of brown rice containing several nutrients and the quality of these noodles were evaluated. White rice noodles, fermented white rice noodles, brown rice noodles, and fermented brown rice noodles were developed using white rice and brown rice, respectively. We found that the content of crude proteins present in the noodles during the fermentation process increased and the content of crude fat and carbohydrates in the noodles was reduced. In addition, the water content of brown rice noodles was twofold higher than that of white rice, although under fermentation conditions, the water content of brown rice noodles decreased slightly. A slight change of chromaticity was observed during the fermentation process. In cooking, the weight and volume of the noodles increased, with the change being lowest in noodles based on white rice. White rice-based noodles exhibited significantly higher turbidity in the cooked noodle soup, while other noodle products showed relatively constant turbidity. Most of the products showed a decreased texture, becoming soft with cooking; however, the elasticity of the cooked products increased. Our results suggest that the disadvantages of producing rice noodles can be overcome by the development of fermented brown rice noodles containing a variety of nutritional components. This would potentially develop a market for rice-based manufactured foods that appeal to modern preferences.

• Korean Journal of Food Science and Technology
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• v.17 no.5
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• pp.406-408
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• 1985

n-Hexanal in headspace over the cooked brown rice stored at $5^{\circ}C$ and $35^{\circ}C$ for 0. 4, 8 and 12 months was determined by a modified direct vapor injection gas chromatographic method. The retention time of n-hexanal was 3.5 min and n-hexanal could be rapidly separated from other compounds at the operational conditions of gas chromatography. n-Hexanal contents of cooked brown rice also showed a standard deviation of less than 10% of the average.

• Korean Journal of Food Science and Technology
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• v.54 no.1
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• pp.8-16
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• 2022

Rice (brown rice: milled rice=50:50) was cooked using different concentrations of hyaluronic acid (HA) solution (0.1, 0.3, 0.5, and 0.7%, respectively) as the cooking water, and the properties of the cooked rice were compared. As the HA content increased, the moisture content of the cooked rice significantly increased, and the textural properties, including hardness, cohesiveness, and adhesiveness, except springiness, significantly decreased. For color, as the HA amount increased, the L^* value decreased, whereas the b^* values increased. The free radical scavenging effect and total polyphenol content also increased significantly as the amount of HA increased. In the sensory test, the hardness of the samples containing HA was higher than that of the control; however, there was no significant difference in the overall acceptability. Based on the above results, much softer cooked brown rice could be produced using HA solution (up to 0.7%) as the cooking water, and additional beneficial characteristics, such as antioxidant effect, can be obtained.