• The Korean Journal of Food And Nutrition
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• v.31 no.5
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• pp.760-765
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• 2018

In order to observe physical properties of rice depending on reheating, the study cooked rice developed for high quality cooked rice and analyzed physical properties of rice depending on reheating following 24 hr refrigeration. As a result of palatability of cooked rice, Samgkwang had the lowest hardness, while Daebo and Haiami had the highest one. With respect to adhesiveness, toughness and stickiness, Sindongjin exhibited lowest properties. After cooking each rice by cultivars, the study observed their color, texture properties, and microstructure immediately after cooking, after 24 hr of refrigeration and further on. Lightness of cooked rice tended to drop because of refrigeration and reheating. Analysis of texture properties after cooking revealed that Haiami marked the highest points in all categories. When stored for 24 hr after cooking, hardness, viscosity and chewiness increased in cooked rice followed by a decrease after reheating. Observation of the microstructure of cooked rice using a scanning electron microscope revealed that Haiami had its particles in the center as closely condensed. It was apparent that all the cultivars formed stoma in an obvious manner because of refrigeration and reheating. The results of the present study show that physical properties of cooked rice varied according to reheating after cooking and storage depending on the inherent characteristics of rice cultivars.

• Journal of the Korean Society of Food Culture
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• v.38 no.5
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• pp.326-335
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• 2023

This study aims to analyze the sensory characteristic of cooked rice made with 10 types of rice varieties produced in South Korea using descriptive analysis. Twelve subjects who cook rice regularly, at least once a week, were recruited for the study and participated as descriptive panelists. A total of 29 descriptive terms were developed to describe the sensory characteristics of cooked rice. The findings showed that there were significant differences in the sensory attributes, specifically the appearance and texture attributes among the rice varieties. Among the varieties, Haedeul, Ilpum, and Koshihikari were observed to have a large quantity of rice germ and a relatively yellowish appearance. In contrast, Samkwang, Chamdream, and Yeonghojinmi were relatively whiter than the other samples. Odae, Saecheongmoo, and Sindongjin were rated high in the attributes of roughness, hardness, and chewiness, and Jinsang was rated high in moisture, bitterness, stickiness, and wholeness of rice grains. The differences in the appearance and texture of these rice varieties are likely to significantly impact consumer preferences. Furthermore, the development of customized menus based on the sensory characteristics of the different varieties of rice could encourage consumers to purchase these varieties.

• The Korean Journal of Food And Nutrition
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• v.36 no.6
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• pp.506-514
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• 2023

Reported positive ion fragmentation of phenolic acid derivatives in rice (Oryza sativa L.) were summarized based on the literature. A total of eight phenolic acids (4 derivatives of ferulic acid, 3 derivatives of sinapic acid and p-coumaric acid) were isolated and identified from rice (raw and steamed) using UPLC-DAD-QToF/MS. Results revealed that 6-O-feruloylsurose was the major component with 3'-O-sinapoylsucorse being tentatively identified in Oryza sativa L. for the first time as a new hydroxycinnamoyl derivative in rice grains. In our study, raw brown rice had the highest phenolic acid contents with Samkwang showing higher phenolic acid content than Saeilmi and Sindongjin (12.41 vs. 7.89 and 3.10 mg/100 g dry weight, respectively). Of all varieties, brown rice had higher phenolic acid contents than white rice. These contents decreased considerably when rice was steamed whereas, p-coumaric acid and ferulic acid contents were increased. Additionally, contents of rice (raw and steamed) can be used as a fundamental report for new rice varieties.

• Journal of Biosystems Engineering
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• v.42 no.1
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• pp.69-74
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• 2017

Purpose: The purpose of this study is to analyze turbidity and quality characteristics of white rice as a function of main shaft blast velocity and to verify the optimum processing conditions in the cutting type white rice processing system (CTWRPS). Methods: Sindongjin, one of the rice varieties, which used to be produced in Gimje-si, Jeollabuk-do, in 2015, was used as the experimental material. Turbidity and quality characteristics of white rice were measured at three different main shaft blast velocities: 25, 30, and 35 m/s. The amount of test material used for a single experiment was 20 kg, and after processing, whiteness was found to be $42.5{\pm}0.5$, following which, turbidity and quality characteristics were measured. Results: Turbidity decreased with increase in the shaft blast velocity, and as a result, was lowest at 35 m/s of shaft blast velocity among all the other experiment velocities. The trend of cracked rice ratios was similar to the turbidity. Broken rice ratio turned out to be less than 2.0% in all the test conditions. In the first stage of processing, the processing pressure decreased as the main shaft blast velocity increased. Additionally, in the second stage of processing, the processing pressure was at its lowest value at the main shaft blast velocity of 35 m/s. Energy consumption, too, decreased as the main shaft blast velocity was increased. Conclusions: From the above results, it is concluded that the main shaft blast velocity of 35 m/s is best for reducing turbidity and producing high quality rice in a CTWRPS.

• The Korean Journal of Food And Nutrition
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• v.31 no.2
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• pp.278-283
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• 2018

The objective of this study was to evaluate quality properties of high quality rice. Seven rice varieties, Dabo, Daebo, Samkwang, Sindongjin, Sukwang, Jinsumi, and Haiami, were investigated for proximate contents and physicochemical characteristics. Moisture content was highest in the Jinsumi (13.13%). Protein and lipid content was highest in the Haiami. The amylose content of the rice cultivars was 20.15~22.51%. The degree of amylopectin polymerization (DP) was analyzed, and in all cultivars, DP 13-24 content was found to be highest, at more than 53%, whereas DP ${\geq}37$ content was lowest, at less than 5.81%. With regard to free sugar, maltose content in rice was the highest (${\geq}46%$). Toyo value of rice was highest in Samkwang, Daebo, and Jimsumi. Palatability characteristics were highest in Daebo and Jimsumi. Thus, the results of this study suggested that Samkwang, Daebo, and Jinsumi can be effectively used as processed cooked rice, though further studies should be required regarding changes in the quality of rice after cooking.

• Journal of The Korean Society of Agricultural Engineers
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• v.61 no.4
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• pp.1-10
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• 2019

Unmanned aerial vehicle(UAV) can acquire images with lower cost than conventional manned aircraft and commercial satellites. It has the advantage of acquiring high-resolution aerial images covering in the field area more than 50 ha. The purposes of this study is to develop the rice grain yield distribution using UAV. In order to develop a technology for estimating the rice yield using UAV images, time series UAV aerial images were taken at the paddy fields and the data were compared with the rice yield of the harvesting area for two rice varieties(Singdongjin, Dongjinchal). Correlations between the vegetation indices and rice yield were ranged from 0.8 to 0.95 in booting period. Accordingly, rice yield was estimated using UAV-derived vegetation indices($R^2=0.70$ in Sindongjin, $R^2=0.92$ in Donjinchal). It means that the rice yield estimation using UAV imagery can provide less cost and higher accuracy than other methods using combine with yield monitoring system and satellite imagery. In the future, it will be necessary to study a variety of information convergence and integration systems such as image, weather, and soil for efficient use of these information, along with research on preparing management practice work standards such as pest control and nutrient use based on UAV image information.

• Journal of agriculture & life science
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• v.53 no.2
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• pp.87-95
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• 2019

This study was carried out to select the rice variety for high quality rice according to reducing N application level (7 kg/10 a) in medium altitude and plain of southern Korea. It was cultivated to seven varieties and ten varieties in medium altitude and plain region respectively in this study. In medium altitude region, the yield of head rice was higher in most varieties except for Borami (526 kg/10 a) than the control variety, Chucheongbyeo (533 kg/10 a). On the other hand, Borami, Gopumbyeo, and onnuri were lower in head rice rate than the other varieties. In addition, Borami and Chucheongbyeo shown a lodging risk but the other varieties were safe against lodging. The milled rice protein content of Chucheongbyeo was 6.1% and the other varieties protein content was similar or lower than that of control except for Borami(6.3%). In plain region, the head rice yield of Nampyeongbyeo (527 kg/10 a) was higher than that of control variety, Ilmibyeo (503 kg/10 a). Head rice rate was lower in Hopumbyoe, Sindongjin, and Chilbobyeo than the other varieties. The varieties contained lower protein content compared Ilmibyeo (6.1%) were Hopumbyeo (5.9%), Jinsumi (6.0%), Sindongjin (5.9%), Chilbobyeo (6.0%), Hwangeumnodeul (5.8%), Hopyeongbyeo (6.0%). Amylose content, whiteness, and palatability (Toyo value) were no significant difference among varieties in two different regions. In conclusion, considering head rice rate, yield of head rice, protein content, lodging resistance, ripening rate and palatability, Pungmi1ho, Saenuri, Chilbobyeo in medium altitude region and Jinsumi, Hwanggumnodul in plain region were selected as proper rice varieties for high quality rice production in southern Korea.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.4
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• pp.262-275
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• 2023

This study aimed to assess the preferences of African, American, and Asian panels, in comparison to a Korean panel, for various Korean rice varieties, including three japonica, two indica, and one Tongil-type, all developed by the Rural Development Administration in Korea. Regarding rice appearance, most panelists, except for the Koreans, favored long and slender rice varieties like 'Hanyeol', 'Hyangyeol', and 'Amissal'. In contrast, the Koreans preferred wider varieties like 'Sindongjin' and 'Deuraehyang'. Notably, the overseas panelists consistently favored rice varieties with high appearance quality in sensory evaluations of cooked rice. Both overseas and Korean panelists strongly preferred the indica rice variety 'Hanyeol' in terms of appearance quality and sensory evaluations. However, Korean rice varieties like 'Amissal' and 'Sindongjin' scored high in appearance quality with overseas panelists but received low ratings in sensory aspects, including shape, stickiness, and taste, compared to those for 'Hanyeol'. This suggests that considering sensory characteristics is important when exporting Korean rice varieties. Regarding taste characteristics preferred by the panelists derived from the correlation analysis between taste traits, Africans preferred rice with a smooth texture and no stickiness, especially favoring long-grain rice. Americans leaned towards rice with a slightly firm texture, some stickiness, and late aging characteristics. Asians preferred rice with a smooth texture, low stickiness, and long-grain varieties. In contrast, Koreans favored round rice with a glossy appearance, a slightly firm texture, late aging traits, and some stickiness. These research findings can serve as valuable data for the development of rice varieties for overseas markets and are expected to contribute to securing competitiveness in international markets.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.317-317
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• 2017

We performed this experiment to select high quality rice adapted to wheat-rice double cropping system. We sowed barley and wheat seed in November 2, 2015. After harvesting barley and wheat, we transplanted high quality rice cultivars: 'Unkwang', 'Hopun', 'Haepum', 'Hyunoum' in June 17 and 24. We used 'sindongjin' rice as a control. As a result, 'Hyunpum' had a highest head rice yield regardless of transplanting date. Head rice yield of 'Hyunpum' was 488.1kg/10a when transplanted in June 17, and 453.6kg/10a when transplanted in June 24. The reason for this highest head rice yield was not percentage of head rice but milled rice yield. Milled rice yield of 'Hyunpum' was 526.5kg/10a when transplanted in June 17, and 490.0kg/10a when transplanted in June 24. Percentage of head rice had little differences between rice cultivars. Among yield components, only number of panicle per $m^2$ had an effect on the differences of yield between rice cultivars. The other yield components didn't have an effect on the differences of yield between rice cultivars. Compared to June 17, only 'Unkwang' had higher head rice percentage and head rice yield in June 24. Head rice percentage of 'Unkwang' changed from 67.3% to 85.0% and head rice yield changed from 324kg/10a to 393.8kg/10a when transplanting date delayed from June 17 to June 24. When transplanting date was delayed, heading date of 'Unkwang' was more delayed than other rice cultivars. By delay of heading date, mean temperature for 40days changed from $25.0^{\circ}C$ to $22.9^{\circ}C$ which improved temperature condition during grain filling stage. This improved head rice percentage and head rice yield of 'Unkwang' transplanted in June 24. If transplanting date is more delayed than June 24, 'Unkwang' could have higher head rice percentage and head rice yield. Therefore, if you transplant rice before June 24 in rice-wheat double cropping system, 'Hyunpum' is recommended as adequate rice cultivar. But if you transplant rice after June 24, further research is needed to find out adequate rice cultivar.

• The Korean Journal of Food And Nutrition
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• v.33 no.2
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• pp.149-158
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• 2020

The purpose of this study was to investigate antioxidant characteristics and anti-adipogenic effects of colored rice and brown rice extracts in 3T3-L1 adipocyte depending on cultivar (Josaengheugchal, Heugjinmi, Hongjinju, Geongganghongmi, Seolgaeng, Milyang 320, Sindongjin, Baegjinju). Colored rice and brown rice was extracted with 100% ethanol, followed by the analysis of polyphenol, flavonoid, anthocyanin, antioxidant, and anti-adipogenic activity. Total polyphenol and flavonoid content ranged from 6.86~314.08 mg GAE/g and 1.47~56.88 mg CE/g the highest total polyphenol and flavonoid content was observed in Heugjinmi cultivar. Anthocyanin composition was analyzed by HPLC, cyanidin-3-gluoside and peonidin-3-glucoside was found in black rice including Josaengheugchal and Heugjinmi. Also, the ABTS and DPPH radical scavenging activity of colored rice cultivars was higher than that of brown rice cultivars, the highest ABTS radical scavenging activity also was observed in Heugjinmi (128.20 mg TE/g). The anti-adipogenic effects of colored rice and brown rice extracts on differentiation of 3T3-L1 preadipocytes evaluated that extracts of Heugjinmi cultivar significantly reduced intracellular lipid accumulation. These results provide valuable information for the use of Korean colored rice cultivar as a functional food materials relative to anti-obesity.