• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.7
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• pp.962-968
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• 2011

The objective of this study was to investigate the chemical components and quality characteristics of three waxy corn varieties (Heukjinju, Ilmi, and Yeonnong1) harvested by conventional cultivation (CC) and environmentally-friendly cultivation (EFC). Crude ash content of the three corn varieties was higher, but not significant, in CC than EFC. Crude fat and protein contents in Heukjinju were higher in EFC, and amylose content was significantly higher (p<0.001). Free sugar, minerals, and fatty acid composition patterns varied according to the cultivation method. Vitamin E contents in the Heukjinju and Yeonnong1 cultivars were higher in CC than EFC. Total polyphenol content of waxy corns on EFC and CC were 175.28 and 204.00 mg/100 g, respectively, in the Heukjinju cultivar (p<0.01), and 148.64 and 158.42 mg/100 g, respectively, in the Ilimi cultivar, and 123.24 and 128.30 mg/100 g, respectively, in the Yeonnong1 cultivar. 2,2-Diphenyl-1-picrylhydrazyl radical scavenging activity on EFC and CC was 1.51 and 1.76 in Heukjinju cultivar (p<0.05), 0.29 and 0.34 in Ilmi cultivar (p>0.05), and 0.39 and 0.42 mg trolox eq/g in Yeonnong1 cultivar (p>0.05), respectively. However, 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonate) radical scavenging activity was higher in CC than EFC.

• Journal of the Korean Society of International Agriculture
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• v.30 no.4
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• pp.347-356
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• 2018

Genetically modified (GM) crops have been increased continuously over the world and concerns about the potential risks of GM crops have also been increasing. Even though GM crops have not been cultivated commercially in Korea, it should be necessary to develop the safety assesment technology for GM crops. In this study, we investigated the influence of heading date difference on gene flow from GM to non-GM rice. In the experimental plot design, The PAC GM rice was placed in the center as a pollen donor and non-GM rice were placed in eight directions as pollen receivers. Five pollen receiver rice cultivars were Unkawng, Daebo, Saegyejinmi, Nakdong-byeo, and Ilmi which had different flowering times. A total of 266,436, 300,237, 305,223, 273,373, and 290,759 seeds were collected from Unkawng, Daebo, Saegyejinmi, Nakdong, and Ilmi, respectively, which were planted around PAC GM rice. The GM${\times}$non-GM hybrids were detected by repeated spraying of herbicide and PAT immunostrip assay. Finally, the hybrids were confirmed by PCR analysis using PAC gene specific primer. The hybrids were found in Nakdong-byeo which had the same heading date with PAC GM rice. The hybridization rate was 0.0007% at Nakdong-byeo plot. All of GM${\times}$non-GM hybrids were located within 2 m distance from the PAC GM rice zone. The physiological elements including rice heading date were found to be important factors to determine GM?rice out crossing rate with GM rice. Consideration should be taken into for many factors like the physiological elements of field heading date of rice cultivars to set up the safety management guideline for prevention of GM rice gene flow.

• Korean journal of food and cookery science
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• v.23 no.4 s.100
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• pp.452-460
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• 2007

As a preliminary study for developing cooking techniques to improve cooked rice flavor, we surveyed consumer perceptions on purchasing rice and the consumption of cooked rice. The quantity of rice purchased by consumers was in the range of $1O{\sim}20$ kg. The purchase criterion for 50% of the subjects was the taste of the cooked rice, and half of the subjects bought their rice at a supermarket. A majority (90%) of the subjects consumed the rice within 1 to 4 months, storing it raw in the package (32.4%) or in a container at room temperature. The rice was cooked for 2 to 5 persons (65%), 1 to 2 times a day (70%) with a pressure cooker (76%). The rice and water volume were measured by eye. The cooked rice was eaten immediately (41.8%) or in 1 to 2 days (48.6%) by keeping it in an electric cooker (63.6%). The subjects perceived the rice cultivar (37.9%) as the major factor for the cooked rice flavor, as well as the region of origin (21.3%), and storage period (11.9%); the cultivars of Ilmi, Ilpoom and Chuchung were preferred. In conclusion, the consumers regard rice as a principal food; however, the methods to measure rice and water are not standardized. To improve the taste of cooked rice, consumers depend on cooking equipment and the rice cultivar.

• Journal of Biosystems Engineering
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• v.38 no.2
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• pp.95-102
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• 2013

Purpose: Using a laboratory indented cylinder separator, broken rice separation experiments were conducted and the characteristics of the separation process were studied to provide information for developing a prototype indented cylinder broken rice separator. Methods: Rice (Ilmi variety) milled in a local RPC was used for the experiment. Rice kernels were classified into four groups according to their length l; whole kernels (I > 3.75 mm), semi-whole kernels (2.5 < I < 3.75 mm), broken kernels (1.75 < I < 2.5 mm), and foreign matters (I < 1.75 mm). A laboratory grain cleaner, Labofix '90 (Schmidt AG, Germany) was used for the experiments. Experiments were designed as a $4{\times}4$ factorial arrangement in randomized blocks with three replications. Cylinder rotational speeds (17, 34, 51, 68 rpm) and trough angles (15, 37.5, 60, $82.5^{\circ}$) were the two factors and feed rates (25, 50 kg/h), indent shapes (Us, $S_1$ type), and indent sizes (2.5, 3.75 mm) were treated as the blocks. Two 125 g samples and one 125 g sample were taken at the cylinder outlet and from the trough, respectively. The whole, semi-whole, and broken kernel weight ratio of the samples and feed was determined by a rice sizing device. From these weight ratios, purities, degrees of extraction and coefficient of separation efficiency were calculated. Results: Trough angle, cylinder speed, and their interaction on the coefficient of separation efficiency were statistically significant. Cylinder speed of 17, 34, and 51 rpm made the most effective separation when the trough angle was $15^{\circ}$ or $37.5^{\circ}$, $60^{\circ}$, and $82.5^{\circ}$, respectively. Maximum values of coefficient of separation efficiency were in the range of 60 to 70% except when the indent size was 2.5 mm and were recorded for the combinations of low cylinder speed (17 rpm) with medium trough angle ($37.5^{\circ}$ or $60^{\circ}$). Indent shape did not appear to make any noticeable difference in separation efficiency. Conclusions: Due to the interaction effect, the trough angle needs to be increased appropriately when an increase in cylinder speed is made if a rapid drop of effectiveness of separation should be avoided. In commercial applications, $S_1$ type indents are preferred because of their better manufacturability and easier maintenance. For successful separation of broken kernels, the indent size should be set slightly bigger than the actual sizes of broken kernels: an indent size of 3.0 mm for separating broken kernels shorter than 2.5 mm.

• Food Science and Preservation
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• v.22 no.6
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• pp.823-830
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• 2015

Physicochemical properties of five commercial rice products were investigated in order to select the appropriate rice varieties for the preparation of frozen fried rice. Among the evaluated rice varieties, Onnuri (16.06%) had the highest amylose content, while Beakjinju (11.83%) had the lowest. The water absorption index ranged from 1.45 to 1.65 g/g. Regarding the Hunter's color values, the L and a values of all rice varieties decreased while the b value increased with freezing-storage following the cooking process. The initial pasting temperature showed no significant differences among the five rice varieties. The highest viscosity (peak, trough, and final) and setback were found in the Sindongjin, while the lowest breakdown was found in the Baekjinju variety. Hardness, chewiness, and cohesiveness of all five cooked rice varieties decreased while their adhesiveness increased after freezing-storage. Under electron microscopy scanning, pores were observed inside the tissue of frozen cooked rices manufactured from Baekjinju and Hopum varieties, while substantially smooth tissue structure was observed in Sindognjin, Onnuri, and Ilmi rice varieties.

• Food Science and Preservation
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• v.19 no.6
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• pp.925-932
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• 2012

This study was performed to improve quality of traditional Yakju and compares quality of Yakju according to different rice cultivars. The pHs of Ilmi Yakju and Hanarum Yakju showed 4.14 and 4.07, respectively and the other Yakju's pHs were ranged from 3.92 to 3.98. The content of total acid of Yakju using Indica rice imported from Thailand was the highest among the samples. The major components of free sugar was glucose and the highest content of total free sugars was found in Indica Yakju. The content of reducing sugars in Yakju using Indica rice was the higher than other samples. The ethanol content of Hanarum Yakju showed higher than those Yakju's and the lowest ethanol content found for the indica Yakju. The volatile compounds from the rice Yakju were identified by GC-MS. Twenty-one volatile compounds were found in rice Yakju. And the major volatile compounds were ethanol, acetic acid, 1-methyl-1-propanol, 2-methyl-butane, 3-methyl-1-butanol, iso-amylalcohol and 1-hexanol from Yakju. As the result of sensory test, higher scores for smell and color were found for the Yakju used Hanarum Yakju. The highest score sweat and acid were found for the Anda rice Yakju in sensory test. The result of sensory evaluation indicated that Hanarum Yakju and Anda Yakju were better than the other samples, and the value of bitterness was no significant in this test.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.1
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• pp.17-24
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• 2016

Drought caused by global climate change is one of serious problems for rice cultivation. However, it was little reported the impact of drought on rice cultivation in Korea. In here, to assess impact of drought on rice varieties in Korean climate condition, growth characteristics and yield components of rice were compared on irrigated and partially irrigated rice paddy field. First, we have chosen 11 rice varieties including 'Saeilmi' and 'Shindongjin' which are widely cultivated in Korea. For partially irrigated rice paddy treatment, we have withheld irrigation from 25 days after transplanting and water supply was totally dependent on rainfall for rice cultivation. When we examined early plant height and tiller number of these varieties on partially irrigated rice paddy were reduced 1.6% to 18.4% and 10.4% to 33.1%, respectively, and these reduction rate were highly correlated with yield loss in our experimental conditions. Among rice yield components, panicle number was decreased 10.5% to 30.1% according to rice varieties and reduced panicle number was highly correlated with yield loss. Grain number per panicle, grain filling rate and 1,000 seeds weight did not have correlation with yield loss of rice varieties. These result means that growth stage, especially the tillering stage, is seriously affected by drought on rice cultivation in Korea. And we suggest that 'Saeilmi', 'Ilmi' and 'Ilpum' are good for rice cultivation on drought prone rice field in Korea.

• Korean journal of food and cookery science
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• v.22 no.6 s.96
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• pp.949-956
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• 2006

Eleven rice varieties, five normal-yielding and six high-yielding, were examined for proximate composition, mineral and fatty acid composition, and antinutrients. The proximate rice compositions for moisture, crude protein, crude fat, carbohydrate, crude fiber and crude ash were 10.70${\sim}$15.88%, 5.03${\sim}$7.73%, 0.45${\sim}$1.33%, 74.56${\sim}$82.05%, 0.30${\sim}$0.73% and 0.31${\sim}$0.91%, respectively. The proximate composition of the various rice varieties was not significantly different except for moisture and carbohydrate. The contents of saturated fatty acid, monounsaturated fatty acid and polyunsaturated fatty acid of the rice varieties were 22.45${\sim}$25.99%, 36.50${\sim}$44.99% and 32.01${\sim}$46.02%, respectively. Several high-yielding rices varieties had higher oleic acid or linoleic acid. Ilmi and Nampyung had high oleic acid contents at ever 40%, and Dongjin No. 1, IlPum, Junam and Seachuchung had high linoleic acid contents at over 37%. The major minerals of rice were K and Mg and their respective contents were 85.62% and 25.55%. High-yielding rice varieties had significantly higher Mn and Na contents and lower Mg and Fe contents than normal-yielding rice varieties (p<0.05). Antinutrients such as lectin, phytic acid and trypsin inhibitor were not detected in any of the rice varieties.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.4
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• pp.347-352
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• 2008

This study was carried out to estimate the quality of Jeonbuk-originated brand rice by comparing with other domestic brand rices and imported market rices. Rice variety, "Ilmi" was a major portion of brand rices in Jeonbuk region, and in few portion, there were variety-mixed brands, Shindongjin, Kosihikari, and Hitomebore. Comparing the ratio of head rice of high-quality Jeonbukoriginated brand rice with other domestic brand rices were not significantly different. Head rice ratio and mechanical taste values were not significantly different between high-quality Jeonbuk-originated brand rice and the other domestic brand rices. The contents of protein, moisture, amylose of rice were also not significantly different between them. The quality of high-quality Jeonbuk-originated brand rice was as good as that of other domestic brand rices and had not changed it by period. The foreign rice imported from United States, Chinese (involved parboiled), Thailand and the domestic rice cultivated in Jeonbuk province were investigated. There could get difference on the major component related to palatability of rice as country in this study. Comparing with foreign rices. protein content of domestic rice (6.1%) was similar with that of United States, lower than those of Chinese and Thailand. The head rice ratio of the domestic rice was 92%, which was similar with those of Unite State and Chinese but the Chinese parboiled rice was completely cracked during processing. The setback viscosity of domestic rice related to retrogradation was lower than those of the imported rice except United States. The Ad (Adhesiveness / H(Hardness) ratio was higher in the domestic and United States rice.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.4
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• pp.323-335
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• 2019

Rice is sensitive to day-length and short-day plants. It has a characteristic that the photosensitivity response required for flower bud differentiation decreases under long-day conditions. To identify critical photoperiod required for flower bud differentiation of major cultivation rice varieties, the average temperature was fixed at 28 ℃, and the day length was set at 12 hours and 10 minutes intervals from 13 hours to 14 hours 30 minutes. The critical photoperiod for each cultivar was set to day-length, where the daily cumulative response [(X_{(Critical Photoperiod)}-Y_{(Set day-length)})/(X_{(Critical Photoperiod)}-12:00_{(Optimal Day-length)}) × (28.0_{(Set Temperature)}-10_{(Minimum Temperature)})/(29.2_{(Maximum Temperature)}-10_{(Minimum Temperature)})] was the same for each day-length conditions. The flower bud differentiation time of all varieties was 32 days before heading at the average temperature of 28 ℃ conditions. The critical photoperiod of the early maturing type, such as Woonkwang, Odae, Koshihikari, Jopyeong, were 19:20, 18:14, 18:58, 17:30, respectively. Medium maturing type, such as Daebo, Haiami, Samdeok, were 16:08, 16:15, 16:55, respectively. Mid-late maturing type, such as Saenuri, Sindongjin, Chucheong, Samkwang, Ilpum, Saeilmi, Hwangkeumnuri, Dongjinchal, Ilmi, Hopum, Yeonghojinmi, were 15:58, 15:56, 16:36, 16:44, 15:35, 16:26, 15:33, 16:20, 16:29, 16:13, 15:41.