• Korean Journal of Plant Resources
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• v.30 no.4
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• pp.450-465
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• 2017

This study was conducted to characterize the amylose and protein contents of 4,948 rice landrace germplasm using the NIRS model developed in the previous study. The average amylose content of the germplasm was 20.39% and ranged between 3.97 and 37.13%. The amylose contents in the standard rice were 4.99, 18.63 and 20.55% in Sinseonchal, Chucheong and Goami, respectively. The average protein content was 8.17% and ranged from 5.20 to 17.45%. Protein contents in Sinseonchal, Chucheong and Goami were 6.824, 6.869 and 7.839%, respectively. A total of 62% germplasm were distributed between 20.06% and 27.02% in amylose content. Germplasm of 81.60% represented protein content of 6.78-9.75%. The distinguishable ranges of amylose contents according to origin were 16.58-20.06% in Korea, 20.06-23.25% in Japan, 23.25-27.02% in North Korea, and 27.02-37.13% in China. In the protein content, approximately 30% of Chinese resources ranged from 9.75 to 17.45%, whereas less than 10% were detected in other origin accessions. Fifty resources were selected with low and high amylose ranging from 3.97-6.66% and 30.41-37.13%, respectively. Similarly, fifty resources were selected with low and high protein ranging from 5.20-6.09% and 13.21-17.45%, respectively. Landraces with higher protein could be adapted to practical utilization of food sources.

• Korean Journal of Food Science and Technology
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• v.16 no.4
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• pp.398-402
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• 1984

These experiments were conducted to investigate the substrate specificity, the hydrolysis products on the various carbohydrates and the hydrolysis rate on the various raw starches of the two purified glucoamylase produced by Rhizopus oryzae. Both of the glucoamylases hydrolyzed amylose, amylopectin, glycogen, soluble starch, pullulan, maltose, maltotriose, maltotetraose, maltopentaose, maltohexaose, maltoheptaose and maltooctaose, but did not act on ${\alpha}-cyclodextrin$, ${\beta}-cyclodextrin$, raffinose, sucrose and lactose. When the reaction mixture of glucoamylase and polysaccharides were incubated $37^{\circ}C$for 32 hours, glucoamylase I hydrolyzed amylopectin, soluble starch and amyloses completely, but hydrolyzing glycogen up to only about 88%. Glucoamylase II hydrolyzed the previous four polysaccharides up to about 100%. Both of the glucoamylases produced only glucose for various substrates and did not have any ${\alpha}-glucosyl$ transferase activity. Both of the glucoamylases hydrolyzed raw glutinous rice starch almost complety, wheras they acted on raw potato starch, raw green banana starch, raw arrow root starch, raw corn starch, raw yam starch and raw high amylose corn starch weakly. Glucoamylase II hydrolyzed raw starches at the higher rate than glucoamylase I.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.185-185
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• 2017

In previously study, we evaluated seed germination for longevity derived from a cross between 'Ilmi' and 'Dharial', a weed rice collected in Bangladesh. The strong germination trait originated from 'Dharial' was incorporated into 'Ilmi', through backcross method. The germination ratio was evaluated after two years of room temperature storage conditions. A high germination ratio of 80.5% in donor plant of 'Dharial' and 77.3% in an introgression lines was observed based on the two years of storage while the recurrent japonica cultivars, 'Ilmi' was failed in germination. In this study, we investigate changes in physicochemical properties of 'Ilmi' and introgression lines (ILs) stored at room temperature. We analyzed germination rate, texture of cooked rice, toyo glossiness value, pasting properties, amylose content, protein content and ${\alpha}-amylase$ content of 'Ilmi' and 5 introgressions every 4 months on the room temperature condition. Seed germinations were decreased by storage periods. Three ILs germination rate was slowly decreased more than 'Ilmi' and 2 another ILs after 4 months. Toyo glossiness value of 'Ilmi' and three ILs were no difference, but, 2 ILs gradually decreased every 4 months at storage periods. Pasting properties were affected by storage temperatures and periods of 'Ilmi' and ILs. The increase at breakdown was observed but setback was decreased by storage periods. Amylose content and protein content were no significant difference at storage periods, respectively. The ${\alpha}-amylase$ content was gradually increased during the storage periods. The introgression line could be useful to increase longevity and maintain quality during storage of japonica rice seed.

• Korean journal of food and cookery science
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• v.32 no.5
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• pp.531-540
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• 2016

Purpose: To improve the cooking quality of brown rice, newly inbred soft rice cultivars were investigated. Methods: The physicochemical properties of brown rice flour and water absorption patterns and cooking characteristics of brown rice grain were compared to Ilmi white and brown rice. Results: General composition and total dietary fiber contents of five rices were significantly different with higher ash, protein, and total dietary fiber contents in soft brown rice than white rice. The hardness of raw rice grain was higher in Ilmi brown rice than in soft brown rice. The water absorption increased rapidly in 30 min of white rice and in 4-6 h of brown rices. The apparent amylose content of soft brown rice was lower than that of Ilmi rice. The initial pasting temperature and all viscosities were significantly different, but the trend was not similar. The textural properties of hardness and roughness were higher, but adhesiveness, cohesiveness, and stickiness were lower in Ilmi brown rice than white and soft brown rices. In sensory preference test, not only textural properties, hardness, adhesiveness, cohesiveness, stickiness, and roughness, but also color, glossiness, and roasted flavor were higher in soft brown rices. Especially soft brown rice B showed the best cooking quality among all rices. Conclusion: The results of the study suggested that soft brown rice is developed for cooking with high nutritional and functional quality.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.9
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• pp.1407-1414
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• 2014

Physicochemical properties of rice-based expanded snacks extruded with rice flour, high amylose starch, and isolated soy protein were investigated using a twin-screw extruder. The ingredients were extruded at various feed moisture contents (19~23%) and screw speeds (200~400 rpm) at a constant feed rate (43.4 kg/hr). Bulk density and apparent density of rice snacks were 0.06~0.21, and 0.55~0.65 respectively. Bulk density, apparent density, water absorption index, and breaking strength of rice snacks increased with increasing feed moisture content and decreasing screw speed. However, expansion and water solubility index of rice snacks increased with decreasing feed moisture content and increasing screw speed. Hunter's color L values of rice snacks was lower with increasing screw speed at feed moisture contents of 19% and 21%, but was not significantly different from a feed moisture content of 23%. On the other hand, a and b values of rice snacks were higher with increasing screw speed a feed moisture content of 19%. X-ray diffraction intensity of rice snacks decreased with decreasing feed moisture content and increasing screw speed. X-ray diffraction of rice snacks was V-type at feed moisture contents of 19% and 21% and screw speeds of 300, and 400 rpm. In the microstructure of the cross section of rice snacks, air cells in rice snacks were not well formed, and cell walls were thicker with increasing feed moisture content and decreasing screw speed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.4
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• pp.388-392
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• 2013

The proteins from functional rice cultivars (Nogwonchalbyeo, Giant embryonic, Arhyangchalbyeo, and Goamibyeo) and general white rice were extracted and separated using two-dimensional (2D) gel electrophoresis. A wide variation in the molecular weight (MW) and pH range of the expressed proteins in rice samples were observed. The green-kerneled rice (Nogwonchalbyeo) exhibited proteins with MW of 9-57 kDa and appeared at a pH range of 4-7. The Giant embryonic contained proteins with MW of 31-63 kDa and a pH range of 5-6. The aromatic glutinous rice (Arhyangchalbyeo) showed proteins with MW of 24-28 and pH of 5.8-6.8. The high-amylose rice (Goamibyeo) exhibited proteins with MW of 3-63 and pH of 5.2-5.6. The identified proteins uniquely found and highly expressed in each cultivar may have a significant role on rice functionality. The results illustrate that the 2D gel electrophoresis is a valuable method in the determination of the protein expression profiles in functional rice grains and may be useful in the identification of specific marker proteins associated with the functional property of rice.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.8
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• pp.1160-1171
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• 2013

A feeding trial was conducted in tilapia to determine the growth performance, nutrient digestibility, digestive enzymes, and postprandial blood metabolites in response to different dietary amylose-amylopectin ratios. Five isonitrogenous and isolipidic diets containing an equal starch level with different amylose-amylopectin ratios of 0.11 (diet 1), 0.24 (diet 2), 0.47 (diet 3), 0.76 (diet 4) and 0.98 (diet 5) were formulated using high-amylose corn starch (as the amylose source) and waxy rice (as the amylopectin source). Each diet was hand-fed to six tanks of 15 fish each, three times a day over a 6-wk period. After the growth trial, a postprandial blood metabolic test was carried out. Fish fed diet 2 exhibited the highest percent weight gain and feed efficiency and protein efficiency ratio, whereas fish fed with diet 5 showed the lowest growth and feed utilization among treatments. The digestibility for starch in fish fed diet 1 and 2 was higher than those in fish fed with other diets (p<0.05). The highest activities for protease, lipase and amylase were found in fish fed the diet 2, diet 1, and diet 1 respectively among dietary treatments, while the lowest values for these indexes were observed in fish fed the diet 3, diet 5 and diet 4, respectively. The liver glycogen concentrations in fish fed diets 4 and 5 were found higher than in fish fed other diets (p<0.05). The feeding rate, hepatosomatic index, condition factor, and plasma parmeters (glucose, triglyceride, total cholesterol, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol) did not differ across treatments. In terms of postprandial blood responses, peak blood glucose and triglycerides were lower after 3 or 6 h in the fish fed with diets 3-5 than in the fish fed diet 1, but delayed peak blood total amino acid time was observed in fish fed with the diets 1 or 2. The lowest peak values for each of the three blood metabolites were observed in fish fed diet 5. The results indicate that high-dietary amylose-amylopectin ratio could compromise growth, but help in reducing the blood glucose stress on fish caused by postprandial starch load.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.3
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• pp.196-204
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• 2018

The main objective of this study was to identify the best quality rice for cultivation on reclaimed land in Jeollabukdo-Province based on yield, head rice ratio, protein content, amylose content, and Toyo taste value evaluations. Seven varieties of rice were grown for two years on the reclaimed land. The Sukwang variety had the earliest heading date. The tiller number for the Younghojinmi variety was 19 on average, and its variation in tiller number was the lowest, which showed that the safety for cultivation of the variety was high on the reclaimed land with respect to that of the other varieties. The culm and panicle lengths of the Sukwang and Hyunpum varieties were the highest at 81.8 and 21.3 cm, respectively. Shindongjin produced the highest thousand grain weight at 27.7 g, whereas Haepum produced the lowest at 22.3 g. The number of grains per panicle for 7 all varieties was statistically equal for both years. The yield order for the varieties was Shindongjin (590) > Hopum (575) > Younghojinmi (552) > Sukwang (551) > Hopum (543) > Mipum (534) > Haepum (498 kg/10a), which showed that there was no significant difference in average yield between the varieties when both years are taken into consideration. However, the annual difference in Haepum yield between 2015 and 2016 was the highest at 108 kg/10a, indicating low cultivation safety. The head rice ratio of Younghojinmi was higher than for the other cultivars in both 2015 and 2016. However, there was no significant difference between the 2 years when the averages for all varieties were analyzed. There was was a considerable difference in protein and amylose content between the varieties in the two years, although this was not apparent in the results when the average over 2 years for each variety was calculated. There was no significant difference between the two years with respect to the average head rice ratio, and the protein and amylose contents of the seven varieties. The Toyo taste values for the Sukwang and Mipum varieties were higher than for the other varieties. Based on the principle characteristics, such as Toyo value, the Sukwang variety is a suitable substitute for Shindongjin, which has been previously used to produce high-quality rice on the reclaimed land.

• 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.

• Korean Journal of Breeding Science
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• v.42 no.1
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• pp.1-10
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• 2010

Five mutants were investigated at the molecular level to determine the factors responsible for mutated endosperm types. They were classified as high (HA) or low amylose (LA) phenotypes based on the amylose content in endosperm. The five were previously produced from Ilpum and Shindongjin cultivar treated with N-methyl-N-nitrosourea and gamma-ray irradiation, respectively. Analysis of the genomic structure and expression of Granule-bounded Starch Synthase I (GBSSI) genes revealed that mutants generally showed a higher incidence of nucleotide transition than transversion, and the $A:T{\rightarrow}G:C$ transition was particularly prevalent. The rates of nucleotide substitution in HA mutants were generally higher than those in the LA mutants, leading to higher substitutions of amino acid in the HA mutants. Neither nucleotide substitutions interfering with intron splicing or causing early termination of protein translation were found, nor any large-sized deletions or additions were found in all the mutants. In principle, amylose content can be regulated by three factors: internal alterations of GBSSI protein, the strength of gene expression, and other unknown external factors. Our results indicate that the endosperm mutants from Shindongjin arose from internal alterations of GBSSI proteins, which may be the result of amino acid substitutions. On the other hand, the Ilpum mutants might be principally caused by the alteration of gene expression level. Analysis of another three glutinous cultivars revealed that the major factor leading to glutinous phenotypes is the 23-bp duplicative motif (5'-ACGGGTTCCAGGGCCTCAAGCCC-3') commonly found in exon 2, which results in the premature termination of protein translation leading to the production of a non-functional GBSSI enzyme.