• Applied Biological Chemistry
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• v.15 no.1
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• pp.35-40
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• 1972

The contents of free amino acids in deembryod brown rice of two varieties were investigated by amino acid autoanalizer in relation to specific gravity grade. The analytical methods of free amino acid were also discussed. 1) The lower the specific gravity of the unhulled rice the higher the content of total free amino acids in the deembryod brown rice, and the similar trend appears to hold on each amino acids. 2) Main free amino acids were serine+asparagine, glutamic acid, aspartic acid, alanine and valine, and maximum values of them were 7.3, 5.1, 4.0, 3.4, 0.9mg/100g rice, respectively. They consist about 85% of total free amino acids in most cases. 3) The contents of soluble nitrogen and free amino acids appear to be lower in high protein variety (IR 667) than in low protein variety (Jinhung). The percentage of free amino acid nitrogen to soluble nitrogen, however, appears to be higher in high protein variety (IR 667). 4) Alanine was much lower than aspartic acid in IR 667 having Indica blood while alanine appears to be higher than aspartic acid in Jinhung (Japonica rice) suggesting varietal difference in amino acid metabolism. 5) Threonine peak was overlaped with glutamine, and serine was with asparagine in this study.

• Plant Biotechnology Reports
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• v.5 no.4
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• pp.309-315
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• 2011

Rice grown in anaerobic waterlogged soil accumulates ammonium as a major source of nitrogen (N). We have compared the physiological symptoms of rice seedlings subjected to N-starvation stress with those receiving sufficient N, based on measurements of shoot/root length and weight and an analysis of protein expression patterns. N starvation marginally increased root growth but notably decreased shoot biomass. N uptake was reduced by >50% in the roots and shoots of N-starved seedlings. To better understand the mechanism of N starvation in rice, we performed a comparative proteome analysis of proteins isolated from rice leaves. Twenty-five differentially expressed proteins were analyzed by matrixassisted laser desorption/ionization time-of-flight (TOF) mass spectrometry and electron spray ionization quadrupole TOF. Functional analysis of the N-starvation response proteins suggested their involvement in protein synthesis and fate, metabolism, and defense. These results indicate that these proteins may play important roles in regulating the plant's complex adaptation responses for N use during N starvation. The proteins may be useful for further characterization of protein function in plant N nutrition.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.9
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• pp.1268-1273
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• 2011

The present study was conducted to determine a feasible method of protein concentrate extraction from rice bran (RBPC) and its effect as a substitution for skim milk in early weaning pig diets. An investigation to extract protein concentrate from full fat rice bran was undertaken to determine the best ratio of water and rice bran, the amount of NaOH and a HCl solvent to use in a simple paddle-type mixer with modified spinning to produce RBPC. The results stated that the best ratio for water mixing in the RBPC extraction process was 1:5 with 20 g NaOH and 30 min in a paddle-type mixer at 300 rpm. A mix of 250 ml 0.2 N HCl was optimum for neutralization and protein precipitation. After the fluid was spun out with a washing machine, the sediment was left for 12-14 hours to complete the filtration. One kilogram of rice bran could produce an average of 324.5 gram RBPC and it contained 3.40% ash, 496.48 kcal of GE/100 gram, 1.94% crude fiber, 28.20% ether extract, 7.64% moisture and 16.66% crude protein, respectively. A total of 45 crossbred piglets, weaned at 3 weeks of age were allotted into control diet (A) and dietary treatments formulated with a four different rates of RBPC substitution for skim milk at a percentage of 25 (B), 50 (C), 77 (D) and 100 (E) respectively, in a randomized complete block (RCB) design. All piglets had free access to feed and water until 8 week of age when the experiment ended. Feed intake, average daily gain, growth rate and feed efficiency were not affected by dietary treatments. Blood test parameters after completion of the growth trial indicated normal health. Even though the mean of cell hemoglobin concentration was significantly different between treatments (p<0.05) it was still within the normal range. The cost difference for BW gain of 100% RBPC substituted for skim milk in the weaning diet was approximately 35% lower than that of the control and the relative cost of production was 96.67, 92.85, 70.75 and 64.48% lower for the replacement of 25, 50, 75 and 100% of skim milk respectively. These results implied that this technology is feasible for use by small scale farmers to improve their self-reliance.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.8
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• pp.1385-1389
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• 2003

The objectives of this study were to analyze amino acid composition of brown and milled rice of five varieties (Kwngan, Daean, Daejin, Sura, Hwaseong) and to evaluate their protein quality by several chemical scores. The protein contents of brown rice ranged from 6.7 to 8.0% and those of milled rice ranged from 6.1 to 7.5%. Daejin showed the highest protein contents in brown and milled rice among five rice varieties. Glx (glutamate + glutamine), Asx (asparagine + aspartic acid), arginine, leucine and valine were dominant amino acids in brown and milled rices and the most limiting amino acid was lysine. Ratios of essential amino acids to total amino acids were 36.8∼38.3% in brown rice and 35.8∼37.7% in milled rice. Protein scores were 76.4 to 79.6 in brown rices and 66.9 to 77.9 in milled rices, respectively. Chemical scores ranged from 60.7 to 63.2 in brown rices and from 55.5 to 62.4 in milled rices, respectively. The first limiting amino acid was lysine, the second threonine, and the third isoleucine in chemical scores.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.10
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• pp.1460-1466
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• 2016

This study was conducted to develop a savory ingredient using rice material. We made hydrolysates with ratios of rice bran and rice protein of 4:0, 3:1, 2:2, and 1:3 (w/w) using commercial enzymes, and then investigated their quality properties. At a ratio of 3:1, nitrogen degradation ratio (NDR), savory taste, and overall acceptability were the highest compared to other ratios. Rice bran and rice protein with a ratio of 3:1 were hydrolyzed for 13 days, and characteristics of the hydrolysate were investigated after 3, 5, 7, 10, and 13 days. Total nitrogen, amino nitrogen, and NDR of the hydrolysate after 10 days were higher than those of other hydrolysates. SDS-PAGE showed that the molecular weight of the hydrolysate peptide became smaller as hydrolysis time increased. Glutamic acid content was highest among all amino acids in the hydrolysate for 13 days. Amino acids related to bitter taste decreased from 5 to 13 days, whereas amino acids related to sweet taste substantially increased over time. Sensory evaluation showed that the hydrolysate after 10 days was best. These results suggest that rice bran and rice protein at a mixing ratio of 3:1 and hydrolysis for 10 days were optimal hydrolysis condition for development of natural savory ingredients.

• Journal of Crop Science and Biotechnology
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• v.11 no.2
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• pp.135-140
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• 2008

Improving eating quality is one of the most important objectives in japonica rice breeding programs in Yunnan Province of China. Eating quality and its relevant traits of nine Korean and 11 Yunnan rice cultivars were comparatively analyzed in this study. The grain shape of most Yunnan japonica rice cultivars have a relatively slender shape and are slightly larger than Korean rice cultivars. Palatability value of cooked rice of Yunnan rice cultivars was significantly lower, while the protein content of Yunnan rice cultivars was significantly higher than that of Korean cultivars. Peak viscosity and breakdown viscosity of the Yunnan rice cultivars were significantly lower, while setback viscosity of the Yunnan rice cultivars was significantly higher than in Korean rice cultivars. Palatability value of cooked rice was negatively correlated with protein content and setback viscosity but positively correlated with peak viscosity, breakdown viscosity, and cool paste viscosity. Through multiple linear regression analysis, an equation for estimating palatability value(PV) of cooked rice based on quality traits was generated as dependent only upon protein content(PC), PV=139.024-(10.865$\times$PC) with an $R^2$ value of 0.822. The results suggest that reducing protein contents should be the major target in improving eating quality of Yunnan japonica rice cultivars through integrated approaches of both cultivar development and appropriate cultural practices. Genetic similarities among cultivars based on DNA markers which had been identified as associated with grain quality seemed not to be directly related to PV.

• Journal of Nutrition and Health
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• v.5 no.3
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• pp.135-140
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• 1972

Rice and other corns as well as potato were mixed, as indicated in the following table, and fed to the experimental animals for 14 weeks. It was observed that the 9th and 10th dietary groups, whose protein values were higher among the experimental groups, displayed the more ideal growth and development as compared with other groups, and that the mixing ratio in these groups was proved to be better nutritionally as judged from the serum protein levels. Ratio of food Mixture Control Standard diet : Group 1 rice 80% Barley 20% Group 2 rice 80% Wheat 20% Group 3 rice 100% Group 4 rice 80% millet 20% Group 5 rice 80% Potato 20% Group 6 rice 80% Barley 20% Group 7 rice 80% Potato 10% Barley 10% Group 8 rice 80% Barley 10% Potato 10% Group 9 rice 80% Soybean 10% Potato 10% Group 10 rice 80% Soybean 10% Barley 10%(wheat 10%)

• Korean Journal of Organic Agriculture
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• v.19 no.4
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• pp.513-528
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• 2011

This study was conducted to evaluate the nutritional value of locally produced organic agricultural by-products to substitute imported organic feeds for organic ruminant farming. Imported organic feeds (corn grain, soybean meal, soybean seed, oat grain, barley grain, wheat grain, buckwheat, sunflower seed meal) and byproducts (rice bran, grape seed meal, rice straw, soybean hull, soybean curd, rice hull, green kernel rice, and crushed rice grain) were analyzed for chemical composition and NDF, ADF, mineral, and amino acid contents and anti-nutritional factors. Dry matter, NDF and ADF contents in organic feeds were higher than those in conventional feeds. Especially, the 9.65% fat content of organic soybean meal was 6 times higher than the 1.95% fat content of conventional soybean meal. Fat contents of rice bran, grape seed meal, green kernel rice, and crushed rice grain were 25.66, 6.09, 3.57 and 1.59%, respectively. Protein contents of soybean hull and soybean curd were 14.68 and 19.87%, respectively, which are highest among organic by-products. Levels of aflatoxin in all feeds were below the safety level. Therefore, organic rice bran, green kernel rice and crushed rice as energy source, and soybean hull and soybean curd as protein source could partial replace imported feeds for organic ruminant farming.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.2
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• pp.134-140
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• 1997

The monoclonal antibody against a novel protein, which was induced in the roots of rice seedlings treated with NaCl, was produced. Oryzea sativa L. cv. Annapruna grains were sown on clean sands and grown for 10days and then the seedlings were soaked in 50mM NaCl aqueous solution. In 48hrs of the NaCl treatment, the roots were collected and homogenated with liquid nitrogen and extraction buffer. The homogenate was centrifuged and to the supernatant 75％ ammonium sulfate was added to pre-cipitate proteins. From these proteins a novel protein was purified through DEAE-ion chromatography and FPLC(Phenyl column). This protein appeared as a single band in the native electrophoresis. Using this protein as antigen, monoclonal antibody was produced. Five cell lines that secreted antibodies specifically bound to this protein were constructed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.1
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• pp.1-21
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• 2020

Association mapping is widely used in rice and other crops to identify genes underlying important agronomic traits. Most association mapping studies use diversity panels comprising accessions with various geographical origins to exploit their wide genetic variation. While locally adapted breeding lines are rarely used in association mapping owing to limited genetic diversity, genes/alleles identified from elite germplasm are practically valuable as they can be directly utilized in breeding programs. In this study, we analyzed genetic diversity of 179 rice varieties (161 japonica and 18 Tongil-type) released in Korea from 1970 to 2006 using 192 microsatellite markers evenly distributed across the genome. The 161 japonica rice varieties were genetically very close to each other with limited diversity as they were developed mainly through elite-by-elite crosses to meet the specific local demands for high quality japonica rice in Korea. Despite the narrow genetic background, abundant phenotypic variation was observed in heading time, culm length, and amylose and protein content in the 161 japonica rice varieties. Using these varieties in association mapping, we identified six, seven, ten, and four loci significantly associated with heading time, culm length, and amylose and protein content, respectively. The sums of allelic effects of these loci showed highly significant positive correlation with the observed phenotypic values for each trait, indicating that the allelic variation at these loci can be useful when designing cross combinations and predicting progeny performance in local breeding programs.