• Journal of Crop Science and Biotechnology
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• v.10 no.1
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• pp.33-38
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• 2007

Nitrogen management at the panicle initiation stage(PI) should be fine-tuned for securing a concurrent high yield and high quality rice production. For calibration and testing of the recommendation models of N topdressing rates at PI for target grain yield and protein content of rice, three split-split-plot design experiments including five rice cultivars and various N rates were conducted at the experimental farm of Seoul National University, Korea from 2003 to 2005. Data from the first two years of experiments were used to calibrate models to predict grain yield and milled-rice protein content using shoot fresh weight(FW), chlorophyll meter value(SPAD), and the N topdressing rate(Npi) at PI by stepwise multiple regression. The calibrated models explained 85 and 87% of the variation in grain yield and protein content, respectively. The calibrated models were used to recommend Npi for the target protein content of 6.8%, with FW and SPAD measured for each plot in 2005. The recommended N rate treatment was characterized by an average protein content of 6.74%(similar to the target protein content), reduced the coefficient of variation in protein content to 2.5%(compared to 4.6% of the fixed rate treatment), and increased grain yield. In the recommended N rate treatments for the target protein content of 6.8%, grain yield was highly dependent on FW and SPAD at PI. In conclusion, the models for N topdressing rate recommendation at PI were successful under present experimental conditions. However, additional testing under more variable environmental conditions should be performed before universal application of such models.

• Korean Journal of Microbiology
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• v.19 no.1
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• pp.14-22
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• 1981

Protein content of cellulosic wastes, such as spent grain, hop bark, spent rye, rice straw, rice hull, saw dust and used newspaper, was increased by a mixed culture of C. utilis wastes having 66-75% moisture. Among the fungal strains tested. A.phoenicis KU175 was the most powerful to increase the protein content of A. phoenicis during the mixed culture with C. utilis in the CMC medium reached at the peak for one day culture after inoculation of the both strains at the same time, while it reached at peark from the beginning of the mixed culture, when A. phoenicis was inocultated for 12-24hours prior to the inoculation of C.utilis. To increase the protein content of the cellulosic wastes by the mixed culture of C.utilis and A.phoenicis, the inoculation of both strains at the same time was more effective than the preinoculation of A. phoenicis for 6-24 hours. Content of crude cellulose in the used newspaper, saw dust and spent grain was high relatively, and the lignin content of spent grain, spent rye, and rice strew was reduced more than half by the treatment of 2% NaOH. However, effect of alkali treatment of increase the protein content of the cellulosic wastes was not prominent in the case of mixed culture. Protein content of the cellulosic wastes was increased prominently by the mixed culture of C.utilis and A.phoenicis in semi-solid substrate, compared with the single culture of C. utilis, although the latter increased the protein content of cellulosic wastes considerably. The effect of mixed culture of C. utilis and A. phoenicis increased 4-fold the protein content of spent grain, and more than doubled crude protein in hop bark and rice straw.

• Animal Bioscience
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• v.35 no.2
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• pp.260-271
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• 2022

Objective: We aimed to investigate the effect of the differing amino acid (AA) release dynamics of two protein sources on the growth performance, nitrogen deposition, plasma biochemical parameters, and muscle synthesis and degradation of piglets when included in their diets at normal and low concentrations. Methods: Forty-eight piglets (Duroc×Landrace×Large White) with initial body weight of 7.45±0.58 kg were assigned to six groups and fed one of 6 diets. The 6 dietary treatments were arranged by 3×2 factorial with 3 protein sources and 2 dietary protein levels. They are NCAS (a normal protein content with casein), NBlend (a normal protein content with blend of casein and corn gluten meal), NCGM (a normal protein content with corn gluten meal), LCAS (a low protein content with casein), LBlend (a low protein content with blend of casein and corn gluten meal), LCGM (a low protein content with corn gluten meal). The release dynamics of AA in these diets were determined by in vitro digestion. The digestibility, utilization and biological value of nitrogen in piglets were determined by micro Kjeldahl method. Plasma insulin was measured by enzyme-linked immunosorbent assay kits. The protein expression of mediators of muscle synthesis and degradation was determined by western blotting. Results: Although the consumption of a low-protein diet supplemented with crystalline AA was associated with greater nitrogen digestion and utilization (p<0.05), the final body weight, growth performance, nitrogen deposition, and phosphorylation of ribosomal protein S6 kinase 1 and eIF4E binding protein 1 in the muscle of pigs in the low-protein diet-fed groups were lower than those of the normal-protein diet-fed groups (p<0.05) because of the absence of non-essential AA. Because of the more balanced release of AA, the casein (CAS) and Blend-fed groups showed superior growth performance, final body weight and nitrogen deposition, and lower expression of muscle ring finger 1 and muscle atrophy F-box than the CGM-fed groups (p<0.05). Conclusion: We conclude that the balanced release of AA from CAS containing diets and mixed diets could reduce muscle degradation, favor nitrogen retention, % intake and improve growth performance in pigs consuming either a normal- or low-protein diet.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.2
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• pp.101-104
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• 1998

This study was conducted to establish a rapid analysis method for determining protein and moisture contents of pea. Ninety and eighty pea (Pisum sativum L.) lines were analyzed to determine protein and moisture contents, respectively using near-infrared reflectance spectroscopy. Simple correlations (${\gamma}$) of protein content in a ground sample and an intact grain sample by an automatic regression method were 0.978 and 0.910, respectively. Simple correlations by partial least square regression/principal component analysis (PLS/PCA) methods were 0.982 and 0.925, respectively. Standard error of performance (SEP) in protein content was the lowest value, 0.446 in ground sample by PLS/PCA methods. Simple correlation of moisture content was the highest at 0.871 in ground samples. when using a standard regression method. Accuracy for the moisture content was slightly lower than for protein content. It was concluded that the NIRS method would be applicable only for rapid determination of protein content in pea.

• Journal of the Korean Society of Tobacco Science
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• v.17 no.1
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• pp.20-26
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• 1995

This study was carried out to obtain the basic data which include the change of the photosynthetic rate and protein content according to growth stage in the process of senescence of tobacco plant The photosynthetic rate was the maximum with 26.31$\mu$mol.CO2/m2.sec and stomatal resistance was the minimum with 0.2552cm/sec at 15th days after leaf emergence. However, after 50 days the photosynthesis was very little occurred. During leaf developments the number of chloroplast was increased and reached at the maximum at 25th days after emergence of leaf, thereafter, it was decreased gradually. The content of protein increased continuously and showed the highest value at 15th days after leaf emergence. The degradation rate of soluble protein was more rapid than that of insoluble protein at early stage of senescence. The range of decrement in the insoluble protein was low at late stage of senescence. The content of Rubisco, the key enzyme of photoamthesis, corresponded to about 50% of soluble protein and reached to the maximum at 150 days after leaf emergence. As the senescence progressed, the content of large subunit(UV) of Rubisco showed a tendency to decrease more rapidly than that of small subunit(SSU). The total amount of amino acids was the highest at 15th days after leaf emergence.

• Fisheries and Aquatic Sciences
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• v.18 no.3
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• pp.265-271
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• 2015

A feeding trial of four dietary protein levels (20, 30, 40, and 50%) and two lipid levels (7 and 14%) with a factorial design was conducted to determine the optimal dietary protein and lipid levels for juvenile Israeli carp Cyprinus carpio. Triplicate groups of fish (average body weight, $1.3{\pm}0.02g$) were fed the experimental diets for 9 weeks. Survival of fish was not affected by either dietary protein or dietary lipid level. Weight gain and feed efficiency increased as dietary protein levels increased up to 40 and 50%, respectively. Weight gain was higher in fish fed the high-lipid diets with 20 and 40% protein content. Feeding efficiency increased as the dietary lipid level increased for the 30, 40, and 50% protein diets. Daily feed intake decreased with increasing protein level and the minimum feed consumption was observed in fish fed the 50% protein diet with 14% lipid content. Moisture and lipid contents of the whole body were affected by both dietary protein and lipid levels. The crude lipid content of fish fed the 14% lipid diet was higher than that of fish fed the 7% lipid diet at each protein level. The results of this study indicate that a diet containing 40% protein with 14% lipid content is optimal for the growth and effective protein utilization of juvenile Israeli carp.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.3
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• pp.433-438
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• 2005

This investigation was undertaken in order to elicit the relationship between the extent of ultrafiltration processing of whey and its effect on composition and yield of resultant whey protein concentrate (WPC). Cheddar cheese whey was fractionated through ultrafiltration to an extent of 70, 80, 90, 95, 97.5% and 97.5% volume reduction followed by I stage and II stage diafiltration. After each level of ultrafiltration, the composition of WPC was monitored. Similarly, the initial whey was adjusted to 3.0, 6.2 and 7.0 pH levels and ultrafiltration was carried out to elicit the effect of pH of ultrafiltration on the composition. Further, initial whey was adjusted to different levels of whey protein content ranging from 0.5 to 1.0 per cent and subjected to ultrafiltration to different levels. The various range of retentate obtained were further condensed and spray dried in order to assess the yield of WPC per unit volume of whey used and the quantity of whey required to produce unit weight of product. With the progress of ultrafiltration, there was a progressive increase in protein content and decrease in lactose and ash content. The regression study led to good relationships with $R^2$ values of more than 0.95 between the extents of permeate removed and the resultant changes in composition of each of the constituents. Whey processed at pH 3.0 had significantly a very low ash content and high protein content as compared to processing at 6.2 and 7.0. The yield of WPC per unit volume of whey varied significantly with the initial protein content. Higher initial protein content led to higher yield of all ranges of WPC and the quantity of whey required per unit weight of spray dried WPC significantly reduced. Regression equations establishing the relationship between initial protein content of whey and the yield of various types of WPC have been derived with very high $R^2$ values of 0.99. This study revealed that, the yield and composition of whey can be monitored strictly by controlling the processing parameters and WPC can be produced depending on the food formulation requirement.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.1
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• pp.14-25
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• 2006

Response of grain yield and milled-rice protein content to nitrogen (N) rates at various growth stages is critical for quantifying real-time and real-amount of applied N requirement for target grain yield and protein content. An experiment including 10 N rate treatments at transplanting, tillering and panicle initiation stages with four rice cultivars in 2003, 6 N treatments with two rice cultivars in 2004 and 2005 was conducted. Increase of N rates at PIS significantly increased both grain yield and milled-rice protein content but increase of N rates at tillering stage significantly increased grain yield but not milledrice protein content. Therefore, high grain yield and low milled-rice protein content would be difficult to obtain only by adjusting N rates at PIS. Internal N use efficiency (INUE) was 60.5 kg grain/kg N accumulation on an average over N treatments, cultivars, and experimental years, showing considerable reduction especially at high shoot N accumulation in the experimental year of low sunshine duration. Milled-rice protein content tended to increase almost linearly with increasing shoot N accumulation, but it revealed big variation even at the same shoot N accumulation at harvest. Milled-rice protein content decreased with increasing INUE. N accumulation in the milled rice increased at an almost constant proportion of 45.5 percent of the shoot N accumulated at harvest, showing slight decresing proportion with the increasing shoot N accumulation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.spc
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• pp.78-83
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• 2008

Soybean [Glycine max (L.)] is a major source of protein for human and animal feed. Inter- and intra-genotype variation of soybean protein has been investigated by soybean researchers. However, limited sample amount of soybean single seed there is no report that investigated intra-plant variation of soybean protein within soybean plant. Recently a non-destructive NIR (near-infrared reflectance) spectroscopy using single seed grain to analyze seed protein was developed. The objectives of this study were to understand variation of seed protein content within plant and to determine the amount of minimum sample size which can represent protein content for a soybean plant. Frequency distribution of protein content within plant showed normal distribution. There was an intra-cultivar variation for protein content in soybean cultivar Seonnogkong. Difference of protein content among single plants of Seonnokong was recognized at 5% level. Seeds in lower position on plant stem tended to accumulate more protein than in higher position. There was significant difference for protein content between sample size 5 seeds and sample size of more than 5 seeds (10, 20, 30, 40, and 50 seeds) at a soybean plant with 57 seeds however no difference was recognized among sample size (5, 10, 20, and 30 seeds) at a soybean plant with 33 seeds. Around 20% seeds of soybean from single plant needed to determine the protein content to represent protein content of single soybean plant. This study is the first one to report evidence of intra-plant variation for proteincontent which detected by non-destructive NIR spectroscopy using single seed grain in soybean.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.5
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• pp.464-475
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• 1990

To obtain the basic informations about the repeseed Quality improvement, If varieties were analyzed for their seed protein content and amino acid composition, and discussed comparing to several other oilseed crops or varietal origin and seed weight or maturity. Total protein content of the tested varieties were ranged from 15.3 to 36.2% with mean protein content of 23.2%. The highest protein content was recorded in B. hirta var. Ochre, whereas the lowest in B. napus var. Mirado. Grouped by seed weight, small seed varieties were higher in protein content. A high negative correlation (-0.524) was observed between the content of protein and oil. Further, more the relationship between protein content and 1,000 seed weight was also very significant with the correlation coefficient of -0.622. The amino acid composition of rapeseed meal was characterized by a relatively high methionine and lysine content. Main amino acids were glutamic and aspartic acid in rapeseed.