• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.6
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• pp.843-852
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• 2010

Hydroxycinnamic acid derivatives (HADs) and anthocyanins in corn (Zea mays L.) have recently been reported to have anticarcinogenic, anti-hypertensive, antidiabetic, antifungal, antioxidant, and anti-melanogenic activities. Five HADs and anthocyanins in corn were quantified by HPLC according to cultivars and heat processes. In addition, major anthocyanin of a black waxy corn was isolated and identified by several instrumental analysis, and its content was also quantified by HPLC according to heat processes. Of the ten corn cultivars, five waxy corn cultivars had moderate five HADs contents except "Baksa" waxy corn with higher two free cinnamic acids (FCAs), p-coumaric and ferulic acids. In contrast, three dent corn cultivars contained higher levels of three polyamine conjugates (PCs), CFP, DCP and DFP, and especially "P3394" had the highest amount of the three PCs. Two sweet corn cultivars had generally intermediate HADs levels between waxy and dent corn cultivars. Of the three colored-waxy corns, a black Mibaek waxy corn had the highest anthocyanin content. During heat processes, levels of two FCAs in the black waxy corn generally increased, whereas no significant change on three PCs contents was observed except the puffing process. Roasting, retort and puffing processes significantly increased two FCAs and especially, the puffed black waxy corn had the highest amount of FCAs. Meanwhile, most heat treatments except retort process, considerably decreased total anthocyanin contents, and especially the puffed black waxy corn had nearly no anthocyanin. Level of one major anthocyanin, pelargonidin 3-glucoside (P3G) isolated from a black waxy corn was appreciably decreased by heat treatments except retort process, which greatly increased P3G content. These results suggest that the retorted black waxy corn may be a promising high quality functional corn product.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1521-1521
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• 2001

The objective of the research being presented was to construct and calibrate a spectrometer for the analysis of single kernels of corn. In light of the difficulties associated with capturing the spatial variability in composition of corn kernels by single-beam spectrometry, a hyperspectral imaging spectrometer was constructed with the intention that it would be used to analyze single kernels of corn for the prediction of moisture and oil content. The spectrometer operated in the range of 750- 1090 nanometers. After evaluating four methods of standardizing the output from the spectrometer, calibrations were made to predict whole-kernel moisture and oil content from the hyperspectral image data. A genetic algorithm was employed to reduce the number of wavelengths imaged and to optimize the calibrations. The final standard errors of prediction during cross-validation (SEPCV) were 1.22% and 1.25% for moisture and oil content, respectively. It was determined, by analysis of variance, that the accuracy and precision of single-kernel corn analysis by hyperspectral imaging is superior to the single kernel reference chemistry method (as tested).

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.324-324
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• 2017

Total 15 different corn hybrids, Kwangpyeongok, Gangdaok, Yanganok, Singwangok, Jangdaok, Cheonganok, Cheongdaok, Andaok, Dapyeongok, Pyeongkangok, Pyeonganok, Daanok, Sunwon P3394, Gangilok, P3394, had been used to investigate the plant growth and yield of corn hybrids depends on the sowing date. Sowing dates were April 5th, June 25th, and July 5th and all experiments had three repeats. The growth of Gangdaok was the best. However, in the case of Kwangpyeongok, the growth was not the best to compare with Gangdaok, but the stem to ear height ratio was lower than Gangdaok, it may be better for the stable cultivation. Both of the growth and yield of Daanok was not good regardless of planting date, but the yield and ear shape of Pyeongkangok and Dapyeongok were good for fresh corn. The growth and yield of 15 different corn hybrids were variable depends on the planting date, however, the growth degree days (GDD) was the most important factor for the maturity of the corn. More than $1500^{\circ}C$ of GDD was enough to harvest mature corn hybrids in the central region of Korea. Besides the yield and growth, other characters such as sweetness and taste as a food should be investigated further for the fresh corn to be suggested.

• Journal of The Korean Society of Grassland and Forage Science
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• v.15 no.3
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• pp.215-221
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• 1995

Three fistulated nonlactating Holstein cows were used to examine the change in ruminal characteristics when fed diets of 100% corn silage, 50% corn silage + 50% wet brewers' grain(WBG) and 100% WBG, and also twenty Holstein heifers averaging 156 $\PM$ 3.2kg BW were randomly assingned to determine the adequate feeding level of concentrate with the following treatments ; Only WBG, concentrate to 0.5, 1.0 and 1.5% of BW under feeding WBG ad libitum. Tne main results were as follows : I. Ruminal pH was minimized 3 hrs after feeding and then gradually increased. The mean ruminal pH was highest in feeding only WBG (6.72) and lowest in only corn silage(6.0) 2. Ruminal $NH_3$-N concentration was maximized 1 hr after feeding and then gradually decreased regardless of diets, n7e average ruminal $NH_3$-N content was highest in diet of 100% WBG(12.9 rngldl) and lowest in 100% corn silage(5.9 mg/dl) 3. Acetic acid percent among VFA was highest when WBG replaced 50% corn silage and acetic to propionic acid ratio was higher in order of feeding only corn silage, 50% corn silage + 50% WBG and only WBG. 4. Ruminal bacteria and protozoa number in diet of 50% corn silage + 50% WBG were 8.14 $\times$ > $10^5$ and 1.45 $\times$ $10^5$, respectively, which were most of all treatments. 5. Daily gain and feed efficiency of Holstein heifer in feeding concentrate to 0.5% of BW and forage hay to about 20% of total DM intake when fed free WBG were better

• Journal of The Korean Society of Agricultural Engineers
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• v.59 no.1
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• pp.71-79
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• 2017

Climate change phenomenon is posing a serious threat to sustainable corn production in Ghana. This study investigated the impacts of climate change on the rain-fed corn yield in the Dangme East district, Ghana by using Aquacrop model with a daily weather data set of 22-year from 1992 to 2013. Analysis of the weather data showed that the area is facing a warming trend as the numbers of years hotter and drier than the normal seemed to be increasing. Aquacrop model was assessed using the limited observed data to verify model's sufficiency, and showed credible results of $R^2$ and Nash-Sutcliffe efficiency (NSE). In order to simulate the corn yield response to climate variability four climate change scenarios were designed by varying long-term average temperature in the range of ${\pm}1^{\circ}C{\sim}{\pm}3^{\circ}C$ and average annual rainfall to ${\pm}5%{\sim}{\pm}30%$, respectively. Generally, the corn yield was negatively correlated to temperature rise and rainfall reduction. Rainfall variations showed more prominent impacts on the corn yield than that of temperature variations. The reduction in average rainfall would instantly limit the crop growth rate and the corn yield irrespective of the temperature variations.

• Journal of The Korean Society of Grassland and Forage Science
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• v.12 no.3
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• pp.185-192
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• 1992

This experiment was conducted to compare the productivity of five silage corn varieties. Corn varieties were Pioneer 3144(P 3144), 3160(P 3160), 3282(P 3282), 3352(P 3352) and Suweon 19(S 19) and were seeded on May 2 and harvested on August 15. Ratios of stalk, leaf and ear, chemical composition and yields of nutrients were investigated in respective corn part. Experimental design was accepted by Latin square arrangement with five replicates and each plot had twenty two plants. The results obtained were as follows: 1. Crude portein, crude ash and nitrogen free extract(NFE) contents of whole plant ranged from 6.32 to 7.18%, 5.16 to 7.43% and 52.62 to 57.90%, respectively, and there were no significant(P>.Ol) differences between varieties. Crude protein and NFE content were the highest in ear between corn parts. 2. Crude fiber conent of whole plant ranged from 18.98 % to 24.01 %, and was the highest in suweon 19 and the lowest in P 3352(P<.01). Crude fiber content was the highest in stem and the lowest in ear, However, crude fat content(2.03-3.66 %) vice versa. 3. Yields of organic matter, crude protein, crude fat, NFE and TDN per 10a were the greatest(P< .01) in P 3282, however crude fiber yield was the highest(P<.Ol) in P 3352. 4. Ratios of different part to total dry matter yield ranged from 12.7 %(P 3352) to 17.8 %(P 3160) for leaf, 44.5(P 3352) to 66.9 %(P 3160) for stem and husks, and 16.9 %(P 3282) to 42.8 %(P 3352) for ear, and there were significant differences between corn varieties(P<.Ol). Consequently, P 3352 has the greatest nutrient yields, particularly by ear, and P 3282 has a great nutrient yield by stem. This result suggested that could be appear a better character of silage corn by hybridization of this two corn varieties.

• Korean Journal of Environmental Agriculture
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• v.16 no.4
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• pp.365-372
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• 1997

Biochemical characteristics and activities of glutathione-S-transferases(GSTs) and carboxylesterase extracted from soybean and corn plants treated with quizalofop-ethyl were investigated. Km value and Vmax of GSTs extracted from soybean and corn plants were $6.7{\times}10^{-3}M$ nmole/mg/min, 50, 20 nmole/mg/min, respectively. Optimum pH of carboxylesterase from soybean and corn was 7.0. Km value and Vmax of carboxylesterase extracted from soybean and corn plants were $4.2{\times}10^{-4}M$, $2.5{\times}10^{-4}M$ nmole/mg/min, 33, 10 nmole/mg/min, respectively. GSTs and carboxylesterase activity were reduced by quizalofop-ethyl. GSTs and carboxylesterse activity of corn was more reduced than that of soybean. When soybean and corn were treated by 80 ppm of quizalofopethyl. Soybean recovered after 10 days elapsing, but corn withered after 3days elapsing.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.289-289
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• 2022

Waterlogging tolerance of corn is one of the important factor for cultivate in paddy soil condition to increase cultivation area and self-sufficiency of corn in Korea. In order to develop elite waterlogging tolerance corn, the new corn lines bred by crossing wild corn, Teosinte, and cultivated corn inbred lines. Five accessions among the 2 species, Zea mays sub spp. mexicana and Zea mays spp. parviglumis, of 81 Teosinte were selected through the waterlogging treatment. The waterlogging treatments were implemented for 7 days at the seedling(V3) stage. The inbred lines were developed by crossing 5 teosinte accessions and cultivated corn lines and they were estimated waterlogging tolerance. It was screened and analyzed the metabolites extracted from roots of 19KT-32(KS141 × teosinte) that was treated waterlogging. We selected 8 of 180 metabolites like as γ-aminobutyric acid(GABA), putrescine, citrulline, Gly, and Ala that expression was remarkably changed over 2.5-times, 7 metabolites increased and 1 metabolite decreased in waterlogging, respectively. Glutamate decarboxylase(GAD) catalyzing GABA accumulation gene have 10 haplotypes, and exon1 was highly conserved, but identified to 135 SNPs after the first intron. Among the 135 SNPs, the number of transversion mutations (52) surpassed the number of transition mutations (38). Most of metabolites were related to abiotic stress in plant that it regulated to pH, osmotic pressure K⁺/Ca⁺⁺ and ATPase activity. We are analyzing the association using these results for increase breeding efficiency.

• Journal of The Korean Society of Grassland and Forage Science
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• v.43 no.3
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• pp.129-137
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• 2023

Corn silage is extensively utilized in ruminant feeding on a global scale, with substantial research efforts directed towards enhancing its nutritional worth and managing moisture content. The purpose of this study was to assess the impact of normal cutting height and elevated cutting height on whole-crop corn silage. Corn was harvested at heights of 15 cm and 45 cm above the ground, respectively, 45 days after heading. The harvested corn was cut into 2-3 cm lengths and packed into 20-liter plastic silos in triplicate. The results showed that dry matter (DM), crude protein (CP), water soluble carbohydrates (WSC), and in vitro dry matter digestibility (IVDMD) of C45 were significantly higher than those of the control, while the neutral detergent fiber (NDF) was significantly lower in C45 (p<0.05). The C15 had higher yields than C45 (p<0.05). There was no significant difference in the total digestible nutrients (TDN) yield of whole-crop corn silage. The increase in cutting height resulted in a larger change in moisture content and NDF per centimeter. After 60 days-ensiling, C45 showed significantly lower NH₃-N concentrations. Moreover, C45 had significantly higher lactic acid concentration, lactic acid/acetic acid ratio, and lactic acid bacteria count compared to the control. Mold was not detected and the yeast count was less than 2 log10 cfu/g fresh matter in both control and C45. In summary, C45 improved the feeding value and fermentation quality of whole-crop corn silage at the expense of forage productivity.

• The Korean Journal of Food And Nutrition
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• v.36 no.5
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• pp.395-402
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• 2023

As the consumption of corn increases, the production of by-products is also increasing. In this study, functional substances and antioxidant activities of corn by-products were investigated to determine their applicability as functional materials. Total polyphenol, flavonoid contents, and ABTS antioxidant activity were the highest in leaves. The total phenolic acid content was the highest in cobs; p-coumaric and ferulic acid were the main components. Phytosterol content in leaves and stems was high at 64 and 50 days after sowing, 261.4 and 274.7 mg/100 g, respectively. β-sitosterol of the leaves and stems was the highest, 149.2 and 138.7 mg/100 g. The total phytosterol content of grains and by-products harvested 106 days after sowing was in the order of: corn silk, husk, grain, leaf, stem, and cob. Among the phytosterols, β-sitosterol was the highest, followed by stigmasterol and campesterol, and the composition was different depending on part. The total phytosterol content was the highest in husk and corn silk, but the stems and leaves, which account for 50% of the total corn biomass, also contained high phytosterol content. Therefore, corn leaves and stems are expected to be used as functional raw materials for the development of functional materials in the future.