• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.2
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• pp.187-195
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• 2008

Polyphenol oxidase (PPO) is implicated in discoloration of white salted noodles and other wheat based foods. PPO activity was evaluated to determine the effect on discoloration of noodle dough sheets prepared from 25 Korean wheat flours during storage and to screen experimental lines with low PPO activity in 52 Korean wheats. PPO activity was assayed with whole-seed and performed with L-dihydroxyphenylalanine (L-DOPA) as substrates. Absorbance by L-DOPA assay of 25 Korean wheats was from 0.285 to 1.368 at 475 nm. PPO activity was significantly related with grain characteristics, including 1000-kernel weight and grain colors. In flour characteristics, PPO activity positively correlated with ash and protein content (r = 0.658, P < 0.001 and r = 0.424, P < 0.05, respectively) and negatively correlated with $L^*$ value of flour (r = 0.412, P < 0.05). In the changes of color of noodle dough sheet, $L^*$ and $b^*$ values consistently decreased and $a^*$ value increased during storage. PPO activity negatively correlated with $L^*$ value of noodle dough sheet during storage (r = 0.566, P < 0.01 at 2 hr, r = 0.547, P < 0.01 at 24 hr, and r = 0.509, P < 0.01 at 48 hr). But, no significant relationship was found in between PPO activity, $a^*$ and $b^*$ values during storage. The 52 Korean wheat lines examined in this study were divided into 3 different groups, low (< 0.500), medium (0.501-0.999) and high level (> 1.000), on the basis of the level of PPO activity. Twenty two Korean wheat lines showed low level of PPO activity and Suwon 252, 277 and 280 showed lower PPO activity (< 0.200) than others.

• Korean Journal of Food Science and Technology
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• v.11 no.2
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• pp.81-85
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• 1979

A Neotec infrared instrument was evaluated for determination of protein contents of wheat and barley. Correlation coefficients between protein content determined on the instrument and by the Kjeldahl method were highly significant (0.97 to 0.98). Accuracy of analyses, measured by the standard error of a single test was 0.07 to 0.16, giving a coefficient of variability of 0.6 to 1. 1%. Method of grinding samples affected particle size and type. Particle size did not directly influence protein values; however, greater accuracy and reproducibility were achieved with smaller particle sizes. Packing density inside the loading tell also influenced the analytical results.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.12
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• pp.1699-1707
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• 2000

Thirty-one multiparous Bos indicus${\times}$Bos taurus cows were offered concentrate supplements based on (1) 2 kg wheat bran; (2) 4 kg wheat bran; and (3) concentrate (30 maize: 67 wheat bran) at 0.5 kg per 1.0 kg milk produced, in a one year study in India. All supplements also contained 2 parts of a mineral mixture and 1 part salt. Cows were allocated to treatments at calving on parity (2nd and 3rd calf) with 13, 8 and 10 cows respectively in treatments 1, 2 and 3. They were individually fed for whole lactation, the basal diet being ad libitum berseem clover plus 2 kg wheat straw in the cool season/winter (period 1) and chopped maize in summer (period 2). Diets with berseem offered TDN and CP contents of 67.6, 18.2; 65.5, 16.8; and 67.5, 16.8 percent; and with maize fodder 62.6, 12.0; 62.6, 12.5; and 63.3, 12.5 percent for treatments 1, 2 and 3, respectively. Total dry matter (DM) intakes (1) 9.9 kg, (2) 10.9 kg and (3) 11.1 kg DM/day and intake of nutrients (TDN, CP) increased with level of supplementation (p<0.01), but effects of treatment on animal performance were not significant. Cow milk yields averaged (1) 7.9 kg, (2) 8.1 kg and (3) 8.8 kg milk/day (p>0.05) for lactation lengths of 252, 270 and 220 days (p>0.05) and cows gained +7.3; +8.1; and +12.0 kg respectively over their lactation (p>0.05). Wheat bran was used effectively as the sole energy component in concentrates for lactating dairy cows. Its use could potentially reduce feed costs and demands for cereal grain. Reduced concentrate levels may be considered if green forages of high nutrient content are fed ad libitum. Associated economic advantages or disadvantages require further evaluation.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.6
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• pp.635-642
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• 1997

This experiment was conducted to determine apparent ileal and fecal digestibilities of some grains for young pigs (15.6 kg BW). Ileal and fecal digestibility of corn, milo, wheat, barley, rice and tapioca were measured with pigs fitted with simple ileal T-cannula. Rice was the highest (p < 0.05) and tapioca was the lowest (p < 0.05) in the digestibilities of gross energy. For the crude protein digestibilities, rice, barley and wheat were higher (p < 0.05) than corn, milo and tapioca. The average ileal digestibilities of essential amino acids (AAs) were 89.9, 85.8, 81.5, 80.9, 80.2 and 76.3% for those fed rice, barley, milo, wheat, corn and tapioca diets, respectively. Regardless of the dietary carbohydrate sources, among the dispensable amino acids, glycine had lowest digestibility except for barley and milo. The apparent ileal digestibility of lysine and methionine were 90.7, 94.0% in rice, 88.3, 86.5% in barley and 86.3, 82.3% in wheat. The apparent fecal digestibility of average essential AAs were 90.8, 89.9, 87.7, 85.1, 82.5 and 77.9% in pigs fed the rice, barley, wheat, corn, milo and tapioca diets, respectively. The fecal digestibilities of essential AAs and nonessential AAs, in general, were higher than the ileal digestibilities, which indicating a loss of nitrogenous components in the cecum and colon. For all AAs, differences between ileal and fecal amino acid digestibilities ranged from 0.0 (valine) to 5.8 (threonine) in rice, 0.1 (arginine) to 14.5 (glycine) in barley, 2.8 (lysine) to 12.4 (glycine) in wheat, 1.0 (isoleucine) to 12.9 (glycine) in corn, 0.2 (serine, glutamic acid) to 6.5 (methionine) in milo and 0.5 (valine) to 22.1 (glycine) percentage units in tapioca diets. In conclusion, whether it is ileal or fecal, rice and barley appeared to be excellent alternative carbohydrate sources for young pigs in terms of AAs digestibility. However, energy value and cost for each grain should be considered when formulating diets.

• Journal of Climate Change Research
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• v.4 no.4
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• pp.371-384
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• 2013

The appearance of abnormal weather caused by climate change have both direct and indirect impact on the society. Especially, agriculture is brought up as a socially important interest having direct impact of climate change in growth and harvest of crops. This study aims to perform vulnerability assessment for the South Korea's two main imported grains, maize and wheat. The production vulnerability assessment of maize and wheat in USA and China to temperature variability, which has a great impact in production, is performed. First, grain cultivation period which affects productivity of main grain production country was selected based on the main cultivation period from several references and previous studies. Then, Intergovernmental Panel on Climate Change AR5 greenhouse gas scenario RCP(representative concentration pathways)8.5 scenarios was used to select the future climate that correspond to the cultivation period of maize and wheat for each producing country. According to the result of production vulnerability analysis using adaptation (temperature changing trend) and sensitivity(temperature variability), the productivity of wheat was higher in USA, while productivity of maize was higher in China. In the future, the result showed that productivity of all two grains will be favorable in USA. The result of production vulnerability assessment through this study can later be used as a preparation data for the coming fluctuation in grain price due to climate change.

• Korean Journal of Agricultural and Forest Meteorology
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• v.4 no.1
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• pp.18-22
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• 2002

This experiment was conducted to investigate the effect of night illumination on the growth and yield of wheat and barley. Three varieties of barley and four cultivars of wheat were tested under the different night illuminance which was controlled in the range of 1.2∼20 Lux during whole growth season at night. As night illumination was stronger, the culm length of all varieties tended to be shorter. The shortening was greater in barley than wheat. Node number, awn length and culm diameter tended to decrease as the light intensity was stronger. Internode length above the 4th and 5th node was remarkably decreased by the stronger illuminance. The degree of decrease in spike length affected by the night illuminance was much larger in the late-maturing variety among wheat cultivars. As night illumination was stronger, days to heading was shortened in general. The range of decrease was 2 to 10 days under 10∼20 Lux condition similarly in both barley and wheat. Effect of night illumination on heading date and days from initial heading to full heading was not considerably different between the crops and among varieties except Kangbori. Night illumination decreased the grain yield by 12.5% in barley, and 11.0% in wheat at 2.1∼5.0 Lux condition, and 34.6% in barley, and 29.3 % in wheat at 10∼20 Lux condition compared to control. Yield reduction was significantly different among varieties, being greatest in Kangbori among barley varieties, and in Chokwang (late-maturring variety) and Changkwang (late-maturring variety) among wheat varieties. It was interpreted that the decrease of grain yield was resulted from the decrease in the number of spikes and the number of grains per spike under the stronger night illumination. The decrease of grain yield was more directly attributed to the decrease in the number of grains per spike.

• Korean Journal of Organic Agriculture
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• v.29 no.2
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• pp.223-240
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• 2021

This study was carried out to investigate the economic value of organic wheat production using gelatin·chitin microorganisms in Gwangsan-gu, Gwangju city. The soil condition of experiment field was clay loam Jisan series. The organically cultivated fields were sprayed gelatin and chitin degrading bacteria. The test was performed at conventionally cultivated field and organically cultivated field. Emergence of weed on organically cultivated field was significantly higher than conventionally cultivated field which sprayed herbicide before seeding. Weed emergence have a critical impact on grain yield. Occurrence of diseases and insect pests were higher than conventionally cultivated fields. In 2019, the amount of lodging in conventionally cultivated field were higher than conventionally cultivated field. In 2020, lodging and wet injury were occur in both field. Comparing yield element between organically and conventionally cultivated experimental area, grain yield in organically cultivated field was shown slightly higher amount than conventionally cultivated field. However in the actual yield of 2019, organically cultivated field shows 20% deceased yield because of overgrown weed. In 2020, weed emergence and yellow mosaic virus by wet injury cause 30% decease in the grain yield in organically cultivated field. Content of protein, carbohydrates, ash, water and fat in the grain were not different significance. In 2019, net incomes of conventionally cultivated wheat was 461,031 won/0.1 ha while organically cultivated wheat was 443,437 won/0.1 ha. In the rate of income, conventionally cultivated field was 83.0% as against organically cultivated field (73.3%). In 2020, net incomes of organically cultivated wheat was 437,812 won/0.1 ha while conventionally cultivated wheat was 418,281 won/0.1 ha. In the rate of income, conventionally cultivated field was 81.6% as against organically cultivated field (73.0%).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.3
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• pp.188-196
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• 2023

Wheat (Triticum aestivum L.) is an important crop in Korea, with a per capita consumption of 31.6 kg in 2019. In the southern region, wheat is grown after paddy rice, and it is harvested during the rainy season in mid-June. This timing, in combination with high humidity and untimely rainfall, activates the enzyme alpha-amylase, which breaks down starch in the wheat grains. As a result, sprouted grains have lower quality and value for flour. However, seeds that absorb water before sprouting are expected to maintain better quality. The aim of the study was to identify the critical period during wheat maturation when rainfall has the greatest impact on grain quality, to prevent price declines due to quality deterioration. Two wheat cultivars, Jokyoung and Hwanggeumal, were grown in a speed breeding room, and artificial rainfall was applied at different times after heading (30, 35, 40, 45, 50, and 55 days). The proportion of vitreous grains decreased from 40 to 55 days after heading (DAH). Both cultivars had chalky grain sections from 35 DAH, with Hwanggeumal having a higher proportion of vitreous grains. Starch degradation was observed using FE-SEM (Field Emission Scanning Electron Microscope) at 40 DAH for Jokyoung and 50 DAH for Hwanggeumal. Color measurements indicated increased L and E values from 40 DAH, with rain treatment at 55 DAH leading to a significant increase in L values for both cultivars. Ash content increased at 45 DAH, whereas SDSS decreased at 35 DAH. Overall, grain quality from 40 DAH until harvest was found to be affected to the greatest extent by direct exposure of the spikes to moisture. Red wheat showed better quality than white wheat. These findings have implications for the cultivation of high-quality wheat and can guide future research efforts in this area.

• Food Science and Preservation
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• v.15 no.2
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• pp.219-224
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• 2008

"Charmdlerak" a new high-quality Korean wheat, was produced with production management from the Rural Development Administration (RDA). We evaluated the characteristics of grain, flour, and end-use quality of "Charmdlerak" wheat to assess consumer satisfaction with this new variety of wheat. Eighty-two farmers (450MT/100 ha) in Gwangju metropolitan city produced Keumkangmil wheat and 23 farmers (30 ha) produced "Charmdlerak" wheat "Charmdlerak" wheat had 1.55% ash content and 11.0-13.0% protein content "Charmdlerak" flour was milled by a commercial machine in Samyang Milmax. The protein content of "Charmdlerak" was slightly higher than that of flour from Hard Red Winter Wheat (HRWW), the most popular multipurpose flour in Korea. The ash content and color of "Charmdlerak" wheat were similar to those of HRWW. End-use quality testing of cooked noodles and bread indicated that "Charmdlerak" flour resulted in softer noodles and similar bread loaf volume compared with products made from Keumkangmil wheat.

• Korean Journal of Plant Resources
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• v.36 no.3
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• pp.225-236
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• 2023

Stomatal traits such as stomata density (SD), aperture length (APL) and width (APW), guard cell length (GCL) and width (GCW), and distance between stomata (DIS) were investigated to identify correlation with agronomic traits for 35 Korean wheat cultivars. Flag leaf width (FLW) of Korean wheat cultivars was the widest in Ol-mil, and the narrowest in Keumkang. SD tended to be higher on the adaxial side than on the abaxial side in Korean wheat cultivars. SD of adaxial and abaxial sides was classified into a cultivar with a significantly different or not. In APL, 18 wheat cultivars showed significant differences according to leaf side, and APL of adaxial was longer than APL of abaxial in 13 wheat cultivars. In APW, 15 wheat cultivars showed a significant difference, and APW of abaxial was wider than APW of adaxial among them. In GCL, 14 wheat cultivars showed a significant difference, and the GCL of abaxial was longer than the GCL of adaxial in 10 wheat cultivars. In GCW, 10 wheat cultivars showed a significant difference, GCW of adaxial was wider than GCW of abaxial and in 6 wheat cultivars. FLW of adaxial and abaxial showed a negative correlation with GCL and a positive correlation with grain number per panicle. FLW of only abaxial showed a positive correlation with DIS. The SD of the adaxial showed a negative correlation with GCL, while the SD of the abaxial showed a negative correlation with APL. APL of both sides of the leaf showed a positive correlation with GCL, and APW of only abaxial showed a negative correlation with GLC. DIS of adaxial showed a negative correlation with tiller number (TN), while DIS of abaxial showed a positive correlation with GNP.