• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.4
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• pp.277-282
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• 2016

The consumption of waxy corn is steadily increasing in Korea. Waxy corn is harvested before it reaches full maturity and consumed immediately or follwing cold storage. Glutinous and sweet kernels are preferred due to their high palatability. The kernel properties can change rapidly following harvest, and, therefore, optimal conditions to maintain the kernel quality of corn should be identified. In addition, the timing of harvest of waxy corn ear should be also determined for optimal marketable corn production. From 10 days after silking (DAS) to25 DAS. fresh ear weight and single kernel weight rapidly increased from 78.3 g and 1.13 g, respectively, to 224.9 and 3.61 g, respectively. However, by 30 DAS both fresh and single kernel weight decreased by 10.6% and 6.1%, respectively. Kernel hardness significantly increased up to 25 DAS, and a further slight increase in kernel hardness was observed at 30 DAS. Total sugar content in kernel decreased from 12.5% at 10 DAS to 3.5% at 35 DAS, which was the result of the conversion of sugars to starch during ear development. Crude protein content in kernel did not vary significantly in comparison to kernel hardness. During storage of ear, kernel hardness increased from $726g\;cm^{-2}$ at harvest to $1894g\;cm^{-2}$ following 28 days of storage at a low temperature ($0^{\circ}C$). Kernel hardness increased 2.5 fold from 15 DAS to 30 DAS. Soluble protein level in kernel increased until 10 DAS, following which a slight decrease was observed. The soluble protein content decreased from 1.85% at 5 DAS to 1.45% at 35 DAS. Total sugar content in kernel decreased regardless of storage temperature; however, the rate of reduction was lower at $0^{\circ}C$ than that observed following storage at $4^{\circ}C$ and $10^{\circ}C$. The rate of reduction in kernel moisture content was also lower at $0^{\circ}C$ than that observed at $4^{\circ}C$ and $10^{\circ}C$.

• The Korean Journal of Food And Nutrition
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• v.26 no.1
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• pp.92-100
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• 2013

This study investigated the quality and antioxidative properties of a Korean fried rice cake, Gaeseong-Juak (doughnut of waxy rice) added with Prunus yedoensis Matsumura (PYM) extract, vitamin C and BHT. Gaeseong-Juak was prepared by adding PYM extract at 0, 0.5, 1, and 2% of waxy rice powder. The moisture contents of Gaeseong-juak added with PYM extract varied between 17.50% and 21.70%. Among the samples, the lowest moisture content was 2% Gaeseong-juak added with PYM extract. The contents of the samples obtained from crude protein, crude fat, crude ash were 4.47~4.73, 11.15~12.50, and 0.73~0.82%, respectively. The as the content of PYM extract increased, L-values significantly decreased while a-value and b-value significantly increased (p<0.001). The texture profile analysis of the Gaeseong-Juak was not significantly different at the samples. In the sensory test, the sample containing 0.5% PYM extract obtained good scores. The antioxidative effect of the Gaeseong-Juak significantly increased as the addition level increased, compared to the original Gaeseong-Juak (p<0.001). From these results, we suggest that PYM is a good ingredient for increasing the consumer acceptability and the functionality of Gaeseong-Juak.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.spc1
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• pp.152-160
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• 2005

This study was carried out to investigate selectable criteria in evaluating waxy corn $F_1$ hybrids for developing good eating quality waxy corn variety. The physicochemical property analysis of 6 waxy corn $F_1$ hybrids - Chalok1, Chalok2, Heugjeomchal, Yeonnongl, Chalok4, and Suwon45- showed a range of $11.2\~13.1\%$ for crude protein, $5.1\~6.0\%$ for crude fat, $91.8\~92.6\%$ for amylopectin, and $4.5\~6.6\%$ for free sugar content. The pericarp thickness which is one of the most important characteristics related to tenderness in waxy corn was ranged $34\~47{\mu}m$ in 4 waxy corn hybrids - Yeonnongl, Chalok4, Suwon45, and Heugjeomchal. On the other hand, it was ranged $64\~81{\mu}m$ in Chalok1 and Chalok2. The amylogram analysis by rapid visco analyzer showed that in fresh waxy corn hybrid (DAP25), all amylogram properties except setback were higher in Yeonnongl, Chalok4, and Suwon45 compared to those of Chalokl, Chnlok2, and Heugjeomchal. However, in matured waxy corn hybyids (DAP45), the result was the opposite - the amylogram properties were higher in Chalokl, Chalok2, and Heugjeomchal than those of Yeonnongl, Chalok4, and Suwon45. The texture analysis showed that gumminess, chewiness, and hardness increased dramatically with the time after the cooking in Chalokl and Beugjeomchal. On the other hand, these above pyoperties did not change as rapidly with the time in Yeonnongl, Chalok4, and Suwon45. Gumminess, chewiness, and hardness did not increase much within 6 hours after steamingr but increased significantly 32 hours after steaming. Therefore, we have reached a conclusion that texture analysis of cooked waxy corn should be carried out 6 hours after steaming. In the sensory evaluation, Yeonnongl, Chalok4, and Suwon45 revealed higher palatability -6.8, 7.1, and 6.9 respectively - than. that of Chnlokl, Chalok2, and Heugjeomchal. The palatability analysis of 6 waxy corn hybrids showed palatability positively correlating with free sugar content,100-kernel weight, kernel length, kernet width, and consistency, but negatively correlating with pericarp thickness, hardness, gumminess, and chewiness.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.3
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• pp.242-253
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• 1984

Four different levels of nitrogen were applied to 3 naked barley cultivars (Hordeum vulgare L.) Yonezawa, Baekdong and Yeongsanbori. Changes in physico-chemical properties were examined upon these treatments. Total protein content as well as glutelin increased as N level increased. Baekdong contained the highest protein content (13.7%) at N$_2$. Yonezawa and Baekdong contained more lysine than Yeongsanbori. Increased lysine was measured in all cultivars by increased nitrogen application. Among all amino acids proline was the highest in all cultivars, and its increase was paralled to the N levels. Magnesium and potassium were declined and calcium was increased with increased levels of nitrogen fertilizer. Ash content was decreased as nitrogen increased and as the plants have become matured. Three minutes pearling in Yonezawa was not sufficient in terms of water absorption ratio and whiteness. Sixty percent pearling rate in Yonezawa showed a higher absorption ratio and cooking whiteness than non-waxy Baekdong and Yeongsanbori. Gelatinization temperature was lower but maximum viscosity was higher in waxy than non-waxy barley.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.2
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• pp.177-186
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• 2010

This study was carried out to compare the physicochemical characteristics and preference as a sensory quality of Sogokju (Korean traditional rice wine) from waxy rice varieties. The protein and moisture contents of milled waxy rice varieties were ranged 6.9~7.2% and 12.1~ 12.6%, respectively. Nunbora had the largest grain size. In pasting properties, Hangangchalbyeo had the highest peak, trough and final viscosities, and Dongjinchalbyeo had the lowest viscosity curve. These differences suppose to be caused by the amylopectin(AP) structure: Dongjinchalbyeo has the largest short AP chains (degree of polymerization (DP) 6-12) and the smallest middle AP chains (DP 13-24) in 9 waxy rice varieties, while Hangangchalbyeo has the smallest short AP chains and the largest middle AP chains. The alcohol contents of Sogokju brewed from 9 waxy rice varieties were 17.6～19.9%. The brix degree were ranged $20.5{\sim}23.9^{\circ}Bx$. The organic acid of Sogokju consisted mainly of succinic acid, and the free sugar of it consisted mostly of glucose. The sensory evaluation showed the highest palatability at the Sogokju from Baegseolchalbyeo. The palatability was positively correlated with the brix degree, the glucose content, and the turbidity, and negatively correlated with the production yield of Sogokju.

• Korean journal of food and cookery science
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• v.21 no.5
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• pp.733-741
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• 2005

Waxy barley flour was fermented by two kinds of starter cultures; L. plantarum and L. brevis, alone or in combination and the effect was evaluated on waxy barley and wheat composite bread quality. In all three barley sourdoughs, fermentation decreased the pH, total sugar and reducing sugar, and increased lactic acid bacteria cell numbers. However yeasts (S. cerevisiae) were reduced. There was significant difference in physicochemical characteristics between the reference(composite barley dough containing improvement agent) and the barley sourdoughs (p <0.05). Barley sourdough fermented by L. plantarum showed more desirable farinogram properties of peak time, stability and elasticity than that of the reference. The rheofermentometer data for L. brevis produced the most $CO_2$ release curve, whereas L. plantarum held maximum $CO_2$ retention differed significantly from that of the breads made with barley sourdoughs fermented with the respectives starter cultures (p < 0.05). Barley sourdough bread fermented with L. plantarum resulted in better bread quality than the reference bread. The positive effect of fermentation with L. plantarum on bread quality was evident when comparing the well developed protein-starch matrix structure of the bread baked with barley sourdough with the reference bread.

• Animal Bioscience
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• v.35 no.7
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• pp.1021-1029
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• 2022

Objective: The study was aimed to investigate the rules of postprandial changes in intestine digesta dry matter (DM) flow and amino acid digestibility of growing pigs fed low-protein (LP) diets made of different starch. Methods: Eight barrows (28.8±2.1 kg) with a T-cannula at the distal ileum were randomly allotted to an 8×3 Youden square design. Treatments included: waxy corn starch LP (WLP); corn starch LP (CLP) and pea starch LP (PLP). Diets were given at 08:00 and 20:00. Digesta samples were collected in six 2-h stages from 08:00 to 20:00. Results: The Cr concentrations of ileal digesta increased and then decreased in WLP and CLP, while increased continuously in PLP as time passed after postprandial (p<0.05). Higher average Cr concentrations (0.78% and 0.84% vs 0.70%; p<0.05) and lower average DM flow (181.1 g/kg and 166.3 g/kg vs 240.3 g/kg; p<0.001) were observed in WLP and CLP, compared with PLP. The apparent ileal digestibility coefficient of most amino acids in WLP and CLP increased compared with that in PLP. No difference in lysine or methionine digestibility was observed. When digesta were collected in 2-h periods, the apparent ileal digestibility coefficient of amino acids did not change over time. When digesta was collected in 4-h periods from 16:00 to 20:00 and 6-h periods from 14:00 to 20:00 (p<0.05), WLP and CLP showed markedly higher amino acid digestibility than PLP Conclusion: High-amylose slowly digested starch can increase the DM flow at the distal ileum and reduce the apparent ileal digestibility coefficient of amino acids of pigs fed LP diets. Compared with waxy corn starch and corn starch, pea starch reduced the digestibility of amino acids in digesta collected after 4 h postprandial.

• Korean Journal of Plant Resources
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• v.31 no.5
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• pp.498-514
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• 2018

A statistical analysis for 3651 genetic resources collected from China (1,542), Japan (1,409), Korea (413), and India (287) was conducted using normal distribution, variability index value (VIV), analysis of variation (ANOVA) and Ducan's multiple range test (DMRT) based on a data obtained from NIRS analysis. In normal distribution, the average protein content was 8.0%, whereas waxy type amylose and common rice amylose were found to be 8.7% and 22.7%, respectively. The protein contents ranged from 5.4 to 10.6% at the level of 95%. The waxy amylose and common rice amylose ranged from 5.9 to 11.5%, and from 16.9 to 28.5% at 95% confidence level, respectively. The VIV was 0.59 for protein, 0.64 for low amylose, and 0.81 for high amylose contents. The average amylose contents were 18.85% in Japanese, 19.99% in Korean, 20.27% in Chinese, and 25.46% in Indian resources, while the average protein contents were found to be 7.23% in Korean, 7.73% in Japanese, 8.01% in Chinese, and 8.17% in Indian resources. The ANOVA of amylose and protein content showed significant differences at the level of 0.01. The F-test for amylose content was 158.34, and for protein content 53.95 compared to critical value 3.78. The DMRT of amylose and protein content showed significant difference (p<0.01) between resources of different countries. Japanese resources had the lowest level of amylose contents, whereas, the lowest level of protein content was found in Korean resources compared to other origins. Indian resources showed the highest level of amylose and protein contents. It is recommended these results should be helpful to future breeding experiments.

• Korean journal of food and cookery science
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• v.33 no.2
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• pp.198-208
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• 2017

Purpose: To improve the quality of basic gluten-free rice bread composed of white rice flour, salt, sugar, yeast, skim milk powder, olive oil, and water, the effects of transglutaminase (TGase), whey protein (WP), propylene glycol alginate (PGA), and hydroxypropylmethylcelluose (HPMC) were investigated. Methods: TGase, WP, PGA, and HPMC were added to rice flour cumulatively. The pasting properties of rice flour blends as well as volume, shape, color value, textural properties and sensory evaluation of basic rice bread (RB1) RB1+TGase (RB2), RB1+TGase+WP (RB3), RB1+TGase+WP+PGA (RB4), and RB1+TGase+WP+PGA+HPMC (RB5) were compared. Results: Consistency of rice batter increased upon addition of TGase, WP and PGA, and RB3 and RB4 had higher specific volumes than others. PGA improved volume, crumb air cell uniformity, and resilience but lowered elasticity and moistness of RB. HPMC increased, hardness, moistness and softness, and slightly reduced volume. Conclusion: Therefore, it is suggested that hydrocolloids, PGA and HPMC may be necessary to improve volume, crumb structure, textural properties and overall eating quality of gluten-free rice bread.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.spc1
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• pp.161-166
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• 2005

Objectives of this study were to select inbred lines which have a good eating quality and desirable segregates during inbreeding of waxy corn. The 64 inbred lines showed a large variance in their kernel shape and weight. 100-kernel weight, pericarp thickness, kernel length, kernel width, and kernel thickness ranged $11.7\~37.3g,\;11\~77{\mu}m,\;5.8\~9.6mm,\;6.5\~10.0mm$, and $4.1\~6.8mm$, respectively. The physicochemical analysis of 64 waxy corn inbred lines showed crude protein, crude fat, free sugar, and amylopectin content ranging $8.7\~15.8\%,\;2.3\~5.8\%,\;1.1\~11.0\%,\;and\;78.5\~93.8\%$, respectively. The texture property analysis of 64 inbred lines by texture analyzer showed a big difference. Gumminess, hardness, and chewiness of 64 inbred lines ranged $91\~383,\;181\~394,\;and\;73\~370$, respectively. The principal component analysis for 14 characteristics related to kernel quality showed that $73.1\%$ of the total variation could be attributed to the first five principal components. Biological meaning of the principal component was explained clearly by the correlation coefficient between principal components and characters. The first principal component appeared to correspond to small kernel and bad eating quality, The second principal component appeared to correspond to large kernel and good eating quality. The 64 inbred lines were classified into 8 groups by the cluster analysis using the first and second principal component. Among the groups, group VII and VIII included inbred lines with good eating quality that had thin pericarp thickness, low protein content, large kernel, and soft tenderness.