• Korean Chemical Engineering Research
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• v.56 no.1
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• pp.139-142
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• 2018

Silicon (Si) is a promising anode material for next-generation lithium ion batteries (LIBs) because of its high capacity of 4,200 mAh/g ($Li_{4.4}Si$ phase). However, the large volume expansion of Si during lithiation leads to electrical failure of electrode and rapid capacity decrease. Generally, a binder is homogeneously mixed with active materials to maintain electrical contact, so that Si needs a particular binding system due to its large volume expansion. Polyvinyl alcohol (PVA) is known to form a hydrogen bond with partially hydrolyzed silicon oxide layer on Si nanoparticles. However, the decrease of its cohesiveness followed by the repeated volume change of Si still remains unsolved. To overcome this problem, we have introduced the electrospinning method to weave active materials in a stable nanofibrous PVA structure, where stresses from the large volume change of Si can be contained. We have confirmed that the capacity retention of Si-based LIBs using electrospun PVA matrix is higher compared to the conservative method (only dissolving in the slurry); the $25^{th}$ cycle capacity retention ratio based on the $2^{nd}$ cycle was 37% for the electrode with electrospun PVA matrix, compared to 27% and 8% for the electrodes with PVdF and PVA binders.

• Journal of the Korean Chemical Society
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• v.57 no.3
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• pp.389-397
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• 2013

In this study, the effects of STAD cooperative learning strategy on students' achievement, learning motivation, perceptions of learning environment, and perceived classroom goal structure were investigated in terms of students' collectivism level. Two classes (64 students) from an elementary school were respectively assigned to a control group and a treatment group. A individualism-collectivism test, a learning motivation test, a perceptions of learning environment test, and a perceived classroom goal structure test were administered as pretests. The intervention of cooperative learning lasted for 24 class periods. After instruction, an achievement test, the learning motivation test, the perceptions of learning environment test, and the perceived classroom goal structure test were administered. The results indicated that the students of the treatment group significantly outperformed those of the control group in the achievement test. There was a significant treatment-aptitude interaction effect in the scores of the attention subcategory of the learning motivation. In the perceptions of learning environment, the score of the treatment group was significantly higher than the control group in the cohesiveness subcategory, whereas the score of the treatment group was significantly lower than their counterpart in the competitiveness subcategory. It was also found that the score of the treatment group was significantly higher than the control group in the performance subcategory of the perceived classroom goal structure.

• Food Science of Animal Resources
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• v.27 no.4
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• pp.424-431
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• 2007

This study was conducted to investigate the effect of intramuscular fat scores on pork quality assurance. Pork loins were collected from animals (110-120 kg body weight) slaughtered in a commercial slaughterhouse, assigned an IMF score (1-3) from and stored for 24 hrs at $-3^{\circ}C$. Samples were analyzed for chemical composition, pH, cooking and drip loss, shear force, meat color, and texture characteristics. The moisture, crude protein and crude ash content were not significantly different among the various IMF score groups. The crude fat content of the IMF score 3 group was significantly higher than the IMF score 1 and 2 groups (p<0.05). The pH values of the IMF score 2 and 3 groups was significantly higher than the IMF score 1 group (p<0.05). There was a no significant difference in shear force value and cooking loss among the IMF score groups. The purge loss content of the IMF 3 group was significantly lower than that of the IMF score 1 group (p<0.05). The increase in IMF score resulted in lower hardness, gumminess, and brittleness values. The hardness and gumminess of the IMF score 3 group were significantly lower than those of the IMF 1 score group. The adhesiveness, cohesiveness, and springiness were not significantly different among the IMF score groups. With regard to meat color traits, lightness ($CIE\;L^*$) was not significantly different among the IMF score groups. The $a^*\;and\;b^*$ values correlated positively with the IMF score. In general, the results of this study show that the CIE color values and drip loss had a positive correlation, while only redness was positively correlated with shear force and hardness. pH was negatively correlated with CIE color values and drip loss, while positively correlated with moisture content.

• Journal of Food Hygiene and Safety
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• v.34 no.5
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• pp.463-472
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• 2019

This study investigated the quality characteristics and antioxidant activities of morning bread containing various amounts of aronia sourdough starter. Morning breads were prepared with different volumes (0% (AS0), 15% (AS1), 25% (AS2), and 35% (AS3)) of aronia sourdough starter based on wheat flour. In AS3 group (35% added group), the specific volume and baking loss rate were the highest but the bread height was the lowest. When the aronia sourdough starter was added up to 25%, the expansion power, specific volume, and bread height were significantly increased (P<0.05). According to the added amount of sourdough starters, the lightness and yellowness of the morning bread were decreased, however, redness was increased (P<0.05). In the rheology analysis, hardness, gumminess, and chewiness were significantly decreased with increasing amounts of aronia sourdough starters (P<0.05). However, cohesiveness was the highest in the AS2 group (25% added group). In consumer preference, the highest scores were shown in AS2 group (25% added group) in color, texture, and appearance. The total polyphenol and DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging ability were both significantly increased along with aronia sourdough content (P<0.05). In conclusion, morning bread with 25% aronia sourdough starter showed the best quality characteristics and antioxidant activities.

• The Korean Journal of Food And Nutrition
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• v.23 no.4
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• pp.607-614
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• 2010

The aim of this study was to investigate the quality characteristics of sponge cakes with added rice flour produced by a modified genoise method to prevent volume reduction. A control group and experimental group I were prepared by the genoise method and experimental groups II, III, and IV were produced by a modified genoise method in which they were mixed with wheat flour and water to a make paste to form gluten for 3, 6, and 9 minutes, respectively. One third of the wheat flour in all experimental groups was replaced by rice flour. The control and experimental groups were compared in terms of quality characteristics, including batter specific gravity, volume, color, textural characteristics, and sensory qualities, to determine the optimal pasting time for wheat flour in the formulation. The specific gravity of the experimental groups was higher than that of the control and decreased with increasing wheat flour pasting time. The volume of experimental group I was lower than that of the control group, and the volume values of experimental groups III and IV, made by the modified genoise method, were higher than that of the control group. $dL^*$ and $db^*$values for the crust and inside of the cake were lower in the experimental groups than in the control. The $dL^*$ value, indicating brightness, increased as pasting time increased. The hardness values of experimental groups I and IV were higher than that of the control whereas experimental groups II and III had lower hardness values. Chewiness was higher in the control group, as well as experimental groups I and IV than in the experimental groups II and III. The gumminess of experimental group IV was highest. Cohesiveness decreased by adding rice flour to the sponge cake. Sensory attributes of cell uniformity, tenderness, moistness, taste, and overall acceptability had the highest scores in experimental group III. Based on these results, we conclude that the quality of sponge cake containing one third of the wheat flour replaced by rice flour is best with 6 minutes pasting of the wheat flour to form gluten.

• Journal of the East Asian Society of Dietary Life
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• v.22 no.3
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• pp.414-421
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• 2012

Moisture content of muffin tended to increased as increasing mixing rate of maesangi. For crude protein, sample group of 9% replaced by maesangi powder was the highest. For crude fat and crude ash, there was no significant difference among sample groups. The average height of muffin was 4.7 cm, but was no significant difference among sample groups. Volume of muffin has been gradually increased as increasing mixing rate of maesangi powder, but was no significant difference among sample groups. From the SEM (scanning electron microscope) result, thick cell wall and rough blowholes were appeared. L-, a and b-values of muffin was declined as per increase of mixing rate of maesangi powder. Hardness was inclined as per increase of mixing rate of maesangi powder. There were significant differences between sample groups and reference group for adhesiveness, springiness and cohesiveness, but was no significant difference among sample groups. For gumminess, sample group of 9% replaced by maesangi powder was the highest, but there were no significant difference from sample groups of 3% and 6% replaced by maesangi powder. Chewiness was inclined as per increase of mixing rate of maesangi powder, and sample group of 9% replaced by maesangi powder was the highest. From sensory test result, sample group of 9% replaced by maesangi powder was the highest for color, and there were significant differences among sample groups. Sample group of 6% replaced by maesangi powder was the highest for flavor and taste, and there were significant differences among sample groups. Sample groups of 6% and 9% replaced by maesangi powder were the highest for texture. Sample group of 9% replaced by maesangi powder was the highest for overall preference. From all these results, the most suitable one would be the sample group of 9% replaced by maesangi powder.

• Korean journal of food and cookery science
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• v.14 no.4
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• pp.313-326
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• 1998

The quality of physical characteristics were measured, using sensory evaluation and mechanical characteristics where different storing temperature and period on Gukhwa-Byung, which is made of different percentages of Gukhwa (0%, Gukhwa powder：1%, 3% and 5%, and Gukhwa flower：1%, 3% and 5%) were added to rice flour, to promote the use of and liking for rice cakes that are a kind of korean traditional foods. The sensory evaluation showed that it is generally fine right after being made. Especially group F3 was evaluated the best for color, feeling after-swallow and overall-quality. As for color alone, it fumed out to be most distinctive in group F3 after storing 24 hours at 4$^{\circ}C$, in group F1 after 24 hours at 10$^{\circ}C$, in group F1 and F3 after 24 hours at 30$^{\circ}C$ and in group F1 after 48 hours at 30$^{\circ}C$, Gukhwa-Byung added with Gukhwa flower takes the higher degree of preference than the one with Gukhwa powder. Moisture decreased and overall-quality deteriorated as the storing time passed. The value of lightness in the color of Gukhwa-Byung, reduced as Gukhwa content increased and storing temperature rose. The values of red color and yellow color increased as Gukhwa content increased. In a mechanical texture measurement, springiness was high in group P5 right after being made. And it was high after storing 72 hours at 4$^{\circ}C$ and after 96 hours at 10$^{\circ}C$, and there was a significant difference according to Gukhwa content (p＜.05). Springiness remained unchanged after storing, 24 hours at 30$^{\circ}C$. Cohesiveness was high in every group of P1, P3 and P5, in which Gukhwa powder was added, right after being made, but as temperature rose and time passed, it heightened in group F3, in which 3% of Gukhwa flower was added. In all the samples, hardness gradually increased as the storing time at each temperature passed, and decreased as Gukhwa content increased. Chewiness was getting high as the storing time passed and temperature lowered. Color in sensory evaluation and the value of lightness in mechanical measurement showed a positive correlation at storing temperature 4$^{\circ}C$ and 10$^{\circ}C$ (p<.01). Softness and the value of lightness showed a negative correlation (p<.05). In sensory evaluation, softness and moisture showed a negative correlation with the value of lightness when storing at 30$^{\circ}C$.

• Food Science of Animal Resources
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• v.27 no.2
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• pp.137-141
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• 2007

This study was conducted to investigate the proximate composition and physico-chemical characteristics of Berkshire pork by gender. A total of 40 pigs(60 kg) were divided into 2 groups(gilt and barrow) and raised to 110 kg of live weight. pigs were conventionally slaughtered, and then chilled overnight. Pork loin(longissimus dorsi) muscle was removed from each left side and meat qualities were evaluated. The proximate composition was no different between genders, and the pH was higher iii the barrow group(p<0.05). The water holding capacity, cooking loss, shear force, and cholesterol content were no different between genders. With regard to meat color, the $L^*$ value was higher in the barrow group(p<0.05), but the $a^*\;and\;b^*$ values were no different between genders. The fat color was also no different between genders. The texture properties, brittleness, hardness, and gumminess of the gilt group were higher than those of barrow group(p<0.05), but cohesiveness, springiness, and chewiness were no different. In conclusion, the pH and $L^*$ values of the barrow group were higher than those of gilt group, and tenderness was higher in the barrow group.

• Korean journal of food and cookery science
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• v.19 no.3
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• pp.354-362
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• 2003

higher. The Hunter color test showed lower L values with higher amounts of added JP to the Jeung-Pyun. In the sensory test. the 7 % added group had the strongest color according to the texture; the highest cohesiveness was shown in the 5 % added group, and the highest springiness was shown by the 3% added group, but none of these showed any significant differences. As for flavor, the more JP added the higher the stale grain flavor and bitterness. In the result of the overall acceptability test, the stale grain flavor of the 5% added group showed the highest values for the favorite texture and flavor. From the results of this experiment, when making stale grain flavored Jeung-Pyun, the 3 and 5% added groups were the optimum concentrations for the observed improvements in the quality. This study was carried out to investigate the possibility of improving the quality characteristics of Jeung-Pyun, by the addition of Paecilomyces japonica powder (JP). Regarding the volume of the Jeung-Pyun fermentation, with respect to the different amounts of JP added, the groups containing JP showed increased volumes, and as for the pH. the group containing 5% showed the lowest value. Regarding the moisture content, the groups containing JP showed lower moisture contents than the control group. Regarding the amino acid content, the control group showed a higher amino acid content than those of the JP containing groups, and contained an even amount of essential amino acids. and Leucine, Phenylalanine and Arginine were especially.

• Culinary science and hospitality research
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• v.23 no.1
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• pp.28-36
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• 2017

This study made macaroon with the addition of Helianthus tuberosus L. powder so as to increase the application of Helianthus tuberosus L. powder (HTP) to food products and look into the quality characteristics depending on an addition ratio. Helianthus tuberosus L. powder 0%, 0.5%, 1.0%, 1.5%, and 2.0% were added, respectively, to make macaroon. As Helianthus tuberosus L. powder was added more, the moisture content tended to decrease more significantly (p<0.001). As Helianthus tuberosus L. powder was added more, lightness and yellowness tended to reduce more significantly (p<0.001). As Helianthus tuberosus L. powder was added more, the content of total phenol compounds and DPPH radical scavenging activity were significantly increased (p<0.001). In terms of texture analysis, hardness, gumminess, cohesiveness and chewiness were significantly increased, as the Helianthus tuberosus L. powder was increased (p<0.05). In terms of sensory test, regarding taste, 0.5% HTP group had the highest points. And as color, flavor, and texture were improved, 1.5% HTP showed the most desirable result in terms of overall acceptability. Results, if Helianthus tuberosus L. powder is added for cooking macaroon, it seems to increase anti-oxidation function and develop functional macaroon with excellent sensory factors.