• The Korean Journal of Community Living Science
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• v.23 no.3
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• pp.233-243
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• 2012

This study was performed to determine the quality characteristics of Jeungpyun with added modified starch. The addition of modified starch did not change the pH level of the samples, but it did increase the volume. The b-value of Jeungpyun with 3% modified starch was significantly lower than that of the control group. The addition of 3% modified starch also significantly increased the hardness, adhesiveness, gumminess and chewiness of the experimental group over the control group. In the test of sensory characteristics, the cell size of Jeungpyun with 2 and 3% modified starch was larger than that of the control group. Cell uniformity of Jeungpyun with 2% modified starch was lower than that of the control group. The hardness of Jeungpyun with modified starch was significantly higher than that of the control group. In the test of taste preference, Jeungpyun with modified starch beat the control group substantially. The quality of Jeungpyun with 1 and 3% modified starch showed a higher overall score than that of the control group.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1410-1414
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• 1999

The granular size and shape of durian seed starch were $2.0-10.0\;{\mu}m$ and oval and polygonal. Amylose contents of durian seed, corn, sweet potato and potato starch were 28.3%, 27.5%, 20.3% and 21.7%, respectively. Blue value of durian seed (0.370) higher than that of corn (0.368), sweet potato (0.332), and potato starch (0.338). Alkali numbers of durian seed, corn, sweet potato and potato starch were 7.39, 9.02, 7.08 and 5.43, respectively. Swelling power of durian seed starch was similar to that of sweet potato starch. X-ray diffraction patterns of durian seed starch showed an A-type crystalline structure. According to pasting properties by Rapid Visco-Analyzer, the gelatinization temperature of durian seed starch $(76.6^{circ}C)$ was higher than that of corn $(73.0^{circ}C)$, sweet potato $(72.3^{circ}C)$ and potato starch $(70.2^{circ}C)$. The breakdown of durian seed starch were lower than that of corn, sweet potato and potato starch.

• Korean journal of food and cookery science
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• v.10 no.2
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• pp.87-93
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• 1994

The sensory and instrumental characteristics of defatted and lipid-reintroduced kidney bean, mung bean and corn starch gels stored for 3 hrs and 24 hrs at room temperature were investigated. In sensory evaluation of starch gels, acceptability was highly correlated with hardness, bend property, cohesiveness and springiness. Mung bean starch gels showed sinigficantly highest value and followed by corn and kidney bean starch gels. Generally as for these factors, defatted starch gels were higher than untreated ones. The properties of defatted and lipid-reintroduced corn starch gels were similar to those of mung bean starch gels. In instrumental analysis, hardness was more important factor than any other ones. Hardness showed significantly higher value in the other of mung bean, corn and kidney bean starch gels, but it was highest in defatted starch gels among all treated gels. Hardness and springiness of defatted and lipid-reintroduced corn starch gels were similar to those of mung bean starch gels. Hardness of 24 hr stored starch gels increased more than that of 3 hr stored ones, but other textural factors did not change.

• Korean Journal of Human Ecology
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• v.14 no.6
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• pp.1037-1046
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• 2005

Using three consecutive years' harvested rices and their starches isolated from rice flours by alkaline method, it was found that no significant aging effect on rice flour and starch was observed based on following results. Proximate data of flours or starches showed in similarity, except high level of crude fat in rice flour and rice starch harvested in 2002. In SEM, the surface of aged rice flour had slightly layered shape due to possible abrasion during storage, and that of aged starch showed more smooth and less rigid polygonal shape. X-ray diffraction patterns of flours and starches were all A type, and crystallinity of rice starch harvested in 2000 had the smallest. From tristimulus colorimetry (Hunterlab Color), total color difference ($\Delta$E) calculated from L, a, and b gave less color difference with the darkest in 2002 harvested one among flours and the lightest in 2001 one among starches. WBCs of both 2002 rice flour and starch were the lowest among samples studied. At 80$^{\circ}C$, swelling power and solubility of rice starches harvested in 2000, 2001 and 2002 were 14.35, 9.75; 14.04, 9.6; and 12.49, 8.82, respectively. The highest peak viscosities measured by RVA were shown both in 2001 rice flour and in its starch. Starch and milled rice flour harvested in 2000 had higher hydrolytic $\alpha$-amylase, compared to other flour and starch samples.

• The Korean Journal of Food And Nutrition
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• v.28 no.1
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• pp.126-133
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• 2015

Ohmic heating uses electric resistance heat which occurs equally and rapidly inside food when the electrical current is transmitted into. Prior to the study, we have researched the potato starch's thermal property changes during ohmic heating. Comparing with conventional heating, the gelatinization temperature and the range of potato starch treated by ohmic heating are increased and narrowed respectively. This result is appeared equally at wheat, corn and sweet potato starch. At this study, we treated potato, wheat, corn and sweet potato starch by ohmic/conventional method and observed change of external structure by microscope and internal structure by X-ray diffractometer. Conventional heated at $55^{\circ}C$ potato starch was not external structural changes. But ohmic heated potato starch is showed largely change. Some small size starch particle were broken or small particles are made of larger particle together or small particles caught up in the large particle. Changes in ohmic heated potato starch at $60^{\circ}C$ was greater. The inner matter came to an external particle burst inside and only the husk has been observed. The same change was observed in the rest of the starch. The change of internal structure of potato starch was measured using X-ray diffraction patterns. There was no significant difference between ohmic and conventional heating at $55^{\circ}C$. But almost every peak has disappeared ohmic at $60^{\circ}C$. Especially $5.4^{\circ}$ peak to represent the type B was completely gone. When viewed from the above results, external changes with change in the internal crystal structure of the starch particles were largely unknown to appear. In conclusion, during ohmic heating changes of starch due to the electric field with a change in temperature by the heating was found to have progressed at the same time.

• Korean journal of food and cookery science
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• v.10 no.4
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• pp.386-393
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• 1994

This study aims to establish the most favorable recipe for Mokwapyun. The ingredients were changed in a variety aspects. The kind and amount of sugar and starch are following: white sugar, brown sugar, honey(4T, 5T); white sugar and honey, brown sugar and honey(2T+2T, 3T+1T, 3T+2T). There are potato starch and mungbean starch. In this, the amount of starch to water are 4t to 3t and 5t to 3t. The moisture content of Mokwa was 76.23%, and that of Mokwapyun made of mungbean starch 41~50%, and the Mokwapyun made of potato starch was 38~47%. The pH of Mokwa juice was 3.15~3.43. The brix of Mokwa juice was 5.3%, and that of Mokwapyun made of potato starch was 43.1~45.9%, and the Mokwapyun made of mungbean starch was 40.1~46.5%. Mokwapyun tasted the best when it was made of potato starch(starch to water=4t to 3t) mixed white sugar(3T) and honey(1) than that of made of one kind of sugar, and was higer evaluated the texture.

• Journal of Plant Biotechnology
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• v.36 no.3
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• pp.207-213
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• 2009

Starch serves not only as an energy source for plants, animals, and humans but also as an environmentally friendly alternative for fossil fuels. Progress in understanding of starch biosynthesis, and the isolation of many genes involved in this process have enabled the genetic modification of crops in a rational manner to produce novel starches with improved functionality. Starch is composed of two glucose polymers, amylose and amylopectin. The amylose and amylopectin ratio in starch affects its physical and physicochemical properties. Alteration in starch structure can be achieved by modifying genes encoding the enzymes responsible for starch biosynthesis and starch hydrolysis. Here, we describe recent findings concerning the starch modification in sweetpotato. Sweetpotato [Ipomoea batatas (L.) Lam] ranks seventh in annual production among food crops in the world as an important starch source. To develop transgenic sweetpotato plants with modifying starch composition, we constructed transformation vectors overexpressing granule bound starch synthase I and inhibiting amylopectin synthesis genes such as starch branching enzyme and isoamylase under the control of 35S promoter, respectively. Transformation of sweetpotato (cv. Yulmi) is in progress.

• Korean journal of food and cookery science
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• v.15 no.2
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• pp.185-190
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• 1999

In order to develop the techniques for isolation and production of barley starch from Youngsan variety, optimum conditions of isolation processes of barley starch was investigated. The effect of steeping temperature and time in wet-milling process was examined and the results showed that optimal steeping temperature and time were 30$^{\circ}C$ and 12 hr. The barley starch isolated under these conditions contained 5.7% crude protein, 69% starch content and 83% white value by 100 mesh process. The optimum condition of alkali treatment was showed that concentration of NaOH and treating time were 0.2% and 6 hr, respectively. To remove the fat content of barley starch, after alkali process obtained barley starch with the addition of 10% (v/v) EtOH was attempted. As the result, the barley starch contained 0.1% of crude fat. Under the optimized isolation conditions, the barley starch finally contained 0.1% protein and 95% starch content. The isolated barley starch were superior to commercial corn starch in purity and white value.

• Journal of Ginseng Research
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• v.9 no.2
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• pp.270-284
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• 1985

In order to investigate the change of physicochemical properties of ginseng root starch during storage and heat treatment, the roots were stored for 15 days at 5 $^{\circ}C$, 15 $^{\circ}C$, 3$0^{\circ}C$ and 45$^{\circ}C$, and heated for 15 hours at 6$0^{\circ}C$, 7$0^{\circ}C$, 8$0^{\circ}C$, 9$0^{\circ}C$, respectively. The starch content was decreased from about 40% to 23-26% and sucrose content was increased from 4% to 12-16% during storage for 15 days at 5-45$^{\circ}C$. Maltose, which was not detected in fresh samples, was increased up to 8.5% during storage or heat treatment. Granular size of the starch was decreased and some of the granules were broken during storage. Amylose content in the starch was decreased from 33% to 20%, and blue value and alkali number of the starch were increased slightly, and solubility and swelling power of the starch were decreased during storage. 3 The higher storage temperature and the longer storage time, the starch was more susceptible to gelatinize, and the viscosity of the starch was lowered with the susceptibility of gelatinization. The susceptibility of degradation of the starch by the amylase was increased and amylolytic activities in ginseng root were, also, increased during storage.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.12
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• pp.1749-1754
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• 2006

Two slaughter experiments were conducted to determine the effects of rumen escape starch, by altering dietary starch concentration and corn particle size, on ${\alpha}$-amylase activity in the pancreas and the small intestinal digesta of lambs. In experiment 1, 18 wether lambs (28.5${\pm}$1.6 kg) were fed low, medium or high starch diets for 35 d and slaughtered. Dietary starch concentrations linearly increased rumen escape starch (p<0.05). Pancreatic ${\alpha}$-amylase activity was lower (p<0.05) in lambs fed the low starch diet. When expressed per gram of digesta, ${\alpha}$-amylase activity was lower in lambs fed the low starch diet. However, expressed as total activity, ${\alpha}$-amylase in the digesta was greater in lambs fed the medium starch diet. In experiment 2, 12 wether lambs (23.5${\pm}$0.3 kg) were fed diets with finely cracked corn, coarsely cracked corn and whole corn. These dietary treatments continued for 35 d before tissue collection. Rumen escape starch increased with increasing corn particle size (p<0.05). ${\alpha}$-amylase activity in the pancreas and the small intestinal digesta was significantly greater (p<0.05) in lambs fed the coarsely cracked corn. These data suggest that increasing rumen escape starch results in a quadratic increase in total ${\alpha}$-amylase activity in the pancreas and the small intestinal digesta. Maximum ${\alpha}$-amylase activity is reached when rumen escape starch is about 100-120 g/d in 25-30 kg lambs.