• Korean journal of food and cookery science
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• v.27 no.2
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• pp.19-29
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• 2011

Sweet potato powders made from eight Korean varieties, including purple-fleshed, orange-fleshed, and commercial dry type sweet potatoes, were investigated for physicochemical and pasting properties to develop processed food. Crude protein and lipid contents of Shinjami and Borami were higher than those of other varieties. The lightness value of raw sweet potato flesh was the highest value in Shinchunmi, and the lowest in Shinjami. Using the color difference (${\Delta}E$), color similarities compared to the white plate occurred in the following order; purple-fleshed > orange-fleshed > commercial dry type sweet potatoes. Total and damaged starch contents were significantly different (p<0.05). Total starch content of sweet potatoes was higher in commercial dry sweet potatoes (61.89-70.46%), particularly Shinchunmi (70.46%) but lower in orange-fleshed sweet potato (48.87 and 49.53%, respectively). Water binding capacity of Yeonwhangmi, swelling power and solubility of Shinyulmi were the highest values (174.70, 25.54 and 87.49%, respectively) among them (p<0.05). But oil absorptions of Shinyulmi and Shinchunmi showed lower values (97.08 and 97.54%, respectively). All sweet potato powders had an A type x-ray diffraction pattern. The initial pasting temperatures of sweet potato powders ranged from 69.50 to $75.95^{\circ}C$ and the amylolytic enzyme in sweet potato powder lowered pasting viscosity.

• Journal of the East Asian Society of Dietary Life
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• v.24 no.2
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• pp.224-233
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• 2014

In this study, instead of arrowroot starch sesame mook(Gomadoufu) used in the manufacture of expensive sesame mook the quality of the material characteristics and commercialized for to find out the possibility of replacement of other starch, propose. Potato starch RVA analysis was quick pasting temperature $70.3^{\circ}C$, peak viscosity 740 RVU, break down 579.9 final viscosity 433.8, set back 275.7 arrowroot starch than 4.5 times, sweet potato starch than 6.9 fold the highest value showed Japanese sesame results starch (Atarigoma) concentration increased, the measured starch, different kinds of manufacturing quality characteristics of sesame mook tended to increase the moisture content, texture measurements on the hardness and springiness, gumminess and chewiness was gradually decreased. Sesame mook in sensory evaluation, color and aroma, taste, texture and overall-acceptability, sweet potato starch, arrowroot starch 60% addition, 50% added, potato starch 40% group containing most symbols highest was, and the experimental results used in the manufacture of arrowroot starch instead of expensive replacement of other starch is deemed.

• Korean Journal of Food Science and Technology
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• v.26 no.5
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• pp.638-643
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• 1994

Gelatinization and retrogradation properties of modified starches which were prepared by steeping sweet potato at $40^{\circ}C$ for 2, 4, 7 and 10 days were investigated. The peak temperature of gelatinization and enthalpy of untreated starch by DSC were $53.9^{\circ}C\;and\;1.32\;cal/g$, respectively, but those of modified starch were increased by steeping. In gelatinization by alkali, starches with 2, 4 and 7 day steeping showed higher viscosities than untreated starch, whereas the viscosities of starches with 10 day steeping decreased. The clarities in paste decreased during storage in all starches and decreased in starches with steeping. The degrees of retrogradation by ${\alpha}-amylase-iodine$ method were higher in starches with steeping than untreated starch. The enthalpy of retrograded starches by DSC increased by steeping except 4 day steeping starch. The sweet potato extract containing sugar inhibited the retrogradation of starch paste and the degree were higher in residual starches than in untreated starch.

• Korean Journal of Food Science and Technology
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• v.19 no.5
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• pp.435-440
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• 1987

Gelatinization properties of heat-mositure treated potato and sweet potato starches were investigated. Water-binding capacity of starch was increased by heat-mositure treatment, which was more pronounced in sweet potato starch. Blue value was not affected by the treatment. Amylograph viscosities were decreased by heat-mositure treatment, which was more pronounced in potato starch. Critical concentration of NaOH for gelatinization of starch increased as moisture level increased. Gel volume of starch upon KSCN gelatinization was higher in potato starch. Gelatinized starches showed Binghamapseudoplastic behavior. Consistency index and yield stress were drastically decreased upon heat-moisture treatment.

• Microbiology and Biotechnology Letters
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• v.17 no.1
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• pp.14-18
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• 1989

As the final experiment to assess the possibility of industrial application of FSC14-75, ethanol productivity from liquefied sweet potato starch was examined in a pilot scale of 300 liters. FSC14-75 produced 6.6％(v/v) of ethanol from 13.3％ of liquefied sweet potato starch in 8 days, and the residual sugar was 3.15％. The corresponding efficiency was 70％ of the theoretical maximum. Since we could isolate unicellular cell and flocculent cell from the fermentation broth, we designated them FSC14-75(S) and FSC14-75(F), respectively. We investigated ethanol productivity of FSC14-75(F) compared with that of FSC14-75(S) from liquefied potato starch in a mini·tar tormentor scale of 2.5 liters. FSC14-75(F) was found more favorable than the counterpart in terms of ethanol productivity, and produced 8.1％(v/v) of ethanol from 15％ of liquefied potato starch with an efficiency of 75％. In a pilot scale fermentation with 15％ of liquefied sweet potato starch, ethanol productivity of FSC14-75(F) reached maximum level of 7.7％(v/v) after 8 days, and the residual sugar was 1.9％. However, the ethanol productivity was not enhanced by a supplementary addition of Thermamyl to the fermentation broth after sterilization.

• Korean journal of food and cookery science
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• v.7 no.2
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• pp.7-18
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• 1991

This study was experimented saccharification process added malt extract solution into cooked sweet potato and potato with time, temperature and was tested reducing sugar changes, structural changes, pH and sensory evaluation about cooked shik-hae of rice, glutinous rice, potato, sweet potato. The results are summarized as follows: 1. Enzyme activity was highest in malt after four days of barley germination at a room temperature. 2. Electronmicroscopic observation indicated that raw starch granule of potato and that of sweet potato was 25-60$\mu\textrm{m}$ and 8~18$\mu\textrm{m}$ in size, respectively and its shape is oval and globular for potato and sweet potato respectively. 3. Reducing sugars were 1,682.6mg and 1,695.6mg in rice and glutinous rice, respectively, for 6-hour-saccharification at $50^{\circ}C$. Reducing sugars were 1,689.1mg and 1,497.8mg in sweet potato, potato, respectively, for 6.hour-saccharification at $60^{\circ}C$. 4. pH variation during saccharification for sweet potato and potato was pH 5.8~5.4. 5. Sensory evalution showed that there were more significant differences in sweety odor, roasted nutty taste and sweety taste of sweet potato among four samples than the other's color shininess.

• Korean Journal of Microbiology
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• v.7 no.4
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• pp.153-158
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• 1969

It is the most important thing to substitute sweet potato for wheat flour as the brewing material of Maggerley(Korean wine) in order to save precious wheat flour which is now consumed as the sole material in it. In this study, the fermenting mash material has been prepared with combination of wheat (KIorean wine) as a first step of sabing wheat flour consuming. The combination ratio of wheat flour and sweet potato starch in mashing, in this experiment, are such as mashing plot of 100% wheat flour (No.3 plot), 50% wheat flour plus 50 % of sweet potato starch (No.2plot), 30% wheat flour plus 70% starch syrup of sweet potato (No. 4 plot), and 60% wheat flour plus sweet potato starch (No. 1 plot). The results of fermentation and chemical components of each mash in experimental plot are as following : 1. Alocholic fermentation was most vigorous in No.4 plost among them, the next are in order to hydrolyze and break down the protein sourece to glucose and amino acid, the new enzymic source were added in experimantal amsh before putting yeasts, those enzymic sources have been developed and prepared in this laboratory No.4 and No.2 plot at same degree. Generally, the activities of alcholic fermentation of all plots are vigorous and fair. The acidity of each fermented mash is in the rangw of 3.7-4.8. 2. Amounts of amino acids in fermented mash are in the range of 145 mg per 100 ml and 158 mg for all experiments, and these amounts are much more than those of present commerical Maggerley. However, the amount of it in the No.4 plots is much less among the m, this is due to the lack of protein source in starch syrup. 3. Amounts of organic acids in fermented mash are in the range of 0.44g per 100ml and 0.62g, these amounts are generally much more than those of the present commercial Maggerley. 4. The result of sensory test for the experimental Maggerley shows good taste and flavour in comparison with those of commercial Maggerely. 5. It is proved that these experimental fermentation of Maggerley is succesful in the partial substitution of sweet potato starch potato starch for wheat flour, and it is also be able to make a good Maggerley in all aspects of quality.

• Culinary science and hospitality research
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• v.20 no.4
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• pp.310-321
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• 2014

This study investigated the effects of starches(potato, sweet potato, and corn starch) on the quality characteristics of raw and cooked noodles. The moisture content, color, mixogram, texture profile and sensory evaluation were performed. The mixogram showed the addition of starches shortened the kneading time. Mixing tolerance was higher in the noodles with starch than the control group, which indicates that the addition of starch increases dough durability. Moisture content of raw noodles was the highest in the samples with potato starch. L-value of raw noodles was the highest in the samples added with corn starch, whereas that of cooked noodles was the highest in the samples added with potato starch. The hardness of raw noodles was the highest in the control sample, and the chewiness of raw noodles was the highest in the samples added with sweet potato starch. The hardness of cooked noodles was the highest in the samples added with corn starch and the lowest in the control group. The tension distance of raw noodles was the longest in the control group and the tension force of raw noodles was the highest in the noodle with sweet potato starch. The acceptance test indicated that the noodles prepared with the addition of sweet potato starch scored the highest in flavor, taste, texture and overall acceptability.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.198-198
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• 2017

Cultivated varieties of sweet potato were from dry texture type to tender texture type on the basis of consumer preferences. There are many differences in the quantity of sweet potato, starch content, pigment, and sugar content depending on the cultivation season and area, even in the same variety. Therefore, in this study, we attempted to establish optimum time of harvesting through growth characteristics and variation in component like starch, sugar, polyphenol and flavonoid. Four sweet potato varieties were used in this experiment. Among them, Jinhongmi (JHM) & Yulmi (YM) were as dry texture type and Pungwonmi (PWM) & Hogammi (HGM) were as tender texture type. Sweet potatoes were transplanted on 23 May, 2016 and were investigated storage root weight and component contents every 20 days from 60 days to 120 days and surveyed yield at 110, 120, 130 days after transplantation. Result revealed that storage root weight of YM, JHM, and HGM were 30.1, 38.9, 20.8 g respectively in 60 days after transplanting. Storage roots of PWM gerw faster with the weight of 88.2 g. In 120 days after transplanting, storage root weight varied from 88.3 to 118.7 g, HGM was the smallest, and PWM was the largest. Sugar contents of sweet potato ranged from 21.0 to $23.8Brix^{\circ}$ in 60 days after transplanting and from 27.5 to $30.78Brix^{\circ}$ in 120 days after transplanting. In particular, the sugar content of HGM was the highest over $30Brix^{\circ}$ after 80 days. The starch content of dry texture type (YM, JHM) increased from 15.5% to 20.4% and tender texture type (PWM, HGM) increased from 11.0% to 17.3%. Starch content tended to be high in dry type sweet potatoes. The content of polyphenol and flavonoid were highest in 60 days after transplanting and was reduced according to cultivation period. The total yield of PWM was high as 3,154 kg/10a and large storage root of over 250 g accounted for 47.4% in 110 days after transplanting. Storage root (YM, JHM, HGM) of 81~150 g accounted for 34.9% ~ 43.2% in 120 days after transplanting. These are the most marketable. Because consumer in Korea prefers small, round and about 100g size sweet potato. The ratio of large storage root (over 250 g) were increased in all varieties at 130 days after transplanting. Therefore, it is considered appropriate to harvest PWM at 110 days and YM, JHM, HGM at 120 days after transplanting, which planted in late May.

• Korean Journal of Materials Research
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• v.32 no.12
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• pp.533-537
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• 2022

Flexible zinc-air batteries have many merits, including low cost, high safety, environmentally friendliness applicability, etc. One of the key factors to improve the performance of flexible zinc-air batteries is to use a gel electrolyte. In this study, gel electrolytes were synthesized from potato, sweet potato, and corn starch. In a comparison of each starch, the corn starch-based gel electrolyte showed the highest discharge capacity of 12.41 mAh/cm² in 20 mA and 6.47 mAh/cm² in 30 mA. It also delivered a higher specific discharge capacity of 7.06 mAh/cm² than the other materials after 100° bending. In addition, the electrochemical impedance spectroscopy (EIS) was analyzed to calculate the ionic conductivity. The potato, sweet potato, and corn starch-based gel electrolytes showed electrolyte resistances (Re) of 0.306, 0.298, and 0.207 Ω, respectively. In addition, the corn starch-based gel electrolyte delivered the highest ionic conductivity of 0.121 S cm^-1 among the other gel electrolytes. Thus, the corn starch-based gel electrolyte was verified to improve the performance of flexible zinc-air batteries.