• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.9
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• pp.1317-1324
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• 2015

The objective of this study was to examine both antioxidant activities and quality characteristics of sausages made from a mixture of purple sweet potato powder and pigment. Five sausages were manufactured: F0 (control), F1 (0.15%-sodium nitrite), F2 (0.2%-purple sweet potato pigment), F3 (0.2%-purple sweet potato pigment and 5%-purple sweet potato powder), and F4 (0.2%-purple sweet potato pigment and 10%-purple sweet potato powder). Sausages were stored at $4{\pm}1^{\circ}C$ for 30 days. Total polyphenol, 2,2-diphenyl-l-picrylhydrazyl (DPPH) radical scavenging activity, acid value, peroxide value, volatile basic nitrogen (VBN), and total bacterial cell contents were analyzed. Total polyphenol content and DPPH radical scavenging activity increased according to the amount of purple sweet potato, whereas acid value, peroxide value, and VBN decreased. Addition of 0.2% purple sweet potato pigment increased lipid oxidative stability and protein deterioration inhibitory effect compared to F0, but not to the levels of 0.15% sodium nitrite. However, F2 showed the lowest pH during storage due to the pH (2.52) of the pigment. Microorganism analysis revealed that total bacterial counts of sausage added with 0.2% purple sweet potato pigment were significantly lower (P<0.05) than that of sodium nitrite-supplemented sausage. As a result, purple sweet potato powder and pigment demonstrate antioxidative activity and lipid oxidative stability in sausages, making them suitable ingredients for manufacturing sausages.

• Culinary science and hospitality research
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• v.18 no.1
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• pp.54-64
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• 2012

The purpose of this study is to develop $Sulgidduk$ which meets the consumers' taste by using cooked purple sweet potato. The samples of $Sulgidduk$ were prepared with different ratios of cooked purple sweet potato(0, 10, 20, 30, 40%) and analyzed for moisture content, Hunter's color value and texture characteristics and sensory evaluation. The moisture contents of the samples ranged 40.83% to 44.91% The L-value and b-value decreased, while a-value increased, with increasing amounts of cooked purple sweet potato. In the mechanical evaluation of physical properties, hardness, adhesiveness, springiness, gumminess and cohesiveness showed no significant difference with the increasing amount of cooked purple sweet potato. However, chewiness decreased significantly with the increasing amount of cooked purple sweet potato. Based on the quantitative descriptive sensory evaluations on $Sulgidduk$ samples, purple color, sweet potato flavor and taste, sweetness, and moistness significantly increased, while hardness decreased significantly with the increasing amount of cooked purple sweet potato. $Sulgidduk$ added 40% cooked purple sweet potato showed the highest in overall acceptability and the slowest hardening in the textural changes during storage.

• Culinary science and hospitality research
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• v.16 no.1
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• pp.127-136
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• 2010

This study is to analyze the sensory and mechanical characteristics, moisture content and color values of purple sweet-potato powder sulgidduk prepared with various concentrations of purple sweet-potato powder; 0%(PP0 group), 1%(PP1 group), 2%(PP2 group), 3%(PP3 group), and 4%(PP4 group). As a result of analyzing the texture, sulgidduk with more purple sweet-potato powder added and that used adhesiveness, springiness, cohesiveness, gumminess and chewiness of sulgidduk decreased but hardness was not significantly different by increasing the amount of Purple Sweet-Potato powder. The moisture content of purple sweet-potato powder sulgidduk ranged from 37~39%. Hunter color L-value of sulgidduk decreased and a, b-value increased significantly by increasing the amount of purple sweet-potato powder. The results of the study support the benefits of purple sweet-potato powder supplementation in sulgidduk in the aspects of taste and functionality. Above results indicated that sulgidduk added 3% purple sweet-potato powder(PP3) showed the best quality through the sensory and texture analysis.

• Korean journal of food and cookery science
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• v.27 no.4
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• pp.1-16
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• 2011

The purpose of this study was to investigate the physicochemical and sensory properties of various breads prepared with purple-fleshed sweet potatoes and their powders. As the amount of purple-fleshed sweet potato and its powder increased, pH of the dough and bread, volume, dough yield, baking loss rate, and fermentation power of the dough decreased, whereas acidity of the bread increased. The lightness and yellowness of the breads decreased significantly, but redness increased with increasing content of purple-fleshed sweet potato and its powder. The textural properties, such as hardness, chewiness, springiness, and brittleness were significantly higher in groups with added purple-fleshed sweet potato and its powder compared to those in the control. The anthocyanin content and DPPH radical scavenging of dough and bread were higher in groups with purple-fleshed sweet potato and its powder than those in the control group. The groups with 5% and 10% purple-fleshed sweet potatoes and their powders had significantly higher scores for overall acceptability as compared to the control group.

• Journal of the East Asian Society of Dietary Life
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• v.23 no.2
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• pp.211-217
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• 2013

We investigated the quality characteristics of rice noodles supplemented with turmeric, purple sweet potato, or seaweed (Hizikia fusiforme). RVA (Rapid Visco Analyser), color, water activity, texture, and cooking properties were tested. Initial gelatinization temperature of noodles containing turmeric were the highest. Peak viscosity, holding strength, break down, final viscosity, and set back of noodles containing purple sweet potato were highest, indicating that the gelatinization state was more unstable and retrogradation would occur faster. The L value of the seaweed noodle was the lowest, while the a and b value of the turmeric noodles were $7.3{\pm}0.3$ and $40.2{\pm}1.3$ respectively, higher values than turmeric and seaweed noodles. Water activity of the seaweed noodle was 0.665, higher than turmeric and purple sweet potato noodles. Cooking properties (including weight, volume, and water absorption) and turbidity of seaweed noodles showed the highest growth rate. In terms of texture, the hardness was highest in purple sweet potato noodles, and the cohesiveness and gumminess was highest in seaweed noodles. The quality characteristics of rice noodles supplemented with turmeric, purple sweet potato, or seaweed showed that seaweed noodles were stable in gelatinization and cooking properties.

• Journal of the East Asian Society of Dietary Life
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• v.20 no.2
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• pp.272-278
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• 2010

Various quality attributes were determined in muffins prepared using purple-colored sweet potato flour. Height of control muffins was 5.8 cm lease clarify. Height decreased with increasing quantity of sweet potato powder. Muffin volume was not appreciably affected. Moisture of control muffins was 21.84. The moisture value decreased with increasing quantity of sweet potato powder. Scanning electron microscopy examination revealed thick cell wall and rough stoma in muffins prepared with purple-colored sweet potato powder. The amount of gluten decreased as the quantity of purple-colored sweet potato powder increased. Brightness L values significantly changed as the amount of powder increased, indicative of a progressively darker product. Red index a values decreased as the quantity of purple-colored sweet potato powder increased. Yellow index b values decreased significantly in the control group as powder quantity increased. Hardness increased with increasing addition of powder, but no significant difference was evident between 6% and 9% amended samples. There were also no significant differences in springing in samples containing 3% and 6% powder but 9% powder produced a significant difference. Cohesiveness did not differ in unamended samples and samples amended with 3% and 9% powder, however a significant difference was evident in samples prepared with 6% powder. Gumminess and chewiness increased as the quantity of purple-colored sweet potato powder increased. Color did not differ appreciably in sample prepared with 3% and 9% Sample prepared with 3% additives showed the highest What? Color score? Something else? Please clarify with 6.4. There was no significant difference of the flavor in samples prepared with 3% and 6% powder, or in taste among samples prepared 3%, 6%, and 9% powder. No significant differences in texture were evident in any sample Overall acceptability was highest (7.2) in samples prepared with 3% of purple-colored sweet potato.

• Journal of the Korean Society of Food Culture
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• v.32 no.4
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• pp.323-331
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• 2017

This study examined the quality characteristics of Jeung-pyeon made with wet non-glutinous rice flour and rice wine. The samples of Jeung-pyeon were prepared with different ratios of cooked purple sweet potato (0, 3, 6, 9, and 12%) to analyze the water content, sugar content, pH, chromaticity, texture characteristics, and sensory evaluation. No significant difference in water content, sugar content, and springiness was observed among the 5 samples. The pH and volume showed the highest level at 0%. The L-value and b-value decreased while the a-value increased. The hardness, chewiness, and gumminess were highest at 9% and lowest at 12%. The extent of violet chromaticity and pore size were optimal in 9%. In addition, 9%-added purple sweet potato showed the highest score of odor, taste, texture, and overall acceptability. In conclusion, the optimal addition for the highest acceptability of cooked purple sweet potato was 9%.

• Journal of the Korean Dietetic Association
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• v.16 no.4
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• pp.341-352
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• 2010

The aim of this study was to use purple sweet potato powder to develop a recipe for a nutritional cookie with an optimal composition of ingredients and texture, in order to acquire strong preference responses by all age groups in sensory tests. Wheat flour was partially substituted with purple sweet potato powder to reduce the wheat flour content of the cookies. Measurements were made and analyzed according to the Response Surface Methodology technique, which showed 16 experimental points including 3 replicates for the purple sweet potato powder, sugar, and butter. The compositional and functional properties of the sample were measured, and the values obtained were applied to a mathematical model. A canonical form and perturbation plot showed the influence of each ingredient on the final product mixture. The results of sensory evaluations showed very significant values for flavor (P<0.0071), texture (P<0.0306), taste (P<0.0190), and overall quality (P<0.0142). Instrumental analysis showed significant values for hardness (P<0.0027), yellowness (P<0.0061) and spread ratio (P<0.0001). The optimal compositional ratios were determined to be 21.75 g for the purple sweet potato powder, 37.05 g for the sugar, and 60.59 g for the butter.

• Culinary science and hospitality research
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• v.18 no.5
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• pp.279-292
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• 2012

This study was performed to investigate the quality characteristics and antioxidant activity of noodle added freeze-dried purple sweet potato powder. For Hunter's color resulted, as the amount of purple sweet potato powder increased, L-value and b-value decreased, the a-value increased. Anthocyanin contents of purple sweet potato powder at concentration of (mg/100 g) were 99.62%. DPPH radical scavenging activities of purple swe et potato powder at concentration of $1,000{\mu}L/mL$ were 84.60%. The texture of cooked noodles appeared no significant differences in cohesiveness, Springiness, Hardness, Gumminess and Chewiness decreased as the am ount of purple sweet potato powder increased. The weight, volume, moisture contents of noodles were not significantly. Sensory evaluation of acceptability including color, aroma, taste, chewiness and overall-acceptabi lity appeared the 6% added group was the best for higher. According to the positively evaluated anthocyanin content, DPPH radical scavenging activities, quality characteristics and sensory evaluation, a purple sweet pota to powder content 6% appears to be most appropriate.

• Korean Journal of Plant Resources
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• v.28 no.3
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• pp.363-369
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• 2015

Sweet potato has low regeneration capacity, which is a serious obstacle for the fruitful production of transgenic plants. Simple and rapid regeneration method from storage root explants of purple sweet potato (Ipomoea batatas L.) was investigated. The embryogenic callus was observed from 4 cultivars and its highest rate was induced at 1 μM 2,4-D after 5 weeks of culture. Result revealed that a low concentration of 2,4-D and low light intensity was important factors for embryogenic callus formation. After subculture on medium with 5 μM ABA for 4 days, subsequently, occurred the regeneration of shoots within 4 weeks when these embryogenic callus was transferred onto the MS hormone free medium. Regenerated shoots were developed into platelets, and grown normal plants in the greenhouse. We developed a simple and quickly protocol to regenerate plantlets in storage root explants of purple sweet potato. This regeneration system will facilitate tissue culture and gene transfer research of purple sweet potato.