• Korean journal of food and cookery science
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• v.18 no.6
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• pp.593-602
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• 2002

The objective of this study was to investigate the sensory and quality characteristics of Gamjeobyung containing different ratios of ingredients such as heated potato flour(30%, 40%, 50%), potato starch(30%, 40%), sugar, honey, and water by sensory evaluation and mechanical examination. The results of sensory evaluation showed that Gamjeobyung containing 30% heated potato flour, and potato starch had higher scores in overall acceptability, color, flavor, grain, moistness, chewiness and sweetness preferance. In the textural analysis of Gamjeobyung, the cohesivenss, springiness, adhesiveness were the highest in the samples with 30% potato starch, and the chewiness, gumminess, and hardness were the highest in the 40% added samples. The hunter's color L value and b-value of Gamjeobyung was decreased and a-value was increased of potato starch. The moisture content of Gamjeobyung was higher in the samples with heated potato flour than the samples with potato starch.

• Korean journal of food and cookery science
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• v.20 no.3
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• pp.271-278
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• 2004

As an attempt to develop new functional beverages for breakfast, sweet potato based beverages were prepared with hydrolyzed sweet potato, potato, and carrot products (sample : water = 1 : 1), and their chemical and sensory properties were evaluated. The content of reducing sugar and soluble solid of the sweet potato, potato, and carrot increased with enzyme treatment, while their viscosity decreased without significant change of color. The hunter color test showed that the beverages with 10％ carrot content were high in redness leading to a decrease in their acceptability for sensory evaluation. The sensory score of the mixture containing 5％ carrot was good, but beverage with 0％ carrot reduced the sensory properties. The results showed that the final ratio of sweet potato to potato to carrot for the new functional beverage was 5 : 4.5 : 0.5. The pH of the beverage was adjusted to 5.0, 4.5, and 4.0 using an organic acid mixture. In the sensory test of the new functional beverage, the best sensory score(color, taste, smell, and texture) was the mixture of sweet potato : potato : carrot equaling 5 : 4.5 : 0.5 with a pH of 4.5.

• Korean Journal of Organic Agriculture
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• v.10 no.4
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• pp.69-78
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• 2002

This experiment was conducted to investigate the changes of sugar contents and chip color during 104days storage after harvesting of five potato varieties. The potato varieties were planted on 1st April in 1999 and harvested on 10. July in 1999. $No_2$ contents in potato petiole tended to decrease repidly at tuber maturing stage. $K^+$ contents in potato petiole tended to in crease at 70 days ofter planting on medium maturing varieties, and at 90 days after planting on late maturing variety. Snowden variety was no desirable cultivar for processing on spring cultivation due to long growth period. Contents of solid and sugar in potatoes affected on potato chip color. Higher contents of solid in potato varieties showed low sugar contents and no change on chip color during storage.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.5
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• pp.769-775
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• 2009

This study was performed to investigate the quality characteristics of yanggeng added with Purple Sweet Potato. The yanggeng was prepared with purple sweet potato, Agar, Sugar and Salt. The yanggeng is made with various levels(0, 2, 4, 6, 8%) of purple sweet potato added. Hunter's color value, texture profile analysis, and sensory characteristics of purple sweet potato yanggeng were examined. The addition of purple sweet potato has tendency to decrease the water content of yanggeng. As the content of purple sweet potato increased, the lightness(L) and yellowness(b) decreased and redness(a) increased. In texture profile analysis, hardness decreased with increasing purple sweet potato content. Cohesiveness and springiness didn't showed significant differences according to amount of purple sweet potato. The results of the sensory evaluation showed that the sweetness, softness and overall acceptability were the highest scores at yanggeng containing 4% level of purple sweet potato. In conclusion, the result shows that the yanggeng with 4% of purple sweet potato is the best.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.3
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• pp.460-465
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• 2016

The market for potato chips has expanded due to increased consumption of seasoned potato chips. However, the deep-frying process facilitates development of a browning color and formation of acrylamide. The objective of this work was to minimize browning color and acrylamide formation by fermentation prior to deep-frying. Potato slices were fermented by using three Bacillus strains, B. licheniformis (BL), B. methylotrophicus (BM), and B. subtilis, for 6 h at $30^{\circ}C$. In all fermentation groups, contents of total sugars in potato slices decreased. The color of fermented potato chips improved compared to the control. BM potato chips showed the best color values (76.33 in L value, 5.67 in a value, and 34.79 in b value). All fermentation processes reduced levels of acrylamide in deep-fried potato chips. Fermentation of potato slices for 2 h by BL reduced up to 96.1% acrylamide content. It was concluded that the fermentation process can positively affect color development and acrylamide formation.

• The Korean Journal of Food And Nutrition
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• v.13 no.1
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• pp.71-77
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• 2000

New type yogurt base were prepared from milk added with skim milk powder or purple sweet potato, and fermented by lactic acid bacteria (Streptococcus thermophilus and Bifidobacterium infantis, 1:1, v/v). The yogurt proudcts were evaluated for acid production(pH, titratiable acidity), number of viable cell, viscosity, sensory properties, and color value. The composition of some organic acids was also analyzed by GC. The acid production slightly decrerased by addition with purple sweet potato. There was no significant difference in viable cell counts between control (yogurt added with only skim milk powder) and yogurt added with purple sweet potato, and viable cell counts of all samples were above 9.08 log cfu/ml. Viscosity of yogurt added with purple sweet potato(36,800∼46,000 centipoise) was higher than that of yogurt added with only skim milk powder(32,200 centipoise). The overall sensory score of yogurt added with purple sweet potato(38.6%, dry base) was the best of tested yogurt. The major organic acid of yogurt added with purple sweet potato was lactic acid. its content was 0.997∼1.203%. malic acid, succinic acid, oxalic acid, and fumaric acid were analyzed out a little. Lightness and yellowness decreased by addition with purple sweet potato but redness increased. Total color difference($\Delta$E) with yogurt addition with purple sweet potato and only skim milk powder were very high(above 11.46).

• 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.

• Korean Journal of Food Science and Technology
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• v.29 no.3
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• pp.497-501
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• 1997

Kinetic parameters on heat-induced color changes of anthocyanin pigment from purple sweet potato were determined in the temperature range of $121{\sim}141^{\circ}C$. Color change determined by a browning index $(A_{532}\;nm/A_{420}\;nm)$ followed second order reaction kinetics. Activation energy values of purple sweet potato pigment solutions of pH 2.0, 3.0, 4.0 and 5.0 were 69.57, 76.68, 81.07 and 92.98 kJ/mol, respectively, indicating that temperature dependency of the reaction increased with pH. Apparent kinetic compensation effect between preex-ponential factor and activation energy value was observed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.6
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• pp.943-947
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• 1995

The sweet potato drinks were prepared with the reaction of sweet potato and complex enzyme(${\beta}-amylase,\;{\alpha}-amylase$, protease). The reducing sugar and soluble solid of sweet potato drinks were the highest on reaction of sweet potato : water(1 : 1) and complex enzyme(pH 4.5). In the color of the sweet potato drinks, hunter value(L, a, b) were the lowest on reaciton of sweet potato : water(1 : 1) and complex enzyme, and were the highest on reaciton of sweet potato : water(1 : 3) and complex enzyme(pH 4.5). In the sensory test of the sweet potato drinks, the sensory score(color, taste, flavor, texture) were the best on reaction of sweet potato : water(1 : 1) and complex enzyme(pH 4.5). These results demonstrated that the sweet potato drink was good to drink when sweet potato : water(1 : 1) were treated with complex enzyme at pH 4.5, $60^{\circ}C$ for 5 hrs.

• Korean Journal of Plant Resources
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• v.16 no.3
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• pp.264-274
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• 2003

Many potato genetic resources have been collected and improved for their diverse traits over the years using breeding program in KPGR. To select potential varieties for table and processing in Korea, 58 elite potato breeding lines and several 'Valley' varieties were cultivated and harvested at Korea Alpine area in 2001. The cultivated lines and varieties were evaluated using their cultural adaptability in the environment and tuber characteristics, such as the depth of tuber eye, tuber shape, skin color, flesh color, scab resistance, yield, and the resistance of hollow heart and internal brown spot disease. Additionally, in the selection of potential processing varieties, reducing sugar content (sum of glucose and fructose concentration) of tubers is critically considered, because it mainly influence on the chip color of processing potato tuber. For table stock varieties with white skin color, 'Early Valley', 'Summer Valley', 'Winter Valley', and 'Taebok Valley' were selected. In the aspect of diverse potato tuber color, several varieties were selected such as 'Golden Valley' for its yellow fresh and skin color, 'Gogu Valley', 'Juice Valley', and 'Rose Valley' for their red skin color, and 'Purple Valley' for its purple skin. Compared with world wide known processing cultivar 'Atlantic', 24 lines (or varieties) were selected for the potential potato processing industry due to their low reducing sugar contents (below 0.3％), high yield (above 4.0 ton/ha), and unique chip colors. Selected white chipping varieties were 'Taedong Valley', 'Kangshim Valley', and 'Kangwon Valley', which have 0.23％, 0.27％, and 0.29％ of reducing sugar contents, respectively. 'Bora Valley', having deep purple color in both skin and fresh, was selected for purple chip variety and has 0.26％ of reducing sugar content. Light yellow chip varieties (lines) were 'Rose Valley' and Valley 54, having 0.19％ and 0.269％ of reducing sugar content, respectively. For French frying potatoes, 'Stick Valley' of 0.22％ and Valley 72 of 0.151％ in reducing sugars were selected. All of these selected lines and 'Valley' varieties can be used as parents to improve potato genetic resources and to develop better varieties with unique traits and colors.