• Journal of Applied Biological Chemistry
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• v.54 no.3
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• pp.147-152
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• 2011

The physical properties of puffed snack by pellet with sweet potato flour, brown rice flour and wheat flour were evaluated at different moisture content, puffing temperature, and puffing time. The sweet potato pellets were tempered to 14, 16, and 18% moisture content and were puffed at 233, 238, and $243^{\circ}C$ for 4, 5 and 6 s. The whitness ($L^*$) value decreased as the heating temperature and time increased. The redness ($a^*$) and yellowness ($b^*$) values increased with increasing heating temperature and time. The specific volume of sweet potato puffed snacks showed an increasing trend with higher puffing conditions. The hardness of sweet potato puffed snacks increased as heating time and heating temperature increased. The sweet potato puffed snacks prepared with increasing moisture content (18%), heating times (6 s), and heating temperatures ($243^{\circ}C$) were awarded the highest scores for most of the sensory attributes and hence declared as best sweet potato puffed snacks.

• The Plant Pathology Journal
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• v.39 no.3
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• pp.255-264
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• 2023

Sweet potato symptomless virus 1 (SPSMV-1) is a single-stranded circular DNA virus, belonging to the genus Mastrevirus (family Geminiviridae) that was first identified on sweet potato plants in South Korea in 2012. Although SPSMV-1 does not induce distinct symptoms in sweet potato plants, its co-infection with different sweet potato viruses is highly prevalent, and thus threatens sweet potato production in South Korea. In this study, the complete genome sequence of a Korean isolate of SPSMV-1 was obtained by Sanger sequencing of polymerase chain reaction (PCR) amplicons from sweet potato plants collected in the field (Suwon). An infectious clone of SPSMV-1 (1.1-mer) was constructed, cloned into the plant expression vector pCAMBIA1303, and agro-inoculated into Nicotiana benthamiana using three Agrobacterium tumefaciens strains (GV3101, LBA4404, and EHA105). Although no visual differences were observed between the mock and infected groups, SPSMV-1 accumulation was detected in the roots, stems, and newly produced leaves through PCR. The A. tumefaciens strain LBA4404 was the most effective at transferring the SPSMV-1 genome to N. benthamiana. We confirmed the viral replication in N. benthamiana samples through strand-specific amplification using virion-sense- and complementary-sense-specific primer sets.

• Journal of Plant Biotechnology
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• v.47 no.2
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• pp.124-130
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• 2020

The sweet potato (Ipomoea batatas [L.] Lam.) is the sixth-most important crop in the world following rice, wheat, potato, maize, and cassava. Four varieties ('Beniharuka', 'Annobeni', 'Pungwonmi', 'Hogammi') and their Japanese cultivars are broadly distributed in South Korea. In the Korean marketplace, sweet potatoes are classified by color and shape, not by variety, making it necessary to differentiate varieties for uniform production and consumption. In this study, molecular markers were developed to distinguish the four varieties of sweet potato using SNPs and genotyping-by-sequencing (GBS) analysis via a tetra-primer amplification refractory mutation system (ARMS)-PCR. The results revealed that three variety-specific fragments (164 bp and 241 bp of SNP 04-27457768 and 292 bp of SNP 03-16195623) were amplified in the 'Beniharuka', 'Pungwonmi', and 'Annobeni' sweet potato varieties. There were instances where some varieties produced three bands within the gel electrophoresis, indicating heterozygosity at the given SNPs loci. DNA sequencing analysis also confirmed the results of electrophoresis at the SNPs loci. Overall, these molecular markers would provide a useful, rapid, and, simple evaluation method for the Korean sweet potato marketplace, where the mixing of varieties is a serious issue.

• 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 Korean Society of Food Science and Nutrition
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• v.39 no.10
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• pp.1476-1480
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• 2010

Physicochemical properties of flours prepared from sweet potatoes with different flesh color (white, yellow/orange and purple) were investigated. Sweet potatoes were soaked in solutions of antibrowning agents such as sodium metabisulfite and citric acid, and freeze or hot air-dried prior to grinding to produce sweet potato flours. Sweet potato flours with different flesh colors showed differences in chemical composition. Purplefleshed sweet potato flour had higher protein, ash, and dietary fiber contents that white and yellow/orangefleshed sweet potato flours. Average particle size of yellow/orange-fleshed sweet potato flour was higher than those of white/yellow or purple-fleshed sweet potato flour. Both water absorption index (WAI) and oil absorption capacity of flours prepared from sweet potatoes by hot-air drying were higher than those from sweet potatoes by freeze drying.

• The Plant Pathology Journal
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• v.31 no.4
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• pp.388-401
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• 2015

Sweet potatoes (Ipomea batatas L.) are grown extensively, in tropical and temperate regions, and are important food crops worldwide. In Korea, potyviruses, including Sweet potato feathery mottle virus (SPFMV), Sweet potato virus C (SPVC), Sweet potato virus G (SPVG), Sweet potato virus 2 (SPV2), and Sweet potato latent virus (SPLV), have been detected in sweet potato fields at a high (~95%) incidence. In the present work, complete genome sequences of 18 isolates, representing the five potyviruses mentioned above, were compared with previously reported genome sequences. The complete genomes consisted of 10,081 to 10,830 nucleotides, excluding the poly-A tails. Their genomic organizations were typical of the Potyvirus genus, including one target open reading frame coding for a putative polyprotein. Based on phylogenetic analyses and sequence comparisons, the Korean SPFMV isolates belonged to the strains RC and O with >98% nucleotide sequence identity. Korean SPVC isolates had 99% identity to the Japanese isolate SPVC-Bungo and 70% identity to the SPFMV isolates. The Korean SPVG isolates showed 99% identity to the three previously reported SPVG isolates. Korean SPV2 isolates had 97% identity to the SPV2 GWB-2 isolate from the USA. Korean SPLV isolates had a relatively low (88%) nucleotide sequence identity with the Taiwanese SPLV-TW isolates, and they were phylogenetically distantly related to SPFMV isolates. Recombination analysis revealed that possible recombination events occurred in the P1, HC-Pro and NIa-NIb regions of SPFMV and SPLV isolates and these regions were identified as hotspots for recombination in the sweet potato potyviruses.

• 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 Biosystems Engineering
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• v.31 no.4 s.117
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• pp.369-375
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• 2006

Mechanical properties of potato and sweet potato were measured under impact and compression loading. The test apparatus consisted of disgital storage oscilloscope and simple mechanisms which can apply compression and impact forces to potatoes and sweet potatoes. The mechanical properties could be measured while the tissues were ruptured in a very short period time less than 10 ms by impact loading. Rupture force, energy, and deformation were measured as mechanical properties of potatoes and sweet potatoes under impact and compression loading. Rupture forces under impact and compression loading were in the range of 84.1 to 93.7N and 128.9 to 132.2N for external tissues and 60.1 to 64.8N and 158.9 to 171.1N for internal tissues of potato and sweet potato, respectively. Compression speeds and drop heights for each test were in the range of 1.25 to 62.5mm/min and 8 to 24cm.

• Korean journal of food and cookery science
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• v.19 no.6
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• pp.772-776
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• 2003

This study was performed to determine the quality characteristics of lemon pyun with various kinds of getting agents: agar, gelatin, sweet Potato starch, corn starch and Potato starch. Lemon Pyun was made with lemon juice(21.4％), gelling agent(6.7％), water(53.3％), sugar(13.3％) and honey(5.3％). The quality characteristics of the sample were estimated in terms of pH, color difference, texture profile analysis and sensory evaluation. (Ed- as this is an abstract this introductional clause is unnecessary) The PH of lemon pyun showed no significant difference among the different gelling agents. Lightness was significantly(p＜0.05) lowered in the agar and gelatin groups, a value was significantly(p＜0.05) lowered in the sweet potato starch and potato starch groups, and b value was significantly(p＜0.05) lowered in the sweet potato starch group. In texture profile analysis, chewiness, gumminess and hardness were significantly(p＜0.05) increased in the sweet potato starch group. According to sensory evaluation, elasticity and hardness of the sweet potato starch and cornstarch groups were stronger(p＜0.05) than of other gelling agent groups. Lemon pyun containing sweet potato starch was most preferable in terms of Vitamin C provision.

• Mycobiology
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• v.35 no.2
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• pp.97-99
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• 2007

Specimens collected from sweet potato plants with slime mold symptoms in fields in Daejeon, Korea were examined. Two species of Myxomycetes, Fuligo septica and Stemonitis herbatica were identified based on their morphological characteristics. This is the first report that the two species of Myxomycetes cause slime mold of sweet potato in Korea.