• 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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.1
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• pp.1-5
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• 2000

Physicochemical properties and gelatinization patterns of purple-fleshed sweet potato starch were studied. Shape of starch granule was round and polygonal, X-ray diffraction pattern was Ca-type. Amylose content was 14.4% which was lower than that of other sweet potato starch. Water binding capacity was 82.54%, swelling power and solubility at 8$0^{\circ}C$ were 27.94% and 15.35%, respectively. Initial temperature of gelatinization was 72$^{\circ}C$ using Brabender/Visco/Amylograph, consistency and setback were lower than those of other sweet potato starch. The peak temperature and enthalpy determined by DSC were 68.1$^{\circ}C$, 1.24cal/g, respectively. The transmittance of starch dispersions in alkaline solutions increased with NaOH concentration up to 0.17N, and then changed slowly at 0.19N or above. The apparent viscosities were similar to the transmittance of starch dispersions in alkaline solutions, but drastically increased above 0.21N.

• Plant Resources
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• v.7 no.3
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• pp.200-205
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• 2004

Sweet potato infected with a viral disease (SPFMV) showed irregular chlorotic patterns, so called feathering associated with faint or distinct ring spots that have purple-pigmented borders. SPFMV was eliminated from sweet potato plants using meristem tip culture. MS medium supplemented with BAP (2mg/L) and NAA (0.05 mg/L) was used for shoot proliferation and 1/2 MS medium for rooting of the plants. Highest percentage of regenerated plants (60%) was obtained from the optimum size (0.3-0.5mm) meristem tips. Of these, 60% plants were found negative for SPFMV by RT-PCR. Virus detection by RT-PCR was found to be a reliable method. Meristem-tip culture to produce SPFMV-free quality sweet potato and virus detection by RT-PCR is an efficient, time saving and reliable method for production of SPFMV-free tissue culture raised plants.

• Journal of Life Science
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• v.16 no.3 s.76
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• pp.396-399
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• 2006

Crude extract prepared from sweet potato possessed inhibitory activity toward mushroom tyrosinase. The inhibitory activity was dependent upon the addition amount of sweet potato extract. After heating the sweet potato extract at $95^{\circ}C$ for 20 min, its inhibitory activity retained 37.3%. Its optimum activity was shown at pH ranges of 5.0-7.0. The tyrosinase inhibitory activity was disappeared by dialysis, which suggests the inhibitory activity of sweet potato extract is caused by some compounds of low molecular weight.

• 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.

• Korean Journal of Food Science and Technology
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• v.47 no.1
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• pp.51-55
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• 2015

Four varieties of the Korean sweet potato, Yeonmi, Jeungmi, Shincheonmi, and Shinyeulmi, were chosen to prepare the distilled koguma-soju (sweet potato-soju). The relationship between the flavor of the koguma-soju and the content of monoterpene alcohols (MTAs) was studied. The MTAs investigated here were linalool, nerol, geraniol, citronellol, and ${\alpha}$-terpineol. The ranges of MTA concentrations in the koguma-soju made from the four sweet potato varieties were $14.0-16.6{\mu}g/L$ for nerol, $24.8-34.7{\mu}g/L$ for linalool, $32.8-38.5{\mu}g/L$ for geraniol, $37.8-54.2{\mu}g/L$ for citronellol, and $76.6-94.7{\mu}g/L$ for ${\alpha}$-terpineol. Geraniol, nerol, and linalool were found in lower concentrations, while ${\alpha}$-terpineol was present in a higher concentration compared to their average content in the imo-shochu, a distilled Japanese sweet potato-soju. The concentrations of citronellol in the koguma-soju and imo-shochu were similar. The flavor evaluation tests revealed that the koguma-soju produced from the Yeonmi variety had a leafy vegetable or a grass-like, sharp flavor, whereas the Jeungmi-soju was characterized by a fruity or a sulfur-like sharp taste. Floral, vanilla-like, and mild flavors were predominant in the Shincheonmi-soju, while the Shinyeulmi-soju had either a fruity, citrus-like flavor or a rubber-like, rough taste. This study demonstrates that koguma-soju made from different sweet potato varieties have unique characteristic flavors.

• Korean journal of applied entomology
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• v.46 no.1 s.145
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• pp.165-168
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• 2007

This experiment was conducted to investigate population dynamics of white grubs and its damages in sweet potato fields. There were three species of white grubs that fed on the roots of sweet potato in Honam area. Among them, Holofrichia parallela was a major insect pest. Damage rate of sweet potato by white grubs were about 2 to 40% differed with regions. In some region where it was severe the damage rate of sweet potato was about 80% or more. H. parallela overwintered as a late 3rd instar larvae in soil from late October to late-June, and the survival rate of them was 92%. The occurrence pattern of H. parallela larvae varied in different seasons. In sweet potato field, H. parallela larvae populations started being observed during late-July to mid.-August. The damage by the grub began to occur late-August in field and lasted to the harvest time.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.9
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• pp.1205-1212
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• 2010

The aim of the present study was to evaluate the effects of replacing 70% of the protein from fish meal by protein from ensiled or dry cassava leaves and sweet potato vines on the performance and carcass characters of growing F1 (Large White${\times}$Mong Cai) pigs in Central Vietnam. Twenty-five crossbred pigs (Large White${\times}$Mong Cai) with an initial weight of 19.7 kg (SD = 0.84) were allocated randomly to five treatment groups with 5 animals per group (3 males and 2 females). Pigs were kept individually in pens ($2.0{\times}0.8\;m$) and fed one of five diets over 90 days. The control diet was formulated with fish meal (FM) as the protein source while the other four diets were formulated by replacing 70% of fish meal protein by protein from ensiled cassava leaves (ECL), dry cassava leaves (DCL), dry sweet potato vines (DSPV) or ensiled sweet potato vines (ESPV). Animals were fed their diets at 4% of BW. Results showed that final BW, ADG, DMI and feed conversion ratio (FCR) among the experimental treatments were not significantly different (p>0.05). ECL or DCL and ESPV reduced feed cost per unit gain by 8-17.5% compared to the fish meal diet. There were no significant differences in carcass characters among the diets (p>0.05). Lean meat percentages and protein deposition ranged 41.5-45.8% and 40.2-52.9 g/d, respectively. Using ensiled or dry cassava leaves and sweet potato vine can replace at least 70% of the protein from fish meal (or 35% of total diet CP) without significant effects on performance and carcass traits of growing (20-65 kg) pigs. Including cassava leaves and sweet potato vines could improve feed cost and therefore has economic benefits.

• 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.

• Journal of the Korean Society of Food Culture
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• v.33 no.6
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• pp.597-607
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• 2018

This study examined the nutrient components and measured the physicochemical properties of 23 Korean sweet potato cultivars. The proximate composition, free sugars, organic acids, and dietary fiber of sweet potato were analyzed and the water binding capacity, oil absorption and pasting characteristics were measured. The proximate composition was the highest in Happymi and was higher in colored sweet potato than in general sweet potato (p<0.05). The sucrose content was the highest among the free sugars in the general cultivars and yellow/orange colored cultivar. The major organic acids were oxalic acid, citric acid, malic acid, succinic acid, fumaric acid, and acetic acid. Oxalic acid and citric acid were high in the purple colored cultivars and malic acid was high in yellow/orange colored cultivars. Each total dietary fiber content of the general and colored cultivars was 7.51-13.94 and 13.04-16.97%, respectively, but there was no significant difference. The water binding capacity and oil absorption of Juhwangmi was high in all cultivars (p<0.05). The peak viscosity of sweet potato powder showed highest a significant difference of 12.50-1342 cP (p<0.05). The breakdown of Sincheonmi was 512, which was the highest value (p<0.05). The setback of Geonpungmi was significantly low, 6.0 (p<0.05).