• Journal of the Korean Society of Food Culture
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• v.27 no.6
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• pp.730-736
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• 2012

This study was performed to investigate the qualities of jelly supplemented with purple sweet potato (C:0 g, P1:1 g, P3:3 g, P5:5 g, P7:7 g). The pH decreased (acidity increased) with the addition of purple sweet potato powder (p<0.01). The sugar content of the jelly also significantly increased when purple sweet potato was added. The DPPH radical scavenging activities of jelly increased as the addition of purple sweet potato increased. As the content of purple sweet potato increased, the L and b values decreased and the "a value" increased. In terms of textural characteristics, the addition of purple sweet potato increased hardness and springiness, while it decreased the cohesiveness. The results of the sensory evaluation showed that the appearance, flavor, taste, texture, and overall acceptability gave the highest score for jelly containing 5 g of purple sweet potato (P5).

• The Plant Pathology Journal
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• v.18 no.3
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• pp.126-129
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• 2002

Infected sweet potato (Ipomoea batatas) showing symptoms of sunken veins, stunting, mosaic, and mottling were collected from Gimje, Cochang, Iksan, and Haenam provinces in Korea. Electron microscopic (EM) observation of the infected tissue revealed rod and filamentous rod type virus particles of various lengths. Western blot analysis of the protein samples extracted from infected sweet potato and partially purified virus identified the isolates as Sweet potato feathery motile virus (SPFMV), Sweet potato latent virus (SwPLV), and Sweet potato chlorotic stint virus (SPCSV). Sweet potatoes were occasionally infected with more than one of these viruses. This is the first report of SwPLV and SPCSV in Korea.

• Journal of the Korean Home Economics Association
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• v.42 no.4
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• pp.187-194
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• 2004

The concentration of potato(Solanum tuberosum L.) glycoalkaloids(PCA) (i.e., ${\alpha}$-chaconine and ${\alpha}$-solanine) in Korean cultivated potato plant, and in the different varieties, parts and weights of the potato tubers, were determined by high-performance liquid chromatography(HPLC). The highest concentrations of PGA in potato plants were found in the roots, followed by the stems and leaves. A large quantity of PGA existed in the periderm of 'Atlantic' potatoes, whereas 'Irish Cobbler' contained the lowest amount in five cultivated potato tubers.'Irish Cobbler' potatoes were divided into three parts and the PGA content in each part was determined. It was found that both of the end parts of the potatoes contained higher PGA than the middle part. The PGA contents in four different sizes of potatoes increased toward the smaller size. Thesignificantly high level of PGA was contained in the smallest size potato tubers, which have been used widely for Korean cooking.

• Journal of the East Asian Society of Dietary Life
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• v.23 no.2
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• pp.234-240
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• 2013

This study investigated the quality characteristics of gruel supplemented with purple sweet potato. The gruel was prepared with rice powder, salt, and various amounts of purple sweet potato (0, 2, 4, 6, 8%). Increasing the content of purple sweet potato decreased the pH and viscosity of the gruel, whereas sugar content and spreadability gradually increased. In addition, the content of purple sweet potato increased, the lightness (L) significantly decreased, while redness (a) and yellowness (b) increased. The results of the sensory evaluation show that overall-acceptability was highest for the gruel containing 6% purple sweet potato. In conclusion, the results shows that the gruel with 6% purple sweet potato is the best. This study indicates that it is possible to enhance the quality and acceptability of gruel by adding purple sweet potato powder.

• Journal of the East Asian Society of Dietary Life
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• v.23 no.6
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• pp.750-759
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• 2013

In the study, purple sweet potato sponge cake was prepared with different ratios of purple sweet potato powder in order to examine the antioxidative activities and gelatinization characteristics. For DPPH radical scavenging effect, content of $IC_{50}$ came out with (+) control group of BHA. Sponge cake with purple sweet potato powder of 0% showed a range of 49.7 mg/mL, The treatment groups with purple sweet potato powder of 5~30% showed a range of 25.0 mg/mL~6.0 mg/mL. That was, the higher the added quantity of purple sweet potato powder was, antioxidative activities increased. With the higher quantity of purple sweet potato, the content of phenols and flavonoids also increased. As a result of examining the gelatinization activity with DSC, the group with purple sweet potato powder showed a faster progress in temperature for starting gelatinization compared to the control group. Gelatinization activity increased in proportion to the content of purple sweet potato powder. Based on the above study results, it was proved that there is a possibility to produce baking processed foods using purple sweet potato with stable gelatinization and excellent antioxidative activities.

• The Plant Pathology Journal
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• v.30 no.4
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• pp.416-424
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• 2014

Sweet potato is grown extensively from tropical to temperate regions and is an important food crop worldwide. In this study, we established detection methods for 17 major sweet potato viruses using single and multiplex RT-PCR assays. To investigate the current incidence of viral diseases, we collected 154 samples of various sweet potato cultivars showing virus-like symptoms from 40 fields in 10 Korean regions, and analyzed them by RT-PCR using specific primers for each of the 17 viruses. Of the 17 possible viruses, we detected eight in our samples. Sweet potato feathery mottle virus (SPFMV) and sweet potato virus C (SPVC) were most commonly detected, infecting approximately 87% and 85% of samples, respectively. Furthermore, Sweet potato symptomless virus 1 (SPSMV-1), Sweet potato virus G (SPVG), Sweet potato leaf curl virus (SPLCV), Sweet potato virus 2 ( SPV2), Sweet potato chlorotic fleck virus (SPCFV), and Sweet potato latent virus (SPLV) were detected in 67%, 58%, 47%, 41%, 31%, and 20% of samples, respectively. This study presents the first documented occurrence of four viruses (SPVC, SPV2, SPCFV, and SPSMV-1) in Korea. Based on the results of our survey, we developed multiplex RT-PCR assays for simple and simultaneous detection of the eight sweet potato viruses we recorded.

• Food Science and Preservation
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• v.8 no.1
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• pp.60-65
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• 2001

To investigate the effect of Acetobacter on qualities of potato vinegars, potato vinegars were produced through acetic acid fermentation using 3 Acetobacters such as Acetobacter sp. PA97, Acetobacter sp. PA96 and Acetobacter pasterianus JK 99. There were little difference in pH(2.90∼3.09) and total acidities(5.30∼5.60%) of 3 potato vinegars. However potato vinegar(II) fermented by Acetobacter sp. PA96 showed a little difference in color values with other potato vinegars. Except acetic acid in each potato vinegars, the contents of citric acid, oxalic acid, succinic acid were high in potato vinegar(I), malic acid in potato vinegar(II) and lactic acid in potato vinegar(III). The contents of glutamic acid alanine, histidine and proline were high in all potato vinegars. The major volatile components in 3 potato vinegars were acetic acid, isoamyl acetate, isobutyl acetate, 3-methyl-1-butanol, 3-methyl-butanoic acid and phenethyl alcohol. Also composition ratio of volatile components was a little difference among 3 potato vinegars.

• Research in Plant Disease
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• v.12 no.1
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• pp.28-31
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• 2006

One of major potato viruses is Potato virus Y (PVY) in Korea. In the southern part of Korea, potatoes have been grown as double crops in a year by using cv. 'Dejima' and 'Chubak' due to very short dormancy. However, they have caused a serious problem such as a rapid degeneration. It has been thought that the degeneration is affected by the high incidence of PVY in neighboring potato fields. Therefore, the investigation of factors causing the degeneration is very important in the production of healthy seed potato. In this study, the PVY reinfection rates of several potato varieties and the different seed sources of cv. 'Chubak' have been investigated. Results show that the lowest infection rate of PVY among four potato cultivars derived from minitubers is cv. 'Superior'. The others are in order of 'Dejima', 'Atlantic' and 'Chubak'. Also, the incidences of PVY differ significantly when several seed sources are examined. When the seed potatoes (G2, the progeny of microtuber) as spring potato crops are planted in area without potato field nearby, the infection rate of PVY is as low as that of microtubers. However, PVY incidence in the progenies of minitubers as fall potato crops largely increases. Therefore, the best way of potato production under double cropping system is to use the healthy seed potato produced in area without potato field and plant relatively resistant cultivar such as Dejima.

• Food Science and Preservation
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• v.19 no.3
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• pp.433-437
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• 2012

The fusel oils and the volatile flavor compounds of two potato sojues, one of which was produced with the traditional distillation apparatus(soju-gori) and the other, with the reduced pressure distillation system, were examined. The fusel oil content was high in the potato soju that was distilled under reduced pressure (potato soju(II)). The relative ratio of the isoamyl alcohol to the isobutyl alcohol and the n-propanol was 3.1:0.8:1.0 in the potato soju that was distilled with soju-gori (potato soju(I)), and 4.0:1.2:1.0 in potato soju(II). The chromatograms of the volatile components apparently differed between potato soju(I) and potato soju(II). Potato soju(I) contained four kinds of alcohol, six kinds of ester, n-valeraldehyde, and acetic acid. Potato soju(II) contained seven kinds of alcohol, 14 kinds of ester, two kinds of aldehyde, acetic acid, and three other compounds. Potato soju(II) significantly scored higher for flavor property than potato soju(I).

• Korean journal of food and cookery science
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• v.24 no.4
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• pp.501-510
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• 2008

In this study, we evaluated the quality characteristics of sweet potato Sulgidduk produced with varying amounts of fresh sweet potato, after three days of storage. The more fresh sweet potato was added, the higher were the levels of crude protein and crude lipid; however, crude ash contents were lowest in the control sample, and no significant differences in this value were detected among the samples to which fresh sweet potatoes were added. Moisture contents evidenced a tendency to decrease with increases in the amount of added fresh sweet potato and increased storage time, but pH rose with increases in the amount of added sweet potato. Total cell counts showed a tendency toward decrease with increases in the amount of added fresh sweet potato. L values tended to be low with increases in the amount of added fresh sweet potato and a values were lowest immediately after its production, although no consistent tendencies were noted in correlation with the amount of added fresh sweet potato. b values tended to increase directly with the amount of added sweet potato . With increasing storage time, the L and a values decreased, whereas the b value tended to increase. Upon textural assessment, it was observed that hardness, adhesiveness, springiness, gumminess, and chewiness(all textural components except for cohesiveness) increased with increasing quantities of added fresh sweet potato, and these factors also tended to increase with the progression of storage time. After observation via scanning electron microscopy(SEM), it was noted that the cohesiveness also increased with increasing amounts of added sweet potato. With regard to the sensory evaluation, the samples to which 15% fresh sweet potato had been added evidenced the highest acceptability in terms of color, flavor, and s0weetness, and softness and moistness in these samples decreased with increasing percentages of added sweet potato. It has been previously demonstrated that the addition of 15% fresh sweet potato resulted in optimal overall acceptability. In accordance with the aforementioned results, it has been verified that the use of fresh sweet potato in Sulgidduk is possible and probably desirable, and an addition of 15% sweet potato appears to be the optimal approach in terms of overall quality and functionality.