• Journal of the Korean Society of Food Culture
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• v.10 no.2
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• pp.89-95
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• 1995

Three potato cultivars, Sumi,Daejima and Namjak, were prepared as slices. They were dipped in distilled water for 20 seconds. The potato slices were packed in polyethylene bags and stored at $5^{\circ}C$. Browning degree, total phenol and chlorogenic acid contents and polyphenol oxidase (PPO) activity were measured. And the correlation analysis of browning parameters were conducted. The results were as follows. There were increase in browning degree, phenolic content and PPO activity during cold storage of potato slices with different cultivars. Among three cultivars, Sumi showed the highest browning degree, phenolic content and PPO activity and also showed the highest % increse of browning and PPO activity during cold storage. On the contrary, Daejima was the lowest. But Daejima showed the highest % increase in phenolic contents during cold storage. With Sumi, browning degree was significantly correlated with PPO activity and phenolic contents (p<0.05). With Daejima and Namjak, a significant correlation was found between browning degree and PPO activity (p<0.05). From the above results, enzymatic browning reactions of potato slices and factors affecting them were dependent on cultivar. Among the tested three cultivars, Daejima showed the lowest browning degree during cold storage and thus seems to be desirable for minimal processing.

• 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.

• 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.

• The Korean Journal of Food And Nutrition
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• v.27 no.4
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• pp.558-569
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• 2014

The quality and characteristics of purple sweet potato sponge cake were studied with the addition of different proportions of purple sweet potato powder depending on storage period The pHs, heights, and weights of doughs were in the ranges of 6.3~6.5, 4.8~4.4 cm and 397~418 g, respectively. The sponge cake groups with the addition of different proportions of purple sweet potato powder showed significantly different characteristics in hardness, adhesiveness, cohesiveness, gumminess, and chewiness, according to texture profile analysis. The difference in colors of sponge cakes with addition with purple sweet potato revealed that L-value and b-value were significantly reduced but a-value especially increased according to the density. Using scanning electron microscopy (SEM), it was confirmed that the stoma size of purple sweet potato sponge cake become smaller and the stoma wall became thicker in proportion to the contents of purple sweet potato powder, which could result in an increased level of water content after a long period pf storage. According with the observations, water content remarkably increased after 4~6 days of storage and the ability to keep water content seemed to contribute to extention the shef-life of sponge cakes. In sensory evaluation, sponge cakes with high contents of purple sweet potato were preferred and cakes with the addition of 25% and 30% purple sweet potato powder was most preferred. It was expected that the shelf-life of purple sweet potato sponge cake was 4 days under the normal temperature.

• The Korean Journal of Food And Nutrition
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• v.20 no.4
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• pp.421-426
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• 2007

This study was carried out to investigate the properties of Kimchi made with potato as compared to Kimchi made with radish. The pH, acidity, hardness, and number of lactic acid bacteria were examined as properties of the Kimchi to determine the suitability of adding the potato and with focus on the possible duration of storage. First in the case of pH, the storage duration at pH $4.2{\sim}4.3$, which is the state for optimal tasting Kimchi, was approximately 10days in the control group, while that of the experimental group was 10 to 16 days, and thus, longer than the control. Second in the case of acidity, representing the maturity of Kimchi, we examined the time it took to reach 0.6% acidity, in which the experimental group took more longer time than the control. Although the experimental group was slower to mature than the control, the period for keeping at the proper pH was longer than that of the control group. Thirdly, in the case of hardness, which relates to softening, the experimental group had remarkably high values. This suggests that the Kimchi in the experimental group had a more rigid texture and more difficultly softening than the control group. Lastly in the case of the number of lactic acid bacteria, which closely relates to the process of fermentation, there were no significant differences. In conclusion, these results indicate that adding potato to Kimchi can extend its storage period.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.2
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• pp.214-219
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• 2007

A $3{\times}3$ factorial design experiment was conducted to investigate the effect of temperature and duration of storage on the fermentation quality of potato pulp ensiled with two fungal inoculants under laboratory conditions. The inoculants, Rhizopus oryzae (R) and Amylomyces rouxii (A) were each added to potato pulp material to contain at least $1{\times}10^6$ CFU/g fresh matter, and silages without additives served as controls. The silages were stored under three temperature regimes; 4, 12 and $25^{\circ}C$. Three silos per treatment from every temperature regime were opened on days 7, 24 and 40 days after ensiling to investigate treatment effects on fermentation quality, starch and sugar concentrations. Increase in temperature and duration of storage had a positive significant effect (p<0.01) on the fermentation quality of potato pulp silage (PPS). The inoculants had little effect (p>0.05) on the fermentation quality of the silages. Sugar concentration in the silages decreased with increase in temperature (p<0.01) but increased (p<0.05) with progression of duration of storage. The fungal inoculants had no effect on starch degradation in PPS. The results suggest that storage temperature and duration of storage are more important in determining the rate of fermentation than addition of the fungal inoculants in PPS.

• Korean Journal of Environmental Agriculture
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• v.24 no.1
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• pp.61-65
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• 2005

This study was to evaluate whether ionizing gamma radiation could be applied to break the dormancy of a potato minituber. The respiration rate of the minitubers was significantly affected by the storage temperature and a low dose gamma radiation. Ionizing radiation of 8 Gy enhanced the respiration rate of the potato tuber stored at $10^{\circ}C$ for 20 days. The potato tuber subjected to 4 and 8 Gy after 40 days storage at 10 and $20^{\circ}C$ exhibited higher respiration rates compared to the control (non-irradiated), but not at st. However, the ionizing radiation did not exhibit on significant effect on the respiration rate of the potato tuber stored for 60 days. It was observed that minitubers stored for 20 days had significant response to the storage temperature in terms of the total sugar content the higher the storage temperature, the lower the total sugar content. It was measured that the reducing sugar content was increased under the storage conditions both 5 and $10^{\circ}C$ for 40 days, but not to $20^{\circ}C$. The total sugar contents in the minituber stored for 60 days were similar to those stored for 40 days. The data was discussed on the relationships among the storage duration, temperature and ionizing radiation.

• Journal of Plant Biotechnology
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• v.39 no.4
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• pp.300-304
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• 2012

In order to research changes of asparagine content according to stage after harvest to storage, it was analysed asparagine content of potato tuber and potato sprout. The results of the asparagine content in potato cultivars after harvest ranked in cv. Superior, cv. Gahwang, cv. Atlantic and cv. Goun in descending order. The content of asparagine in potato was approximately 1300 mg/100g (D.W.) The changes the asparagine content according to storage condition and the difference of asparagine between tuber and sprout can be summarized as follows. In the asparagine content of potato cultivars, Little variation in the content was observed while potato tubers were stored at $4^{\circ}C$. However, after 3 months of storage at $10^{\circ}C$, the content increased by 9.7%, indicating that the content increases as the storage temperature and period increases. The content of asparagine also increased during sprouting of potato tubers. In the sprout, the proximal region contained 21% higher content of asparagines than the distal region, which suggests that the sprout develops with the increasing of the content of asparagines.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.129.2-130
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• 2003

Tomato soil pathogens(Phythopthora spp.) analyed high rates in series culture soil and existed in culture parts. To make a diagnosis of Phythopthora sp. and Its concentration, potato slices were manufactured to a round shape(2.5cm) or retangular form(1x4cm). and then, The potato slices dipped into diagnostic reagents with an antibiotic substance for 2∼4hours. Potato slices treated with a few reagents varied into 15cm depths in innoculated soils for 24hrs. Mycelium of the Phytophthora root rot fungus, Phythopthora capsici, were produced easily on potato slice. We collected many potato slice samples on diseased fields in various area. After storage of 24hrs in 20$^{\circ}C$ incubator, White mycelium of Phythopthora sp. formed on potato slice surface. Dilute concentrations of Phythopthora sp. was detected very low contents(1${\times}$10$^1$sporangia/g). But expressing Phythopthora root rots on potato slice did not developed larger lesions upon storage time in room temperature. These results suggest that the use of potato slice in a series of soil cultural system may still serve as efficient means of diagnosis of Phythopthora root rots in the absence of control measures.

• 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.