• Food Engineering Progress
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• v.14 no.2
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• pp.135-145
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• 2010

In order to enhance overall quality of the Backsulki, a sweet potato flour (SPF) which is rich in sugar and dietary fiber was added into the rice flour at 0, 5, 15, and 25% (w/w, db) ratios. Quality changes of the products were evaluated by storing at 5, 15, and 25$^{\circ}C$ for 4 days. Water binding capacity, swelling power, and solubility of the products increased as the SPF increased. Hunter colorimetric a- and b-value increased while L value of the products decreased as the SPF increased. Retarded retrogradation of the flour mixtures containing the SPF was shown from the DSC thermogram as indicated by the decreased $\Delta$H values. Increases in $T_{i}$ and $T_{p}$ values in relation with the starch gelatinization were shown from the DSC thermogram with a temperature margin of 15-20$^{\circ}C$ as the SPF increased. Increases in softness along with decreases in springiness and chewiness of the products were shown as the SPF increased. It was not so much the storage temperature as the added SPF affected the final texture of the products. Retarded growth of the total microbes of the products was noted by the added SPF during storage at 25$^{\circ}C$ for 3 days. Regarding the above and additional sensory preference scores of the products, a 15%(w/w) level of the SPF was suggested as optimum for the best Backsulki with improved qualities.

• Korean Journal of Food Science and Technology
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• v.38 no.2
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• pp.183-187
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• 2006

Surface browning, caused by cutting and other wound during minimal processing, is very important quality criterion to consumers. Shelf-life of fresh-cut potatoes was extended using natural antibrowning treatments. Fresh-cut potatoes dipped with licorice and green tea extracts were packed with LDPE film and stored at $4^{\circ}C$ for 14 days. Quality characteristics of fresh-cut potatoes were investigated during storage. During storage, L value decreased and PPO activity increased. PPO showed the lowest activity at around 7 days storage, during which browning was effectively inhibited in licorice- and green tea extract-treated potatoes. Total phenol and chlorogenic acid contents increased for 7 days. Results suggest natural licorice extracts with ascorbic acids are effective antibrowning agents for maintaining quality of fresh-cut potatoes.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.1
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• pp.43-49
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• 2013

This work was conducted to obtain some information about stable production of high quality seed-tubers in the late season cultivation of virus-free sweet potato [Ipomoea batatas (L.) Lam.]. Growth characteristics and storage root yield between virus-free and farmer's slips in 9 cultivars were investigated using black-film vinyl mulching cultivation with $75{\times}25cm$ planting density on July 10. At 30 days after planting, vine length, vine diameter, number of node, and number of branch in virus-free slips were significantly increased than those in farmer's slips. The vine growth was significantly different among cultivars, and vine elongation was excellent in 'Kogeonmi', 'Shincheonmi', 'Shinhwangmi', 'Shinyulmi', and 'Yeonhwangmi' compared to the other cultivars. At 110 days after planting, vine length, vine diameter, number of node, number of branch, and fresh weight were significantly different among cultivars, but no significant differences between virus-free and farmer's slips were seen except number of node. Total yield in virus-free slips was increased by 12-49% among cultivars than that in farmer's slips. The mean yields between virus-free and farmer's slips were 1,625 kg/10a and 1,230 kg/10a, respectively, and it was significantly different between virus-free and farmer's slips. Percentage of marketable storage root in virus-free slips was 65.6%, and it was significantly higher than 57.8% in farmer's slips. Marketable yields ($40g{\leq}$) between virus-free and farmer's slips were 1,067 kg/10a and 710 kg/10a, respectively. Marketable yield in 'Shincheonmi', 'Shinyulmi' and 'Shinzami' was more than 1,300 kg/10a, and these cultivars showed to be highly adaptable for the late-season cultivation among 9 tested cultivars.

• Korean journal of food and cookery science
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• v.32 no.3
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• pp.253-260
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• 2016

Purpose: To develop fat-free dressing containing a resistant starch (RS) as a dietary fiber, the viscosity and stability of various type RSes prepared from wheat, maize, potato, rice, waxy rice, and amaranth starches were investigated by using Brookfield viscometer. The shape of RS granule in the dressing during storage was also observed. Methods: The viscosity of fat free dressing with different retrograded RS3 (RS3V) prepared from waxy rice starch with 0.1% lemon vinegar and ascorbate mixed solution had higher RS3 that was maintained constant during storage. Annealing and heating prior to cross-linking, and heating after cross-linking increased RS level of RS4 type starches. Results: The viscosities and stabilities of dressings with RS were different depending on starch sources and RS preparation conditions. The heated RS4 (HRS4) increased in viscosity and stability with RS4 addition. Especially the fat-free dressings with HRS4 prepared from rice and waxy rice starches maintained stability regardless of separation after one month storage with only 7% separation after 6 month storages. The shape of RS4 granule in acidic medium of dressing did not change until 6 months. Conclusion: In this study, RS4 made by the rice and waxy rice starches showed high viscosity and maintained stability of the fat-free dressings during storage.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.49-49
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• 2022

One of the major problems with sweetpotato (Ipomoea batats Lam.) is the tough thread tissue that occurs in the storage root, which has a negative impact on the sales of sweet potato because it impairs the texture during cooking and the processing quality. The fiber contents in storage roots of sweetpotato is affected by cultivation conditions and environment. To investigate the effect of fiber generation at different levels of irrigation, the sweetpoatoto "Hogammi" was transplanted in greenhouse. Sweetpotato was grown in styrofoam beds(W1605*D330*H300mm) to block moisture flowing from the outside. The irrigation was carried out as 3 levels (5,10, and 20 mm through drip irrigation facilities) at 20-day intervals. Five plants were harvested per plot at 90, 100 and 120 days after transplanting (DAT). The size of the storage root was large in the order of irrigation conditions 10mm>20mm>5mm treatment. And the longer cultivation period, the larger size of the storage root was observed. As a result of the analysis of the fiber content, it showed a tendency to decrease as the cultivation period increased (90days→120days). In addition, the fiber contents of sweetpotato harvested at 90, 100 and 120 DAT in the level of 5 mm irrigation plot were 351, 324 and 207 mg/100g, respectively, which were higher than those of other irrigation level plots. During all cultivation periods, the 10mm treatment group showed the lowest fiber content of 280, 228 and 127 mg/100g. At 20 mm irrigation level, the fiber content was less than that of 5mm irrigation level, but showed a tendency to increase compared to that of 10 mm irrigation level. These results suggested that drought stress or excessive-irrigation increases the fiber content of sweetpotato, which reduces their commercial value.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.1
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• pp.51-59
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• 2017

To obtain basic data on the effects of differences cultivation periods and methods on growth and development of sweet potato tuber. We investigated growth and development of six major cultivars showing different characteristics, such as dry type(Yulmi, YM; Jinhongmi, JHM), intermediate type(Pungwonmi, PWM; Hogammi, HGM), and purple type(Sinjami, SJM; Danjami, DJM). The average tuber weight of YM and JHM was 4.1 and 8.6 g respectively, 50 days after transplant. At 80 days, the weight of YM and JHM rapidly increased to 25.2 and 26.1 g, respectively. Finally, at 120 days, the weight of YM and JHM increased to 120.7 and 79.4 g, respectively. The average tuber weight of PWM and HGM was 13 and 3.3 g, respectively, 50 days after transplant. The development pattern of PWM showed a consistent increase in tuber weight during the cultivation period, an average weight of 104.2 g at 120 days. However, the tuber development pattern of HGM was different from that of PWM. The average tuber weight of HGM rapidly increased for 100 days after transplant and then showed no increase at 120 days. In case of purple type sweet potato, the average tuber weight of SJM consistently increased during the cultivation period, whereas DJM showed rapid increase in average tuber weight at 80 days after transplant. Korean consumers prefer small, round sweet potato approximately 100g in weight. Based on the results, YM, PWM and SJM are classified as early developing cultivars that can be harvested approximately 120 days after transplant. On the other hand, JHM, HGM, and DJM are classified as late developing cultivars that can be harvested approximately 130 days after transplant.

• Horticultural Science & Technology
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• v.32 no.2
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• pp.171-177
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• 2014

In an effort to investigate special distribution of glucose content of potato tuber of a cultivar 'Superior' after harvest, a whole tuber was longitudinally cut into halves and cut-surface was divided into 11 regions. Approximate glucose concentration of each section was determined using a commercial blood glucose meter. Higher level of glucose was detected in the outer layers of tissue than inner part of tuber although there were lower coefficients of variation value, 37.4% and 34.1% among individual tubers and among defined sections, respectively. A positive correlation between the whole tuber and individual section was existed in glucose content, where the central pith tissue gave the highest coefficient (r = 0.921) and bud end tissue did the lowest (r = 0.544). Glucose content of the tubers stored for 4 months at $2.0^{\circ}C$ was 5.5 fold higher compared to the tubers kept in ambient temperature. The chip color of the former tubers was much brighter than those of the latter tubers. The result obtained in the present study suggests that the blood glucose meter can be used to a rapid and simple evaluation of glucose content and therein be applied to estimate the processing quality of potato tubers during postharvest handling.

• Korean Journal of Environmental Agriculture
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• v.20 no.2
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• pp.116-121
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• 2001

To observe the stimulating effects of low dose ${\gamma}$ - radiation on the dormancy breaking and physiological activity, potato (Solanum tuberosum L. cv. Dejima) were irradiated at the dose of $0.5{\sim}30$ Gy. Low dose ${\gamma}$ - radiation exhibited promoting effects on the sprouting rate within the range of optimum dose of 1 Gy and 2 Gy and on the sprout length within the range of optimum dose of 2 Gy and 4 Gy. Regardless of storage duration and irradiation doses, the number of sprouts was enhanced. The number of sprouts, which were reserved for 15 days after production (DAP), were significantly increased under 4, 8 and 16 Gy irradiation. The growth of 45 DAP sprouts was extremely stimulated under 4 Gy irradiation accompanying the increase of peroxidase activity in the plantlet. In this study, it was also suggested that the activities of antioxidative enzymes of potato plantlets were not related to the irradiation dose during the plantlet development with the exception of decrease in catalase activity.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.453-456
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• 2000

Antifungal activities of domestic plants were examined to develope natural antimicrobial agents, able to protect citrus fruits from spoiling microorganism during their storage. A fungus was isolated from citrus fruits' storage and identified to Penicillium sp. CF-301, based on the morphological characteristics of conidiophore and conidia; flask shape of phialide, simple branching type of conidiophore, and columnar shape of conidial head, in malt extract agar and potato dextrose agar media. Chloroform extracts of Juniperus chinesis Linnaeus, J. chinesis var. horizontalis showed remarkable antifungal activities against Penicillium sp. CF-301.

• Research in Plant Disease
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• v.23 no.4
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• pp.372-378
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• 2017

In this study, we identified the causative agent of post-harvest gray mold on broccoli that was stored on a farmers' cooperative in Pyeongchang, Gangwon Province, South Korea, in September 2016. The incidence of gray mold on broccoli was 10-30% after 3-5 weeks of storage at $3^{\circ}C$. Symptoms included brownish curd and gray-to-dark mycelia with abundant conidia on the infected broccoli curds. The fungus was isolated from infected fruit and cultured on potato dextrose agar. To identify the fungus, we examined the morphological characteristics and sequenced the rDNA of the fungus and confirmed its pathogenicity according to Koch's postulates. The results of the morphological examination, pathogenicity test, and sequencing of the 5.8S rDNA of the internal transcribed spacer regions (ITS1 and ITS4) and three nuclear protein-coding genes, G3PDH, HSP60, and RPB2, revealed that the causal agent of the post-harvest gray mold on broccoli was Botrytis cinerea. To our knowledge, this is the first report of post-harvest gray mold on broccoli in Korea.