• Korean journal of food and cookery science
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• v.27 no.6
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• pp.671-680
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• 2011

In this study, frying mix was prepared containing 0.5, 1.0, 1.5 or 2.0% brown rice fiber(BRF). The samples along with a control were then compared regarding their quality characteristics, including pasting properties, spreadability, pick-up ratio, color, textural characteristics, moisture and oil contents, and sensory qualities, all to determine the optimal ratio of BRF. For the pasting properties of frying mix, the control group was evidenced by a significantly higher peak viscosity, through viscosity, and final viscosity than that observed in the BRF samples. Breakdown was the highest at the 1.0% addition level, and time to peak viscosity and pasting temperature were maximal with the 0.5% addition. There was no significant difference in setback among the experiments. Spreadability and pick-up ratio of frying batter were not significantly different among the samples. As the BRF content increased, the lightness, greenness decreased, whereas yellowness increased. The BRF samples presented significantly higher hardness of fried batter than the control group and there was no significant difference in crispiness among the samples. Moisture content of fried sweet potato decreased with increasing BRF and oil content was the maximum on the control group. In the sensory evaluation, appearance, color, flavor, savory taste, yellowishness, coating thickness, off-flavor, and oiliness were not significantly different among the fried sweet potato samples. Bindingness, crispiness, and chewiness were highest in the control samples but minimal at a addition level of 2.0%. The control group evidenced significantly higher overall acceptability than were observed in the BRF samples. In conclusion, the results demonstrated that 0.5~1.0% BRF may prove quite useful as a additive for frying mix in the preparation of fried sweet potato and may provide favorable textural and functional properties.

• The Korean Journal of Food And Nutrition
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• v.27 no.5
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• pp.897-905
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• 2014

The foliage of sweet potato [Impomoea batatas (L.) Lam] is an excellent source of food material due to the functional components of polyphenol and carotenoid. In this study, the lightness (L-value), polyphenol contents, and DPPH radical scavenging activity of the foliage of Shinwhangmi, Hayanmi and Suioh cultivars harvested after different cultivation periods (60, 90 and 120 days after planting) and according to tip locations (1st~5th, 6th~10th, 11th~15th tips) were investigated. As a result, Shinwhangmi showed a lower lightness value (60 days after planting and 1st~5th tips). The longer the cultivation periods and the closer the tips, the higher the contents of polyphenol and DPPH radical scavenging activity were in lyophilized foliage of Shinwhangmi, Hayanmi and Suioh. In the 1st~10th tip of Shinwhangmi, Hayanmi and Suioh cultivated for 90 days and dried by 2 step hot-air (1st: $70^{\circ}C$ for 8 hr, 2nd: $80^{\circ}C$ for 4 hr), the polyphenol and ${\beta}$-carotenoid contents were 5.0, 3.9 and 4.0 mg/g and 75.6, 71.6 and 63.1 mg/g, respectively. The DPPH radical scavenging activities and ABTS radical scavenging activities ($EC_{50}$) were 0.29, 0.36 and 0.33 mg and 0.12, 0.15 and 0.11 mg, respectively. These antioxidative activities were over two times stronger than spinach.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.11
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• pp.1343-1349
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• 2017

This study was carried out to determine the simultaneous extraction conditions of functional components (lutein, ${\beta}$-carotene, total polyphenol, flavonoids, and phenolic compounds) from sweet potato leaves and to evaluate the antioxidant activities. Extraction conditions included different ethanol concentrations (1st extraction: 99.9% ethanol; 2nd extraction: 50~90% ethanol) and times (30, 60, and 90 min). The highest values of lutein and ${\beta}$-carotene content were obtained by the 2nd extraction at an ethanol concentration of 90%. The extraction yields of lutein and ${\beta}$-carotene decreased with increasing extraction time. The maximum polyphenol, flavonoid, and total phenolic acid contents and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and 1,1-diphenyl-2-picrylhydrazyl radical scavenging activities were 32.3 mg gallic acid equivalent/g, 17.0 mg catechin equivalent/g, 2,842.6 mg/100 g, 17.0 mg ascorbic acid equivalent/g, and 1.94 mg/mL ($IC_{50}$) at the 2nd extraction with an ethanol concentration of 60%. The optimum extraction conditions were as follows; ethanol concentrations of the extraction solvent were 99.9% (1st extraction) and 60% (2nd extraction), and extraction time was 30 min.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.12
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• pp.1656-1662
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• 2012

This study was conducted to evaluate the vegetative value of sweet potato leaves and stalks by investigating their chemical composition and antioxidant activity. The major minerals were found to be Ca and K. The crude protein content of the leaves ranged from 15.57% in Geonpungmi to 20.34% in Yeonhwangmi, while that of stalks was between 3.71% in Yulmi and 5.97% in Sinchunmi. The total phenolics and flavonoids content of the leaves were about 3.0~4.0 times higher than those of stalks. The levels of polyphenols and flavonoids were high in Geonpungmi leaf and in Sinchunmi stalk. ABTS radical activities were high in Geonpungmi leaf (58.75 mg AA eq/g) and in Daeyumi stalk (14.95 mg AA eq/g). DPPH radical scavenging was high in Geonpungmi and Jeungmi leaves ($IC_{50}$, 0.11 mg/mL) and in Sinchunmi stalk ($IC_{50}$, 1.09 mg/mL).

• Korean Journal of Food Science and Technology
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• v.45 no.1
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• pp.47-52
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• 2013

The feasibility of incorporating purple sweet potato concentrate (PSPC) as a value-added food ingredient in convenient food products, using a model system of jelly, was investigated. The pH and soluble solids content gradually increased with the increasing levels of PSPC added (p<0.05). The moisture content ranged from 82.03-83.82%. Lightness decreased, whereas redness and yellowness increased significantly with the higher amount of PSPC in the formulation (p<0.05). Turbidity and hardness also increased significantly (p<0.05). Total polyphenol content and DPPH radical scavenging activity increased significantly with the addition of PSPC (p<0.05). The consumer acceptance test indicated that the addition of PSPC had a favorable effect on consumer acceptances in all attributes. The jelly with 2% PSPC is recommended (with respect to the overall acceptance score) for taking advantage of the functional properties of PSPC without sacrificing consumer acceptability.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.4
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• pp.447-452
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• 2007

This experiment was conducted to enhance the colored potatoes utilization and to determine the biological activity of colored potato extracts. In order to understand the factors responsible for the potent antioxidant and antihypertensive ability of colored potatoes, it has been evaluated for anti-oxidative activity using Fenton's reagent/ethyl linoleate system and for free radical scavenging activity using the 1,1-diphenyl-2-picryl hydrazyl free radical generating system. There were significant differences of antioxidant activities in $50{\mu}g/mL$ extracts treatment among different colored potatoes. About two-fold higher radical scavenging activity was found in 'Daegwan 1-102', 'Daegwan 1-104' and 'Jasim' compared to that in 'Superior'. Based on the flesh color tested, potatoes with purple tuber showed higher radical scavenging activity than red potatoes, while white potato showed the lowest radical scavenging activity. The ability of 80% ethanol extracts from colored potatoes to influence the inhibitory activity of angiotensin converting enzyme(ACE) and xanthine oxidase(XOase) has also been investigated. Expect 'Jasim', the high levels of inhibition activity of xanthine oxidase in two colored potatoes such as 'Daegwan 1-102' and 'Daegwan 1-104' were highly correlated to $IC_{50}$ values of ACE inhibition activity. The various therapeutic benefit claims in the new functional medicinal usage of colored potatoes ascribed to the phenolic compounds and anthocyanin. This result revealed that the extracts of colored potatoes are expected to be good candidate for development into source of free radical scavengers and anti-hypertentive agent.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.6
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• pp.791-795
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• 2011

This study examined the inhibitory activity of Ecklonia cava (EC) against ${\alpha}$-amylase to evaluate the availability of EC extract as a functional food agent. To verify the inhibitory activity of EC against porcine pancreatic ${\alpha}$-amylase, potato starch was used as a substrate. This analysis revealed that EC ethanol extract exhibited high ${\alpha}$-amylase inhibitory activity. For potential application within the food industry, the stability of the activity of EC ethanol extract under various heat and pH conditions was examined. The ${\alpha}$-amylase inhibitory activity of EC ethanol extract was not affected by the heat and pH treatment conditions used in this study. These results suggest that EC has the potential for development as a functional food agent.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.3
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• pp.403-409
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• 2013

We investigated the quality characteristics of sweet potatoes [Shinyulmi (SM), Yeonhwangmi (HM) and Yunmi (YM) variety] baked and subsequently freeze thawed. Baking was performed with a far infrared radiation oven at $250^{\circ}C$ for 40 minutes. Baked sweet potatoes were frozen at $-18^{\circ}C$ for 30 days, and thawed by a microwave oven for 3 minutes. The crude fat and protein content of HM were higher than the SM and YM varieties. Total sugar, reducing sugar, and free sugar content were increased after baking. Lightness, redness, and yellowness, as well as content of ${\beta}$-carotene, decreased after baking and freeze-thawing. Hardness, gumminess, and cohesiveness decreased during thawing after freezing, except for the YM variety. In a sensory evaluation, appearance, flavor, sweetness and overall acceptance were higher from baking and freeze-thawing the SM variety, instead of the HM and YM variety. From the results, the SM variety is preferred for the production of baked sweet potatoes.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.2
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• pp.233-238
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• 2008

This experiment was conducted to enhance the colored potatoes utilization and to determine the biological activity of colored potato extracts. In order to understand the factors responsible for the potent anti-oxidant ability of colored potatoes, it has been evaluated for anti-oxidative activity using oxygen radical absorbance capacity (ORAC) assay. 'Hongyoung' extract was significant anti-oxidant activities in ORAC assay. About two-fold higher radical absorbance capacity was found in 'Hongyoung' compared to that in 'Jayoung'. The ability of 80% ethanol extracts from colored potatoes to influence the inhibitory activity of nitric oxide (NO) and nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) has also been investigated. The various therapeutic benefit claims in the new functional medicinal usage of colored potatoes ascribed to the phenolic compounds and anthocyanin. This result revealed that the extracts of colored potatoes are expected to be good candidate for development into sources of free radical scavenger or COX-2 inhibiting agents.

• Korean Journal of Plant Resources
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• v.26 no.5
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• pp.533-538
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• 2013

Potatoes were first introduced outside the Andes region four centuries ago, and have become an integral part of much of the world's food. Potatoes were first introduced into Europe in the 16th century and Korea in the early 19th century. In the nutritional aspects, potatoes contain abundant vitamins and minerals, as well as an assortment of phytochemicals such as carotenoids and natural phenols. Chlorogenic acid constitutes up to 90% of potato natural phenols. Due to the high content of potato functional compounds, it has known that potatoes are effective in the prevention of various human diseases. Recently, color-fleshed potatoes 'Hongyoung' and 'Jayoung' were developed by RDA, and it has reported that they have high content of anthocyanin. Additionally they show higher radical scavenging activity compared to white or yellow fleshed potatoes. So it will be expected that the consumption of color-fleshed potatoes grandually increase by pre-peeled potatoes and color potato chips. This study was conducted to enhance the peel of color-fleshed potatoes utilization and to determine the biological activity of peel of color-fleshed potatoes extract. The anti-inflammatory effects on ethanol extract and its solvent fraction were also evaluated. The anti-inflammatory activities of $CHCl_3$ fraction was evaluated for inhibitory activities against lipopolysacchride(LPS) induced nitric oxide(NO) and prostaglandin $E_2(PGE_2)$ production as well as inducible nitric oxide synthase(iNOS) and cyclo oxygenase-2(COX-2) protein expressions in RAW264.7 cell lines. The fraction inhibitory activity for both tests with $IC_{50}$ values showed in the ranges of $25{\sim}50{\mu}g/ml$. This result revealed that $CHCl_3$ fraction of Jayoung's peel is expected to be good candidate for development into source of anti-inflammatory agent.