• Fashion & Textile Research Journal
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• v.5 no.4
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• pp.399-407
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• 2003

The natural dyeing of silk fabric with Purple-Fleshed Sweet Potato (PSP) was investigated. The colorant was extracted with distilled water, and the color difference (${\Delta}E^*$) was increased with increasing the amount of PSP in extraction. The proper temperature and time for the extracting of colorant with PSP were $60^{\circ}C$ and 60 minutes. The optimum temperature, time and pH for the dyeing of silk with extracted PSP were $60^{\circ}C$, 60 minutes and pH 4 respectively. In various mordanted methods, the color difference values of post-mordanted silk fabric were higher than those of pre- and simultaneous-mordanted method. And the wide range of colors( GY, Y, YR, R, RP) were obtained according to various mordants, mordanting methods and mordant concentrations. Light colorfastness of the mordanted silk fabric was improved. Laundering colorfastness, dry cleaning colorfastness and perspiration colorfastness were shown to be good.

• The Korean Journal of Food And Nutrition
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• v.10 no.4
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• pp.458-461
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• 1997

Yogurts were prepared by the fermentation of milk containing purple sweet potato powder(PSPP). The effect of PSPP addition on quality and sensory evaluation were as follow ; acidity, brix and viable cell count of PSPP yogurt was higher than the control. As the level of PSPP lightness and yellowness decreased. Redness increased significantly wit increases in viscosity. In consideration with the sensory evaluation of the PSPP yogurt, texture and color was better than the control, and taste was similar to the control. The sensory test of yogurt ranked highest at 3%~40% PSPP.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.10
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• pp.1476-1480
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• 2010

Physicochemical properties of flours prepared from sweet potatoes with different flesh color (white, yellow/orange and purple) were investigated. Sweet potatoes were soaked in solutions of antibrowning agents such as sodium metabisulfite and citric acid, and freeze or hot air-dried prior to grinding to produce sweet potato flours. Sweet potato flours with different flesh colors showed differences in chemical composition. Purplefleshed sweet potato flour had higher protein, ash, and dietary fiber contents that white and yellow/orangefleshed sweet potato flours. Average particle size of yellow/orange-fleshed sweet potato flour was higher than those of white/yellow or purple-fleshed sweet potato flour. Both water absorption index (WAI) and oil absorption capacity of flours prepared from sweet potatoes by hot-air drying were higher than those from sweet potatoes by freeze drying.

• Food Science and Preservation
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• v.8 no.1
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• pp.102-108
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• 2001

Flow properties of the concentrated pigment solutions extracted from purple-fleshed sweet potatoes were determined using a cone and plate rotational viscometer for soluble solids concentration range of 25 to 65% at temperature range of 20 to 60 $^{\circ}C$. The purple-fleshed sweet potato pigment solutions exhibited Newtonian behavior. Temperature dependency for the viscosity of the solution followed the Arhenius relationship with activation energy values between 14.23 and 43.00 kJ/mol, which increased linearly with soluble solids concentration. A relationship between viscosity, temperature and soluble solids concentration was investigated. At the same temperature, the viscosity of the concentrated pigment solutions increased exponentially as the concentration increased with higher degree of such phenomena at lower temperatures.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.4
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• pp.555-560
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• 2000

Anthocyanin pigments of purple-fleshed sweet potato (Ipomoea batatas) were extracted with methanol containing 1% HCL and purified with Amberlite IRC-50 cation exchange resin column chromatography. ndividual pigments were isolated by paper chromatography. Among the four bands obtained by paper chromatography, three major bands were identified to be pure pigments by HPLC system. Two pigments were identified through the analysis of acyl moiety, sugar moiety, alkaline degradation products of aglycone, Rf value of paper chromatogram and retention time of HPLC. The anthocyanin pigments of purple-fleshed weet potato seemed to be composed of peonidin-3-diglucoside-5-glucoside acylated with caffeic or ferulic acids.

• Korean Journal of Food Science and Technology
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• v.31 no.4
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• pp.1090-1095
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• 1999

Antioxidative and antimicrobial activities of ethanol extracts from 2 colored sweet potatoes such as purple and yellow, 5 pale yellow sweet potatoes, and 8 general cultivars of sweet potato were investigated. Colored sweet potatoes showed the highest antioxidative activity, followed by Saengmi and Yeonmi, which were pale yellow sweet potato cultivars, and Hwangmi, which was a general cultivar of sweet potato. Colored sweet potatoes also showed distinctively lower mold and surface microbial number (cfu) than the pale yellow sweet potatoes and the general cultivars of sweet potato. Although all sweet potatoes tested did not represent any antimicrobial activity against yeast and mold, they exhibited strong antimicrobial activity against Streptococcus faecalis. Especially, purple and yellow sweet potatoes showed antimicrobial activity against wide range of bacteria.

• Journal of Korean Ophthalmic Optics Society
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• v.17 no.4
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• pp.395-401
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• 2012

Purpose: The purpose of this study was to research any effect on vision protecting or decreasing VDT syndrome of extracted anthocyanine from fermented purple sweet potato and blueberry. Methods: Subjects were aged 19-20 years old who do not have ophthalmic and systemic diseases and over -N4.00 D of refraction error. 40 mg of extracted anthocyanine from fermented purple sweet potato, from blueberry, and control group, placebo were dosed at separate try. After 2 hours later, subjects were directed perform visual display terminal (VDT) work for 2 hours. Objective refractive error was measured before dosing anthocyanine and after VDT work for 2 hours. Degree of head ache, eye pain and strain and subjective symptoms of neck, shoulder and waist was also examined through interviews by dividing its degree into severe, moderate, slight or none. Results: After 2 hours VDT work, vision protection effect in terms of refractive error for dominant eye was decreased by $0.031{\pm}0.21$ D in the group of extracted anthocyanine from fermented purple sweet potato, $0.006{\pm}0.32$ D in the group of extracted anthocyanine from blueberry. However, there was significantly myopic progression in the placebo group by $0.144{\pm}0.28$ D (t=2.27, p=0.03). Conclusions: It is considered that extracted anthocyanine from fermented purple sweet potato inhibits increase of refraction anomalies of dominant eye rather than non-dominant eye after VDT work.

• Food Science and Preservation
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• v.6 no.4
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• pp.442-447
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• 1999

A curd yogurt was prepared by fermenting milk added with skim milk powder and purple sweet potato by culture of 5 types of lactic acid bacteria(Lactobacillus delbruekii sub. sp. lactis, Streptococcus lactis, acidity, number of viable cell, stability of purple sweet potato's pigment and keeping qualify. Among the organisms tested, the acid production and number of viable cell by the culture of L bulgaricus remarkably increased for the first 12 hem which showed 1.04${\times}$10$\^$9/ CFU/mL in number of viable cell and 4.22 In pH where as fermentation by the culture of B. bifidum was slow. After 36 hours of incubation which showed 3.3 ${\times}$ l0$\^$8/ CFU/mL in number of viable cell and 5.1 in pH. In stabilities of purple sweet potato anthocyanin pigment n fermentation, yogurt by B. bifidum was found to be most stable followed by Leuc. lactis, L. delbruekii sub. sp. lactis, L bulgaricus, but yogurt by St. lactis was not stable. When curd yogurt added with Purple sweet Potato was kept at 2∼3$^{\circ}C$ for 14 day, its keeping quality(pH, titratable acidity, number of viable cell) was relative good except product by L. bulgaricus was found to be decreased most of viable cell. After 2 weeks of keeping, pigment of yogurt was decreased by B. bifidum, stable by L. delbruekii sub. sp. lactis.

• Food Science and Preservation
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• v.18 no.3
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• pp.414-422
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• 2011

The optimum condition for phenolics contents extraction from purple sweet potato was 12 hrs. in 50% ethanol. The electron donating scavenging activities (DPPH), ABTS radical cation decolorization (ABTS) and antioxidant protection factor (PF) of Jami, Yeonjami and Shinjami were higher than general sweet potato, and thiobarbituric acid reaction substance (TBARs) was below 30%. The minimum inhibitory concentration (MIC) against Staphylococcus aureus and Escherichia coli on skin were each 5,000 and 2,500 ppm in all purple sweet potatoes, and MIC of Jami was the lowest as 2,500 ppm against Staphlococcus epidermidis. The whitening (tyrosinase inhibitory) activity of purple sweet potatoes was the highest as 62.5% and 48.7% in Jami water and ethanol extracts. The anti-inflammation (hyaluronidase inhibitory) activity of purple sweet potatoes was the highest as 25.3% and 94.4% in Jami water and ethanol extracts. The safety of cosmetic with Jam; extracts was assessed by various safety profiles. pH and viscosity change of essence for 90 days was not detected. Cosmetic was stable to temperature and light for 90 days. The result to measure changes of skin color and pore size of the skin was that an aged skin was more effective than young skin.

• Korean Journal of Food Science and Technology
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• v.33 no.6
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• pp.808-811
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• 2001

Performance of pilot plant scale extraction and concentration of purple-fleshed sweet potato anthocyanin pigment was tested and the characteristics of pigment extracts and concentrates were investigated. Fifty kilograms of purple-fleshed sweet potato was extracted with 500 L of 1% citric acid in 20% ethanol. As a whole, extraction pattern of the large scale extraction was similar to that of the laboratory scale extraction. The extracted pigment solution was filtered twice with a bag filter and a winding type microfilter and the filtrate was concentrated by a large scale vacuum evaporator at $40^{\circ}C$ and 600 mmHg vac. The mean values of total optical density (TOD) of the extract and the concentrate were 6.53 and 120.45, respectively. Browning index (BI) and Degradation index (DI) of extract were 5.86 and 1.55 and those of concentrate were 5.89 and 1.56, respectively, which indicated that the pigments were not changed or degraded through the extraction and concentration process.