• Journal of the Korean Dietetic Association
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• v.13 no.4
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• pp.368-378
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• 2007

This study was conducted to develop a optimal composite recipe of a functional muffin including Sweet pumpkin powder and to have the high preference to all age groups. Wheat flour was partically substituted by Sweet pumpkin powder to reduce the content of wheat flour. This study has produced the sensory optimal composite recipe by making muffin, respectively, with each 5 level of Sweet pumpkin powder($\X_1$), sugar($\X_2$), butter($\X_3$), by C.C.D(Central Composite Design) and conducting sensory evaluation and instrumental analysis by means of RSM(Response Surface Methodology). Sensory items showed very significant values in appearance, flavor, texture, overall quality(p<0.05), color(p<0.01), and instrumental analysis showed significant values in lightness, redness(p<0.01), yellowness(p<0.001), hardness, gumminess(p<0.05). Also sensory optimal ratio of Sweet pumpkin muffin was calculated as Sweet pumpkin powder 29.5g, sugar 72.6g, butter 79.3g, and it was revealed that the factors of influencing muffin aptitude were in order of Sweet pumpkin powder, butter, sugar.

• Korean journal of food and cookery science
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• v.7 no.2
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• pp.7-18
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• 1991

This study was experimented saccharification process added malt extract solution into cooked sweet potato and potato with time, temperature and was tested reducing sugar changes, structural changes, pH and sensory evaluation about cooked shik-hae of rice, glutinous rice, potato, sweet potato. The results are summarized as follows: 1. Enzyme activity was highest in malt after four days of barley germination at a room temperature. 2. Electronmicroscopic observation indicated that raw starch granule of potato and that of sweet potato was 25-60$\mu\textrm{m}$ and 8~18$\mu\textrm{m}$ in size, respectively and its shape is oval and globular for potato and sweet potato respectively. 3. Reducing sugars were 1,682.6mg and 1,695.6mg in rice and glutinous rice, respectively, for 6-hour-saccharification at $50^{\circ}C$. Reducing sugars were 1,689.1mg and 1,497.8mg in sweet potato, potato, respectively, for 6.hour-saccharification at $60^{\circ}C$. 4. pH variation during saccharification for sweet potato and potato was pH 5.8~5.4. 5. Sensory evalution showed that there were more significant differences in sweety odor, roasted nutty taste and sweety taste of sweet potato among four samples than the other's color shininess.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.6
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• pp.943-947
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• 1995

The sweet potato drinks were prepared with the reaction of sweet potato and complex enzyme(${\beta}-amylase,\;{\alpha}-amylase$, protease). The reducing sugar and soluble solid of sweet potato drinks were the highest on reaction of sweet potato : water(1 : 1) and complex enzyme(pH 4.5). In the color of the sweet potato drinks, hunter value(L, a, b) were the lowest on reaciton of sweet potato : water(1 : 1) and complex enzyme, and were the highest on reaciton of sweet potato : water(1 : 3) and complex enzyme(pH 4.5). In the sensory test of the sweet potato drinks, the sensory score(color, taste, flavor, texture) were the best on reaction of sweet potato : water(1 : 1) and complex enzyme(pH 4.5). These results demonstrated that the sweet potato drink was good to drink when sweet potato : water(1 : 1) were treated with complex enzyme at pH 4.5, $60^{\circ}C$ for 5 hrs.

• Food Engineering Progress
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• v.15 no.1
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• pp.34-40
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• 2011

As an attempt to develop a value-added food product, purple sweet potato powder was added in a model system of steamed bread as a healthy food ingredient and physicochemical properties such as moisture content, specific volume, spread ratio, color, texture as well as consumer preferences on the attributes such as uniformity, color, flavor, elasticity, chewiness, taste, and overall preference were evaluated. Moisture content ranged from 44.16 to 44.55% (wet basis) and appeared independent on the level of purple sweet potato (PSP) powder incorporation. As a result of the addition of PSP powder, the specific volume of steamed bread decreased from 3.22 to 2.55 mL/g, and value of 4.5% sample was significantly lower than other samples (p<0.05). On the other hand, spread ratio ranged from 2.01 to 2.53, and appeared to decrease as the PSP powder concentration increased (p<0.05), indicating a significant improvement. Lightness $(L^*)$ decreased significantly as the PSP powder content increased (p<0.05) for both dough and skin of the steamed bread. In addition, an increasing trend in redness ($a^*$-value) and a decreasing trend in yellowness ($b^*$-value) were noticed. Firmness increased significantly with the addition of PSP powder regardless of concentration (p <0.05); however, firmness was not significantly different among samples containing 1.5-4.5% PSP powder (p>0.05). Consumer acceptance test indicated that incorporation of 3% PSP powder in the formulation of steamed breads would be recommended.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.1
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• pp.37-46
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• 2011

Polyphenolic content and antimutagenicity of the methanol extracts prepared from 22 cultivars of sweet potato with different flesh colors were investigated using Folin-Ciocalteu's phenol reagent method and Ames test, respectively. There was a remarkable cultivar difference in the polyphenolic content of sweet potato. Su, Hayanmi and Shinhwangmi among 17 cultivars of non-purple sweet potato had higher polyphenolic contents of 21.4, 21.5 and $20.3{\mu}g$ (GAE/g dried sweet potato), respectively, whereas Manami and Yeonhwangmi were very much lower at 4.6 and $4.8{\mu}g$. Mokpo No.62, Borami, Sinjami, Jami and Ayamurasaki had much higher polyphenolic contents of 67.7, 76.9, 44.9, 128.3 and $93.2{\mu}g$, respectively, than non-purple sweet potato. The methanol extract from the sweet potato effectively inhibited the reverse mutation induced by 1-NP, daunomycin, Trp-P-1, Trp-P-2 and 2-AA on S. Typhimurium TA 98, and by 1-NP on S. Typhimurium TA 100. These results suggest that the antimutagencity properties may be influenced by the tested mutagen and strain rather than the polyphenolic content of non-purple and purple sweet potato. However, in the purple sweet potatoes, a high polyphenolic content may influence the antimutagencity properties.

• The Korean Journal of Food And Nutrition
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• v.24 no.4
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• pp.559-566
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• 2011

The effects of pH and temperature on degradation of anthocyanin in purple-fleshed sweet potato cultivars(Mokpo No.62, Borami, Jami, Sinjami and Ayamurasaki) were determined at pH ranges of 1 to 5 and temperature ranges of 20 to $80^{\circ}C$. The anthocyanin contents of five sweet potato varieties were 3.9, 3.8, 4.7, 4.1, 4.2 mg/g of dried sweet potato, respectively. Degradations of anthocyanins at different pHs and temperatures followed the first-order reaction. Our results clearly showed that the anthocyanin stability of purple-fleshed sweet potato was dependent on the source of the sweet potato cultivars. Anthocyanin obtained from Borami showed the highest stability. The half-life of antocyanin degradation of purple sweet potato cultivars(Mokpo No.62, Borami, Jami, Sinjami and Ayamurasaki) at pH 3 were 22.2, 28.3, 26.3, 23.4, 22.7 days at $60^{\circ}C$, respectively. A significant decrease in anthocyanin stability was observed at temperatures above $40^{\circ}C$. Activation energies of purple-fleshed sweet potato cultivars at different temperatures were 54.67, 60.93, 71.73, 59.35, 62.28 kJ/mol, respectively.

• The Korean Journal of Food And Nutrition
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• v.26 no.1
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• pp.29-34
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• 2013

The objective of this study was to manufacture three kinds of domestic sweet potato Makgeolli using a mixture design and an optimization technique. The effects of four different manufacture methods, such as simultaneous saccharification and fermentation (SSF) with or without malt and separate hydrolysis and fermentation (SHF) with or without malt were determined. The SSF methods of Makgeolli produced higher alcohol content than that of SHF methods. The sensory score was not influenced by different making methods. Fourteen experimental points were selected, and rice (10~50%), sweet potato (10~50%) and water (40~60%) were chosen as independent variables. The measured responses were sensory preference, total polyphenol content, and DPPH radical scavenging activities. The ratio of the optimum sweet potato Makgeolli mixture formulation was developed as 15.11 (rice): 44.89 (sweet potato): 40 (water) using the optimization technique. The desirability of the optimum mixture formulation was 0.839. Yellow sweet potato Makgeolli using the optimum mixture formulation produced higher soluble sugar content compared to others. Regular sweet potato Makgeolli produced higher pH. The purple sweet potato Makgeolli's total polyphenol content and DPPH radical scavenging activity were measured to be the highest at $771.91{\pm}1.42mg\;GAE/{\ell}$, $131.55{\pm}4.03%$.

• Korean Journal of Food Science and Technology
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• v.46 no.2
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• pp.224-230
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• 2014

The characteristics and antioxidative activities of yellow and black soybean cheonggukjang prepared with the addition of purple sweet potato (Ipomoea batatas cv. Jami) were evaluated. In sensory evaluation experiments involving the addition of purple sweet potatoes to cheonggukjang at 0, 5, 10, 20, and 30% ratios (w/w), yellow (YCAP) and black (BCAP) soybean cheonggukjang with 20% purple sweet potato were most preferred. The total phenolics and flavonoid contents of YCAP and BCAP were higher than those of yellow (YC) and black (BC) cheonggukjang prepared without added purple sweet potato. YCAP and BCAP also showed higher DPPH radical-scavenging activities than other samples. Moreover, rat blood plasma samples taken 1 h after oral administration of YCAP and BCAP showed higher inhibitory effects against lipid peroxidation than did rats fed YC or BC. These results suggest that the long-term intake of cheonggukjang prepared with purple sweet potato may increase the antioxidative activity in the blood.

• Applied Biological Chemistry
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• v.30 no.4
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• pp.305-310
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• 1987

The enzymatic properties of ${\beta}-amylase$ from soybean and sweet potato were compared. The sweet potato enzyme consists of four identical subsunits whereas soybean enzyme has no subunit $structure^{12,\;15)}$. In the denatured state, both enzymes exhibited the same molecular weight on SDS-gel electrophoresis and on gel-filtration analysis. The spectra of circular dichroism revealed that both enzyme have almost same secondary structure but the environment of aromatic side chains are different. The chemical cleavage of soybean and sweet potato ${\beta}-amylases$ at cysteine residues and methionine residues demonstrated the homology of amino acid sequence between the enzymes. The similarity between soybean and sweet potato ${\beta}-amylase$ was also revealed by immunological method. The antibody for soybean enzyme inhibited the activity of sweet potato enzyme but it did not inhibit the activity of wheat, barley and Japanese-raddish ${\beta}-amylases$.

• Korean Journal of Food Science and Technology
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• v.25 no.6
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• pp.649-654
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• 1993

We investigated the texture of the sweet potato starch gels treated with maltogenic amylase. Effects of branched gluco-oligosaccharides and acorn starch on the texture of the sweet potato starch gel were also investigated. Hardness and cohesiveness of gels were measured by using Instron and sensory evaluation on the gel properties was performed. From the results of the instrumental analysis, it was found that the overall textural properties as Mook could be improved by adding branched glucooligosaccharides, maltogenic amylase or acorn starch to the sweet potato starch gel. As a result, there was a decrease in the cohesiveness of gels while the hardness of gels increased. The sensory evaluation study indicated that the sweet potato starch gels treated with 0.02% maltogenic amylase, or added with 12.5% branched gluco-oligosaccharides, or mixed with 50% acorn starch had preferable quality as Mook.