• Food Science and Preservation
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• v.6 no.1
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• pp.66-70
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• 1999

The mechanism of natural removal of astringency and seasonal changes of tannin substance in sweet persimmon(Fuyu) and astrigent persimmon(Chungdo Bansi)were investigated. Tannin productivity of astringent persimmon fruit was higher than that of sweet perimmon fruit during growth. In the reactivity of tannin to acetaldehyde, it was observed that tannin from sweet persimmon have a milder chemical properties than that from astrigent persimmon. The threshold value of astringency on sweet persimmon tannin was higher than that of astrigent persimmon tannin. Tannin substances from sweet persimmon distributed mainly in lower molecular weight range at harvest stage, but those from astrigent persimmon distributed mainly in higher molecular weight range. Therefore, the natural removal of astringency was related to difference of tannin productivity, threshold value of astringency, reactivity and qualitative difference of tanni.

• Food Science and Biotechnology
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• v.14 no.2
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• pp.177-180
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• 2005

Antioxidant activity of crude extracts from colored sweet potato cultivars by plant parts such as root, stem and leaf was evaluated. The highest TBARS values were obtained from root samples of sweet patato, and followed by stems and leaves, indicating that leaf sample showed the strongest antioxidant activity. Sweet potato cultivars with yellow flesh and leaf part exhibited strong antioxidant activities. Antioxidant activities of leaf and stem extracts were maintained for 21 days and were a little lower than that of BHT. The DPPH radical scavenging activity was the highest in "Sinhwangmi" leaf, and followed by "Jami" root. Chlorogenic acid was detected as the most abundant antioxidant substance among all fractions. These results suggest that the antioxidant activity of sweet potato differs depending on plant part and cultivar.

• Journal of the Korean Society of Food Culture
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• v.32 no.4
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• pp.323-331
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• 2017

This study examined the quality characteristics of Jeung-pyeon made with wet non-glutinous rice flour and rice wine. The samples of Jeung-pyeon were prepared with different ratios of cooked purple sweet potato (0, 3, 6, 9, and 12%) to analyze the water content, sugar content, pH, chromaticity, texture characteristics, and sensory evaluation. No significant difference in water content, sugar content, and springiness was observed among the 5 samples. The pH and volume showed the highest level at 0%. The L-value and b-value decreased while the a-value increased. The hardness, chewiness, and gumminess were highest at 9% and lowest at 12%. The extent of violet chromaticity and pore size were optimal in 9%. In addition, 9%-added purple sweet potato showed the highest score of odor, taste, texture, and overall acceptability. In conclusion, the optimal addition for the highest acceptability of cooked purple sweet potato was 9%.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.1
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• pp.1-5
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• 2000

Physicochemical properties and gelatinization patterns of purple-fleshed sweet potato starch were studied. Shape of starch granule was round and polygonal, X-ray diffraction pattern was Ca-type. Amylose content was 14.4% which was lower than that of other sweet potato starch. Water binding capacity was 82.54%, swelling power and solubility at 8$0^{\circ}C$ were 27.94% and 15.35%, respectively. Initial temperature of gelatinization was 72$^{\circ}C$ using Brabender/Visco/Amylograph, consistency and setback were lower than those of other sweet potato starch. The peak temperature and enthalpy determined by DSC were 68.1$^{\circ}C$, 1.24cal/g, respectively. The transmittance of starch dispersions in alkaline solutions increased with NaOH concentration up to 0.17N, and then changed slowly at 0.19N or above. The apparent viscosities were similar to the transmittance of starch dispersions in alkaline solutions, but drastically increased above 0.21N.

• Preventive Nutrition and Food Science
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• v.11 no.4
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• pp.339-343
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• 2006

Physicochemical properties of bread as influenced by the addition of sweet pumpkin powder (SPP) were investigated. Freeze-dried sweet pumpkin was ground, sieved through a laboratory sieve and a fraction with particles less than $250\;{\mu}m$ was used. Amount of SPP added to the bread was found to affect the bread quality significantly (p<0.05). Loaf volume and weight of the control were significantly higher than others (p<0.05) and decreased significantly (p<0.05) with the addition of SPP. In other words, the enrichment of product with SPP decreased bread volume and weight without significant changes in the moisture content. There were distinctive color changes with the addition of the powder: L- and a-values were reduced but b-value was significantly increased (p<0.05). The hardness, springiness, and gumminess of bread were found to increase with the addition of the powder. Consumer test indicated that bread contained with 3% SPP had the highest overall acceptability score while 1 or 5% addition produced an acceptable quality for the bread.

• The Korean Journal of Food And Nutrition
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• v.19 no.3
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• pp.254-260
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• 2006

The mechanical and sensory characteristics of sponge cake made with different levels (0, 3, 6, 9, and 12%) of added sweet pumpkin powder were evaluated. The Hunter's L value of the crust and crumb of the sponge cake decreased significantly(p<0.05) as the content of pumpkin powder increased. Mechanical texture parameters such as hardness, gumminess and chewiness increased significantly (p<0.05) as the addition of pumpkin powder increased. Significant differences were observed in yellow color of crust and crumb, pumpkin flavor, sweetness and hardness in sensory evaluation of sponge cake added with 12% sweet pumpkin powder. The springiness of the sponge cake in sensory evaluation decreased significantly as the 12% addition of pumpkin powder (p<0.05). The highest overall acceptability was observed with 6% pumpkin powder added to the sponge cake.

• Preventive Nutrition and Food Science
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• v.13 no.3
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• pp.245-248
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• 2008

The effects of native sweet potato starch (NSPS) and sweet potato starch modified by acetylation (MSPS) on dynamic rheological properties of surimi sols were investigated by small-deformation oscillatory measurements. Dynamic frequency sweeps of surimi sols at $10^{\circ}C$ showed that the addition of NSPS and MSPS resulted in a reduction of storage modulus (G') and loss modulus (G"). The tan $\delta$ values (ratio of G"/ G') of all samples were in the range of $0.15{\sim}0.54$ over a wide range of frequency, indicating that all surimi sols are more elastic than viscous. The characteristic G' thermograms of surimi sols during heating from 10 to $90^{\circ}C$ were influenced by the addition of starch. The tan $\delta$ values of all samples were maintained nearly constant above $45^{\circ}C$, showing that the G' is proportional to the G" irrespective of starch effects.

• Korean journal of food and cookery science
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• v.20 no.3
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• pp.271-278
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• 2004

As an attempt to develop new functional beverages for breakfast, sweet potato based beverages were prepared with hydrolyzed sweet potato, potato, and carrot products (sample : water = 1 : 1), and their chemical and sensory properties were evaluated. The content of reducing sugar and soluble solid of the sweet potato, potato, and carrot increased with enzyme treatment, while their viscosity decreased without significant change of color. The hunter color test showed that the beverages with 10％ carrot content were high in redness leading to a decrease in their acceptability for sensory evaluation. The sensory score of the mixture containing 5％ carrot was good, but beverage with 0％ carrot reduced the sensory properties. The results showed that the final ratio of sweet potato to potato to carrot for the new functional beverage was 5 : 4.5 : 0.5. The pH of the beverage was adjusted to 5.0, 4.5, and 4.0 using an organic acid mixture. In the sensory test of the new functional beverage, the best sensory score(color, taste, smell, and texture) was the mixture of sweet potato : potato : carrot equaling 5 : 4.5 : 0.5 with a pH of 4.5.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.4
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• pp.487-493
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• 2012

This study was performed to investigate the effects of a diet with a red yeast sweet potato supplement on fecal amount and lipid metabolism in male Sprague-Dawley rats fed a high-fat diet for 10 weeks. Rats were fed a high-fat diet (15% fat) with additional lard (7%) and cholesterol (1%) based on AIN-93G basal diet (7% fat) for 6 weeks during the first phase. In the second phase, which lasted 4 weeks, the rats divided into four experimental groups which were composed of a high-fat diet group as a control (CON), a high-fat diet with 5% white-fleshed sweet potato supplement group (WFSP), a high-fat diet with 5% red yeast sweet potato supplement group (RYSP), and a high-fat diet with 5% purple-fleshed sweet potato supplement group (PFSP). The fecal amount of group RYSP increased significantly during the second phase compared to the other groups (p<0.05). The fecal total cholesterol (TC) and triglyceride (TG) content of group RYSP were also highest among all experimental groups. The serum TC and TG were shown to have the lowest levels in the group RYSP, and LDL-cholesterol levels were significantly decreased in groups RYSP and PFSP than in group CON (p<0.05). These results indicate that supplementation with red yeast sweet potato seemed to be effective in increasing feces and fecal lipid excretion, and also in decreasing serum lipid levels in rats fed a high-fat diet.

• Journal of the Korean Society of Food Culture
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• v.20 no.4
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• pp.487-497
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• 2005

War against Japanese(1592-1599) and war against Manchurian(1636-1637), which had been occurred in Korean Peninsula throughout the history, and frequent trade with foreign countries since $18^{th}$ century have led to a distribution of foreign food into Korea. Several examples for this include tomato, apple, watermelon, maize, pea, cowpea, peanut, potato from China and red pepper, pumpkin, and sweet potato from Japan. Since these foods had been brought into Korea, they have been cultivated suitable for Korea's climate and land. Foreign foods with a few exceptions tend to have high calories. For instance, along with potato and sweet potato, pumpkin is considered a high-calorie food containing lots of starches as it becomes ripening. This helped a wide spread of the foreign foods across the nation where intake of high-calorie foods was critical for Korean people's nutrition at that time. Among those foods introduced from foreign countries, red pepper had a greatest impact on the dietary life-style of Chosun Dynasty. The use of red pepper has been greatly expanded from main ingredient to seasoning and garnishing in various forms of red pepper such as red pepper paste, red pepper powder, and thick soy paste mixed with red pepper. Red pepper was made eating habits is hot besides dye red colored to traditional food, because steaming and boiling is frequently cook method, fermentation food also food color is achromatic therefore food color is and mixture with red pepper, picked fish and chinese cabbage new kimchi culture came into being.