• Food Science and Preservation
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• v.23 no.4
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• pp.538-546
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• 2016

Kochujang was prepared by replacement of rice (25%, control) with pumpkin or purple sweet potato by 0. 5, 10, and 15% (total addition ratio of rice and sweet potato=25% of sample). Effects of the addition of sweet potato on physiochemical properties of fermented Kochujang were investigated. Viable cells of yeast decreased in the sweet potato-added Kochujang at the later stage of fermentation, while there was no significant difference in the number of bacteria among the test groups. As the addition ratio sweet potato increased, ${\alpha}$-amylase activity increased while protease activity decreased. Hunter L, a, and b values of Kochujang prepared with purple sweet potato were lower than those with pumpkin sweet potato. Changes in ${\Delta}E$ value was greater in Kochujang prepared with pumpkin sweet potato than that with purple sweet potato. Oxidation-reduction potential and water activity were higher in sweet potato-Kochujang than control, but reducing sugar content was higher in control. Alcohol and amino-type nitrogen contents were higher in Kochujang prepared with pumpkin sweet potato than that with purple sweet potato, but it was not significant. Overall sensory acceptability was highest in Kochujang prepared with 10% of purple sweet potato while that with 15% pumpkin sweet potato was the least preferred.

• Journal of the East Asian Society of Dietary Life
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• v.21 no.1
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• pp.60-67
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• 2011

This study was conducted to investigate the anti-oxidative abilities of certain products in Ulleungdo, such as sweet pumpkin (Danhobak), goat's beard (Samnamul), and Aster glegni (Bugigangyi), quality characteristics of sweet pumpkin taffy containing these products. Total polyphenolic contents of the Samnamul water and ethanol extracts were 2.95 mg% and 3.57 mg%, respectively, whereas those of the Bugigangyi water and ethanol extracts were 2.77 mg% and 2.75 mg, respectively. However, the total polyphenolic contents of the pumpkin water and ethanol extracts were 0.32 mg%. Reducing power ($OD_{700}$) of the Samnamul and Bugigangyi water and ethanol extracts (0.01%, w/v) was in the range of 1.62~1.91, which was higher compared to those of sweet pumpkin (0.02~0.03). Electron donating abilities (EDA) of the 0.01% Samnamul and Bugigangyi water and ethanol extracts were in the range of 74.91~79.21%, whereas those of the sweet pumpkin water and ethanol extracts were 3.79~14.99%. Optimum mixing ratio of steamed sweet pumpkin and water taffy for the preparation of taffy was 25:75 (w/w), as evaluated by sensory evaluation. Optimum adding ratio of Samanmul and Bugigangyi ethanol extracts to pumpkin taffy were 0.4% and 3%, respectively. However, the adding ratios of Samanmul and Bugigangyi powder to pumpkin taffy were 0.5~1.0% (w/w) and 1% (w/w), respectively.

• Food Science and Preservation
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• v.15 no.6
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• pp.832-839
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• 2008

The stock that is the first step for preparation of soups and purees links to the taste of food. Many types of vegetable have been used in stocks, but this study focused on stocks prepared with sweet pumpkin. The stock preparation conditions including the weight of sweet pumpkin, the water volume, and the boiling time at $97^{\circ}C$ were optimized by response surface methodology. The quality characteristics of the resulting stock were investigated. The color, flavor, taste and overall acceptability were dependent parameters. A model equation was proposed with regard to the sweet pumpkin weight, water volume, and boiling time at $97^{\circ}C$. A sweet pumpkin weight of 357.9 to 403.0 g, a water volume of 689.8 to 768.5 mL, and a boiling time of 9.9 to 10.3 min at $97^{\circ}C$ were found to be the optimal stock preparation conditions. The quality characteristics of the sweet pumpkin stock prepared under the optimized conditions were pH 6.64, total acidity 0.18%, soluble solids $2.39\;^{\circ}Brix$, color value (L, 99.07 a, -2.43 b, 11.82), total polyphenol 280.75 mg/L, and electron donating ability 21.32%.

• Culinary science and hospitality research
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• v.24 no.3
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• pp.83-92
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• 2018

Sweet pumpkin yanggaeng were produced with stevia leaf powder as a partial sugar replacer(0 to 20% sucrose weight) and antioxidant. Characteristics of the yanggaeng were compared in moisture, total soluble solids, pH, color, texture, antioxidant properties, and preference scores. Moisture and total soluble solids were proportionally increased with increasing addition of stevia leaf powder(p<0.001). pH of control (without stevia) and SLP20(with 20% replacement of sucrose) were 7.05 and 6.82, respectively. L-value, a-value, and b-value were decreased with increasing amount of stevia leaf powder (p<0.001). Antioxidant activities (total polyphenols and DPPH radical scavenging activity) were gradually increased as more stevia leaf powder included in the yanggaeng(p<0.001). SLP20 being significantly different from others (p<0.001) had the highest values of hardness and chewiness, but there was no significant difference between cohesiveness and adhesiveness among samples. SLP4 had the highest preference in appearance and texture, otherwise SLP8 did the highest scores in flavor, sweetness and overall preference. SLP8, in which 8% sucrose was replaced with stevia leaf powder, was considered to be the most desirable for production of sweet pumpkin yanggaeng.

• Research in Plant Disease
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• v.7 no.1
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• pp.31-36
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• 2001

To establish an effective chemical control strategy against powder mildew of sweet pumpkin (Cucurbita maxima Duchesne) caused by Sphaertheca fuliginea, screening of effective fungicides and determination of their application times were conducted. Powdery mildew caused by S. fuliginea began to occur at about 80 days after transplanting and continuously increased until harvesting in Korea. Systemic fungicides, such as difenoconazole, triforine, bitertanol, and triflumizole, were effective for controlling powdery mildew, showing control efficacies of about 80-90%. When the fungicide triflumizole was applied 3 or 4 times from the beginning day of the disease at 10-day intervals, about 92.0% and 94.6% of disease control and yield increase of 7% and 9% were obtained, respectively. Therefore, the proper application of triflumizole for controlling powdery mildew of sweet pumpkin must be done more than 3 times.

• 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.

• Food Science and Preservation
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• v.18 no.5
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• pp.714-720
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• 2011

Sweet Pumpkin (Cucurbita maxima) is rich in minerals, vitamins, and dietary fibers and has less fat. It is thus effective for dieting and for preventing constipation. Sweet Pumpkin contains vitamin A, particularly beta-carotene, which is turned into retinol in the body and helps protect the vision. It is currently on the spotlight as a vision care, anticancer, and diet food, among others, but because it is hard to find yogurt made of Sweet Pumpkin, in this study, Sweet Pumpkin powder was added to yogurt for promotion as a new health food. Yogurt was made with 0, 0.5, 1, 2, and 3% Sweet Pumpkin powder, and the color properties (brightness, redness, and yellowness), viscosity, pH, and acidity were measured through a sensory test (color, flavor, taste, overall acceptability). The storage stability at five-day intervals for one day, five days, ten days, 15 days, etc. was also experimented on. For the color properties, the greater the amount of Sweet Pumpkin powder added, the greater the decrease in the lightness (L) value, but the redness (a) and yellowness (b) values increased (p<0.001). For the viscosity, it was decreased for five days and then increased by 47-68% for ten days. This showed a significant difference in storage stability period: one day (p<0.001), five days (p<0.01), and ten days (p<0.01) (except 15 days). Further, there was a significant difference in pH and acidity [pH: for one day (p<0.001), five days (p<0.01), and ten days (p<0.01); acidity: one day (p<0.001), ten days (p<0.05), 15 days (p<0.001)]. No significant difference in pH was shown, however, for 15 days, and in acidity for five days. The results of the sensory test are highly estimated in the order of 1%>2%.3%>0%>0.5%. The study results indicate that the addition of 1% Sweet Pumpkin powder is most suitable for manufacturing Sweet Pumpkin yogurt.

• Food Science and Preservation
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• v.19 no.5
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• pp.672-680
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• 2012

To determine the characteristics of four different sweet pumpkins (Minimam, Bojjang, Ajikuroi and Kurijiman), juices were made from these varieties. The carotenoids in the flesh were 1.5~2 times higher than those in the skin and were highest in the flesh of the Minimam pumpkin among all the pumpkin varieties studied. The vitamin A contents were higher in the skin than in the flesh, and Minimam had the highest vitamin A content (2,016.57 IU/100 g) while Kurijiman had the lowest (998.83 IU/100 g). The vitamin C contents varied from 43.21 to 82.35 mg%, but there were no significant differences between the flesh and the skin. That of Kurijiman was the highest among the varieties studied. The major mineral of these varieties was potassium, which was highest in the flesh of Ajikuroi, followed by phosphorus. The antioxidant activities of the sweet pumpkin water extracts were higher in the skin than in the flesh. The $EC_{50}$ of the Minimam skin was the highest (4.01 mg/mL), and that of the Ajikuroi flesh was the lowest. The sweet pumpkin juice yields were 69.5~89.4%, with significant differences shown according to the variety. That of the peeled Ajikuroi's flesh was the highest. The pH was 7.17~7.83, and the unpeeled sweet pumpkin's pH was higher than that of the peeled sweet pumpkin. The Brix degree was $12.5{\sim}16.6^{\circ}Brix$, with that of the unpeeled Bojjang being the highest($16.1^{\circ}Brix$) and that of the unpeeled Ajikuroi the lowest ($12.7^{\circ}Brix$). The sweet pumpkin beverage made with pressed juice was adjusted by pH 3.5 with citric acid, and the Brix degree was maintained at the $12^{\circ}Brix$ with sugar. The adjusted beverage, which was the peeled pumpkin flesh juice, had suspension stability for a short time. The sweet pumpkin beverage had a certain flovor and a slimy mouthfeel. Bojjang and Kurijiman were evaluated as the best in the terms of taste and color, but the peeled Minimam and Bojjang showed the best results overall.

• Korean journal of food and cookery science
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• v.27 no.2
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• pp.73-81
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• 2011

Two kinds of steamed sweet potatoes were dried with mild hot air to improve quality, convenience and preference as a snack. Steamed sweet potatoes were dried at temperatures ranging from 35 to $65^{\circ}C$ for 12 hr, and moisture contents, colors, texture, and taste were evaluated. The lowest moisture content was 0.25% at $65^{\circ}C$. Color values (L, a, b and ${\Delta}E$) decreased with increasing drying temperature and drying time in both chestnut-sweet potatoes and pumpkin-sweet potatoes. Reducing sugars and soluble solids increased quickly at high drying temperatures. The highest hardness value for chestnut-sweet potatoes was $26.31\;kg_f /cm^2$when they were dried at $65^{\circ}C$ for 12 hrs. Springiness and cohesiveness were higher than those in chestnut-sweet potatoes. The highest taste score was for a dried chestnut-sweet potatoes at $55^{\circ}C$ for 6 hr and a dried pumpkin-sweet potatoes at 45 or $55^{\circ}C$ for 6 hr.

• Food Science and Preservation
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• v.19 no.4
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• pp.492-500
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• 2012

This study was conducted to develop a sauce prepared with sweet pumpkin and Korea Doenjang. The optimum conditions for manufacturing sweet pumpkin-doenjang sauce were investigated using the response surface methodology, based on the central composition design. The amount of stock added, the thickening agent, and doenjang were used as the independent variables, and the sensory characteristics (taste, flavor, color, and overall acceptability) were used as the dependent variables to evaluate the optimum conditions for the preparation of the sauce. The optimum conditions for the maximized-responses variables in the preparation of the sauce were 448.5 g of sweet pumpkin stock, 331.5 g of the thickening agent, and 20.0 g of doenjang. The quality characteristics of sweet pumpkin-doenjang sauce that was manufactured at optimum conditions were as follow: 89.55% moisture content, 0.70% crude protein, 0.10% crude lipids, and 0.71% crude ash. The pH of the sauce was 5.96; total acidity, 0.08%; and soluble solids, 6.80$^{\circ}Brix$. The total polyphenol content of the sauce was 5.70 mg/L. The electron-donating ability and reducing power of the sauce were, 14.24% and 1.64 OD, respectively.