• Korean Journal of Food Science and Technology
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• v.26 no.4
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• pp.365-369
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• 1994

In attempt to explain the effect of heat processing on the product quality in manufacturing strawberry jam, the heat stability of anthocyanin in strawberry by addition of some sweetners was studied, and the effect of sucrose by concentration and pH were also investigated. The heat stability of anthocyanin was maximum at pH 2.5 when maintaining at $87^{\circ}C$ for 60 minutes initially, but it was shifted to pH 3.0 after additional heating of 120 minutes. When the corn syrup, sucrose and glucose were used as a sweetner for manufacturing strawberry jam, the results showed that heat stability of anthocyanin in corn syrup was higher than that in sucrose and fructose, and the optimum concentration of sucrose for heat stability was 66 Brix%. The results also showed that anthocyanin content in strawberry jam significantly decreased logarithmically at $37^{\circ}C$, and spreadmeter value changed slightly at $37^{\circ}C$storage but it was not significant.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.1
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• pp.48-52
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• 2008

The manufacturing characteristics and physicochemical component analysis of Bokbunja jam made with different additions of materials (Bokbunja, Bokbunja extract, sugar, and pectin) were investigated. There were no changes in the pH, total acidity, and sugar content of all Bokbunja jams that were prepared with different amounts of materials. L-value of color in the jam from the Bokbunja extract was the highest. a-value increased, but b-value decreased with the addition of pectin in jam. Spreadmeter value decreased while hardness increased in the jam added by pectin. The highest overall acceptability values in the sensory test for color, sweetness, adhesiveness, and overall favorite were 4.07, 5.33, 4.33, and 6.00, respectively, with the addition of 0.5% pectin.

• Korean journal of food and cookery science
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• v.16 no.6
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• pp.530-537
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• 2000

Quality characteristics of strawberry jams made of 2 different strawberry cultivars, Bogyo-joseng and Suhong, with 25, 50, 75, 100% fructo-oligosaccharide in place of sucrose were evaluated. Moisture content of Suhong jam was higher than Bogyo-joseng jam. pH of Bogyo-joseng and Suhong jam was not different. The lightness, redness and yellow-ness of Bogyo-joseoung jam were higher than those of Suhong jam. Spreadmeter value of jams decreased with addition of fructo-oligosaccharide. The sweetness of Suhong jam was higher than Bogyo-joseng. Reducing sugar content of Suhong jam was higher than Bogyo-joseng jam. More of fructo-oligosaccharide added, reducing sugar content of jam increased. Residual anthocyanin in Bogyo-joseng strawberry jam was decreased by addition of fructo-oligosaccharide. However, the residual anthocyanin content of Suhong strawberry jams with fructo-oligosaccharide was lower than that of sugar-only control jam with an exception of 50% fructo-oli-gosaccharide jam. The 50% fructo-oligosaccharide jam had a higher residual anthocyanin content than sugar-only jam. As the addition rate of fructo-oligosaccharide increased, springiness and cohesiveness of jam increased, while resilience decreased. In sensory evaluation, Bogyo-joseng strawberry jams obtained highest score with 50% fructo-oligosaccharide, while Suhong strawberry jam was favored most with 25% fructo-oligosaccharide.

• Korean Journal of Food Science and Technology
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• v.39 no.1
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• pp.44-49
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• 2007

The quality characteristics of strawberry jam containing different levels of sugar alcohols, such as xylitol, sorbitol and maltitol were compared with jam containing 35% of sugar only. Addition of 10-30% of xylitol did not influence pH and total acidity. The intensity of redness and amount of residual anthocyanin were increased according to increase of levels of xylitol, which showed a positive effect on color. However, the addition of more than 10% of xylitol resulted in negative changes in hardness and spreadmeter values. These and consumer preference results showed that the optimum amount of xylitol was less than 10%. Substituting sugar with 10% of xylitol and 25% of sorbitol, 10% of xylitol and 25% of maltitol or 10% of xylitol and 12.5% of sorbitol and maltitol did not change the pH, total acidity, hardness or spreadmeter value, but the redness and the amount of residual anthocyanin were still increased by these ratios. The most preferred ratio according to the sensory test was 10% of xylitol with 12.5% of sorbitol and maltitol each.

• Proceedings of the Korean Journal of Food and Nutrition Conference
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• 2000.12a
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• pp.49-49
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• 2000

Influence of onion on the quality characteristics of strawberry jam substituted with 50% fructo-oligosaccharide for sucrose was investigated. Fructo-oligosaccharide strawberry jams with 10, 20, 30, 40% onion in place of strawberry were prepared, and their moisture content, pH, total acidity, color, spread. sweetness, reducing sugar, residual anthocyanin, instrumental texture and sensory characteristics were evaluated. Moisture content of fructo-oligosaccharide strawberry jams with onion was lower than that of strawberry-only control jam with an exception of 10% onion jam. As the addition rate of onion increased, pH increased, total acidity decreased. The lightness and redness decreased with addition of onion, while yellowness was increased. As the addition rate of onion increased, spreadmeter value increased. The sweetness of fructo-oligosaccharide strawberry jams decreased with addition of onion. More of onion added, reducing sugar content of fructo-oligosaccharide strawberry jams decreased. As the addition rate of onion increased, residual anthocyanin of fructo-oligosaccharide strawberry jams decreased. As the addition rate of onion increased. instrumental texture measured in 25% strain, hardness, fracturability, adhesiveness, gumminess, chewiness, resilience of fructo-oligosaccharide strawberry jams decreased, while springiness, cohesiveness of fructo-oligosaccharide strawberry jams with onion was higher than that of strawberry-only control jam with an exception of 10% onion jam. As the addition rate of onion increased, instrumental texture measured in 30% strain, hardness, adhesiveness, gumminess. chewiness, resilience of fructo-oligosaccharide strawberry jams was lower than that of strawberry-only control jam with an exception of 10% onion jam, while fracturability of fructo-oligosaccharide strawberry jams decreased with addition of onion, springiness, cohesiveness of fructo-oligosaccharide strawberry jams increased with addition of onion. In sensory evaluation, as the addition rate of onion increased, sensory evaluation of fructo-oligosaccharide strawberry jams decreased, obtained fairly good score to 10, 20% onion jam.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.7
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• pp.935-945
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• 2009

This study was performed to find the optimum ratio of ingredients in the Chinese quince jam. The experiment was designed according to the D-optimal design of mixture design, which included 14 experimental points with 4 replicates for three independent variables (Chinese quince paste $45{\sim}60%$, pectin $1.5{\sim}4.5%$, sugar $45.5{\sim}63.5%$). A mathematical analytical tool was employed for the optimization of typical ingredients. The canonical form and trace plot showed the influence of each ingredient in the mixture against final product. By use of F-test, sweetness, pH, L, b, ${\Delta}E$, and firmness were expressed by a linear model, while the spreadmeter value, a, and sensory characteristics (appearance, color, smell, taste, and overall acceptability) were by a quadratic model. The optimum formulations by numerical and graphical method were similar: Chinese quince paste 54.48%, pectin 2.45%, and sugar 53.07%. Optimum ingredient formulation is expected to improve use of Chinese quince and contribute to commercialization of high quality Chinese quince jam.