• Journal of the East Asian Society of Dietary Life
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• v.25 no.4
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• pp.660-666
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• 2015

Natural food colorant are widely used to satisfy consumer preferences. Anthocyanins are red, blue and purple natural pigments. Purple-fleshed sweet potato (PSP) contains large quantities of anthocyanins. The aims of this work were i) to investigate the influence of sugars on the purple color of PSP jam and ii) to optimize the ratio of ingredients for sensory characteristics of PSP jam. Korean PSP variety "Sinjami" was used for the preparation of jam. The jams were prepared with various sugar contents (0, 20, 30, 40 and 50% total weight) consisting of steamed purple-fleshed sweet potato, water, lemon juice and apple juice. With increasing sugar contents, lightness (L) and redness (a) of PSP jams decreased while yellowness (b) increased, indicating that anthocyanins were degraded and/or brown pigments were formed due to high sugar content under heat treatment. Hardness, springiness, chewiness and cohesiveness showed significant differences among PSP jams with various sugar contents. In sensory evaluation, addition of sugar significantly increased scores for color and texture as compared to control samples. The color, texture and preference results indicate an optimal sugar content of 40% total ingredient weight for PSP jam.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.12
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• pp.1865-1872
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• 2015

This study attempted to investigate consumer perceptions and attitudes towards reducing sugar intake by providing data to develop guidelines for the government and food-related industries to encourage Korean consumers to maintain appropriate levels of sugar intake. A survey was conducted on 238 adult consumers regarding their purchasing power for products with high sugar content in Seoul and Bundang, Gyeonggi area from September 1~30, 2013. Nutritional information on sugary products had a greater impact than media and others' recommendations on consumer awareness regarding need to reduce sugar intake. External factors such as health and weight control were stronger reasons for consuming reduced amounts of sugar or sugar-free products than internal factors such as sweetness. However, internal factors-such as taste-did not have a greater effect on consuming reduced amounts of sugar or sugar-free products than environmental factors-such as absence of purchase channels. Consumers indicated higher acceptance for 50% reduction in sweetness of existing commercial products. Regarding methods of lowering sugar intake, sugar replacement and reducing sugar consumption both generally and at home were preferred. In addition, consumers were likely to pay 10~14% more for sugar-reduced products than for existing products. Overall, consumers expressed positive attitudes towards reducing sugar intake in the future, although those in their twenties tended to be more passive than other age groups.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.1
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• pp.7-11
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• 2002

Hydrothermal extraction from dates was done, and then 3 groups of the date extract liquid group (A), the date puree group (B) and the jujube skin flesh group (C) were prepared. And, the omija extract liquid was added to the 3 groups at respective rates of 3:7, 5:5 and 7:3. Then, total 9 medicated diet sources were prepared by adding cinnamon, the ginger extract liquid, honey and pectin. And their physicochenmical and sensory attributes were examined. Total sugar, free sugar and pH increased in the samples of the 3 groups as the addition amount of the jujube extract increased. In chromaticity of respective samples, the "L" value did not show any difference among the 3 groups, but the "a" value was the highest in the "A"group, and "b"value was the highest in the "B"group. In the date puree group and the jujube skin flesh group, their viscosity increased as the addition amount of the jujube extract increased, but in the jujube extract liquid group, no difference was found in its viscosity. As a result of conducting the discrimination test, it was identified that the as the addition amount of the jujube extract was increased, color and sweet taste were feltto be stronger and our taste was felt to be weaker in all 3 groups. In the jujube puree group and the jujube skin flesh group, as the addition amount of the jujube extract increased, the jujube fragrance was felt to be stronger, but in the jujube extract liquid group, no difference was found in its fragrance. And, no difference was found in brightness and viscosity between samples. As a result of conducting the palatability test, no difference was showed in the appearance, but as for the overall palatability including texture, taste and fragrance, preference increased as the addition amount of the jujube extract increased.

• Korean Journal of Food Science and Technology
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• v.26 no.6
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• pp.726-732
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• 1994

Development of an effective method for the preparation of dongchimi juice was investigated by addition of NaCl, sucrose and hydrolytic enzymes before fermentation and addition of dongchimi juice during fermentation. The Chinese radish was ground and suspended in water (1:1, w/v) with addition of spices of garlic, green onion and ginger followed by fermentation at $25^{\circ}C$. Increase in NaCl concentration of brinning solution from 1.0 to 5.0% resulted in a significant decrease in the rates of pH decrease and acidity increase. The sugar addition resulted in a faster changes of them, particulary after 24 hours at $25^{\circ}C$. The fermentation rate was also greatly improved by enzymatic hydrolysis with using viscozyme, a commercial polysaccharides hydrolyzing enzyme, before fermentation. When the fermented juices of two stage (pH 5.4 and pH 4.4) were added up to 15% before (pH 5.4 juice) and during (pH 4.4 juice) fermentation, the initial and second stage of fermentation were significantly improved. Therefore a method of addition of sugar, hydrolytic enzymes and dongchimi juice before or during fermentation was suggested for dongchimi juice preparation.

• 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.

• Korean Journal of Food Science and Technology
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• v.30 no.1
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• pp.125-131
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• 1998

The change of pectinesterase (PE) activity and pectin substances in fig fruit were investigated and low sugar jams prepared by various methods from fig fruit were compared. Fig fruit PE, which began to show the activity at the harvest time, was not inactivated and had slight activity during frozen storage at $-25^{\circ}C$. The amount of alcohol insoluble solid (AIS) and the degree of esterification (DE) of AIS were reduced by its own PE activity. However the intrinsic PE of fig fruit was not enough to make low-methoxyl pectin below 50% of DE. Fig pulp treated by its own PE and combination of fig PE and orange PE could make low-methoxyl pectin. After PE treatments, fig pulp adjusted below pH 4.0 by addition of citric acid kept red colour. Fig Jams processed by various methods had lower soluble solid $(31{\sim}49^{\circ}Brix)$ compared with conventional fig jam. Five kinds of fig jams out of those showed higher score than others in the sensory evaluation. For preparation of the five jams, the fig pulps with or without 1% pectin were treated at $50^{\circ}C$ for 25 minutes with addition of orange PE (200 units/400 g pulp). The treated pulps were added with 0.25% citric acid, 0.7% calcium and 20% cane sugar. The mixed pulps were prepared for jams containing low sugar by hot plate or microwave or refrigeration (excepting the mixed pulp without pectin).

• Korean Journal of Food Science and Technology
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• v.27 no.1
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• pp.134-140
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• 1995

Four different mashes using traditional methods in Korea such as Andong soju, Moonbaeju, Leekangju and Jindo hongju, were prepared for distilled liquor. The changes of pH, total acid, reducing sugar, total sugar, alcohol, solid content and ${\beta}-amylase$ activities in their mashes were studied during fermentation. Ethanol content of mashes were increased to the range of $8.8{\sim}11.2%$ after 16 days of fermentation. The group which was brewed by the first addition of mash showed higher ethanol content than the other group which was not added the ones. Total acid content of mashes increased to $0.59{\sim}1.10%$. The total sugar content was decreased to $6.70{\sim}8.94%$, and that of Leekangju type was lower than that of other fermented mashes. Reducing sugar content was in the range of $0.62{\sim}6.42%$ at the initial fermentation and decreased to $0.09{\sim}0.30%$ after 16 days of fermentation. Soju was obtained by distillation of each fermented mashes using the modified traditional Togori. After distillation of mashes, pH was increased and total acid was reduced. Sugar(3.58%) and solid(1.17%) in Leekangju were found to be leached from the mixture of pear, ginger, cinnamon, honey and curcuma rhizome.

• Journal of Nutrition and Health
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• v.53 no.3
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• pp.303-318
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• 2020

Purpose: This study examined the effects of nutritional education related to sugar in elementary school children on nutritional knowledge, attitude, and dietary behavior. Methods: A questionnaire survey on the knowledge, attitudes, and intake related to sugar was conducted on 572 students in grades 4-5, who were attending five elementary schools in Seoul and Gyeonggi-do. Results: Among the survey subjects, 270 (49.8%) were cognitive in education, and 302 (50.2%) were non-cognitive. The sugar-related knowledge score was 3.67 points in the cognitive education group, which was significantly higher than the 3.55 points in the non-cognitive group. The rate of checking the sugar content in the nutrition label was 31.2% in the cognitive education group, which was significantly higher than in the non-cognitive group, 15.4%. The cognitive education group had a higher intake frequency of unsweetened candy, jelly, and raw fruits, and higher sugar intake of unsweetened bread, white milk, and raw fruits than the non-cognitive group. In the case of the cognitive education group, the total knowledge score showed a positive correlation with the food behavior scores, and a negative correlation with the frequency of purchasing snacks after school, and the average sugar intake per day. In the cognitive education group only, the education of nutrition teachers was analyzed as a factor to reduce the total sugar intake. The cognitive group of sugar education tried to eat foods with a lower sugar content than the non-cognitive group, and nutrition education was an important factor affecting the sugar intake. Conclusion: To reduce the sugar intake of elementary school students, it will be necessary to practice oriented-nutrition education by nutrition teachers continuously. In addition, it is important to develop and disseminate various types of nutrition education materials related to sugar that can be utilized easily by nutrition teachers.

• Journal of Microbiology and Biotechnology
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• v.19 no.5
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• pp.482-490
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• 2009

We examined butanol fermentation by Clostridium beijerinckii NCIMB 8052 using various hydrolyzates obtained from rice bran, which is one of the most abundant agricultural by-products in Korea and Japan. In order to increase the amount of fermentable sugars in the hydrolyzates of rice bran, various hydrolysis procedures were applied. Eight different hydrolyzates were prepared using rice bran (RB) and defatted rice bran (DRB) with enzyme or acid treatment or both. Each hydrolyzate was evaluated in terms of total sugar concentration and butanol production after fermentation by C. beijerinckii NCIMB 8052. Acid treatment yielded more sugar than enzyme treatment, and combined treatment with enzyme and acid yielded even more sugars as compared with single treatment with enzyme or acid. As a result, the highest sugar concentration (33 g/l) was observed from the hydrolyzate from DRB (100 g/l) with combined treatment using enzyme and acid. Prior to fermentation of the hydrolyzates, we examined the effect of P2 solution containing yeast extract, buffer, minerals, and vitamins on production of butanol during the fermentation. Fermentation of the hydrolyzates with or without addition of P2 was performed using C. beijerinckii NCIMB 8052 in a 1-1 anaerobic bioreactor. Although the RB hydrolyzates were able to support growth and butanol production, addition of P2 solution into the hydrolyzates significantly improved cell growth and butanol production. The highest butanol production (12.24 g/l) was observed from the hydrolyzate of DRB with acid and enzyme treatment after supplementation of P2 solution.