• Journal of the Korean Society of Tobacco Science
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• v.18 no.1
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• pp.49-53
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• 1996

This experiment was carried out to study the effect of oxygen on chemical composition and physical properties of tobacco leaves during flue-curing. The results obtained were as follows: Starch content decreased and sucrose content increased with increasing oxygen supply during curing. Glucose and fructose of the cured leaves showed high content at the 5-10% oxygen supply. Amino-N and nitrate-N increased with increasing oxygen supply. Total nitrogen and NH4-N showed the lowest value at the 5-10% and 10-15% oxygen supply in the cutters and leaf, respectively. Chlorophyll and chlorogenic acid increased, and total volatile base decreased with increasing oxygen supply. The activity of α-amylase increased at the latter period of flue-curing, and the maximum activity point were delayed 12 hours with increasing oxygen supply. Shatter index of cured leaves decreased with increasing oxygen supply. It was desirable to supply oxygen during flue-curing for the improvement of chemical and physical properties such as starch, total sugar, chlorogenic acid, and shatter index of cured leaves.

• Korean journal of food and cookery science
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• v.14 no.3
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• pp.219-224
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• 1998

Kochujang was prepared by using retrograded rice cakes (Song Pyun, Sym rice cake, Ssuk rice cake, Pat rice cake) as a source starch and the physiochemical and sensory characteristics were compared with traditional kochujang during aging for 60 days. Moisture content of all kochujang groups increased slowly but crude fat content decreased according to aging process. Changes of pH values of all kochujang reduced gradually during aging and the pH of saccharified kochujang was lowered than that of traditional one. Total reducing sugar contents in saccharified kochujang reached the maximum value at 50th day, and decreased thereafter. In contrast, the reducing sugar content in traditional kochujang was the highest at 30-day-aging. After 60 days of aging, the total contents of organic acids were 28.57 mg for P$\_$1/, 27.9 mg for P$\_$4/, 27.05 mg for P$\_$3/ 24.60 mg for P$\_$2/, and 22.30 mg for P$\_$0/. By sensory evaluation, saccharified kochujang prepared with Siru rice cake showed the highest sensory score in its appearance, flavor, texture, color, and taste.

• Journal of Sericultural and Entomological Science
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• v.31 no.1
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• pp.1-11
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• 1989

To investigate changes of dry weight, C/N ratio, carbohydrate, ratein and nucleic acids in the barks of the hardwood cutting of mulberry plants, the barks of the hardwood cutting were taken every 10days from the cutting day to 40days after cutting. Results were summarized as follows : Growth of shoot and root in Keomseolppong (Morus bimbycis KoIDZ.) after cutting was better than that in kaeryangppon (Morus alba L.) and Daeryugppong(Morus Lhou(SER.) KoIDZ.). Dry weight in the barks of the hardwood cutting decreased up to 40days after cutting (decrease percentage of dry weight : about 14%) and Keomiseolppong showed the highest decrease precentage of dry weight. Change of C/N ratio decreased in the initiation, whereas that from 10days after cutting increased with the growth of new shoot, C/N ratio was the highest in Keomseolppong and the lowest in Kaeryangppong. Total sugar showed decreasing tendency up to 40 days after cutting the increase from 10 days to 20 days. Reducing sugar increased in the frist 20days, followed gradually decrease up to 40 days after cutting Starch levels decreased up to 40 days. Change in the content of starch closely paralleled to that of dry weight of bark of the hardwood cutting. Content of total sugar and starch in Keomseolppong was the highest, and was consumed more than that in the rest of varieties. Crude protein and soluble protein increased up to 10 days after cutting, followed decrease up to 40 days. Protein content of Keomseolppong was smaller than that in the rest of varieties. RNA content showed the same tendency with that of protein content, but Keomseolppong showed always the highest. Content of DNA did not show any change and difference among three varieties.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.3
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• pp.405-410
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• 2002

The optimum conditions of the alcohol fermentation with raw tapioca by simultaneous saccharification and alcohol fermentation (SSAF) were studied using raw starch enzyme. The optimum conditions for maximum alcohol production were 0.5% (w/w) of enzyme content, 250% (v/w) of added water content and 96 hr of fermentation time. The alcohol and reducing sugar contents were 11.7% and 306 mg% after 96 hr fermentation, respectively. During the fermentation pH decreased from 6.2 to 4.2 and total acidity increased from 0.11 to 0.43. Alcohol components were detected such as ethanol, methanol, iso-propanol, n-propylalcohol and iso-butylalcohol, besides acetaldehyde. We could construct raw starch fermentation conditions which was 250% (v/w) of added water content and 0.5% (w/w) of enzyme content. However, yield of raw starch alcohol fermentation was lower than that of steaming alcohol fermentation.

• Journal of Life Science
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• v.11 no.1
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• pp.14-21
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• 2001

To investigate the changes of carbohydrate metabolism in the senescing leaves of Zea mays during dark-induced senescence, the changes in the contents of reducing sugar, sucrose and starch as well as the activities of sucrose synthase, three isozymes of invertase, and ${\alpha}$-amylase were measured. In the senescing leaves, the content of reducing sugars temporarily increased at 4 d and rapidly decreased thereafter, whereas sucrose contents gradually decreased thereafter, whereas sucrose contents gradually decreased until 3 d of senscence and significantly decreased thereafter. The activities of intracellular invertases such as soluble acid and alkaline formed gradually enhanced until 4 d of leaf senescence and significantly declined thereafter. The extracellular invertase activity showed no significant changes during leaf senescence. The deactivation of sucrose synthase was observed within 3 d of leaf senscence. On the other hand, the starch contents gradually declined during 2 d of leaf senescence, and showed a temporary increase at 3 d, which is similar to the pattern of sucrose synthase activity., These results imply that sucrose in the senescing leaves. The major enzymes which correlated to the breakdown of sucrose during dark-induced senescence were soluble acid and alkaline invertases, not sucrose and ABA accelerated leaf senescence by inducing the accumulation of reducing sugar. These result, therefore, that leaf senescence may be mediated by the temporary quantitative changes of reducing sugar induced by the activation of intracellualr inveertases.

• Food Science and Biotechnology
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• v.16 no.3
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• pp.381-385
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• 2007

The objective of this experiment was to study the influence of feed moisture content on the degree of enzymatic hydrolysis of com starch in a twin screw extruder and the saccharification yield of the dried extrudate. The feed moisture content was set at 25, 30, and 35% and ${\alpha}$-amylase solution was directly injected into the feed section at a barrel temperature of $95^{\circ}C$ and screw speed of 250 rpm. Amyloglucosidase was used for the saccharification of the dried extrudate at a concentration of 0.055%(w/w). Expansion ratio and swelling factor of extrudates decreased with increasing the feed moisture content. Addition of ${\alpha}$-amylase during extrusion process raised reducing sugar content of extrudates which also increased with the feed moisture content. The saccharification yield of dried extrudate was higher for the extrudate with lower feed moisture content.

• Culinary science and hospitality research
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• v.19 no.1
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• pp.151-163
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• 2013

The purpose of this study was to examine the optimization and quality characteristics of balsamic vinegar jelly by the addition of various gelling agents: agar, gelatin, arrowroot starch, potato starch. For this purpose, mechanical tests(moisture content, color value, pH, sugar content, texture) and sensory tests(quantitative descriptive analysis & acceptance test) were conducted, showing the following results. The moisture content of balsamic jelly was the highest in the gelatin addition group, the color intensity of the L value in the potato starch addition group, redness a value in the gelatin addition group, and the b value(yellowness) in the agar addition group. The pH of balsamic jelly was the highest values in the gelatin addition group while its sugar content was the highest values in the arrowroot starch addition group. As a result of measuring balsamic jelly texture, there were significant differences in hardness, chewiness and gumminess by gelling agents. In the quantitative descriptive analysis of sensory test, the gelatin addition group showed the most high level in purple color intensity, glossiness, transparency, and chewiness. As for the acceptance in the sensory test, the gelatin addition group showed the most high level in appearance, taste, texture, and overall acceptance, which also had a significant difference. In case of balsamic flavor, Arr added arrowroot starch showed the highest values, which also had a significant difference. The result of this study showed that the gelatin addition group made a positive acceptance and improvement of sensory and machinery quality characteristics.

• Journal of the Korean Society of Food Culture
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• v.26 no.6
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• pp.734-742
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• 2011

This study was conducted to investigate the physicochemical characteristics of Eungi, which is used as a breakfast or health food. We manufactured lotus root starch and Eungi by a traditional method and discovered that the viscosity of Eungi with 4-5% starch content was similar to fermented milk. When the physicochemical properties and sensory acceptability of a Eungi beverage combined with different amounts (0.5, 1.0, 1.5, and 2.0%) of lotus root starch were investigated, consumer acceptability was highest with Eungi combined with 0.5% starch and 6% sugar. When the physicochemical properties and sensory acceptability of Eungi beverage combined with different extract bases were investigated, the acceptability of taste and texture was highest with purple sweet potato extract and the acceptability of color was highest with omija extracts.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.5
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• pp.878-885
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• 1997

Effect of various ingredients and cooling methods on the quality of modified Jeung-pyun(traditional Korean steamed rice cake) were studied. Three different kinds of wheat flours(strong, medium, and weak) were studied to evaluate the volume and firmness of Jeung-pyun. Weak flour showed the maximum volume and good sensory results. The optimum ratio of ingredients was flour : water ; sugar ; Tak-Ju=100 : 20 : 20 : 50 for steaned Jeung-pyun. When three different cooking methods were compared, the maximum volume showed from convection oven method, but the crust color of Jeung-pyun was like bread. Steaming method showed higher volume than that of product heated by microwave method. The optimum formula ratio for the microwave method was flour ; water ; sugar ; Tak-Ju = 100 : 30 : 20 : 50, which required 10% higher added water content than that of steaming. When wheat flour was used instead of rice flour, the addition of 5% normal corn starch increased volume of both steamed and microwave cooked products. In the case of added modified starches to Jeung-pyn, 5% $\alpha$-waxy corn starch showed the highest volume in steaming method. When rice flour was used, the addition of 5%$\alpha$-waxy corn starch also showed highest volume f both steamed and microwave cooked products. The firmness of steamed wheat flour Jeung-pyun, containing 5%$\alpha$-corn starch was higher firmness than that of control and other added samples. Microwave cooked products showed two or three times higher firmness of steaming products. The use of wrap(uni-wrap) and stabilizer(METHOCEL) decreased the firmness of microwave cooked wheat flour Jeung-pyun to 200~300g compared with that of untreated Jeung-pyun.

• Korean Journal of Food Science and Technology
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• v.21 no.5
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• pp.691-696
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• 1989

It Is a unique dietary culture in Korea in that starch is isolated and utilized from steeped potato. In this experiment the potato was steeped in water at $30^{\circ}C$ for 7 days and the properties of starch were examined. The pH in steep water decreased, while sugar cotent (total and reducing) increased. The lager granules were diminished during steeping. Holes on the starch granules were observed from the second days of steeping The density, amylose content, phosphorus and lipid content were decreased. Relative crystallinity of starch reached the highest value at 4th day of steeping and decreased thereafter. The changes in enthalpy of gelatinization were similar. Starch was resistant to acid or enzymatic hydrolysis and showed lower values for swelling power and amylograph viscosities.