• Korean Journal of Food Science and Technology
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• v.46 no.2
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• pp.135-142
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• 2014

Physicochemical, pasting, and digestion properties of sweet potato starches from 11 Korean cultivars were investigated. Starch granules were variably oval, round, polygonal, spherical, and bell-shaped, and of 10.2-15.3 ${\mu}m$ in mean particle diameter. Amylose contents varied from 12.3 to 17.4%. A similar chain length distribution of amylopectin was found in each of the cultivars. The portion of $B_3$ correlated with the degree of amylose leaching. Thermal properties determined by differential scanning calorimetry showed high values of gelatinization temperatures in Shinyulmi and Jeungmi starches, but a relatively low value in Daeyumi starch. All starches exhibited a Ca-type diffraction pattern. Differing patterns were observed in swelling factors, depending on temperature. The contents of rapidly digestible starch, slowly digestible starch, and resistant starch ranged from 9.6-17.4, 31.4-45.6, and 35.7-62.8%, respectively. In Rapid Visco Analyser profiles, differences were observed in pasting parameters such as pasting temperature, peak viscosity, final viscosity, and breakdown.

• Korean Journal of Food Science and Technology
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• v.35 no.4
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• pp.696-701
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• 2003

Rice seeds of 4 cultivars including Whachung and Nampung, of the non-waxy rice cultivars, and Shinsunchalbyeo and Whachungchabyeo, of the waxy rice cultivars, were germinated at $27^{\circ}C$ for 3 days to compare the changes in some physico-chemical properties of the starch granules and the starch-hydrolysing enzyme activities during germination, respectively. With the starch granules, the amount of long glucose chains from amylose molecules were reduced in the non-waxy rices, while the chain length increased in the waxy rices. In the distribution profile of the glucose chain length from amylose molecules, we could observed that the chain length with DP (degree of polymerization) ranged 33 to 66 increased with the decreasing rate of the chain length with that above 130, regardless of the waxiness of rices. In addition, we observed that in contrast to a increase in chain length with DP ranged 14 to 33, the amount of short chains from A chain fraction decreased. Germination induced slight reduction in the polymerization rate of starch granules, and decrease in both initiation and termination temperatures for the gelatinization. ${\alpha}-Amylase$ activity of rices germinated for 3 days found to he higher than that of malt. Especially, the activity of Shinsunchalbyeo was revealed to be highest, about two fold higher than that of malt. In contrast, ${\beta}-amylase$ of the waxy rice found to be considerably less active than malt, although the waxy showed prevalent activity as compared to the non-waxy rices.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.spc1
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• pp.88-93
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• 2005

The functional vice (Oryza sativa L.) has been highly regarded recently, in the change of rice maykets in the world. Goami2 (GA), one of the functional rice varieties, was developed from high-quality rice, Ilpumbyeo (IP). From the previous study, GA has been proved its beneficial effect on the improvement of metabolic control and body weight reduction especially in obesity, We could certain that GA was very difficult to be gelatinized due to the micro lump shown in the Scanning electron micrographs (SEM) photos. To improve its cooking quality, we investigated the changes of physicochemical properties, which were differentiated by the conditions of milling and blending. As GA was milled every $2\%$ until eliminating $12\%$, the nitrogen content was decreased linearly. But the decreasing rate of nitrogen content of GA during milling process was relatively lower than that of IP. Thus, we assumed that GA has relatively high nitrogen in inner starch of grain. The degree of milling had no effect on the gelatinization of cooked GA, but affected lightness and whiteness linearly, which were ranged in normal values when the rice was milled more than $10\%$ in weight. So we could concluded that the milling process was not proper to improve cooking quality of GA. And we could suggested that GA was needed to soak into water at least one hour before cooking by it water absorption rate at normal temperature$(21^{\circ}C)$ and sensory evaluation. From the texture analysis, cooked GA had higher hardness than other varieties. Therefore, we blended GA with IP, Baekjinju(BJ) and Hwasunchalbyeo(HS), then subjected to sensory evaluation. All evaluation items including the sensory preference were the highest scores for the rice blended with glutinous rice varieties, BJ and HS.

• Korean Journal of Food Science and Technology
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• v.46 no.3
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• pp.341-346
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• 2014

This study was conducted to evaluate the effect of trehalose on the rheological properties of bread flour dough. Farinographic and viscographic properties, pH, total titratable acidity (TTA), and fermentation power were analyzed for flour dough rheology. Flour dough containing trehalose showed greater water absorption capacity and longer development time. However the stability, degree of softening, and farinograph quality number (FQN) were lower for the trehalose-containing flour dough, however, these factors decreased with increasing amounts of trehalose. Trehalose did not affect the beginning of gelatinization temperature and maximum viscosity temperature of flour. The maximum viscosity was the lowest with 6% trehalose, the end of final holding period, breakdown and setback values decreased with increasing amounts of trehalose. Flour dough with 4% trehalose had the lowest pH value for 120 min fermentation at $30^{\circ}C$, and the highest TTA value. Addition of 4% and 6% trehalose showed larger fermentation volume of dough than the control. The results suggested that trehalose positively affected the rheological properties of flour dough such as bread volume, softness, and staling delay.

• Food Science and Preservation
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• v.20 no.5
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• pp.614-620
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• 2013

The quality characteristics of Backsulgi added with red rice flours at different ratios were investigated to apply in the food industry. The moisture, crude protein, crude lipid, ash and amylose contents of the red rice flour samples were 5.3, 9.5, 2.0, 1.1 and 4.7%, respectively. The pasting properties of the non-waxy rice flour mixtures to which red rice flour samples were added were measured by RVA. As the content of red rice flour increased, the values of peak viscosity, final viscosity, breakdown and setback were decreased, while the pasting temperature was not significantly affected. The lightness (L) value of the Backsulgi decreased, but the redness (a) value, moisture content and the degree of gelatinization increased with an increase in the red rice flour samples. The hardness increased, while cohesiveness, springiness and chewiness decreased with the increase in the red rice flour. The overall acceptance of sensory evaluation showed the highest value for 8% red rice (BRWM8). In conclusion, the addition of 8% red rice flours could improve the sensory quality of the Backsulgi as well retrogradations.

• Applied Biological Chemistry
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• v.46 no.1
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• pp.39-45
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• 2003

This study was conducted to investigate the effect of ash contents of bread flour on the rheology of frozen dough In making frozen dough by measuring amylograph, flrinograph and extensograph. The quality of frozen-stored dough under freezing condition ($-20^{\circ}C$, 12 weeks) was evaluated by measuring final proof time, moisture content, baking loss, loaf volume and hardness of bread with storage time. In bread flour with high ash content farinogram showed that water absorption, degree of softening increased but valorimeter value decreased. In bread flour with low ash content amylogram showed that gelatinization temperature and maximum viscosity increased and extensogram showed that the area and resistance of the bread flour increased. As the proof time increased the extensibility decreased. Final proof time of frozen dough was shortened at the bread flour with low ash content with storage time. In bread using the flour with high ash content, moisture content, increased but baking loss rate decreased while the hardness of product increased slowly with time. But in bread using the flour with low ash content, the loaf volume of baking increased but the hardness of product decreased. As the frozen storage time was shortened, the product was more stable and better in quality.

• Korean Journal of Food Science and Technology
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• v.16 no.4
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• pp.429-436
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• 1984

To expand the utility of barley the experiments on the extrusion characteristics of barley flour for snack processing were carried out and the effects of the extrusion conditions on the quality of the extrudates were investigated. The optimum moisture content of barley flour for snack processing was 20%. The moisture content and the density of the extrudates decreased with increasing extrusion temperature and decreasing die size. The die swell ranged from 0.98 to 2.18 according to various extrusion conditions and decreased with increasing temperature above $150^{\circ}C$. The lightness, redness and yellowness increased at higher temperature. The water absorption index and the water solubility index showed their maximum values at $180^{\circ}C$.The gelatinization degree of the extrudates increased with increasing temperature. The fracture fore, Young's modulus and maximum fiber stress decreased, but the deformation to fracture increased, with increasing temperature and decreasing die size. The yield force in puncture test showed lower values at higher temperature. The size and the fraction of the air cells increased with increasing temperature and decreasing die size. The optimum extrusion conditions of barley for snack processing were at the temperature of $180^{\circ}C$, with the die size of 4.5mm when processed at 160 rpm.

• Korean journal of food and cookery science
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• v.25 no.1
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• pp.106-118
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• 2009

This study was to investigated optimum preparation conditions for Gugija Heukimja jook by response surface methodology (RSM). The important materials used for the Gugija Heukimja product were Lycium chinese, Seasamum indicum L., Ziziphus jujuba Mill. and rice. Moisture content, crude protein, crude fat, crude ash and crude fiber content were 15.62, 16.60, 13.62, 4.93 and 11.17% for Lycium chinese, 3.62, 20.94, 43.56, 5.67 and 10.72% for Seasamum indicum L., 24.12, 5.38, 0.73, 2.30 and 1.25% for Ziziphus jujuba Mill., and 12.36, 6.98, 0.46, 0.43 and 0.41% for rice, respectively. Optimal extraction conditions of brix, color, pH and total acidity in the materials for Gugija Heukimja jook were temperature $80^{\circ}C$, water volume 850 mL and extraction time of 63 min. The spreadability of jook with Lycium chinese and Ziziphus jujuba Mill. extracts was the highest when black sesame was 12 g pH was the lowest when black sesame was 9 g. PH showed a significant difference when the added black sesame ratio changed. The 'value L' of chromaticity was lower with an increase of the black sesame ratio, 'value a' was higher with an increase of the black sesame ratio, 'value b' was lower with an increase of the black sesame ratio. Brix was lower when black sesame in jook was added. Total acidity was highest (7.27%) when black sesame was 12 g. The degree of gelatinization tended to be lower with additional black sesame. Higher scores of sensory evaluation were found for the product containing 9 g black sesame with Lycii furctus and Ziziphus jujuba Mill. extracts ompared to the other samples with 3 and 6g. No significant difference in taste occurred for Gugija Heukimja jook prepared with over 9 g black sesame, while a great difference showed in color, pH and total acid. Therefore, the Gugija Heukimja jook prepared under the optimal conditions of 9 g black sesame with Lycium chinese and Ziziphus jujuba Mill. extracts exhibited higher qualities. Gugija Heukimja jook can use the easier for Yacksun jook. It is expected to become functional in the product's development.

• Food Science and Preservation
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• v.18 no.4
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• pp.517-526
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• 2011

The physical properties of dough with different levels (2, 4, 6, and 8%) of bamboo leaf powder were inverstigated. The bamboo leaf powder had a moisture content of 5.15%, a crude protein content of 10.48%, a crude fat content of 5.21%, a crude fiber content of 22.74%, and a crude ash content of 17.63%. The following parameters showed significant differences with the increase in the amount of bamboo leaf powder added. The gelatinization degree measured by a rapid visco-analyzer increased with the increase in the powder amount added. In the values of the farinogram parameter for dough consistency, the elasticity of the dough increased with the increase in the powder amount added. The alveogram values showed a similar tendency as those of the farinogram in terms of elasticity, absorption rate, absorption time and stability. In the rheofermentometer analysis, the volume decreased with the increase in the powder amount added, but no significant difference was found at up to 4% powder amount addition, suggesting that the about 2% and up to 4% powder amount addition is moderate.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.5
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• pp.603-610
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• 1993

Effects of pine tree(Pinus densiflora) endodermis or china grass leaves(Boehmeria nipponivea) on textural or sensory quality of rice cake were investigated. Rice cakes prepared with the addition of pine tree endodermis or china grass leaves were not remarkably decreased in moisture content during storage. Degree of gelatinization was shown the highest value in the samples 17.28% of pine tree endodermis or china grass leaves added. As a result of the sensory evaluation for the rice cakes, consistency, moistness and cohesiveness were gradually improved with the increase of pine tree endodermis or china grass leaves addition amount. The overall quality was most preferable in the rice cakes prepared with 17.28% of pine tree endodermis or china grass leaves. The detrimental changes were occured in textural quality of the all rice cake samples during storage. Textural quality of rice cakes was higher in pine tree endodermis or china grass leaves addition samples than that of control group. In the texturometer test, hardeness and chewiness decreased in pine tree endodermis or china grass leaves addition samples where as gumminess increased these samples compare to control group.