• Food Science and Biotechnology
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• v.17 no.4
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• pp.705-712
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• 2008

Sweet potato starch was modified using Thermus aquaticus $\alpha$-1,4-glucanotransferase ($Ta{\alpha}GT$), and its structural and rheological properties were investigated. $Ta{\alpha}GT$-modified starch had a lower amylose level and molecular weight than raw starch. The chain length distribution showed an increased number of short and long branched chains and the formation of cycloamyloses. Compared with raw starch, $Ta{\alpha}GT$-modified starch displayed a lower gelatinization enthalpy and a wider melting temperature range. The X-ray diffraction of $Ta{\alpha}GT$-modified starch was a weak V-type pattern with distinct sharp peaks at 13 and $20^{\circ}$. Scanning electron micrographs of modified starch exhibited big holes on the surface and the loss of granular structure. The frequency sweep measurement revealed that the gel of $Ta{\alpha}GT$-modified starch was more rigid than raw starch gel. However, the structure of modified starch gel was destroyed by heating at $75^{\circ}C$, and a firm gel was re-formed by subsequent storage at $5^{\circ}C$, indicating thermoreversible property.

• Journal of Nutrition and Health
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• v.15 no.2
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• pp.83-90
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• 1982

This study was attempted to investigate the effects of adding gelatinized waxy rice flour, wheat flour, and Xanthan Gum to rice flour on the preparation and (quality) of dried noodles. 1) Rice flour demonstrated higher maximum viscosity value as determined by Amylograph than wheat flour. Among the composite flour mixture (Rice Flour 85+Gelatinized Waxy Rice Flour 15 + Xanthan Gum 2%) showed the highest viscosity value and (RF 35+ GWRF 15 + Wheat Flour 50) had the lowest. (RF 35 + GWRF 15 +WF 50) demonstrated gelatinization characteristics which is quite similar to that of wheat flour. 2) Forty and 50% replacement of rice flour and gelatinized waxy rice flour (15%) mixture by wheat flour improved significantly noodle making characteristics and cooking quality of noodles. 3) The addition of 2% XG to (RF 45 + GWRF 15 + WF 40) was effective on noodle making properties and on binding properties of cooked noodles. 4) The cooked noodle made of composite flour (RF 45 + GWRF 15 + WF 40 + XG 2%) received the highest total sensory evaluation score among the testing samples, and it was not significantly different from that of wheat flour.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.s01
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• pp.1-17
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• 1988

Rice Quality is considered to the five catagories ; the nutritional value: the characteristics of cooking. eating and processing: grain size, shape and appearance : milling yields: and storage characteristics. Because most rice is processed and consumed in whole-kernel form. the cooking and eating quality is of important and the physical properties of the intact kernel such as size, shape and general appearance are of particular significance in determining marketing quality. Eating Quality which can be directly evaluated by consumer's panel test is so complicate and variable, and thus the objective and simplified method of evaluation is required of using appropriate instruments. Even though many researches have been done to evaluate the eating quality in various aspects such as the texture of cooked rice kernels, amylogram analysis of rice powder, amylose content. gelatinization temperature. moisture absorption of rice kernel, and cooking characteristics, none of them is satisfied for the evaluation of eating quality. The improving eating quality should be also considered to many cultural factors. such as varieties, climatic and soil conditions, cultural method, handling after harvest. milling and storage conditions. In Korea, many researches in grain size. shape and appearance, and eating quality have been done with the varietal improvement mainly by rice breeders, but no effective method of evaluation was established. A few research have been done in the relationship between rice quality and cultural factors. In the future, research in rice quality should emphasize to establish the standard evaluation method in the physicochemical properties of rice kernels for application of varietal selection. and to develop cultural practices for the preserving quality characteristics of the varieties.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.12
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• pp.1762-1768
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• 2016

The objective of this study was to investigate the physicochemical properties of rice flour at different degrees of milling (DOM) and their influence on cooking, color, textural, and sensory properties of rice noodles. Higher DOM flour resulted in higher value of lightness and lower value of yellowness. Transition temperatures of rice flour were not significant, whereas the enthalpy of gelatinization increased with an increase in milling degree. Rice noodles were prepared with rice flours of DOM, and their quality and sensory properties were investigated. Cooking properties of rice noodles were not affected by DOM; however, color values were affected by DOM. In textural properties, values of hardness and chewiness of rice noodles were significantly reduced with an increase in milling degree. The sensory scores for overall acceptability, appearance, and texture were highest in higher DOM noodles (DOM 10% and DOM 12%).

• Korean journal of food and cookery science
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• v.5 no.2
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• pp.1-8
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• 1989

The physicochemical properties and gel forming properties of mungbean and buckwheat crude starches were investigated. The results were as follows; 1. The granule size and shape of mungbean crude starch were $11~32\mu\textrm{m}$ and oval, and those of buckwheat crude starch were $3~10 \mu\textrm{m}$ and polygonal. 2. The amylose conteut of mungbean crude starch and buckwheat crude starch were 78.0% and 26.4% respectively. 3. The blue value of mungbean crude starch and buckwheat crude starch were 1.030 and 0.409, respectively. 4. Periodate oxidation of mungbean crude starch resulted that amylose had the average molecular weight of 95, 648, degree of polymerization of 590 and amylopectin had the degree of branching of 5.4, glucose unit per segment of 18.6, and periodate oxidation of buckwheat crude starch resulted that amylose had the average molecular weight of 133, 690, degree of polymerization of 825 and amylopectin had the degree of branching of 5.2, glucose unit per segment of 19.2 5. Water binding capacity of mungbean crude starch was 185.1% and that of buckwheat was 209.9% 6. The pattern of change in swelling power of mungbean crude starch for increasing temperature started to increase at $60^{\circ}C$ and increased rapidly from $70^{\circ}C$, and that of buckwheat increased slowly from $60^{\circ}C$ to $90^{\circ}C$ without rapid increase. 7 The ranges of gelatinization temp. of mungbean and buckwheat crude starches were 63. 9-$109^{\circ}C$ and 52.5-84.$2^{\circ}C$, respectively. 8. The gelatinization patterns for 6% munbean crude starch and 8% buckwheat crude starch were investigated by Brabender amglograph. Mungbean crude starch showed the initial pasting temperature of 77.6$^{\circ}C$ without peak height, and buckwheat crude starch showed that of $62.5^{\circ}C$ without peak height. In addition, sensory evaluation for sample starch gels (mungbean, buckwheat, cowpea) was done. 1. The difference of sensory characteristics for each starch gel was significant. 2. The sample starch gels were regarded as 'Mook' by pannels. 3. 74.44% of the degree of Mooklike was explained by hardness.

• Food Science and Preservation
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• v.11 no.2
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• pp.182-188
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• 2004

This study was carried out to investigate nutritional composition and physicochemical properties of waxy(WGR) and nonwaxy(NWGR) germinated brown rice. Amylose contents of WGR(moisture content 15.45 %) and NWGR (moisture content 15.02%) were 4.9% and 17.9%. Reducing sugar of those were 4.91% and 2.28%. The free sugar contents of WGR were glucose 0.42%, sucrose 0.15%, maltose 0.27% and that of NWGR were glucose 0.59%, sucrose 0.50%, maltose 0.24%, respectively. Color value of WGR and NWGR were L=60.30, a=2.12, b=23.52 and L=59.51, a=3.15, b=23.04, respectively. Degree of gelatinization of WGR and NWGR were 7.67%, 5.21% and hardness of WGR and NWGR were 7.53 kg$\_$f//$\textrm{cm}^2$, 8.93 kg$\_$f//$\textrm{cm}^2$. Vitamin E contents of those were 271.8 $\mu\textrm{g}$/kg, 310.6 $\mu\textrm{g}$/kg and total dietary fiber contents of those were 4.21%, 3.17%. Total amino acids of brown rice, nonwaxy germinated brown rice and cooked germinated brown rice were 126.8 mg/l00 g, 90.8 mg/l00 g and 106.5 mg/l00 g, respectively. Among amylogram characteristics of WGR and NWGR, initial gelatinization temperature, peak viscosity, breakdown, setback were 42$^{\circ}C$, 498 B.U., 94 B.U., -48 B.D. and 70$^{\circ}C$, 212 B.D., 0 B.D., 123 B.D., respectively. Sensory properties of germinated brown rices were affected by color and flavor. Palatability score of WGR that intensity score of color and flavor were lower than that of NWGR showed high.

• 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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.10
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• pp.1474-1481
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• 2011

This study investigated the physicochemical characteristics of Korean wheat flour substituted for 0%, 15%, 30%, 45%, and 60% durum rimachinata wheat in order to develop a Korean wheat pasta suitable for consumer-preferred soft textures. The particles of Korean wheat that were less than 250 ${\mu}M$ were 87.03% of all particles, while 68.7% of durum rimachinata had particles more than 250 ${\mu}M$ in size. Durum rimachinata had more protein (13.84${\pm}$0.03) and ash (0.70${\pm}$0.02) than Korean wheat. In farinograph characteristics, water absorption, development time, stability, and weakness increased as the amounts of substituted Korean wheat flour increased. Also, the gelatinization characteristics of the amylograph exhibited an increase of gelatinization temperature and decrease in maximum viscosity. However, maximum viscosity was shown to be more than 550 B.U. until 30% of the substitution level of Korean wheat flour to durum rimachinata wheat. Also, it did not affect the texture of the noodle product. We could make pasta with softness and springiness with less than a 15% substitution level of Korean wheat flour due to similar characteristics in cooking properties such as weight, volume, water absorption, turbidity, and cooking loss when compared to the control. L and a values increased, and the b value decreased in color as substitution amounts of Korean wheat flour increased. The hardness and adhesiveness of cooking noodles was shown to be a low value at more than a 30% substitution level of Korean wheat flour, and springiness, gumminess, and chewiness all exhibited high values. In a sensory evaluation, overall acceptability was shown to have the highest score in control. More than 30% of substitution of Korean wheat flour showed high preferences. Therefore, 15% of the substitution level of Korean wheat flour could be adapted in dough and cooking properties for making pasta-substituted Korean wheat. However, a texture analyzer and sensory evaluation of cooked pasta was shown to have a good quality at more than 30% substitution level of Korean wheat flour.

• Korean Journal of Food Science and Technology
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• v.43 no.5
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• pp.588-596
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• 2011

Wild grape extract (WGE) was added into hwajeon at different concentrations (0, 5, 15, 30, 50% of water). The resulting hwajeon were analyzed for their physicochemical and sensory properties. With increasing concentrations of WGE, the pH of dough and hwajeon decreased, and their degrees brix and color intensity increased, presumably due to the presence of tartaric acid, sugar, and anthocyanin in the WGE. The WGE-enriched hwajeon showed higher hardness, gumminess, and chewiness than control hwajeon, which might have been because the sugar and tartaric acid in the WGE partially inhibited starch gelatinization during heat processing. Nevertheless, all the sensory properties and preference were higher in WGE-enriched hwajeon than controls, which could be partially attributed to the fact of that the WGE-enriched hwajeon retained relatively higher moisture. It is suggested that WGE-enriched hwajeon with high preference could be prepared without loss of hwajeon quality.

• Korean Journal of Food Science and Technology
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• v.40 no.4
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• pp.382-388
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• 2008

This study examined the nutrient components and physicochemical properties of three new potato cultivars: Gui Valley, Bora Valley, and Gogu Valley, which were acquired from PotatoValley Ltd., and compared them to the Superior cultivar that is widely distributed in food markets. Amino acid, fatty acid, and mineral compositions, as well as total starch, reducing sugar, dietary fiber, vitamin C, and phenolic acid contents were measured. The gelatinization and pasting properties of the potatoes were evaluated using differential scanning calorimetry (DSC) and a rapid visco analyzer (RVA). The three new potato cultivars showed differences for various characteristics compared to the existing Superior cultivar. The Gui valley cultivar has a high potential for processing into items such as French fries or chips, due to its high starch content and low reducing sugar content. Bora valley showed an incredibly high phenolic acid contents, and Gogu valley contained high levels of dietary fiber, minerals, vitamin C, and essential amino acids. Overall, these cultivars are expected to be highly valuable items for develpment and applications of functional food.