• Applied Biological Chemistry
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• v.24 no.1
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• pp.59-66
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• 1981

Trichoxanthes Kirilowii with high starch-content was investigated to utilize as a food source. The weight and starch content of Trichoxanthes Kirilowii roots increased rapid1y in proporion to the growth period. The seasonal variations of the starch content were $36.5{\sim}48.0%$ (dry basis) from June to December. The chemical properties of natural growth soils of Trichoxanthes Kirilowii contained more organic matter and total nitrogen content than citrus orchard soils, but less mineral; P,K,Ca and Mg. To prepare starch with the plant root, the centrifugal method(3,000 rpm, 20 min) obtained the highest yield. The industrial-scale method, was similar to the processing of sweetpotato starch (tank precipitation method), and was good in quality. The starch granules were mainly spherical with diameters ranging from $5{\sim}16{\mu}$. The density of the starch was 1.535 and amylose content was about 26.7%. The X-ray diffraction pattern showed that the granules were of the B-type. The blue value of starch, amylose and amylopectin was 0.46, 0.80 and 0.18, respectively. The starch contained 0.05% ash, 0.35% crude protein and 34 mg% phosphorus. and had an inital pasting temperature of $63.5^{\circ}C$. The color intensity of the starch which iodine gave rise to absorption maxima at 670nm. The starch paste showed high stability during cold storage at $5^{\circ}C$.

• Korean Journal of Food Science and Technology
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• v.52 no.1
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• pp.31-39
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• 2020

The effects of heat-moisture treatment (HMT) on the functional properties of high amylose rice starches (HARSes) purified from Korean rice varieties (A-type Goami and Singil and B-type Dodamssal and Goami2) were investigated. HMT was accomplished with moisture contents of 18 and 27% and heated at 100℃ for 16 h. While the amylose content, swelling power and solubility decreased after HMT, the water binding capacity and resistant starch (RS) content increased with increasing moisture content after HMT. The X-ray diffraction patterns of all HARSes did not change after HMT, but a decrease in the intensity of peak at 2θ=5° was observed in B-type HMT HARSes. While the starch granules aggregated after HMT, their shape and size remained unchanged. B-type HARSes exhibited higher gelatinization temperatures and lower pasting viscosities than A-type HARSes following HMT. The results, thus, suggest that while the crystalline intensity of B-type Dodamssal and Goami2 rice starches did not change after HMT, the RS content, water binding capacity, and pasting temperatures of all HARSes increased with increasing moisture content after HMT.

• Korean Journal of Food Science and Technology
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• v.25 no.4
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• pp.400-403
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• 1993

Gelatinization degrees of torn and waxy corn starches in the low-moisture environment were determined by DSC thermogram and enzymatic analysis, the results were compared each other As the moisture content increased from 20% to 70%, the enthalpy of endothermic peak of starch increased linearly in DSC thermograms. When the moisture content exceeded above 70%, the DSC enthalpy of starch remained constant in DSC thermogram. The enthalpies for gelatinization of corn and waxy corn starches were 3.23 cal/g and 4.2 cal/g, respectively. When gelatinization degrees of starches were measured by enzymatic analysis, the gelatinization degree increased linearly as the moisture content increased from 20% to 80%. A linear correlation between DSC and enzymatic analysis was obtained only when the moisture content was under 70%.

• Korean Journal of Food Science and Technology
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• v.23 no.5
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• pp.633-641
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• 1991

Mook, a traditional gel food in Korea, has been made from mainly acorn, buckwheat, and mungbean starches (Mook Starches). Corn, rice, wheat starches (Non-Mook Starches) are not used due to their weak gelation power. In order to know the effects of properties of starch on gelation, some physicochemical properties, molecular structure, and starch lipid of these six starches were investigated and compared with gel hardness. Both amylose content and gel hardness of starches were in order of mungbean, acorn, buckwheat, wheat, corn, and rice and these two parameters showed a very good correlation (r=0.95). The amyloses of Mook Starches had larger molecular size (${\overline}D.P._{n}=1,080{\sim}1,580\;vs\;670{\sim}1,120$ for Mook Starches and Non-Mook Starches, respectively), more average number of chain ($2.9{\sim}5.4\;vs\;1.7{\sim}2.5$), and shorter average chain length ($290{\sim}390\;vs\;390{\sim}450$) than those of Non-Mook Starches. Also, Mook Starches had longer average chain length ($22.2{\sim}22.6\;vs\;18.9{\sim}21.3$) of amylopectin and less starch lipid content ($0.12{\sim}0.49\;vs\;0.68{\sim}1.26%$) than Non-Mook Starches. These properties had good correlations with gel hardness (r=0.76-0.84). Consequently, the gelation power of Mook Starches was thought to be derived from their high amylose content and other properties of starches.

• Journal of the Korean Society of Tobacco Science
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• v.9 no.2
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• pp.59-68
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• 1987

This study was conducted to investigate the change of starch, total sugar, nicotine, and total nitrogen contents in green leaves at various stages of maturity(50-106 days after transplanting), and to relate between chemical constituents for flue-cured tobacco (Cv NC82 and BY 4). For the two cultivars and all stalk positions, starch contents increased with maturation, but decreased with senescence. Nicotine contents increased, while total nitrogen contents decreased with delay of harvest. Total sugar contents had a tendency of decrease. For the two cultivars , starch correlated negatively with total nitrogen, and positively with nicotine. Total nitrogen correlated negatively with nicotine. A delay of 5 to 7 days than conventional harvesting time would reach to the better ratio of the reducing sugar to nicotine ratio.

• Korean journal of food and cookery science
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• v.3 no.2
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• pp.59-67
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• 1987

In order to make use of Job's tears widely, Job's tears starch was analyzed and determinded the contents of amylose, amylographical and other physicochemical properties. And also the yeast breads and rice cakes were made from flour and rice flours with various mixing ratios of Job's tears flour and then they were tested for suitability to preparation of bread and rice cake. 1. The starch contents of Job's tears showed 12~20%. Which was about one third of rice or waxyrice starch. But amounts of crude proteins, fats, and total ashes in Job's tears were higher than rice or waxyrice. Job' tears starch was composed of amylopectins only, and was similar to that of waxyrice starch. 2. Depends upon the Amylogram of each starch, initial gelatinization temperature of Job's tears starch was the highest among three starches of rice, waxyrice, and Job's tears. Maximum viscosity of Job's tears starch was 860BU, then it was about two times of rice starch viscosity. 3. By the sensory evaluation results, the taste of bread prepared with mixing of 10% Job's tears flour was better than flour bread and the volume and grains of the bread made from mixing of 10%, 20% Job's tears flour were similar to that of flour bread, but the taste, volume and grains of bread made from 30% mixed flour were undesirable. The rice cake Prepared from mixed flour with 25% Job's tears flour has shown to be desirable.

• Korean Journal of Food Science and Technology
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• v.20 no.4
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• pp.526-535
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• 1988

To estimate the effect of preventing the Maillard reaction between casein and glucose coated by freeze drying with corn starch slurry or mixture slurry of corn starch and sucrose, the reactants were treated into five groups of nonbrowning material(control), uncoated browning material, browning material coated casein alone with starch slurry, browning material coated both of reactants with starch slurry and browning material coated both of reactants with mixtrue slurry. All samples had a moisture content of about 15%. Browning reaction was carried out by storage for 30 days at $37^{\circ}C$, 67% RH. In vitro available lysine contents were decreased by the browning regardless of coating the reactants and were higher about 20.5% in the browning materials coated with mixture slurry than in the uncoated browning materials. Fructosyl-lysine contents were increased about tenfold by the browning regardless of coating and were decreased about 15.8% in the browning materials coated with mixture slurry as compare with the uncoated browning materials. The materials showing the greatest resistance to the browning reaction in the coated materials were those in which both of reactants were coated with the mixture slurry of corn starch and sucrose.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.6
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• pp.646-652
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• 1991

Factors affecting gelatinization temperature of rice starches from different varieties were investigated. Birefringence end-point temperature(BEPT), amylose content, granule size distribution and degree of crystallinity of rice starches showed the significant varietal differences at ${\alpha}\;=0.01$. Susceptibility of the granule to gelatininzation was dependent mainly on the degree of crystallinity, as indicated by the significant positive correlation between BEPT and the relative crystallinity(r=0.67, p<0.01). However, granule size distribution did not affect the GT(gelatinization temperature) range, nor did amylose electron microscopy (SEM). SEM also confirmed that there is no relationship between the size and the shape and the amylose content of the rice starch.

• Elastomers and Composites
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• v.44 no.4
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• pp.429-435
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• 2009

The pressure sensitive adhesives (PSA) were synthesized by soap-free emulsion polymerization of acrylic monomers such as butyl acrylate, 2-ethyl hexyl acrylate, and acrylic acid in the presence of starch as a protective colloid and copolymer. The peel strength and holding power of PSA were increased with starch contents due to the enhancement of gel content, But the initial tackiness of PSA was decreased with starch contents. The contact angle analysis of PSA indicated that the wettability was increased with starch contents owing to the increase of polarity by hydroxy group in starch. In the pH measurement of emulsion with time for biodegradability, the starch in the PSA accelerated the lowering of pH due to the formation of organic acids followed by decomposition of starch.

• Korean Journal of Food Science and Technology
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• v.17 no.6
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• pp.482-489
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• 1985

The model foods similar to Korean typical foods were propared by combining moisture, protein and starch, and their thermal conductivities were investigated. Thermal conductivity of the model foods had a close relationship with food components such as moisture, protein and starch content. The interaction between the thermal conductivity and food components was not found. Thermal conductivity was proportionally increased as the moisture content increased, and thermal conductivity of starch food was lower than that of protein foods under the same level of moisture content of the model foods. The regression equation between thermal condutivity of the model foods. The regression equation between thermal conductivity of the model foods and moisture, protein and starch content at $20^{\circ}C$ was as follows; k = 0.00421M + 0.03152P + 0.05181. Correlation coefficient between calculated by above equation and measured values showed highly significant ($r=0.8418^{\ast}{\ast}$).