• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.5
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• pp.653-658
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• 2017

To evaluate the effects of amylose content and dissolution media on the molecular structure of maize starch, changes in the hydrodynamic diameter of starch molecules were assessed via dynamic light scattering depending on amylose content and dissolution media. As the amylose content of starch increased, the hydrodynamic diameter of starch molecules proportionally decreased from 204 to 92 nm. To alter ionic strength, hydrogen bonding, or polarity of dissolution media, various contents of NaCl (1, 2, or 3 M), urea (1, 2, or 3 M), or 1-butanol (0.1, 0.5, or 1.0%) were added to media, respectively, resulting in increased hydrodynamic diameter of starch. However, the degree of expansion was dependent on amylose content and the concentration and/or type of additive. The hydrodynamic diameter of starch molecules exhibited significant correlation with amylose content obtained by size exclusion chromatography, regardless of dissolution conditions.

• Journal of Ginseng Research
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• v.9 no.2
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• pp.270-284
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• 1985

In order to investigate the change of physicochemical properties of ginseng root starch during storage and heat treatment, the roots were stored for 15 days at 5 $^{\circ}C$, 15 $^{\circ}C$, 3$0^{\circ}C$ and 45$^{\circ}C$, and heated for 15 hours at 6$0^{\circ}C$, 7$0^{\circ}C$, 8$0^{\circ}C$, 9$0^{\circ}C$, respectively. The starch content was decreased from about 40% to 23-26% and sucrose content was increased from 4% to 12-16% during storage for 15 days at 5-45$^{\circ}C$. Maltose, which was not detected in fresh samples, was increased up to 8.5% during storage or heat treatment. Granular size of the starch was decreased and some of the granules were broken during storage. Amylose content in the starch was decreased from 33% to 20%, and blue value and alkali number of the starch were increased slightly, and solubility and swelling power of the starch were decreased during storage. 3 The higher storage temperature and the longer storage time, the starch was more susceptible to gelatinize, and the viscosity of the starch was lowered with the susceptibility of gelatinization. The susceptibility of degradation of the starch by the amylase was increased and amylolytic activities in ginseng root were, also, increased during storage.

• Korean Journal of Soil Science and Fertilizer
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• v.8 no.1
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• pp.25-29
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• 1975

The weekly change of sugar and starch content in unfilled grain of Jinheung (temperate rice var.) and IR667-Suweon 214 (tropical rice var.) and of filled grain ratio (less than specific gravity 1.06 for Jinheung and 1.03 for IR667), filled grain weight and unfilled grain weight from flowering and the relationship among them were as fallows. 1. Total sugar content in unfilled grain was twice in Jinheung than in IR667 and starch content was higher (about 2.5 to 3.5%) in Jinheung but starch/sugar ratio was greater in IR667. Thus IR667 that was classified as high sugar type in leaf sheath and internode appears to be high starch type in sink (grain). 2. Under the favorable condition the weight of unfilled grain reached to minimum value and followed by maximum filled grain ratio and lastly by maximum weight of filled grains per ear. 3. Sugar and starch content gradually increased and then decreased during ripening and the maximum values reached prior to maximum filled grain ratio (6 weeks). Sugar content reached to maximum much earlier than starch content did and increased again from 8 weeks later. 4. Starch/sugar ratio reached to maximum value earlier than maximum starch content and earlier in IR667 than in Jinheung. 5. Maximum starch content of unfilled grain in Jinheung was 51.1%.

• Food Science and Preservation
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• v.20 no.4
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• pp.539-545
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• 2013

Effects of RS4 type resistant corn starch on the quality characteristics of cookies were investigated by physicochemical, instrumental and sensory evaluation. The resistant starch was made by cross-linking of corn starch as following; corn starch slurry was annealed at pH 2.0 and $50^{\circ}C$ for 2 h followed by the cross-linking reaction. The cross-linking reaction was performed at $50^{\circ}C$ for 12 h in the presence of 1.2%/st.ds NaOH, 10%/st.ds sodium sulfate and 10%/st.ds of sodium trimetaphosphate (STMP)/sodium tripolyphosphate (STPP) mixture. Dietary fiber content of the resistant starch was estimated to be 73.8% by the AOAC method. For quality characteristics, dough pH decreased with the increase of the resistant starch content and spread factor decreased a little at 20% of the resistant starch. The moisture content and L value of cookies increased with the increase of the resistant starch content. However, the hardness and fracturability decreased with the increase of the resistant starch content. In the sensory evaluation, no significant differences were observed between the two cookies with or without the resistant starch. The results of this study suggest that the RS4 type resistant corn starch can be a good ingredient to increase dietary fiber content in cookies without changes of their qualities.

• KSBB Journal
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• v.9 no.4
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• pp.412-417
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• 1994

The biodegradable characteristics of starch-filled polyethylene film by fungi were investigated. Aspergillus niger showed the highest cell growth among five species of fungi used in the experiment. Higher starch content gave the higher growth rate of A. niger; however, the kind of film or cutting direction did not give any effects on the cell growth. The use of vinyl trimethoxysilane for the stronger binding of starch and polyethylene did not inhibit the cell growth. When the starch content was higher than 10%, the elongation of the film decreased significantly after the growth of microorganism in the case of transverse direction samples.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.45 no.6
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• pp.78-87
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• 2013

Even though the notice No. 2010-11 of the Ministry of Food and Drug Safety Administration that has been applied to analyze the content of the water soluble residue eluted from multi-layer paperboard was abolished in 2011, its application for the analysis on evaporation residue is still valid. There are very high possibilities that the noticed existing method gives the misleading result on the evaporation residue due to the water soluble starch eluted from the multi-layer paperboard. The quantitative analysis on water-soluble residue with starch content correction has been carried in the study using UV/Vis spectroscopy and HPLC. The UV/Vis spectroscopy absorbance analysis showed the large amount of the oxidized starch obtained from the aqueous residue eluted out of the multi-layer paperboard after the iodine, ${\alpha}$-amylase reaction, and starch hydrolysis. The residual content decreased by the correction through the enzyme hydrolysis.

• Korean Journal of Food Science and Technology
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• v.20 no.3
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• pp.412-418
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• 1988

Granular shapes and sizes, physicochemical priperties and gelatinization patterns of sweet potato starches from Wonki(the dry type) and Chunmi(the moist type) were investigated. Starch granules of sweet potatoes were round. Granule sizes of Wonki starch were mainly $11{\mu}m$ and those of Chunmi starch were $12{\mu}m\;and\;17{\mu}m$. Wonki starch had lower water binding capacity and swelling power than Chunmi starch. But Wonki starch had higher amylose content, gelatinization temperature, miture content for gelatinization and temperature for gelatinization than Chunmi starch.

• Korean Journal of Food Science and Technology
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• v.30 no.4
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• pp.803-810
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• 1998

The mechanical and thermal properties of solutions of acorn starch were investigated, to determine the effect of sucrose on the retrogradation. The contents of moisture and amylose of purified acorn starch was 9.35, 27% respectively. From the moecular weight distribution, Mw and Mn of acorn starch were 1,220,432 and 137,201 relatively and the polydispersity of acorn starch was 8.8952. The creep compliance of acorn starch with and without sucrose were decreased with increasing sucrose concentration in the short term. The temperatures of DSC curve of 15% acorn starch solution containg sucrose shifted slightly to higher temperatures with increasing sucrose content. The enthalpy change associated with the gelatinization was increased with increasing sucrose content. After 7 days storage, the creep compliance of acorn starch gel with sucrose were shown higher than acorn starch gel. Regelatinization enthalpy of acorn starch/sucrose/water system was decreased with increasing sucrose content and increased with storage time. In addition, the characteristic temperatures such as onset temperature, peak temperature and conclusion temperature was increased by sucrose addition. Retrogradation ratio decreased with increasing sucrose content, thus sucrose inhibit retrogradation in the long term. Sucrose acts as an antistaling reagents and retatards the retrogradation.

• Korean Journal of Food Science and Technology
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• v.30 no.1
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• pp.42-48
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• 1998

Physicochemical properties of waxy maize starch and oxidized waxy maize starch with sodium hypochlorite $(0{\sim}60\;mg\;CL_2/g\;starch,40^{\circ}C,\;pH\;10,\;3.0\;hr)$ were studied. As sodium hypochlorite concentration was increased, the content of crude lipid and crude protein of the oxidized starch were decreased. And crude protein content and whiteness was considered to show negative regression. However, the crude ash content of the oxidized starch increased significantly with oxidation and bore a positive regression to the chlorine content. There was a progressive increase in the carboxyl content with increasing oxidant level. After pasting in hot water and cooling, viscosity of the oxidized starches were drastically lower than that of native starch . As carboxyl contents of the oxidized starch increased, the solubility and swelling power was increased. When waxy maize starch treated with 0, 1.5, 3.0 and 6.0% sodium hypochlorite, temperature of initial gelatinization of oxidized starch was shown to 65, 65, 60 and $50^{\circ}C$, respectively. The oxidized waxy maize starches also form clearer pastes. Water binding capacity of the oxidized starch decreased as the degree of carboxyl group substitution increased. Waxy maize starch has polygonal and some round granules which range from about 3.7 to $20\;{\mu}m$ in diameter. Surface appearance of the waxy maize starch became rough when oxidized with sodium hypochlorite. When homogenate of the oxidized waxy maize starch solution and corn germ oil was stored under room temperature for 24 hours, the emulsion stability was considered to depend on starch concentration and degree of substitution.

• Journal of Ginseng Research
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• v.8 no.2
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• pp.124-134
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• 1984

Ginseng root starch, prepared by conventional method, contained crude lipid of 0.5%, crude protein of 0.4%, crude mineral of 0.17% and phosphorous of 12.5mg% as noncarbohydrate constituents. The amylose content of ginseng root starch picked in Summer (May to August) and Winter (November to March) was 32-35% and 15-20%, respectively, and it was decreased with a growing preiod of ginseng. The blue value, alkali number and ferricyanide number of the starch were 0.14-0.17, 8.50 and 0.781, respectively. The molecular weight of amylose in the starch was estimated to be 1.27-7.95${\times}$105 by means of periodate oxidation, and the degree of branching and glucose unit per segment of amylopectin were 3.50-3.53% and 28.3-28.5, respectively, The starch content of ginseng root was decreased when dried under sunlight and stored at 5$^{\circ}C$ for twenty days. In contrast, sucrose content in the root was increased from 3.8% in fresh state to 11.5% during storage at the above condition. In the other hand, starch was converted to maltose by heating at temperature above 70$^{\circ}C$.