• Korean Journal of Human Ecology
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• v.5 no.2
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• pp.33-43
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• 2002

This study was investigated textural properties of Injulmi affected by milling methods, varieties and added water volume. Sinsunchalbyeo and Hwasunchalbyeo flours were made using Rin-dry milling(PDM) and roll-wet milling(RWM) methods. The proximate composition of waxy rice starches and waxy rice flours were similar. Water binding capacity, soluble carbohydrate and damaged starch of waxy rice flour by RWM: were higher than those of waxy rice flours by PDM. By increasing added water volume, hardness and adhesiveness of Injulmi were decreased. By increasing storage time, hardness of Injulmi was increased, but adhesiveness was decreased. The hardness of Injulmi made from waxy rice flours by PDM was higher than by RDW.

• Korean Journal of Food Science and Technology
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• v.39 no.5
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• pp.534-540
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• 2007

In this study, waxy rice starch was chemically modified using phosphorous oxychloride ($POCl_3$, 0.002-0.008%). Then the physicochemical properties of resulting cross-linked waxy rice starches were investigated in order to reduce the steeping time of Yukwa (a Korean oil-puffed rice snack) processing. The swelling powers of the cross-linked waxy rice starch samples were higher than the native waxy rice starch at temperatures above $60^{\circ}C$, and their increases were proportional to the $POCl_3$, concentration. The solubility of the cross-linked waxy rice starch was lower (1.6-3.4%) than the native waxy rice starch (2.7-6.1%). However, the moisture sorption isotherm of the cross-linked waxy rice starch was not significantly different from the native waxy rice starch. The rapid visco analyze. (RVA) pasting temperatures $(65.4-67^{\circ}C)$ of the cross-linked waxy rice starch were lower than those of the native starch $(67^{\circ}C)$. The RVA peak viscosities (287-337 RVU) of the cross-linked waxy rice starch were higher than that of native starch (179 rapid visco units (RVU)), and increased with increasing $POCl_3$ concentration. For the differential scornning calorimeter thermal characteristics, although Tc shifted toward higher temperatures with cross-linking, the To, Tp, and amylopectiin melting enthalpy of the cross-linked waxy rice starch showed no differences compared to the native waxy rice starch. The X-ray diffraction patterns of both the native and cross-linked waxy rice starches showed typical A-type crystal patterns, suggesting that cross-linking mainly occurs in the amorphous regions of starch granules. Therefore, the cross-linking reaction did not change the crystalline region, but altered the amorphous region of the waxy rice starch molecules, resulting in changes of solubility and RVA pasting properties in the cross-linked waxy rice starch. In summary, since cross-linked waxy rice starch has a high puffing efficiency and no browning reaction, it may be applicable for Yukwa processing without a long steeping process.

• Korean Journal of Food Science and Technology
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• v.27 no.5
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• pp.776-782
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• 1995

The effects of alum$(Al{\cdot}K(SO_4)_2{\cdot}12H_{2}O)$ on the rheological properties of $3{\sim}9%(w/v)$ gelatinized solutions of nonwaxy and waxy rice starches were investigated to evaluate the possibility of utilizing a starch modifying agent. Gelatinized non-waxy and waxy rice starch solutions showed a pseudoplastic flow behavior with yield stress. Pseudoplasticity of two rice starch solutions increased by the addition of alum$(0.05{\sim}1.0%,\;w/w)$. Alum increased the yield stresses and consistency indexes of two rice starches and these values decreased with increasing starch concentration. Also, alum(0.5%, w/w) increased the flow activation energy of gelatinized waxy rice starch solution and activation energy decreased with increasing waxy rice starch concentration in the range of $3{\sim}7%(w/v)$, but for the nonwaxy rice starch, activation energy decreased at starch concentration of 7%(w/v). From the above results, it was found that alum had the possibility of utilizing a modifying agent for the rheological property of gelatinized starch solution.

• Applied Biological Chemistry
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• v.28 no.3
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• pp.137-141
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• 1985

Some properties of six kinds of waxy starches isolated from Olchal and Hankang(both of waxy rice), Chalborie (waxy barley), Yullmoo (waxy Job' tears), Chajoe (waxy foxtail millet), Chalsusu (waxy great millet) and Chalocsusu(waxy corn) were investigated. The average diameters of their starch granules were $4.2{\sim}19.0$ microns. X-ray diffraction study showed that these starches had A pattern. Blue values of iodine complexes of these waxy starches were $0.02{\sim}0.08$. The number of glucose units per segment of amylopectin molecule were $21{\sim}23$. Their raising powers were $180{\sim}280$.

• Food Science and Biotechnology
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• v.16 no.6
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• pp.943-947
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• 2007

The acid modification of waxy rice starch was conducted to improve the yugwa production process. The intrinsic viscosity, paste viscosity, and differential scanning calorimetry characteristics of acid modified starch were measured, and bandaegi and yugwa prepared from acid modified starch were evaluated. The intrinsic viscosities of acid thinned starches were 1.48, 1.27, 1.15, and 0.91 mL/g after reaction times of 1, 2, 3, and 4 hr, respectively. The gelatinization enthalpy was reduced from 16.3 J/g in native starch to 15.8, 15.3, 14.7, and 14.5 J/g in acid thinned starches as the time of acid thinning increased. The peak viscosity and final viscosity decreased with increasing the time of acid thinning, but the pasting temperature was slightly increased in acid thinned starches. The hardness of bandaegi from acid thinned starches under high pressure greatly decreased relative to the control, typical yugwa. Yugwa from acid thinned starch under high pressure maintained a homogeneous structure containing tiny and uniform cells similar to that of native waxy rice starch used for typical yugwa. Acid thinning under high pressure appears to be a good alternative to the existing steeping process for better yugwa quality.

• Korean Journal of Food Science and Technology
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• v.26 no.4
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• pp.428-435
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• 1994

Properties of modified rice starches prepared in drum drying and extrusion were evaluated to use for effective utilization. Blue value was the lowest (p<0.05) for waxy rice starch and L value was decreased after modification of starches. Water solubility index was the highest for modified starches prepared in extrusion, while water absorption index was the highest for modified starches prepared in drum drying. Cold-Water-Solubility was the highest (p<0.05) for modified rice starch prepared in drum drying (RD). Consistency index of RD was drastically increased as shear rate increased and yield stress was the highest for RD. Results of Gel Permeation Chromatography showed that starch components were broken down into lower molecular weight materials and amylose are degraded by modification. Changes in the X-ray diffrectometry pattern indicated the transformation of granule into an amorphous state during modification and illustrated V-type.

• Applied Biological Chemistry
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• v.33 no.3
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• pp.223-230
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• 1990

Gelatinization properties of heat-moisture treated Olchal(japonica) and Hankangchalbyeo(j x indica) waxy rice starches were compared. The blue value, light transmittance of starch suspension and viscosity in sodium hydroxide solution were similar between two starches. Olchal starch showed lower water binding capacity, swelling power md peak viscosity by amylograph than Hankangchalbyeo starch. Upon heat-moisture treatments all above parameters were decreased. The critical sodium hydroxide concentration for gelatinization was increased by treatments. The initial pasting temperature of Olchal starch was higher than that of Hankarlgchalbyeo. All amylograph reference points increased by the treatments, except the maximum viscosity or 2l% moisture-treated Olchal starch. Starches treated at 18% moisture level showd the highest value of consistency index. The activation energy of consistency index for gelatinized Olchal starch was lower than that for Hankangchalbyeo starch. The heat-moisture treatments had no effect on activation energy.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.2
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• pp.219-222
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• 2005

Some structural characteristics of hot-water soluble and insoluble starches (waxy black rice starch) were investigated. The hot-water soluble material content of waxy black rice starch was higher (16.6%) than that (13.4%) of Shinsunchalbyeo starch heated at 98$^{\circ}C$ for 8 min. The Amax and absorbance at 625 nm for hot-water soluble and insoluble material of waxy black rice starch were lower than those of Shinsunchalbyeo. Elution patterns of hot water soluble and insoluble materials by gel permeation chromatography (Sepharose CL-2B) were similar in both samples.

• Applied Biological Chemistry
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• v.34 no.4
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• pp.360-365
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• 1991

Rheological properties of Shinsunchalbyeo(Japonica) and $Hangangchalbyeo(J{\times}Indica)$ waxy-rice starches gelatinized with thermal or alkali solutions were investigated with rotational viscometer(Brabender Viscotron). The two starches showed Bingham pseudoplastics behavior in $4{\sim}8%$ thermal or alkali gelatinized starch solutions. The shear stress of Hangangchalbyeo starch solution gelatinized with thermal or alkali showed higher values than that of Shinsunchalbyeo starch and the difference of the two varieties gelatinized with alkali showed higher values than that gelatinized with thermal. Consistency index and yield stress values of Hangangchalbyeo starch showed higher than that of Shinsunchalbyeo starch in the two gelatinized methods and the difference of the two varieties gelatinized with alkali showed higher values. And it was higher that the deffendence of consistency index on starch concentration and initial starch concentration of yield stress in the alkali gelatinized samples than those of in the thermal gelatinized ones.

• Applied Biological Chemistry
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• v.28 no.4
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• pp.219-225
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• 1985

The viscometric properties of six kinds of waxy starches of Olchal and Hankang(waxy rice), Chalborie (waxy barley), Yullmoo (waxy Job's tears), Chajoe (waxy foxtail millet), Chalsusu (waxy great millet) and Chalocsusu (waxy corn) were investigated. The increase in optical transmittance of 0.1% starch suspensions occurred at $55^{\circ}C$ for Hankang, $60^{\circ}C$ for Olchal, Chalborie, Chajoe and Yullmoo and $65^{\circ}C$ for Chalsusu and Chalocsusu, and further inrreased $70^{\circ}C$ for Hankang and Olchal, $75^{\circ}C$ for Chajoe, Chalsusu, Chalocsusu and Yullmoo and above $85^{\circ}C$ for chalborie. Amylogram on 5%, starch suspensions showed that gelatinization temperature and maximum peak height were 850 B.U. at $62^{\circ}C$ for Hankang, $65^{\circ}C$ and 980 B.U. for Olchae, $64^{\circ}C$ and 1,080 B.U. for Chalborie, and 1,410 B.U. at $69^{\circ}C$ for Yullmoo, and 1,280 B.U. at $71^{\circ}C$ for Chajoe, and 1,260 B.U. at $71^{\circ}C$for Chalsusu and 1,420 B.U. at $70^{\circ}C$ for Chalocsusu. Swelling power of starches was $38{\sim}55$, and Hankang, Olchal, Chajoe, Chalocsusu and Yullmoo starches had higher swelling power than Chalsusu and Chalborie starches. Intrinsic viscosity of them was $1.43{\sim}1.75$ and hardness of them highly relevant to the gelatinization properties.