• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.7
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• pp.1035-1040
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• 2005

This study was conducted to investigate the surface spraying effect of materials on the rheological properties of frozen starch with microwave heating. Microwave helps reduce cooking time by high temperature, but swiftly snatches moisture from foods such as frozen starches (buns and noodles etc) and makes surface of foods harder. Four types of maltodextrin materials have been prepared for different concentration solutions and sprayed on surface doughs of sheet type. Sprayed dough samples were Quickly frozen at $-70^{\circ}C$ and wrapped with polypropylene film. All the treated samples were kept at 0, -20 and $-50^{\circ}C$, and then taken out periodically for measurement of the quality during storage. The quality attributes evaluated after heating with microwave energy include sensory quality retrogradation, texture, surface color and microstructure. The quality of frozen starches deteriorated with long term storage even at low temperatures of -20 and $-50^{\circ}C$, and the spray materials were found to improve the textural and physical properties of frozen starches in the microwave heating. Particularly, maltodextrin with D.E value of $9\~12$ had the most desirable effects of quality improvement.

• Food Science and Preservation
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• v.20 no.1
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• pp.97-103
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• 2013

The effects of gamma irradiation at medium dose levels on commercial starches (corn starch/CS, sweet potato starch/SS, and potato starch/PS) were investigated in terms of its color and lipid oxidation. The CS, SS, and PS samples were irradiated at 0, 1.5, 3, 4.5 and 6 kGy by a Co-60 gamma irradiator and used for measuring Hunter's colors and TBA value. Irradiation doses applied did not cause apparent changes in Hunter color parameters between the control and irradiated groups. But, the decrease in lightness (L value) for CS and the increase in both redness (a value) for SS and yellowness (b value) for PS were observed, respectively, thereby resulting in slight increase in overall color difference (${\Delta}E$) upon irradiation. Browning intensity observed with the naked eye for gelatinized starches by irradiation doses was also gradually increased along with irradiation dose, which was more remarkable in SS. The thiobarbituric acid (TBA) values of samples showed a dose-dependant increase with ${\geq}0.9964$ of $R^2$ (p<0.05).

• Korean Journal of Food Science and Technology
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• v.35 no.2
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• pp.173-181
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• 2003

Physicochemical changes in corn starch caused by irradiation were investigated, and irradiated samples were identified. Viscosity, TBA value, Hunter color, and total viable count were measured after irradiation of corn starch. Corn starches from Korea and China were irradiated at 0, 2.5, 5, 7.5, 10, and 15 kGy using a $Co^{60}$ irradiator and stored for 9 months at $0^{\circ}C$ and $20^{\circ}C$. Viscosity and specific parameter values decreased in all samples with increasing irradiation dosage at 50 rpm, showing a dose-dependent relationship $(above\;R^2=0.80)$ between non-irradiated and irradiated samples during storage. These results suggest that detection of irradiated corn starches is possible using viscometric method during storage. Total viable count, TBA value, and Hunter color were determined as supplemental indices for measuring viscosities of samples. Total viable count and TBA values showed dose-dependent relationship $(2.5{\sim}15 kGy)$. Differences in viscosity and total viable count, and TBA values among non-irradiated samples showed little changes with the lapse of post-irradiation time, but were still distinguishable for more than 6 months at $0^{\circ}C$ and $20^{\circ}C$ for corn starches from korea and China.

• Applied Biological Chemistry
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• v.41 no.7
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• pp.516-521
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• 1998

Solubility patterns and gelatinization properties of two waxy rice starches, Sinsunchalbyeo and Hwasunchalbyeo, were investigated. Shapes of all starch granules were round and polygonal, and their X-ray diffraction patterns were all A type. Amylose content and water binding capacity of Sinsunchalbyeo were similar to those of Hwasunchalbyeo. The swelling powers and solubilities of two starches were increased with increasing temperature in range of $65{\sim}95^{\circ}C$, and those of Hwasunchalbyeo was higher. Iodine affinities of soluble fractions in Sinsunchalbyeo starch were higher than those in Hwasunchalbyeo at the same temperature and both were increased with increasing temperature. λmax of soluble fraction of Sinsunchalbyeo starch was highest at $75^{\circ}C$ of heating temperature. The transmittance of starch suspensions were increased rapidly at $60{\sim}65^{\circ}C$. By Rapid Visco Analyzer, initial gelatinization temperature of Sinsunchalbyeo was $67.2^{\circ}C$, and that of Hwasunchalbyeo was $68.2^{\circ}C$. In DSC analysis, onset temperature for gelatinization of Sinsunchalbyeo and Hwasunchalbyeo were $61.3^{\circ}C\;and\;62.9^{\circ}C$, respectively.

• Korean Journal of Food Science and Technology
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• v.30 no.4
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• pp.787-793
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• 1998

Physicochemical properties of starch of three cultivars of Korean kidney Bean Starches, Pink (PKB), Red (RKB) and White (WKB) were studied. Starch granule was oval/round and smooth in all samples. The amylograms showed a continuous increase of viscosity without peak during heating. The water-binding capacities of starches of PKB, RKB and WKB were 102.1%, 94.7% and 106.9%, respectively. The swelling powers were rapidly incresed in all samples. The amylose content, blue value and relative viscosity of kidney bean starches were $31.1{\sim}32.8%,{\;}0.64{\sim}0.66$ and $2.27{\sim}2.61{\;}mlg^{-1}$, respectively. The transmittance of starch suspension was linearly increased as the temperature raised from $65^{\circ}C{\;}to{\;}85^{\circ}C$. The gelatinization temperature ranges determined by differential scanning calorimetry (DSC) were $71.1{\sim}86.9^{\circ}C for PKB, $71.1{\sim}86.0^{\circ}C$ for RKB and $60.8{\sim}77.9^{\circ}C$ for WKB.

• Food Engineering Progress
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• v.15 no.4
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• pp.332-337
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• 2011

Physicochemical properties of hydroxypropylated and cross-linked (HPCL) rice starch were investigated. Dual modification of rice starch was carried out by hydroxypropylation using propylene oxide (2, 6, and 12%) and then crosslinking using phosphorus oxychloride (0.005% and 0.02%). Swelling power of dual-modified rice starch increased at lower temperature (60$^{\circ}C$) than that of native rice starch (70$^{\circ}C$). HPCL rice starch showed slightly lower solubility (1.6-6.1%) than native rice starch (2.2-13.8%). Solubility and swelling power tended to gradually increase with increasing phosphorus oxychloride contents. RVA pasting temperature (66.2-70.8$^{\circ}C$) and peak viscosity (160.6- 171.1 RVU) of HPCL rice starch were lower than that of those of native starch (71.3$^{\circ}C$, 190.4 RVU) and decreased with increasing propylene oxide concentration. DSC thermal transitions of HPCL rice starches shifted to lower temperature and show less amylopectin melting enthalpy (11.8-9.8 J/g) than that of native rice starch (11.9 J/g). Overall, physicohemical properties of HPCL rice starches were highly dependent on hydroxypropylation rather than crosslinking.

• 한국약용작물학회:학술대회논문집
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• 2008.11a
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• pp.487-488
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• 2008

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2011.04a
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• pp.63-71
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• 2011

• Proceedings of the Korean Society of Crop Science Conference
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• 2006.04a
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• pp.356-357
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• 2006

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2009.04a
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• pp.263-263
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• 2009