• Korean journal of food and cookery science
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• v.3 no.1
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• pp.14-19
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• 1987

The physicochemical properties of acorn starch were investigated by comparing acorn crude starch and refined starch, Proximate composition analysis revealed that the contents of crude protein, fat and ash were higher in acorn crude starch than in refined starch. Water binding capacity and swelling power of crude starch were a little higher than refined starch. Gelatinization temperature determined by optical transmittance and by Amylograph were $68^{\circ}C$ and $73^{\circ}C$, respectively. The viscosity of crude starch had the amylose content of 28.8%, and the molecular weight of amylose was 20, 425 and glucose unit per segment of amylopectin was 21.

• Korean journal of food and cookery science
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• v.5 no.1
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• pp.53-62
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• 1989

Granular shapes and size, physicochemical properties and gelatinization properties of potato starches from Irish cobber (the dry type), Dejima (the moist type), Shepody and Superior were investigated. The starch granule was round or oval and the size of Irish cobbler and Shepody starch were $11~30\mu\textrm{m}$ and those of Superior and Dejima were$ 21~40\mu\textrm{m}$. Blue value, amylose content, relative crystallinity and density of Irish cobbler were the highest, but that of Dejima were the lowest. Water binding capacity, swelling power, transmittance. peak viscosity and breakdown of amylogram of Superior starch were the highest, but that of Irish cobbler starch were the lowest. Gelatinization temperature of DSC of Irish cobbler starch was the highest, but that of Superior starch was the lowest.

• Korean journal of food and cookery science
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• v.5 no.2
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• pp.43-50
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• 1989

Physicochemical properties on defatted potato starches, Irish Cobbler and Dejima, were investigated. The average diameter of the Irish Cobbler and Dejima starch were $22.5-29.8\mu\textrm{m}$, and both the starches had birefringence. Irish Cobbler starch was lower than that of Dejima starch in water binding capacity, swelling power and solubility. Relative crystallinity of both the starches was decreased after defatted. The blue value of Irich Cobbvler and Dejima starch was measured 0.37 and 0.35 respectively Transmittnace of 0.1% starch suspensions was higher on defatted starch than on untreated starch. Differential Scanning Calorimetry of untreated potato starch showeed higher gelatinization temperature in Irish Cobbler starch than in Dejiam starch. The gelatinization enthalpy of untreated starch was higher in Irisch Cobbler starch than in Dejima starch, but, after defatted, it was decreased.

• 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.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 and cookery science
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• v.14 no.3
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• pp.261-265
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• 1998

The activity and characteristics of ${\alpha}$-amylase in soy milk as well as in Jeungpyun batters were determined to investigate the enzyme system related to Jeungpyun preparation. ${\alpha}$-Amylase activity was detected in soy milk as well as in Jeungpyun batters. Soy milk had ${\alpha}$-amylase activity of 0.79 units/mg protein for gelatinized starch and 0.036 units/mg protein for raw starch. ${\alpha}$-Amylase in soy milk showed maximum activities at pH 5.92∼6.87 and at 60$^{\circ}C$ for both gelatinized starch and raw starch. ${\alpha}$-Amylase activities of Jeungpyun batters containing soy milk were 25.59 units/mg protein for gelatinized starch and 1.37 units/mg protein for raw starch. Jeungpyun batters without soy milk demonstrated ${\alpha}$-amylase activities of 3.37 units/mg protein for gelatinized starch and 0.49 units/mg protein for raw starch. ${\alpha}$-Amylase of Jeungpyun batters showed an optimal activity at pH 5.25 and at 60$^{\circ}C$ for both gelatinized and raw starch. The results demonstrated that Jeungpyun batters with soy milk showed significantly higher ${\alpha}$-amylase activity than the ones without soy milk.

• 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.

• Food Science and Preservation
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• v.13 no.3
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• pp.382-388
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• 2006

Physicochemical properties of chufa starch were investigated The result are summarized as follow: Moisture content crude protein and crude fat were 10.10%, 0.31% and 0.41,% respectively. Amylose content of chufa starch was 41.6% and blue value was 0.49. Lightness and whiteness of chufa starch was 96.36 and 92.23 of Hunter's color value. In iodine reaction, maximum absorbance wavelength (${\lambda}max$) was 628 nm. Water binding capacity was 83% and swelling power and solubility of chufa starch were increased slowly to $60^{\circ}C$, but increased rapidly after $60^{\circ}C$. Scanning election microscope(SEM) showed that granule type of chufa starch was round or elliptic type, and average granule size was $10{\mu}m$. The results by differential scanning calorimetry(DSC) revealed that gelatinization patterns were similar to those of potato or rice starch. In rapid viscoanalyzer(RVA) examination, pasting temperature was $79.95^{\circ}C$ and peak viscosity of chufa starch was 385.08.

• 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 and cookery science
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• v.18 no.2
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• pp.157-163
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• 2002

The gelatinization and retrogradation properties of rice starch added with dietary fibers from sikhe were investigated. The pasting temperature and setback of starch measured by using a rapid visco analyzer were increased by the addition of the fiber, whereas the peak viscosity, trough viscosity, end viscosity, breakdown and consistency were lowered. The onset temperature of starch measured by a DSC was increased, but the enthalpy of gelatinization of the starch was decreased as the addition of fiber increased. The melting peak temperature of the retrograded starch gels was 41∼46$\^{C}$ as measured by a DSC. The melting enthalpy of the control retrograded starch gel was increased while storing for 1, 3 and 7 days at 4$\^{C}$, but that of containing sikhe fiber showed no differences.