• Korean Journal of Food Science and Technology
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• v.25 no.1
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• pp.22-27
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• 1993

Crude ${\beta}-glucan$ extracted from Barley was purified by stepwide enzyme treatment with thermostable ${\alpha}-amylase$, amyloglucosidase and protease. The thermal properties of Barley ${\beta}-glucan$ were investigated by Differential Scanning Calorimetry. Three endotherms have been observed on DSC thermograms of Barley ${\beta}-glucan$. The first endotherm which produced the gelatinization phenomena commonly observed in Barley ${\beta}-glucan$ became the focus of this study. The temperature range and the enthalpy of gelation exhibited maximum values with increasing concentration of Barley ${\beta}-glucan$. Gelating Barley ${\beta}-glucan$ registered an enthalpy of approximately 0.23 cal/g and exhibited onset temperature (To), peak temperature (Tp) and conclusion temperature (Tc) of $48.8^{\circ}C,\;61.2^{\circ}C\;and\;78.5^{\circ}C$ respectively. The temperature and enthalpy of gelatinizing Barley ${\beta}-glucan$ at both alkali and acid conditions were lower than those at pH 7. With salt present, the Tp and Tc of gelating Barley ${\beta}-glucan$ produced lower temperatures than in conditions where salt was absent, and the enthalpy abruptly decreased. However, increasing salt concentrations did not affect the gelation temperature and the enthalpy of Barley ${\beta}-glucan$. The 'true melting' temperature of Barley ${\beta}-glucan$ was near $184^{\circ}C$ and the melting enthalpy was approximately 34.6 cal/g. The Barley ${\beta}-glucan$ decomposition temperature was in the range of $316^{\circ}C{\sim}346^{\circ}C$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.5
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• pp.749-753
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• 2002

The effects of green tea powder (GTP) on the rheological properties of dough and gelatinization characteristics were evaluated by farinograph, extensograph, amylograph and DSC. The flours used were high strength flour (HF: 12.5% protein) and blend of 50% high strength flour and 50% low strength flour (HLF: 10.5% protein). As the amount of GTP increased, water absorption, development time and weakness of the dough decreased for both flours, but dough stability increased only for HLF; the extension of the dough decreased but the resistance to extension increased. The pasting temperature increased and maximum viscosity decreased. On the other hand, with the addition of green tea extract to the wheat starch, transition onset temperature, transition peak temper-ature and enthalpy decreased, demonstrating that catechins in green tea facilitate the starch crystal melting.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.7
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• pp.639-644
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• 2006

This study was performed to compare the differences in physicochemical characteristics between head and incomplete kernels separated from Ilpumbyeo, Korean rice cultivar. The contents of mineral and protein were higher in incomplete than head kernels. There was significant difference in composition of fatty acid and amino acids, which affect the taste, between two kernels. The gelatinized head kernel had the higher viscosity than incomplete kernel. The content and chain length of amylose were higher in head than incomplete kernels. Differential scanning calorimeter results revealed that head kernel had lower starting temperature, higher maximum temperature, and higher enthalpy for gelatinization than incomplete kernel. Also we could found that the hydrolysis rate by glucoamylase was higher in the head kernel than incomplete kernel.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.4
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• pp.542-547
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• 2010

Physico-chemical properties of starches from potato cultivars with different colors were investigated. White Atlantic potato had 10% higher starch yield than violet Bora Valley potato. It turned out that the shape and structure of Atlantic and Bora Valley potato starch were the same by mechanical analysis using X-ray and SEM. The ratio of $50\;{\mu}m$ particle in starches from Atlantic and Bora Valley potato was $45.44\pm2.79%$ and $42.37\pm1.03%$ respectively. The particle size of Atlantic potato starch was less than that of Bora Valley; however, there was no significant difference (p<0.05). As for moisture coupling, there was no difference (p<0.05) between the two potatoes. Swelling power showed a high increase from $65^{\circ}C$ to $80^{\circ}C$. The swelling power of Atlantic starch was higher by about 0.3% than that of Bora Valley at $90^{\circ}C$. Since Atlantic has smaller starch particles than Bora Valley, more starch particles are contained in the same size, and hence a difference in swelling power. As a result of measuring the gelatinization of potato starches from Atlantic and Bora Valley, a higher gelatinization start, climax, and complete temperatures occurred at Bora Valley than Atlantic. As for gelatinization enthalpy, Bora Valley starch with a higher gelatinization temperature consumed more energy for gelatinization.

• Korean journal of food and cookery science
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• v.6 no.4 s.13
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• pp.33-39
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• 1990

Rice and waxy rice starches were adjusted to 27% of moisture and heated at $100^{\circ}C$ for 16hours, respectively. After the treatment, their gelatinization properties were investigated. The initial gelatinization temperature, obtained by transmittance and amylogram, of Akkibare and Taebaek starches were $60{\sim}65^{\circ}C$ but those of waxy rice and the U.S.A. rice starches were $55{\sim}60^{\circ}C$ and $70{\sim}75^{\circ}C$, respectively. The gelatinization temperatures of heat-moisture treated starches were higher than those of the untreated starches. Viscosities at each temperature and the highest viscosity reduced by some degrees after the treatment. DSC thermograms of all starches showed single endotherm and the gelatinization enthalpies were $2.26{\sim}2.63\;cal/g$. The gelatinization enthalpy tended to decrease after the treatment. Transmittance and viscosity by alkali showed in this order; Akkibare and Taebaek starches>waxy starch>the U.S.A. rice starch. The heat-moisture treated starches increased viscosities in every starch. Transmittance in alkali solution of Akkibare, Taebaek and waxy rice starches decreased. but that of the U.S.A. rice search increased.

• Korean journal of food and cookery science
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• v.8 no.1
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• pp.57-63
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• 1992

The purpose of this study was to investigate the rheological and thermal properties of yam starch. Yam starch had a hydrodynamic volume with the intrinsic viscosity,［$\eta$］, of 0.29dl/g deionized water. The values of the intrinsic viscosity of yam starch, determined to pH 2-11, varied between 0.07 to 0.18 dl/g. The highest intrinsic viscosity was obtained at pH 7. At salt concentrations 0-0.2 M NaCl, the intrinsic viscosity of yam starch was decreased up to 0.05 M NaCl concentration then increased to 0.07 M NaCl concentration and remained constant to reach 0.2 M NaCl concentration. The overlap parameter, calculated with the intrinsic vicosity data, was 3.45 g/dl in deionized water. The thermal properties of yam starch were investigated by Differential Scanning Calorimetry. Three endotherms were observed both pH solution and salt concentation. In the presence of pH 9, the onset temperature of gelatinization peak was the lowest temperature of 50.$32^{\circ}C$ and the enthalpy ($\Delta$H) was increased in this solution. The effect of salt on the thermal properties of yam starch was determined at salt concetration of 0-0.2 M NaCl. The enthalpy significantly decreased to salt concentration 0.07 M NaCl and the lowest onset temperature of this concentration was 52.$90^{\circ}C$.

• Korean Journal of Food Science and Technology
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• v.32 no.3
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• pp.500-506
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• 2000

The effects of sodium stearoyl lactylate(SSL) on the thermal properties of wheat starch and amylopectin, and the crystallinity properties of amylopectin were investigated using differential scanning calorimetry(DSC) and X-ray diffractometer. On the rescan(second heating), amylopectin produced the featureless thermogram shown at the second heating, and SSL alone melted at $40{\sim}55^{\circ}C$, while the mixture of amylopectin containing 8% water and SSL(10:1), presenting the evidence of AP-SSL complex, showed differentiate melting temperature(other crystallinity) from SSL alone. Also, the melting enthalpy of AP and SSL mixture by subsequent heating and cooling were continuously increased. Further, the mixtures of wheat starch: SSL (5:1, w/w) and amylopectin: SSL(5:1, w/w), indicated AP-SSL complex, showed the reversible melting peak at temperature range of $60{\sim}70^{\circ}C$ together with melting peak of SSL observed at temperature range of $40{\sim}55^{\circ}C$. AP-SSL complex in the X-ray diffraction, compared V-form of amylose-lipid complex, exhibited characteristic peaks($2{\theta}$, 5.57, 20.903, 23.227). The gelatinization enthalpy value of wheat starch in the presence of SSL, observed at temperature range of $50{\sim}70^{\circ}C$, was decreased at total water content 60%, whearas had no significant effect at total water content 40, 50%, and also, SSL increased melting enthalpy of amylose-lipid complex. The extent of AP and wheat starch retrogradation wasreduced significantly by SSL.

• Korean journal of food and cookery science
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• v.12 no.4
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• pp.557-561
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• 1996

Physicochemical properties of nonwaxy (Dongjin byeo) and waxy (Sin-seunchal byeo) brown rice flour were investigated. The proximate composition of nonwaxy brown rice flour was 7.02% of protein, 1.14％ of ash, 3.2% of lipid and that of wfny brown rice was 7.74% of protein, 1.48% of ash,4.83% of lipid. X-ray dif- fraction patterns were A types, and relatives crystallinity of nonwaxy brown rice flour was higher than that of waxy brown rice flour. Swelling power and solubility increased with the increase of temperature, waxy brown rice flour showed higher than nonwaxy rice flour until 70$^{\circ}C$, but lower after 80$^{\circ}C$. The gelatinization temperature, breakdown and consistency of nonwaxy brown rice flour by amylogram were higher than those of the waxy brown rice flour but setback was same. The initial gelatinization temperature and the enthalpy of nonwaxy brown rice flour by DSC were higher than those of the waxy brown rice flour.

• The Korean Journal of Food And Nutrition
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• v.25 no.4
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• pp.762-769
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• 2012

In order to study the cooking characteristics of four rice cultivars of Seolhyangchal, Baegjinju, Ilpum and Haiami, we investigated the relationship between the textures of cooked rice and their physicochemical properties. Different levels in grain weight. length/width ratio and amylose content were observed among the four rice cultivars. There was no significant difference in the amylopectin chain length distribution among the cultivars. Water absorptions of rice grains during soaking were completed between 30 and 40 min, with Haiami showing the slowest absorption. Significant differences in the viscosity properties of rice flour were found by a Rapid Visco Analyser. Baegjinju with low amylose content had the highest viscosity in paste breakdown. According to the DSC results of rice starches, there were significant differences in the onset, peak and conclusion temperatures of the endothermic peak. Gelatinization enthalpy showed energy content changes between 4.20 and 6.97 J/g, with the lowest change in Haiami. Texture properties of cooked rice were assessed using a Texture Analyzer, which showed that the hardness of cooked rice was decreased with soaking than without soaking. However, this finding was not applicable for Haiami rice.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.3
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• pp.285-291
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• 2008

This study was performed to find out starch properties of rice grains in three varieties with different amylose content, Ilpumbyeo (non-waxy), Goami2 (high amylose), and Hwasunchalbyeo (waxy rice). There was no difference among physico-chemical characteristics of rice grains, but Goami 2 showed $2{\sim}3$ folds higher crude fat (1.36%) than Ilpumbyeo. Pasting properties of RVA showed the highest values of maximum viscosity, breakdown, and final viscosity in Ilpumbyeo. A similar chain length distribution of amylopectin was found in Ilpumbyeo and Hwasunchalbyeo, indicating that DP 12 had the highest distribution. Goami 2 had the highest distribution in DP 14, and showed the lower percent (14.1%) than other rice cultivars. Thermal properties of DSC showed that the values of Tc and Tp of Hwasunchalbyeo were similar to Ilpumbyeo, whereas a slightly higher Tc was observed. The absorbtion enthalpy was also the highest (11.1 mJ/mg) in Hwasunchalbyeo. Goami 2 showed higher To, but the lowest enthalpy (6.52 mJ/mg) compared to Ilpumbyeo (7.92 mJ/mg). Retrogradation properties, which were measured with the gelatinized rice sample used for DSC, and stored in $4^{\circ}C$ during 6 days, indicated that retrogradation absorbtion peak was the first peak at $52.6{\sim}55.2^{\circ}C$, and the second peak above $95^{\circ}C$. Retrogradation enthalpy of Goami 2 was the highest value (5.12 mJ/mg).