• Journal of Ginseng Research
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• v.5 no.2
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• pp.114-121
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• 1981

Starch was isolated from 4-year-old and 6-year-old ginseng roots and its physical and chemical characteristics were studied. The results obtained were summarized as follows. 1. The shape of ginseng starch granules was polygonal and rounded with its granule size ranging from 2.0 to 7.5$\mu$. The swelling power of 4-year-old ginseng starch was much greater than that of 6-year old ginseng starch. Gelatinization pattern showed that 6-year-old ginseng starch gelatinized rapidly at $65^{\circ}C$, whereas 4-year-old starch continued to gelatinize, without having a definite gelatinization temperature as temperature increased 3. Amylogram of ginseng starch showed that gelatinization initiated at 61$^{\circ}C$ and was completed at 88$^{\circ}C$ with its viscosity reaching at 810 B.U. 4. The amylose contents were 32% and 9% for 4-year-old and 6-year-old ginseng starch, respectively. 5. X-ray diffraction analyses indicated that there were some structural differences between 4-year-old and 6-year-old ginseng starch.

• Korean Journal of Food Science and Technology
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• v.41 no.4
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• pp.369-373
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• 2009

${\alpha}$-Waxy corn starch was used as a feed for twin-screw extrusion in order to enhance starch liquefaction with added thermostable ${\alpha}$-amylase (derived from Bacillus licheniformis). The residence time distribution and starch liquefaction were investigated. The starch liquefaction was analyzed in terms of reducing sugar contents, molecular size from gel permeation chromatography (GPC), and microstructure from scanning electron microscopy (SEM). The use of ${\alpha}$-starch contributed to the production of more reducing sugar than the use of raw starch use alone. From GPC, the effect of ${\alpha}$- starch on the molecular size reduction was shown to be small. From SEM, irregular and damaged surface were observed on the extrudate from ${\alpha}$-starch, as compared to those from raw starch. The spread of residence time distribution curves was greater with feed of ${\alpha}$-starch than raw starch, indicating that ${\alpha}$-starch was hard to flow forward during extrusion. This could be improved by increasing the feed moisture content and barrel temperature of extruder.

• Preventive Nutrition and Food Science
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• v.11 no.2
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• pp.146-154
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• 2006

Structural modification of corn starch by gamma irradiation was evaluated for under dry conditions at varied intensities from 0 to 40 kGy. Under scanning electron microscopy, the granule shape of corn starch was not significantly affected by the irradiation up to 40 kGy. In addition, X-ray diffraction and melting patterns of the irradiated starches were similar to those of the native starch, indicating that crystalline regions in the starch granules were not changed by irradiation. However, the pattern of gel permeation column chromatography showed a significant increase in partial hydrolysis of gamma irradiated starch samples. The degree of polymerization and the paste viscosity of irradiated starch samples dose-dependently decreased significantly with irradiation, and increased solubility and clarity were observed in the irradiated starch solution. In addition, the degree of retrogradation decreased as irradiation dose increased. Irradiation of corn starch has advantages over the ordinary acid or the enzyme hydrolysis modification methods. It does not affect the granular shape and crystalline phase of starch during hydrolysis, and the process can be carried out in dry state.

• Korean journal of food and cookery science
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• v.3 no.1
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• pp.54-63
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• 1987

The amino acids ana fatty acids of cowpea were determined and physicochemical properties of cowpea starch and rheological properties of cowpea starch gel were investigated. The results were as following: The proteins of cowpea were particularly rich in glutamic acid (20.02%) and aspartic acid (12.21%) and contained considerable amount of leucine (8.99%), lysine (7.20%) and tryptophan (1.81%), whereas were poor in sulpho-containing amino acids. The lipids of cowpea were mainly composed of 31,43% linoleic acid, 28.34% linolenic acid, 22.9% palmitic acid and 7.63% oleic acid and the small amount of myristic, arachidonic and behenic acid was contained. The ratio of the saturated to the unsaturated in cowpea oil was 32~33/67~68. Cowpea starch gel showed lower values for hardness and brittleness than mung been starch gel, whereas a higher value for cohesiveness than mung bean starch gel, Cowpea starch gel showed lower values for $E_H$, $E_V$ than mung bean starch gel, whereas higher values for $n_V$, $n_N$ than mung bean starch gel. Cowpea starch gel had a lower value for elasticity than mung bean starch gel and had a higher value for viscosity than mung bean starch gel.

• Macromolecular Research
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• v.9 no.6
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• pp.297-302
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• 2001

Rice starch was incorporated into linear low density polyethylene (LLDPE) using a Brabender Plastic-Corder internal mixer at a temperature of 140$\^{C}$ and 40 rpm. The starch loading was varied from 0 to 30% with 5 intervals. Studies on brabender torque development, mechanical properties and water absorption were investigated. The starch loading did not influence the brabender torque significantly. With respect to mechanical properties; the tensile strength and elongation at break decrease with increasing starch loading. The Young's modulus also increases with the starch filling. Mechanical properties were deteriorated as the starch absorbed moisture. The rate of water absorption was dependent on the starch filling in the composites. The scanning electron microscope (SEM) analysis was performed for the tensile fracture surfaces and it revealed the starch agglomeration and a poor dispersion of starch in the LLDPE matrix.

• Korean journal of food and cookery science
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• v.12 no.1
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• pp.1-5
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• 1996

The effects of defatting on sensory and instrumental characteristics of corn and mung bean starch gels during storage were investigated. The untreated and defatted starch gels stored at room temperature for 24 hrs and 72 hrs. The sensory characteristics of defatted corn starch gels were significantly different from untreated ones but the properties of defatted corn starch gels were similar to those of mung bean ones. Mung bean starch gels showed no changes in sensory characteristics by defatting. In the case of instrumental properties, there was highly significant in all characteristics between corn starch gels and mung bean starch gels, but firmness in defatted corn starch gel was similar as in mung bean starch gels.

• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1298-1305
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• 2000

Potato starches were crosslinked with 0.1, 0.5, 1.0, and 2.0% epichlorohydrin. Starch/polyethylene(PE) cast films were prepared to contain 5% of the crosslinked potato starch. Mechanical properties and degradability of these films were measured and compared to those of the films containing native potato starch. Mechanical strength of the films containing crosslinked potato starch was higher than that of the film containing native starch. Thermal degradability measured by a FT-IR and an Instron showed that crosslinked starch/PE films degraded faster than native starch/PE films. Biodegradability of the starch/PE films was accelerated by the addition of crosslinked starch to the PE films.

• Korean journal of food and cookery science
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• v.18 no.5
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• pp.534-542
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• 2002

This study was carried out to determine the effects of various starches (mungbean starch, cowpea starch and corn starch) on the quality characteristics of Omija jelly made of Omija extract. The viscosity of starch suspended in Omija extract and distilled water was measured by using a RVA(Rapid Visco Analyzer), and, color value, syneresis, texture(rupture test and TPA test) and sensory properties of Omija jelly and pure starch jelly were measured. Gelatinization temperature of each starch suspended in Omija extract was higher than that suspended in distilled water, whereas final viscosity of Omija jelly was decreased. Omija extract appeared to retard the gelatinization of starch and recrystallization of gelatinized starch. The viscosity of com starch was lowest among the three types of starch, suggesting thai higher concentration is needed in the use of com starch. The lightness(L) of corn starch gel was the highest among the gels. The syneresis of Omija jelly was lower than that of starch jelly, therefore, Omija extract seemed to be helpful on the stability of starch gel. Rupture properties of Omija jelly was lower than that of starch jelly, whereas the adhesiveness of omija jelly was greater. Omija jelly made of corn starch was less cohesive and more sticky than other gels, and its acceptability was very low. Sensory characteristics of the gel were relatively well correlated with the mechanical characteristics. Overall acceptability of Omija jelly was high in the concentration of 7, 8% of mungbean starch and 8, 9% of cowpea starch. Thus, the optimum concentration of starch for making Omija jelly using mungbean starch was 7, 8% and that using corn starch was 8, 9%.

• Journal of the Korean Society of Food Culture
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• v.26 no.5
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• pp.513-520
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• 2011

This study was carried out to investigate the physicochemical properties of mung bean starch and the texture of cold-stored (5$^{\circ}C$ for 0, 24, 48, and 72 hours) mung bean starch gels added with soy bean oil (0, 2, 4, 6%). The swelling power of mung bean starch added with soy bean oil did not significantly change, whereas solubility increased significantly. Soluble carbohydrate content of mung bean starch added with soy bean oil decreased without any significant differences, whereas soluble amylose content decreased significantly. In RVA viscosity, pasting temperature and peak viscosity of mung bean starch added with soy bean oil were not significantly different, whereas minimum viscosity decreased and breakdown and consistency increased significantly. In RVA viscosity, there were no differences according to concentration of soy bean oil. DSC thermograms show that onset temperature of mung bean starch added with soy bean oil did not significantly change, whereas the enthalpy increased in the case of 4% and 6% oil addition. Rupture properties of freshly prepared mung bean starch gels added with soy bean oil increased in the case of 2% and 4% oil addition, and oil addition to mung bean starch gels suppressed changes in rupture properties during cold storage. There were no significant differences in the texture of freshly prepared mung bean starch gels added with soy bean oil, whereas hardness, chewiness, and gumminess of cold-stored mung bean starch gels added with soy bean oil decreased. In the above textural charactristics, there were no differences due to concentration of soy bean oil. Thus, the addition of 2-4% soy bean oil to mung bean starch is appropriate for improving the quality characteristics of cold-stored mung bean starch gels.

• Microbiology and Biotechnology Letters
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• v.23 no.4
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• pp.416-424
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• 1995

Mechanism of the cyclodextrin (CD) production reaction by cyclodextrin glucanotransferase (CGTase) using swollen extrusion starch as substrate was investigated emphasizing the structural features of starch granule. The degree of gelatinization was identified to be the most representative structural characteristic of swollen starch. The most suitable degree of gelatinization of swollen starch for CD production was around 63.52%. The structural transformation of starch granule during enzyme reaction was also followed by measuring the changes of the degree of gelatinization, microcrystallinity, and accessible and inaccessible portion to CGTase action of residual swollen starch. The adsorption phenomenon of CGTase to swollen starch was also examined under various conditions. The inhibition mechanism of CGTase by various CDs was identified to be competitive, most severely by a-CD. The mechanism elucidated will be used for development of a kinetic model describes CD production reaction in heterogeneous enzyme reaction system utilizing swollen extrusion starch.