• Korean Journal of Food Science and Technology
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• v.23 no.2
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• pp.175-182
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• 1991

Hydroxypropylated starches were prepared by reaction of corn starch with propylene oxide and their physicochemical properties were compared with those of the native starch. Swelling power, solubility and water binding capacity increased with the increase of hydroxypropylation. The hydroxypropylation of corn starch significantly reduced the extent of digestion and iodine absorption. Starch molecules larger than $1.34{\times}10^7{\sim}$ decreased whereas molecules ranging from $1.34{\times}10^7{\sim}1.18{\times}10^5$ increased by hydroxypropylation. Granule size increased by hydroxypropylation but this did not significantly affect the granule surface appearance by SEM. The hydroxypropylation improved the solubility and water binding capacity of corn starch.

• Journal of the East Asian Society of Dietary Life
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• v.7 no.4
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• pp.519-526
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• 1997

Physicochemical properties of potato starches with degree of substitution of 0-0.2645 hydroxypropylated with propylene oxide were examined. Hydorxypropyl group content of the starch was proportional to propylene oxide concentration. Water binding capacity increased but pH decreased with the increase of degree of substitution. Blue value and iodine absorption property decreased with the increase of hydroxypropylation. Differential scanning calorimeter showed that hydroxypropylation lowered the gelatinization temperature of the starch. Relative crystallinity in X-ray diffraction patterns decreased and starch granule observed by scanning electron microscopy was destroyed by hydroxypropylation. This result implied that high level hydroxypropylation affected the crystal region as well as amorphous region of starch.

• Korean Journal of Food Science and Technology
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• v.24 no.1
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• pp.70-73
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• 1992

Gelatinization behaviour and gel properties of corn starch modified either by hydroxypropylation only or by cross-linking and hydroxypropylation were investigated. Gelatinization temperature of corn starch decreased greatly by hydroxypropylation, but increased slightly by cross-linking with epichlorohydrin. The treatment of both hydroxypropylation and cross-linking lowered the gelatinization temperature, although it was not significantly different from that of hydroxypropylated corn starch. The swelling power of the corn starch was reduced and gel strength was increased by both modifications. The results suggested that the gelatinization behaviour and gel properties of corn starch could be improved by both cross-linking and hydroxypropylation.

• Korean Journal of Food Science and Technology
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• v.31 no.4
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• pp.999-1004
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• 1999

Physicochemical properties of the native chestnut starch(NCS) and hydroxypropylated chestnut starch(HCS) with propylene oxide were investigated. The water binding capacity and blue value of chestnut starch were increased by hydroxypropylation. With increasing temperature, the swelling power and solubility were increased and those of HCS were higher. The light transmittance of HCS was higher than it of NCS. Endotherm characteristics were studied with DSC showed that temperatures of initial gelatinization of NCS and HCS were $64.44^{\circ}C$ and $62.80^{\circ}C$, respectively. The temperature of initial gelatinization and enthalpies gelatinization in chestnut starch were decreased by hydroxypropylation. And the viscosity of HCS was higher than that of NCS.

• Proceedings of the Korean Fiber Society Conference
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• 1997.10a
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• pp.76-80
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• 1997

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.2
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• pp.423-428
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• 1999

Potato starches were hydroxypropylated with 2.5, 5.0, 7.5, and 10.0% propylene oxide(PO) to improve mechanical properties of starch polyethylene film. Starch polyethylene cast films were prepared that contained 5% or 10% of the hydroxypropylated potato starch. Mechanical properties of these films were measured and compared to those of the films containing native potato starch. DS(degree of substitution) increased proportionally as propylene oxide concentration increased. Relative crystallinity in X ray diffraction patterns was decreased and starch granule observed by scanning electron micro scopy was destroyed by severe hydroxypropylation. In color properties of films, b value was not significantly different in the films but 5% starch polyethylene films with 2.5 PO starch showed the lowest L and a value. Tensile strength and strain energy of the films except the film containing 10.0 PO starch were higher than those of the containing native starch.

• Korean Journal of Food Science and Technology
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• v.33 no.3
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• pp.313-318
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• 2001

Physicochemical properties of starch vermicelli (Dangmyun) made with different starches in laboratory were determined to develop a modified corn starch comparable to sweet potato starch which is highly expensive than corn starch but commonly used for starch vermicelli in Korea. Initial temperatures (Ti) of gelatinization of starch vermicelli made in laboratory measured by differential scanning calorimeter, which were above $60^{\circ}C$, were higher than those of starch vermicelli in the market. Their X-ray diffraction peaks were relatively sharp compared with those of starch vermicelli in the market, which showed that starches were not completely gelatinized during the process of starch vermicelli preparation in laboratory. Initial temperature (Ti) of corn starch vermicelli was decreased by $3^{\circ}C$ by hydroxypropylation but increased by $2.5^{\circ}C$ by oxidation. Hardness and compression slope of sweet potato starch vermicelli and mungbean starch vermicelli, which were $11,726{\sim}12,555\;g/cm^2$ and $29,914{\sim}30,604\;g/cm^2$, respectively, were the highest in the samples and those of waxy corn starch were lowest. Hardness and compression slope of starch vermicelli made with corn starch slightly oxidized in the concentration of 0.5% NaOCl at pH 9.0, $40^{\circ}C$ for 30 min. increased and found to be comparable to those of sweet potato starch vermicelli.

• 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.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.19 no.2
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• pp.75-80
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• 2013

The physicochemical properties of the hydroxypropylated mung bean, sweet potato and water chestnut starches were studied. The blue value and amylose content of mung bean starch were higher than those of sweet potato and water chestnut. Pasting temperature of hydroxypropylated starches were lower than those of native starch and decreased with increasing contents of propylene oxide. Peak viscosity increased with the increase of degree of hydroxypropylation. With increasing contents of propylene oxide, the clarity and swelling power of all starches were increased and those of mung bean were higher. Mung bean starch produced better hard capsules than sweet potato and water chestnut starch. Hydroxypropylated (>6% propylene oxide) water chestnut starch-based capsules completely dissolved, but hydroxypropylated (>12% propylene oxide) mung bean and sweet potato starch-based capsules were dissolved within 10 min. These results showed that hydroxypropylated starch-based capsules have potentials for pharmaceutical applications as a substitute for gelatin hard capsules.

• Korean Journal of Food Science and Technology
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• v.23 no.3
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• pp.317-324
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• 1991

Gelatinization behaviours and gel properties of hydroxypropylated corn starches (HPCS) were investigated with differential scanning calorimeter, amylograph and rheometer. Gelatinization temperature of HPCS decreased as degree of substitution increased. The retrogradation of corn starch was greatly reduced by hydroxypropylation, indicating that the association of starch molecules was sterically hindered by hydroxypropyl groups. In HPCS, gel was formed slowly and gel strength decreased resulting in soft and sticky texture. Texture profiles of HPCS gels were similar to those of tapioca and waxy corn starch. HPCS has shown a remarkable increase of paste transparency compared to native corn starch.