• Journal of the Korean Society of Food Culture
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• v.33 no.6
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• pp.597-607
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• 2018

This study examined the nutrient components and measured the physicochemical properties of 23 Korean sweet potato cultivars. The proximate composition, free sugars, organic acids, and dietary fiber of sweet potato were analyzed and the water binding capacity, oil absorption and pasting characteristics were measured. The proximate composition was the highest in Happymi and was higher in colored sweet potato than in general sweet potato (p<0.05). The sucrose content was the highest among the free sugars in the general cultivars and yellow/orange colored cultivar. The major organic acids were oxalic acid, citric acid, malic acid, succinic acid, fumaric acid, and acetic acid. Oxalic acid and citric acid were high in the purple colored cultivars and malic acid was high in yellow/orange colored cultivars. Each total dietary fiber content of the general and colored cultivars was 7.51-13.94 and 13.04-16.97%, respectively, but there was no significant difference. The water binding capacity and oil absorption of Juhwangmi was high in all cultivars (p<0.05). The peak viscosity of sweet potato powder showed highest a significant difference of 12.50-1342 cP (p<0.05). The breakdown of Sincheonmi was 512, which was the highest value (p<0.05). The setback of Geonpungmi was significantly low, 6.0 (p<0.05).

• Korean Journal of Food Science and Technology
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• v.27 no.4
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• pp.532-536
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• 1995

Effect of water activity $(0.32{\sim}0.89)$ on the physicochemical properties of sweet potato starch during the storage for 5, 15 and 30 days at $40^{\circ}C$ was investigated. Shapes and sizes of starch granules were not changed. X-ray diffraction patterns of the starches appeared equally Ca-crystal structure. Sorption isotherm with storage day was sigmoidal. A slight loss of iodine affinity, increase in water binding capacity, and decrease in swelling power at $80^{\circ}C$ occurred as water activities increased. Viscosity pattern under Brabender Amylogram was not significantly changed with water activity, but initial pasting temperature decreased as water activity increased. The viscosity at $50^{\circ}C$, consistency and setback were increased with increasing storage day and water activity.

• Applied Biological Chemistry
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• v.34 no.2
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• pp.94-101
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• 1991

Physicochemical properties of waxy and non-waxy naked barley starches were investigated. The starch granules observed by photomicroscope, polarized-light microscope and scanning electron microscope were round. The starch showed a typical A type by X-ray diffraction pattern. Water binding capacity, swelling power and solubility of waxy naked barley starch were higher than non-waxy naked barley starch at the same temperature. Transmittance of 0.1% starch suspension was increased rapidly from $60^{\circ}C$ in case of waxy naked barley starch and from $65^{\circ}C$ in case of non-waxy naked barley starch. Amylogram revealed that the non-waxy naked barley starches had higher initial pasting temperature than waxy naked barley starch. Enthalpy for gelatinization of non-waxy and waxy naked barley starches were 1.12-1.58 and 0.85 cal/g, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.1
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• pp.45-50
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• 2007

This study was investigated the relationship between palatability and physicochemical properties of rice kernels from two rice cultivars, including Gopumbyeo and Palgongbyeo. Major fatty acids of rice were oleic(35% in Gopum, 33.2% in Palgong, respectively) and linoleic acids (42.9% in Gopumbyeo, 40.7% in Palgongbyeo, respectively). There were significant differences in composition of amino acids and content of sugar from non-starch polysaccharide between two rice cultivars. However, no difference was found in mineral contents between Gopumbyeo and Palgongbyeo. In Rapid Visco Analyzer examination, pasting temperature and breakdown of Gopumbyeo were lower than those of Plagongbyeo. In X-ray diffraction patterns of starches separated from two rice cultivars, traditional A type and there was no difference in crystalline of rice starch. We could also obtain the results that Goupumbyeo, known to have good eating quality, had higher palatability value than Palgongbyeo.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.287-287
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• 2017

The objective of this study was to evaluate difference of quality properties of between fresh cooked rice and re-heated cooked rice after retrogradation. Nine rice varieties raised by NICS were compared the properties of physicochemical, texture, sensory evaluation, toyo glossiness value, pasting properties. Among nine rice cultivars, the changes of weight and length-width ratio of after soaking as well as cooking showed how water absorbed in each rice granule. The amount of water absorption after soaking was highest in Wolback (semi-waxy), Hiami and lowest in Samgwang, Seonpum, Ilpum. After cooking, the amount of water absorption was high in Dasan 1 and Andabyeo, however low in Ilpum. In the length-width ratio after soaking, Wolback (semi-waxy cultivar) and Anda (indica cultivar) increase their volume relatively as their shape are while others increased more in length than width. Among cooked rice, the highest value of length-width ratio shows in Anda, Dasan1, Hiami and Seonpum, the Wolbak was similar to that of non-glutinous rice. After cooking, the others stored at $10^{\circ}C$ for 16 hours for retrogradation (imitated at convenience store). Then re-heated using by microwave. Pasting properties were considerably affected by storage temperature and periods of rice. The setback showed in the following order: Wolback (-92.25 RVU, the lowest retrogradation) < Seonpum (-35.20) < Chindle (-22.08) < Jungsanggold (-21.98). Toyo glossiness value of cooked rice showed in the following order: Chindle (82.40) > Samgwang (79.43) > Hiami (79.23). Sensory evaluation of re-heated rice of Jungsanggold, Samgwang, and Chindle were 78.97, 78.36, and 77.35, respectively. Hardness, elasticity, and toughness of re-heated rice ware increased compared to cooked rice, whereas cohesiveness was decreased. Hardness and elasticity is higher in Seonpum, Dasan1 and Hiami, toughness is higher in Jungsanggold, Samgwang and Wolbak. Cohesiveness of Jungsanggold and wolbak showed higher than others.

• Journal of Applied Biological Chemistry
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• v.55 no.3
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• pp.185-189
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• 2012

This study was conducted to investigate the effect of different steam condition and dehydration condition on physicochemical characteristics of Olbyeossal made from Waxy rice. All samples were steamed at $95-100^{\circ}C$ for 60 min or at $121^{\circ}C$ for 20 min and then were dehydrated using hot air 45, 60, $80^{\circ}C$ and sun-dried to achieve moisture contents 13-15%. Initial pasting temperature of Olbyeossal was the lower than that of nontreatment sample by parboiling. The combination in steaming $95-100^{\circ}C$ and hot drying at $45-60^{\circ}C$ was showed appropriate pasting properties compared with other condition. The hardness of Olbyeossal was significantly affected by steaming and dehydration condition. The hardness of Olbyeossal showed the higher value for steaming at $121^{\circ}C$ than $95-100^{\circ}C$. The water binding capacity (WBC) and swelling power (SP) were higher steaming at $121^{\circ}C$ than $95-100^{\circ}C$. No significant differences on WBC and SP of Olbyeossal by dehydration condition were observed. As the sensory evaluation results, the combination in steaming at $121^{\circ}C$ and hot-air drying at 45 or $80^{\circ}C$ led to increase preference for appearance, color, taste and overall acceptability. These results indicate that steaming and dehydration condition were affecting factor on physicochemical characteristics of Olbyeossal.

• Korean Journal of Food Science and Technology
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• v.24 no.4
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• pp.347-352
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• 1992

Physicochemical properties of native and defatted nonwaxy(Dongjin byeo) and waxy(Sinseunchalbyeo) rice starches were investigated. The granule shapes of rice starches were polygonal and X-ray diffraction patterns were A types, but relative crystallinity was decreased by defatting. The amylose content of defatted starches slightly increased, but water binding capacity of defatted starches decreased. Swelling power and solubility of starches increased with the increase of temperature, at each temperature increased by defatting. Transmittance of Dongjinbyeo and Sinseunchalbyeo starch suspensions showed a rapid increase at $60{\sim}65^{\circ}C$, $55{\sim}60^{\circ}C$ respectively. The initial pasting temperature by amylograph of Dongjinbyeo and Sinseunchalbyeo starches were $66^{\circ}C$ and $64^{\circ}C$, respectively. The gelatinization temperature of defatted starches was higher than that of the nondefatted starches. Dongjinbyeo starch decreased peak viscosity and breakdown by defatting, but Sinseunchalbyeo starch unchanged.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.4
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• pp.487-492
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• 2006

Acetylated rice starches were prepared by reaction of rice starch with acetic anhydride, and their physicochemical properties as a function of degree of substitution (DS) were evaluated. The percentage of acetyl group and DS were $0{\sim}2.71%\;and\;0{\sim}0.104$, respectively. DS increased with increase in acetic anhydride content. DS increased swelling power and solubility of rice starch. Light transmittance (%) values of acetylated rice starches were much higher than that of native rice starch and increased with increase in DS. Rapid Visco Analyzer initial pasting temperature of acetylated rice starches decreased with increase in DS, while peak viscosity and breakdown values increased. Starch gets showed a significant decrease in syneresis (%) with the increase in DS.

• Korean Journal of Food Science and Technology
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• v.25 no.4
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• pp.355-359
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• 1993

The effects of alum un the physicochemical properties of non-waxy and waxy rice starches were investigated. The swelling powers of non-waxy and waxy rice starches with $0.05{\sim}1.0%(w/w)$ alum were increased remarkably in comparison with rice starches without alum, but those of rice starches with alum above 1.0%(w/w) concentration were decreased slowly with the increasing amount of alum. While solubility of the non-waxy starch with $0.05{\sim}1.0%(w/w)$ alum was elevated gradually with the increasing temperature. that of the waxy starch was decreased regardless temperature. But solubilities of both rice starches with alum concentration above 1.0%(w/w) exhibited no significant changes. The more alum in the system, the higher and the lower blue value were resulted in non-waxy rice starch and waxy rice starch, respectively. From amylograms, it was found that alum increased breakdown and initial pasting temperatures for both rice starches, but reduced setback.

• 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.