• Applied Biological Chemistry
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• v.33 no.1
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• pp.39-42
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• 1990

The properties of amylose of cow pea starch were investigated. Amylose content of cow pea was 25.1 % and iodine binding capacity was 20.2 %. The ${\beta}-amylolysis$ limit of the amylose was 82.3%. The limiting viscosity number of the amylose fraction was 204 ml/g and the corresponding average degree of polymerization was 1,510 glucose units. The percent distribution of molecular weight of the amylose by gel chromatography was $1{\times}10^4$(0.7 %), $1{\times}10^4{\sim}4{\times}10^4$(4.1 %), $4{\times}10^4{\sim}5{\times}10^5$(44.6 %), $5{\times}10^5{\sim}4{\times}10^7$(49.6 % ).

• Korean Journal of Food Science and Technology
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• v.24 no.6
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• pp.568-573
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• 1992

Molecular structural properties of Japonica and Tongil type waxy rice starches were compared. The general properties including water-binding capacity, swelling power at $80^{\circ}C$, intrinsic viscosity, leach loss at $98^{\circ}C$ and ${\beta}-amylolysis$ limit were similar but the chain length was slightly different between the two starches. Similar elution profiles on Sephadex G-50 were obtained when the starches were treated with ${\beta}-amylase$. The pullulanase treated starches however showed different elution patterns each other. The ${\beta}-amylolysis$ of acid-treated (2 days) starches linearly increased as hydrolysis time prolonged. When the acid-treated starches were hydrolyzed with ${\beta}-amylase$ or pullulanase, the elution profiles on Sepharose CL-2B were considerably different from those of native starches.

• Applied Biological Chemistry
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• v.33 no.1
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• pp.34-38
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• 1990

The molecular structural properties of amylopectins of Chunmabyeo(Japonica), Yongmunbyeo($Indica{\times}Japonica$) and Mahatma(Indica) rice were investigated. The intrinsic viscosity of Chunmabyeo, Yongmunbyeo and Mahatma amylopectin were 148.3 ml/g, 156.6 ml/g and 167.5 ml/g, and ${\beta}-amylolysis$ limit(%) were 54.6, 55.4 and 52.9 respectively. Average unit chain length(${\overline{CL}}$) and average inner chain length(${\overline{ICL}}$) of Mahatma amylopectin were longer than other varieties. Elution profiles by Sephadex G-50 chromatography of debranched amylopectins with ${\beta}-amylase$ showed two peaks (void volume, ${\overline{DP}}$3) and the elution profiles of debranched amylopectins with pullulanase showed three peaks(void volume, ${\overline{DP}}$35-45, ${\overline{DP}}$10-20). The ratio of Peak III(${\overline{DP}}$10-20) to Peak II (${\overline{DP}}$ 35-45) of Chunmbyeo, Yongmunbyeo and Mahatma amylopectin were 3.9, 3.4 and 3.3, respectively.

• Korean Journal of Food Science and Technology
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• v.24 no.2
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• pp.187-192
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• 1992

Some structural characteristics of Japonica and Tongil type rice starches and their fractions were investigated to elucidate the differences between the two rice types. Japonica rice starches showed broader gelatinization temperature ranges and had higher ${\lambda}_{max}$ than those of Tongil ones. Intrinsic viscosity of starch, amylose and amylopectin for Japonica type were lower compared with those of Tongil type. ${\beta}-amylolysis$ limit of rice starch were not different between two rice types, but those of amy_lose and amylopectin of Japonica ty_p_e were lower than Tongil type. The average unit chain length(${\overline}CL$) and average outer chain length(${\overlne}OCL$) of Japonica type amylopectin were shorter than those of Tongil one. Sepharose CL-2B chromatography of hot water soluble starch revealed that each starch had unique elution profile.

• Applied Biological Chemistry
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• v.43 no.4
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• pp.241-246
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• 2000

In order to investigate structural properties of Chindo black rice(grown in Chindo, Chonnam) starch and its amylopectin, Chindo black rice was investigated in comparison to Shinsun waxy rice. The maximum absorbance wave and intrinsic viscosity of Chindo black rice starch and Shinsun waxy rice starch were 523 nm, 521 nm and 183 ml/g, 178 ml/g, respectively. ${\beta}-amylolysis$ limit(%) of Chindo black rice and Shinsun waxy rice starch were 62.8% and 60.3%, respectively. Chindo black rice was determined to be a waxy rice due to the results of iodine reaction and elution profile on Sephroce CL-2B. The chain of amylopectins in Chindo black rice distributed fraction 1$(F_1)$ of above degree of polymerization$({\overline{DP}})$ 55, fraction 2$(F_2)$ of ${\overline{DP}} $40{\sim}50$ and fraction 3$(F_3)$ of ${\overline{DP}} $15{\sim}20$, and the ratio of $F_3$ to $F_2$ for Chindo black rice was higher than that for Shinsun waxy rice. The super long chain of amylopectin in Chindo black rice was consisted much more than that of Shinsun waxy rice. ${\beta}-limit$ dextrins in Chindo black rice amylopectin distributed $F_1$ of above ${\overline{DP}} 55, $F_2$ of ${\overline{DP}} $30{\sim}45$ and $F_3$ of ${\overline{DP}} $10{\sim}20$. Little difference was shown between elution patterns of the pullulanase treated ${\beta}-limit$ dextrins of Chindo black rice amylopectin and Shinsun waxy rice amylopectin. These results suggest that Chindo black rice starch was similar to Shinsun waxy rice starch.

• Korean Journal of Human Ecology
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• v.1 no.1
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• pp.79-83
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• 1992

Cowpea starch which is the main ingredient of Mook(Korean starch gel) was isolated from cowpea and characterized by physico-chemical methods. Gelatinization properties were investigated by using Brabender amylograph. Starch granules were oval-shape and their size range was $5\;-\;25{\mu}m$. Crystalline type observed by X-ray deffraction was C-type. Apparent amylose content was 20.7%, Amylose and amylopectin fractionated from cowpea starch appeared to have vlue value of 0.55 and 0.089, and ${\beta}-amylolysis$ limit of 79.1 and 71.9%, respectively. Brabender amylograph data showed that initial gelatinization temperature of cowpea starch was $75^{\circ}C$. Also, hot and cooled paste viscosity of 8% starch paste were higher than that of 6% paste by more than twice, breakcown value of two different concentration were almost same. However, in the gelation stage, consistancy and setback of 8% starch paste appeared more than 5 times of those of 6% paste.

• Applied Biological Chemistry
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• v.34 no.1
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• pp.26-31
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• 1991

The physicochemical properties of starches from dry(Suwon 147) and moist type(Hwangmi) sweet potato were investigated and molecular structural properties of their amylopectins were also studied by gel chromatography. Suwon 147 starch bad lower swelling power and higher gelatinization temperature than Hwangmi starch. $\beta-Amylolysis\;limit(%)$ of Suwon 147 and Hwangmi amylopectin were 57.6% and 57.0%, respectively. Average unit chain length of amylopectins were 24.8 glucose units for Suwon 147 and 21.9 for Hwangmi. The elution profiles by Sephadex G-50 after debranched amylopectins of the two starches were similar but DPs of each peak were different.

• Korean Journal of Food Science and Technology
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• v.22 no.7
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• pp.753-761
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• 1990

The physicochemical properties of starches from aerial and subterranean tuber of yam were compared with those of rice and sweet potato. Aerial tuber yam contained higher level of amylose than others, whereas water binding capacity, swelling power and solubility was highest in subterranean tuber yam starch. Brabender amylograms of 5% starch suspensions indicated that the initial pasting temperature of yam starches were slightly higher than that of rice and sweet potato starches, the maximum viscosities of starches from subterranean and aerial tuber yam were 860 and 590 B.U., respectively. Yam starches were more difficult to hydrolyze by ${\alpha}-amylase$ than rice and sweet potato starches. ${\beta}-Amylolysis\;limit$ for yam starches and their amylose and amylopectin were higher than rice and sweet potato starches. The elution profiles of starches on Sepharose CL-2B were different from each other but they were similar between yam starches. Incomplete debranched fractions in the aerial tuber yam amylopectin was particularly higher than other samples. The weight ratio of short chains to long chains for debranched amylopectins was the lowest in aerial tuber yam.

• Applied Biological Chemistry
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• v.35 no.3
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• pp.196-201
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• 1992

Characteristics on lintnerization of dry type (Suwon 147) and moist type (Hwangmi) sweet potato starches were investigated. Chain distribution of lintnerized starches was also studied by debranching with pullulanase. Hydrolytic patterns of two starches showed two distinct stages and hydrolysis extents of Suwon 147 starch were lower than those of Hwangmi starch. The relative crystallinities of Suwon 147 starches were higher than those of Hwangmi starch. The elution profiles of lintnerized starches were composed of two peaks about degree of polymerization (DP) 25 and DP 15. The elution profiles of debranched samples showed only one peak about DP 15 and peak DP of Suwon 147 lintnerized starch was higher than that of Hwangmi.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.5
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• pp.684-689
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• 1995

The molecular structure of rice starch was investigated using Korean rice[3 varieties of Japonica type and 3 varieties of Tongi type(Japonica-Indica breeding type)]. The λmax of iodine complex and inherent viscosity of Japonica type were higher than those of Tongil type. $\beta$-Amylolysis limit of the starches was not different between the two rice types. In the distribution of molecular weight of rice starch, the molecular size of amylose and amylopectin for Japonica type were smaller than those for Tongil type. The chain of rice starch distributed F1 of above DP 55, F2 of DP 40~50 and F3 of DP 15~20, and the ratio of F3 against F2 for Japonica type was higher than that of Tongil type. The results suggest that rice of Japonica and Tongil type was different molecular structure of starch.