• Korean Journal of Food Science and Technology
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• v.33 no.1
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• pp.50-54
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• 2001

The amylose content, based on iodine blue value, of eight rice cultivars decreased in order of Nampungbyeo>Whachungbyeo>Punchilmi>Nampung CB243>Whachung du-1>Nampung EM90>Whachungchalbyeo>shr. The amylopectin chain length distribution was obtained by enzyme treatments followed by high-performance size-exclusion chromatographic separation. Chain length distribution profiles of the isoamylase-debranched starches showed distinct patterns according to cultivars. Based on the sensory evaluation result of the bread prepared from gluten and rice flours of eight rice cultivars, chewiness of the product was related with the presence of amylose while the short-chain amylopectin fraction was contributed to the texture and overall quality.

• Food Science and Biotechnology
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• v.14 no.4
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• pp.470-473
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• 2005

Starch was isolated from turnip (Brassica rapa L.), and to elucidate the structure-function relationship its structural and physical properties were characterized. Morphological structure of the starch was analyzed by SEM (Scanning Electron Microscopy). Most of the starch granules were spherical in shape with diameter ranging from 0.5-10mm. Apart from larger granules ($<10\;{\mu}m$) which dominated the population size of turnip starch, significant amount of small ($0.5-2\;{\mu}m$) and mid-size granules (${\sim}\;{\mu}m$) were also detected. It was revealed that presumably, erosion damages occurred due to the attack of amylase-type enzymes on the surface of some granules. Branch chain-length distribution was analyzed by HPAEC (High-Performance Anion-Exchange Chromatography). The chain-length distribution of turnip starch revealed a peak at DP12 with obvious shoulder at DP18-21. The weight-average chain length ($CL_{avg}$) was 16.6, and a large proportion (11.8%) of very short chains (DP6-9) was also observed. The melting properties of starch were determined by DSC (Differential Scanning Calorimetry). The onset temperature ($T_o$) and the enthalpy change (${\Delta}H$) of starch gelatinization were $50.5^{\circ}C$ and 12.5 J/g, respectively. The ${\Delta}H$ of the retrograded turnip starch was 3.5 J/g, which indicates 28.2% of recrystallization. Larger proportion of short chains as well as smaller average chain-length can very well explain relatively lower degree of retrogradation in turnip starch.

• Journal of Food Hygiene and Safety
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• v.23 no.4
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• pp.314-318
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• 2008

This research aimed to compare the detection methods of Anisakis simplex in Sea fish by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and macroscopic inspection. We examined 18 Trichiurus lepturus, 11 Scomber japonicus, and 65 Todarodes pacificus collected from the retail markets in the areas of Uljin, Kyuonggi province and Seoul. As the result of examinations, we found that detection rate of Anisakis simplex by macroscopic observation was 89% in Trichiurus lepturus, 90.9% in Scomber japonicus, 32.3% in Todarodes pacificus. The detection rate of Anisakis simplex by PCR-RFLP was 77.7% in Trichiurus lepturus, 81.8% in Scomber japonicus, 26.1% in Todarodes pacificus. We could conclude that PCR-RFLP method of Anisakis simplex was more specific rather than macroscopic observation.

• Food Science and Biotechnology
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• v.17 no.1
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• pp.176-179
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• 2008

Amylose contents and amylopectin chain architecture of sorghmn and waxy sorghum starches were determined and compared with those of other common cereal and tuber starches. Also, in vitro digestibility of sorghum starch was estimated using a novel methodology. The absolute amylose content of sorghum starch was similar to that of com and wheat starches. The side chain length distribution patterns for sorghum and waxy sorghum amylopectin were very similar to those of com and waxy com, respectively. The $k_{cat}/K_m$ values for sorghum and potato amylopectin did not show a significant difference. The kinetic parameters could be used as novel indicators for starch digestibility.

• Korean Journal of Food Science and Technology
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• v.35 no.4
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• pp.696-701
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• 2003

Rice seeds of 4 cultivars including Whachung and Nampung, of the non-waxy rice cultivars, and Shinsunchalbyeo and Whachungchabyeo, of the waxy rice cultivars, were germinated at $27^{\circ}C$ for 3 days to compare the changes in some physico-chemical properties of the starch granules and the starch-hydrolysing enzyme activities during germination, respectively. With the starch granules, the amount of long glucose chains from amylose molecules were reduced in the non-waxy rices, while the chain length increased in the waxy rices. In the distribution profile of the glucose chain length from amylose molecules, we could observed that the chain length with DP (degree of polymerization) ranged 33 to 66 increased with the decreasing rate of the chain length with that above 130, regardless of the waxiness of rices. In addition, we observed that in contrast to a increase in chain length with DP ranged 14 to 33, the amount of short chains from A chain fraction decreased. Germination induced slight reduction in the polymerization rate of starch granules, and decrease in both initiation and termination temperatures for the gelatinization. ${\alpha}-Amylase$ activity of rices germinated for 3 days found to he higher than that of malt. Especially, the activity of Shinsunchalbyeo was revealed to be highest, about two fold higher than that of malt. In contrast, ${\beta}-amylase$ of the waxy rice found to be considerably less active than malt, although the waxy showed prevalent activity as compared to the non-waxy rices.

• Fisheries and Aquatic Sciences
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• v.11 no.3
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• pp.133-139
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• 2008

Molecular techniques, including restriction fragment length polymorphism(RFLP) and polymerase chain reaction-single strand conformational polymorph isms(PCR-SSCP), were developed to identify salted, dried threadfin(Eleutheronema tetradactylum) and white herring(Ilisha elongata) fish. Using PCR with universal primers, conserved 367-bp fragments of the cytochrome b gene were amplified from fresh fish samples and sequenced. The sequences were then searched for specific restriction sites. The digestion of the PCR products with the endonucleases AvaI, FokI, MboII, and MspI generated RFLP, which was used to identify the commercial products. Similarly, the amplified PCR-SSCP products were developed and the products tested. Overall, similar patterns were found in the majority of the fresh and processed products. Based on the results, both RFLP and PCR-SSCP were useful in determining and validating the authenticity of the fish species used to prepare the commercial salted, dried products. A similar approach can be applied to other species.

• Korean Journal of Food Science and Technology
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• v.21 no.5
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• pp.624-632
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• 1989

Lipids of Liza carinata roe were extracted and separated into detailed lipid classes by column chromatography. About 57-62% of the total lipids consisted of wax esters in which saturated and unsaturated fatty alcohols combined with fatty acids with up to six double bonds. Between the even-numbered wax ester peaks in gas-liquid chromatography, ones with odd chain lengths such as C31, C33 and C35 were eluted in appreciable amounts. Isomers composed of different fatty acids and alcohols at a given chain length were not resolved on 1.5% OV-17 column. The principal component of wax esters in sample A were C32, C34 and C30 (45.0%, 19.2%, and 12.2%), followed by C36 and C38 length (9.5% and 4.7%), while those in sample B were mainly occupied by C34, C32 and C36 length (36.3%, 31.4% and 14.5%) with minor components C30 and C38 length (5.2%, and 3.4%). The wax esters were not a random combination of constituent fatty acids and alcohols. With increase in boiling temperature the wax esters increased slightly in viscosity over the unboiled, showing a tendency toward randomness, and finally were completely randomized at $360^{\circ}C$ for 40 minutes. The enzymes involved in wax ester biosynthesis seemed to have high selectivity for chain length of fatty acids and alcohols.

• Korean Journal of Food Science and Technology
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• v.27 no.1
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• pp.105-111
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• 1995

The relationship betwwen the molecular structure of amylopectin and the texture of cooked rice was investigated using Korean rice [3 varieties of Japonica type and 3 varieties of Tongil type(Japonica-Indica breeding type)]. The molecular structure of rice amylopectin was polymodal and distributed A chain of $\overline{DP}$ 12.4, short B chain of $\overline{DP}$ 20.6, B chain of $\overline{DP}$ 26.3, long B chain of $\overline{DP}$ 45 and super long chain of above $\overline{DP}$ 55. The super long chain of amylopectin was composed of long linear chain with poorly branched chain. Also, the super long chain of amylopectin showed positive correlated with average chain length, inherent viscosity and ${\beta}-amyloysis$ limit$({\%})$, but negative correlated with ${\lambda}max$ of iodine reaction of amylopectin. The structural properties of amylopectin in Japonica type were different from those of amylopectin in Tongil type. In relationship between molecular structure of amylopectin and texture of cooked rice, the average chain length, inherent viscosity, ${\beta}-amyloysis$ limit and super long chain of amylopectin was showed a positive correlation with hardness, but a negative correlation with adhesiveness of cooked rice. The long chain of rice amylopectin is the less, the eating quality of cooled rice was the better. These results suggest that the molecular structure of rice amylopectin could be responsible for the texture of cooked rice.

• 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.

• Korean Journal of Food Science and Technology
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• v.19 no.4
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• pp.371-376
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• 1987

The structral properties of rice starch and its components were investigated. The intrinsic viscosities of rice starch, amylose and amylopectin solutions were 1.053, 1.772 and 1.596 ml/g, respectively. ${\beta}-amlolysis$ limits of rice starch was 73% and those of amylose and amylopectin were 106 and 56%, respectively. The outer chain length $({\overline{OCL}})$ and inner chain length $({\overline{ICL}})$ of amylopectin were 1.56 and 7.7, respectivety. Debranching of rice starch with pullulanase yield two peaks on Sephadex G-75. The peak I at void volume was principally amylose components and peak II at ${\overline{dp}}$ 25-10, constituted of branched amylopectin. However, the elution profile of debranched amylopectin by pullulanase revealed a bimodal peak distribution at ${\overline{dp}}$ 35-25 hydrolyers and ${\overline{dp}}$ 25-10, and no distinct peak at void volume. The elution profile of the debranched, ${\beta}-amylase$ hydrolyrates of starch and amylopectin yielded major peak at ${\overline{dp}}$ 2-10.