• Korean Journal of Food Science and Technology
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• v.51 no.2
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• pp.109-113
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• 2019

The soft rice varieties, Hangaru and Singil, were developed via mutation breeding using N-methyl-N-nitrosourea treatment to obtain dry-milled rice flours. The physicochemical, morphological, and pasting properties of these starches were compared with those of Seolgaeng and Chuchung starches. Singil starch was found to exhibit the highest amylose content and initial pasting temperature, whereas Hangaru starch exhibited the highest water binding capacity and swelling power. Hangaru starch's granule size at $d_{50}$ was the largest among the four different starch types. Some Seolgaeng, Hangaru, and Singil granules were observed to have a round-faced polygon shape. Furthermore, the crystallinity of all four starch types was type A. The peak, trough, and final viscosities of the soft rice starches were also lower than those of normal starches. Notably, Hangaru starch showed the highest breakdown viscosity, but the lowest total setback viscosity among the four starches. From these results, the starch characteristics of the soft rice flours were discovered to be different based on the rice variety.

• Food Engineering Progress
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• v.21 no.3
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• pp.280-285
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• 2017

The objective of this study was to increase the efficiency of starch extraction from potato sludge by different concentration of food-grade hemicellulase. The potato sludge, which is a by-product of potato processing industry, was treated with food-grade hemicellulase. Starch extraction efficiency displayed no significant difference in hemicellulase concentration. The purities of potato starch increased from 83.40 to 95.91, 97.44, 95.58, and 97.79%, with treated 0.5, 0.75, 1.0, and 1.5% hemicellulase, respectively. The physicochemical properties of the starches, such as granule structure, particle size, pasting, and thermal transition, were not affected by the concentration of hemicellulase. These results indicate that food-grade hemicellulase treatment is an efficient method for starch extraction from potato sludge.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.36 no.3
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• pp.275-279
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• 2023

La_0.7Sr_0.3-xMg_xMnO₃ (LSMMO) (x=0.05~0.20) specimens are fabricated by a solid phase sintering method, and the sintering temperature and time are 1,300℃ and 2 hours, respectively. The dependence of the crystalline structure according to the amount of Mg²⁺ contents is not observed, and all specimens show a polycrystalline rhombohedral crystal structure, the X-ray diffraction (110) peaks move to the high angle side with increasing the amount of Mg²⁺ contents. LSMMO specimens exhibit a granule-shaped microstructure with an average grain size of 1 ㎛ or less. Resistivity gradually decrease as the amount of Mg²⁺ contents increased. And in the La_0.7Sr_0.1Mg_0.2MnO₃ specimen, resistivity and B_25/65-value are 36.7 Ω-cm and 394 K at room temperature, respectively. LSMMO specimens show a variable-range hopping (VRH) electrical conduction mechanism, and the negative temperature of coefficient of resistance (NTCR) is approximately 0.37~0.38%/℃.

• Food Science and Preservation
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• v.22 no.2
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• pp.241-250
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• 2015

This study investigated the sensory attributes of Satsuma mandarins to provide basic data for the establishment of a quality grade establishment of mandarins. Samples of the mandarins in different sizes (small, medium, and large) were collected via organic green house cultivation, conventional cultivation without pesticides and conventional cultivation in Jeju Island. Eight trained panels performed the triplicate measurements. From the results of the quantitative descriptive analysis, mandarin samples were selected with five types of appearances (gloss intensity, color intensity, peel width, damage degree, and peel texture), three types of odors (sour, sweet, fresh), six types of tastes (sour, sweet, bitter, fresh, tasteless, and off flavor) four types of texture (hardness, granule toughness, juicy, and tough feel), and three types of after-tastes (sour, sweet, and bitter). The results of the analysis of the quality characteristics of the samples showed that their, pH, total acidity and solids contents differed depending on the size of the samples more than their cultivation methods. The correlation coefficients between the quality properties of the mandarins showed that their, sample size was positively correlated with their peel width and toughness. Moreover, the soluble solid of sample was positively correlated with its color intensity, sweet and fresh orange flavor. However, soluble solid content of the samples was negatively coreelated with their bitter flavor, tastelessness, and off flavor. In the principal component analysis of the sensory attributes data, PC1 represented the soluble solid, gross intensity, orange color, sour and sweet odor, unique mandarin flavor (sweet and, fresh orange), etc., and PC2 (26.77%) the size, pH, sample acidity, and peel texture.

• Korean Journal of Environmental Biology
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• v.23 no.2 s.58
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• pp.191-199
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• 2005

The community structure, vertical distribution and harpacticoids composition of the meiofauna community were observed from five stations in Marian Cove, King George Island and one station on the northeastern side of Nelson Island. Sample was taken by a free-fall corer in December 2002. Generally, 11 taxa of meiofauna were found, and meiofauna abundance ranged from 322 to 1575 indiv. $10cm^{-2}$ (mean 781 indiv. $10cm^{-2}$). Nematodes were the most dominant group, making up $89\%$ of total meiofauna, followed by harpacticoids $(6.8\%)$. Benthic harpacticoids appeared 19 species of nine families at all the stations, and most various taxa appeared at station B (13 species of seven families). For vertical distribution, more than $70\%$ of meiofauna was concentrated in the upper $0\~2cm$ sediment layers, and the density abruptly decreased with depth in all the stations. Total biomass of meiofauna varied between 41 and $360{\mu}gC\;10cm^{-2}$, and overall mean biomass was $205{\mu}gC\;10cm^{-2}$. Also nematodes had the highest percentage of total maiofauna biomass $(62.4\%)$. The analysis results of Canonical Correspondence Analysis between meiofauna community and sediment grain size showed that polychaets, oligochaets and cumaceans were influenced by silt&cray, and sand, granule and pebble had a influence on harpacticoids, kinorhynchs and ostracods respectively. But nematodes were not affected by sediment grain size.

• Korean journal of food and cookery science
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• v.5 no.2
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• pp.1-8
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• 1989

The physicochemical properties and gel forming properties of mungbean and buckwheat crude starches were investigated. The results were as follows; 1. The granule size and shape of mungbean crude starch were $11~32\mu\textrm{m}$ and oval, and those of buckwheat crude starch were $3~10 \mu\textrm{m}$ and polygonal. 2. The amylose conteut of mungbean crude starch and buckwheat crude starch were 78.0% and 26.4% respectively. 3. The blue value of mungbean crude starch and buckwheat crude starch were 1.030 and 0.409, respectively. 4. Periodate oxidation of mungbean crude starch resulted that amylose had the average molecular weight of 95, 648, degree of polymerization of 590 and amylopectin had the degree of branching of 5.4, glucose unit per segment of 18.6, and periodate oxidation of buckwheat crude starch resulted that amylose had the average molecular weight of 133, 690, degree of polymerization of 825 and amylopectin had the degree of branching of 5.2, glucose unit per segment of 19.2 5. Water binding capacity of mungbean crude starch was 185.1% and that of buckwheat was 209.9% 6. The pattern of change in swelling power of mungbean crude starch for increasing temperature started to increase at $60^{\circ}C$ and increased rapidly from $70^{\circ}C$, and that of buckwheat increased slowly from $60^{\circ}C$ to $90^{\circ}C$ without rapid increase. 7 The ranges of gelatinization temp. of mungbean and buckwheat crude starches were 63. 9-$109^{\circ}C$ and 52.5-84.$2^{\circ}C$, respectively. 8. The gelatinization patterns for 6% munbean crude starch and 8% buckwheat crude starch were investigated by Brabender amglograph. Mungbean crude starch showed the initial pasting temperature of 77.6$^{\circ}C$ without peak height, and buckwheat crude starch showed that of $62.5^{\circ}C$ without peak height. In addition, sensory evaluation for sample starch gels (mungbean, buckwheat, cowpea) was done. 1. The difference of sensory characteristics for each starch gel was significant. 2. The sample starch gels were regarded as 'Mook' by pannels. 3. 74.44% of the degree of Mooklike was explained by hardness.

• Korean journal of food and cookery science
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• v.14 no.3
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• pp.225-231
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• 1998

Enzyme-treated glutinous rice flour, which was developed to shorten or skip a steeping process during the preparation of Yukwa, was analyzed for its physicochemical characteristics and compared with glutinous rice flour made by 28-day-steeping method. Total sugar content of the 28-day-steeped flour was the highest among all groups, on the other hand, the reducing sugar content was higher in enzyme-treated glutinous rice flour. The viscosity of enzyme-treated flours was significantly lower than that of the 28-day-steeped and particularly showed the lowest value at 65$^{\circ}C$. The contents of Ca$\^$2+/ and Mg$\^$2+/ in enzyme-treated glutinous rice flours were higher than those of the 28-day-steeped group, however, the content of P$\^$+/ was lower. Free sugar detected in glutinous rice flour prepared from 28-day-steeping method was glucose only, but enzyme-treated flours contained maltose and glucose, and the content of total free sugar was much higher than that of the 28-day-steeped group. In microscopic structure, both 28-day-steeped and enzyme-treated flours showed the particle size decreased and porous surface on some part of the flour granule.

• Korean Journal of Ichthyology
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• v.6 no.2
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• pp.237-243
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• 1994

This work was conducted to study sex differentiation in the black sea bream, Acanthopagrus schlegeli (Bleeker), using a histological method for the appearance of primordial germ cell, formation of primitive gonads, differentiation of female and male from newly hatched larva to the ovotestis stage of fish. The 3~4 primordial germ cells of $6.8{\sim}7.2\;{\mu}m$ in size, which were buried under fibrous mesenchymal tissue between gut duct and notochord of pre-larva with a total length (T.L.) of 2.4 mm at 3 days after hatching. The proto-gonial cells were located in the epithelium of the coelom attached with pigment cells of juvenile with 6.4 mm in T.L. at 21 days after hatching. In juvenile of 20.8 mm in T.L. at 59 days after hatching, the proto-gonial cells were migrated to the retro-peritoneum through the lineshaped primitive gonad composed of fibrous mesenchymal tissue. In juvenile of 7.8 em in T.L. at 186 days after hatching, the mitotic division of proto-gonial cell appeared in the lineshaped primitive gonad having many eosinophilic granule cells and abundant fibrous connective tissue. In juvenile of 9.5 em in T.L. at 254 days after hatching, the gonad was occupied by abundant fibrous connective tissue, bundles of spermatocyte and spermatid. In juvenile of 10.5 cm in T.L. at 13 months after hatching, the gonad was divided into cortical layer and medullary layer. The former was composed of bundles of a few spermatocytes and proto-gonial cells, the latter was filled with the fibrous mesenchymal tissue and a few proto-gonial cells. In juvenile of 14.7 em in T.L. at 16 months after hatching, the gonad was separated into ovarian part and testicular part by the fibrous connective tissue. The ovarian part is consisted of ovarian cavity and oocytes of perinucleolus stage. The testicular part was occupied by spermatogonia in the cyst.