• Korean Journal Plant Pathology
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• v.10 no.4
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• pp.277-283
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• 1994

An antimicrobial chitinase was purified from grapefruit extract and its properties were characterized. The chitinase was purified with a single step chromatography on regenerated chitin affinity gel column. The molecular weight of the purified chitinase was 29 kDa. The grapefruit extract contained the chitinase protein more than 50% of its total soluble proteins measured by coomassie stained protein bands. When the purified chitinase was incubated with polymers of N-acetylglucosamine (NAG), such as mycelia of Fusarium oxysproum and swollen chitin, they were degraded to oligosaccharides, and the oligosaccharides were then further hydrolyzed by the same enzyme to monomer and dimer of NAG. This result suggests that the chitinase contained both endo- and exo- chitinase activities. The chitinase was stable to heat and pH treatment; its activity was not diminished by the heat treatment upto 7$0^{\circ}C$ for 1 hr, and it showed a pH stability in the range of pH 4.0 to 12.0.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2002.10a
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• pp.187-188
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• 2002

Chitosan is a natural biopolymer of N-acetylglucosamine (-1,4 linked 2-acetamido-D-glucose), which is obtained after alkaline deacetylation of the chitin derived from the cell walls of lower plants and in the skeletal tissues of lower animals including arthropods and mollusks. In the recent studies, chitin and chitosan have attracted interest for converting them to oligosaccharides because the oligosaccharides are not only water-soluble but also possess versatile functional properties such as antimicobial activity (Jeon and Kim, 2000; Jeon et al., 2001). (omitted)

• Analytical Science and Technology
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• v.8 no.4
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• pp.859-864
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• 1995

Mono- and oligosaccharides are derivatized with p-aminobenzoic ethyl ester (ABEE), strongly absorbs UV light at 254 nm, in the presence of sodium cyanoborohydride. C18-bonded silica column is used for the separation of sugar-ABEE derivatives in an isocratic mode. RP-HPLC conditions are optimized by using ternary mixture as mobile phase and $45^{\circ}C$ as a column temperature. Sugar-ABEE derivatives are separated well within a short run time (ca. 25 min) by reverse-phase partition chromatographic mode. The ($1{\rightarrow}6$) linkage type of dihexose-ABEE derivatives has shorter retention time than ($1{\rightarrow}4$)-linkage type. After acid hydrolysis of glycoproteins with 2M trifluoroacetic acid, monosaccharide composition and contents are determined. This procedure is very useful for the simultaneous analysis of neutral and amino sugars in a single chromatographic step using RP-HPLC without reacetylation of deacetylated amino sugars, which are produced by acid hydrolysis.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2004.05a
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• pp.384-387
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• 2004

The purpose of the present investigation was to develop a novel method for cell immobilization. Aureobasidium pullulans cells were mixed with an alginate solution, and the mixture was extruded to form small gel beads as hydrated- immobilized cells. The beads were then placed at $-15^{\circ}C$ for 6-24 h to induce freeze-dehydration. The freeze-dehydration resulted in shrinkage of beads due to water removal reducing bead volume by 82% and bead weight by 85%. The dehydrated beads were successfully used for the production of fructo-oligosaccharides in a model reactor system. This study showed that bioreactor performance can be improved up to 2 times by the use of the dehydrated beads.

• KSBB Journal
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• v.8 no.3
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• pp.266-271
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• 1993

The effective diffusion coefficients of glucose, sucrose and fructo-oligosaccharides in Ca-alginate gel beads at high concentration of sucrose solutions were investigated at $50^{\circ}C$. A mathematical model for the kinetics of fructo-oligosaccharide production using immobilized cells was proposed and compared with experimental results varying the bead size, the substrate concentration and the bead ratio. Very low values of diffusion coefficients ranging $1.2-7.6\times10^{-7}\textrm{cm}^2$/sec were obtained, and the predicted results were in good agreement with experimental ones in all cases tested.

• Korean journal of food and cookery science
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• v.13 no.3
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• pp.348-355
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• 1997

As a trial to expand the use of oligosaccharide, tomato jams were made with various kinds and addition rate levels of oligosaccharide and their quality characteristics were evaluated by instrumental analyses and sensory evaluation. As the addition rate of oligosaccharides increased, 1. the sweetness of tomato jams decreased compared to those of control containing sugar, 2. the lightness and yellowness were increased, however, the redness was decreased, 3. the hardness and adhesiveness of tomato jams containing liquid type oligosacchairdes were lower and those of powder type were higher than control. The springiness of the samples containing oligosaccharide was lower than that of control, however, there was no significant difference in cohesiveness. In sensory evaluation, tomato jams containing oligosaccharides were generally similar or better than control. Color, viscosity, flavor and overall acceptability of the samples containing powder type oligosaccharide were higher than those of liquid type. Tomato jams containing 15% powder type oligosaccharide and 35% sugar showed the highest overall acceptability.

• Journal of the Korean Society of Food Culture
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• v.11 no.3
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• pp.299-304
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• 1996

The objective of this study was to investigate important factors affecting food choice, specific dietary changes over past few years and to find out consumer opinions concerning the use of yogurt and oligosaccharides. Results of this study showed that three most important factors in food selection were taste (52.5%), nutrition (23.4%) and safety (15.8%). Three most important nutritive factors were protein (26.3%), calorie (19.2%) and vitamin (13.8%). Specific dietary changes of the respondent over past few years didn't affect meat intake, but increased vegetable and fruit intakes. Majority of the respondent (52.3%) ate yogurt more than 3 times per week and 35.6% of them ate $3{\sim}4$ times per month. Reasons for intake of oligosaccharides were as follows; low calorie (40.8%), sweetener (28.3%)and bifidogenic factor (25.0%). The respondent regarded that yogurt had more preventive effect of disease than that of oligosaccharide.

• Bulletin of the Korean Chemical Society
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• v.22 no.3
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• pp.293-297
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• 2001

The purpose of this paper is to introduce the simplified linkage position determination method using tandem mass spectrometry combined with molecular modeling study. Using low energy tandem mass spectrometric experiments and molecular modeling, it has been suggested that significant differences in glycosidic bond cleavage may occur due not only to ionic considerations but also may have contributions from steric hindrance of the absorbance of collision energy, leading to a statistically higher bond cleavage for sterically crowded linkages. Permethylated derivatives of the linkage-isomeric trisaccharides give useful fragmentation ratios and productions, including a 3-linkage specific ion. The ratios of fragment ions are related to the ability of each linkage position in the oligosaccharide to absorb collisional energy.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.355-355
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• 2005

• Proceedings of the Korean Society of Life Science Conference
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• 2001.09a
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• pp.94-94
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• 2001