• Journal of Dairy Science and Biotechnology
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• v.36 no.3
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• pp.164-170
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• 2018

The objectives of this study were to manufacture casein phosphopeptide (CPP)/chitosan oligosaccharide (CSO) nanocomplexes and to investigate the impacts of manufacturing variables, such as CPP concentration and pH, on their morphological and physicochemical characteristics. Transmission electron microscopy (TEM) and particle size analysis were used to assess the morphological and physicochemical properties of the CPP/CSO nano-complexes, respectively. Based on the images obtained by TEM, the spherical shapes of the CPP/CSO nanocomplexes ranged from 50 to 150 nm. As the concentration of CPP was increased and the pH was decreased, the average particle size of the nanocomplexes significantly (p<0.05) increased. The CPP/CSO nanocomplexes had a highly uniform distribution with a polydispersity index value of less than 0.3. In addition, they had a negative surface charge with a zeta-potential value between -17 and -26 mV. The CPP/CSO nanocomplexes showed good stability during the freeze-drying process. In conclusion, CPP/CSO nanocomplexes were successfully manufactured, and the CPP concentration and pH were found to be key factors that affected their morphological and physicochemical properties.

• Food Science of Animal Resources
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• v.39 no.5
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• pp.831-843
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• 2019

The purposes of this research were to form chitosan oligosaccharide (CSO)/A2 ${\beta}$-casein nano-delivery systems (NDSs) and to investigate the effects of production variables, such as CSO concentration levels (0.1%, 0.2%, and 0.3%, w/v) and manufacturing temperature ($5^{\circ}C$, $20^{\circ}C$, and $35^{\circ}C$), on the production and physicochemical characteristics of CSO/A2 ${\beta}$-casein NDSs to carry resveratrol. The morphological characteristics of CSO/A2 ${\beta}$-casein NDSs were assessed by the use of transmission electron microscopy (TEM) and particle size analyzer. High-performance liquid chromatography (HPLC) was applied to determine the entrapment efficiency (EE) of resveratrol. In the TEM images, globular-shaped particles with a diameter from 126 to 266 nm were examined implying that NDSs was successfully formed. As CSO concentration level was increased, the size and zeta-potential values of NDSs were significantly (p<0.05) increased. An increase in manufacturing temperature from $5^{\circ}C$ to $35^{\circ}C$ resulted in a significant (p<0.05) increase in the size and polydispersity index of NDSs. Over 85% of resveratrol was favorably entrapped in CSO/A2 ${\beta}$-casein NDSs. The entrapment efficiency (EE) of resveratrol was significantly (p<0.05) enhanced with an increase in manufacturing temperature while CSO concentration level did not significantly affect EE of resveratrol. There were no significant (p<0.05) changes observed in the size and polydispersity index of NDSs during heat treatments and storage in model milk and yogurt indicating that CSO/A2 ${\beta}$-casein NDSs exhibited excellent physical stability. In conclusion, the CSO concentration level and manufacturing temperature were the crucial determinants affecting the physicochemical characteristics of CSO/A2 ${\beta}$-casein NDSs containing resveratrol.

• Proceedings of the Korean Society of Life Science Conference
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• 2001.09a
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• pp.33-33
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• 2001

• Journal of Microbiology and Biotechnology
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• v.12 no.3
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• pp.503-507
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• 2002

Chitosan oligosaccharides (COSs) were prepared and fractionated into three groups of COS [a high molecular weight COS (HMWCOS), medium molecular weight COS (LMWCOS), and low molecular weight COS (LMWCOS)] according to their molecular weight, using an ultrafiltration membrane enzymatic bioreactor designed earlier [8]. Antitumor activity of these COSs was then examined against Sarcoma 180 solid (S180) or Uterine cervix carcinoma No. 14 (Ul4) tumor cell-bearing mice. Among these COSs, MMWCOS with molecular weight range from 1.5 to 5.5 kDa effectively inhibited the growth of both tumor cells in the mice. In addition, the administration of MMWCOS resulted in increased thymus weight among lymphoid organs. The mice treated with MMWCOS showed improved survival rate and larger number of survivors after 40 days of feeding. The most effective of MMWCOS far antitumor activity in the S180- or U14-bearing mice was 20 mg/kg/day or more.

• Korean Journal of Food Science and Technology
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• v.32 no.1
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• pp.218-224
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• 2000

The antimicrobial activities of chitosan oligosaccharide(chitohexaose) and two types of chitosans M.W.(10,000 and M.W. 100,000) were examined against Escherichia coli O157 : H7(ATCC 43894), Staphylococcus aureus(ATCC 144458) and Candida albicans(KFRI 432). Chitosan with molecular weight of 10,000 showed the strongest antimicrobial activities to E. coil O157 : H7 and S. aureus, whereas chitohexaose acted most strongly against C. albicans. The most effective concentration of chitosan was measured to be 0.1 mg/mL for E. coil O157 : H7 and S. aureus, and that of chitohexaose to be 1 mg/mL for C. albicans. Antimicrobial activities of chitosans and chitohexaose were maintained for 60 min after their treatment. They were found to induce leakage of intracellular proteins and nucleic acids from treated microorganisms. The efflux determined by assaying the ${\beta}-galactosidase$ leaked from the lactose-induced E. coli O157 : H7 cells was observed to reach the highest level within 60 min after treatment with the antimicrobial agents and chitosan with 10,000 molecular weight gave the highest ${\beta}-galactosidase$ activity. Therefore, it is supposed that the antimicrobial activity of chitosan with its unique polycationic nature might be caused by its binding to anionic component(s) of the cell envelope and thereby inhibiting the membrane metabolism and/or leaking intracellular materials.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.23 no.2
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• pp.48-62
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• 1997

Chitosan oligosaccharides having aldehyde group at reducing end were prepared by oxidative-deamination reaction of chitosan by using sodium nitrite, and the resulting aldehyde group was reduced to 2, 5-anhydro-D-mannitol group. The obtained chitosan oligosaccharides showed an average degree of polymerization 2~3 by gel permeation chromatography analysis. It was highly soluble in hydrophilic solvents and thermally stable. N, N-diacyl, O-acyl chitosan oligosaccharides were obtained from the reaction between chitosan oligosaccharides and acyl chloried under dimethylaminopyridine. From differential scanning calorimetric measurement, N, N-dilauroyl, O-lauroyl chitosan oligosaccharides showed mesophase region, which was confirmed by polarized microscope as a thermotropic liquid crystalline state. X-ray diffraction pattern revealed that N, N-dilauroyl, O-lauroyl chitosan oligosaccharedes were highly crystalline, whereas chitosan oligosaccharides were not.

• KSBB Journal
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• v.15 no.4
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• pp.352-358
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• 2000

Preparation for the simplified separation of chitosandoligosaccharides from enzymatic hydrolysate was investigated. Two different types of chitosan beads as substrate were prepared as organic-based bead by W/O emulsion method and water-based bead by alkaline treatement. The average size of organic-based bead was $200{\mu}m$, and that of water based beads were $4000{\mu}m$, $100{\mu}m$, $30{\mu}m$, in diameter respectively. Enzyme stability was maintained over 80% at PH 6 after 24 hours. The optimal condition for the production of chitosanoligosaccharides was at pH 6.0, $50^{\circ}C$ and 40U (200U/g-chitosan) According to final oligosaccharide concentration water-based bed showed the similar result with that of organic-based bead even through it had smaller surface area attacked by chitosanse than that of organic-based bead. It is probable that the structure of water-based chitosan bead was looser than that of organic-based bead so enzyme penetrated easily into the bead structure. For the oligosaccharide production versus surface area the different size of water-based beads was investigated, Maxiaml production yield was observed in the $30{\mu}m$ beads. Consequently the water-based chitosan bead was better than the organic-based bead in this reaction system.

• Journal of Microbiology and Biotechnology
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• v.13 no.2
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• pp.269-275
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• 2003

Chitosan-degrading activity induced by chitosan was founf in culture filtrate of Aspergillus flavus IAM2044. Aspergillus flavus IAM2044 had a higher level of chitosanolytic activity when chitosan was used as a carbon source, and yeast extract and peptone were supplemented as nitrogen sources. One of the chitosan-degrading enzymes was purified to homogeneity by ammonium sulfate precipitation followed by cation-exchange and gel filtration chromatographies. The enzyme was monomeric, and its molecular mass was 45 kDa. The optimum pH and temperature of the enzyme were 5.0 and $50^{\circ}C$, respectively. The activity was stable in the pH range of 3.5 to 7.0 and at a temperature below $50^{\circ}C$. Reaction products analyzed by the viscosimetric assay and thin layer chromatography clearly indicated that the enzyme was an exe-type chitosanase, $exo-{\beta}-D-glucosaminidase$, that released GlcN from the nonreducing ends of the oligosaccharide chains.

• Polymer(Korea)
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• v.32 no.3
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• pp.263-269
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• 2008

To develop carriers of hydrophobic anticancer agents based on chitosan, chitosan oligosaccharide lactate (COS) was chemically modified with lithocholic acid (LA) which is one of the bile acids as a hydrophobic group. The physicochemical properties of the lithocholic acid conjugated chitosan nanoparticles (COS-LA) were investigated using $^1H$-NMR spectroscopy, dynamic light scattering (DLS) and spectrofluorophotometer. COS-LA-paclitaxel (CLs-Tx) nanoparticles loading paclitaxel as an anticancer agent were prepared by a dialysis method and its loading efficiency was measured through HPLC. On the basis of DLS results, the estimated particle sizes of CLs-Tx were around 300 nm. Also, the critical micelle concentration (CMC) was proven to be dependent on the degree of substitution of lithocholic acid. It showed that the CLs-Tx has the superior potential for the application as a paclitaxel carrier.

• Journal of Dairy Science and Biotechnology
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• v.39 no.1
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• pp.27-35
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• 2021

The aim of this research was to investigate the potential application of casein phospho-peptide (CPP)/chitosan oligosaccharide (CSO) nanocomplexes to dairy foods. The physical stability of CPP/CSO nanocomplexes during storage in model dairy foods including milk and yogurt was assessed by measuring the size and polydispersity index of the nanocomplexes. Encapsulation efficiency and in vitro vitamin D release from CPP/CSO nanocomplexes during gastrointestinal digestion were determined using HPLC. CPP/CSO nanocomplexes with increased CPP concentrations and decreased pH displayed significantly increased average particle size. During storage in model dairy foods, CPP/CSO nanocomplexes prepared with lower CPP concentrations and raised pH exhibited excellent physical stability. Vitamin D encapsulation efficiency increased significantly (p<0.05) as CPP concentration and/or pH decreased. Less than 3% vitamin D were released under gastric digestion conditions in vitro, while 91% of encapsulated vitamin D was released by 2 h of incubation under intestinal conditions, indicating that CPP/CSO nanocomplexes could effectively protect vitamin D from gastric conditions for delivery to the intestines. In conclusion, CPP/CSO nanocomplexes can be applied to dairy foods as an effective vitamin D delivery system.