• Applied Chemistry for Engineering
• /
• v.21 no.6
• /
• pp.593-602
• /
• 2010

Chitosan as a natural polymer has superior physicochemical properties such as biocompatibility, biodegradability and nontoxicity, but application of chitosan for therapy of cancer and gene related-disease has been limited by poor solubility in aqueous solution. Therefore, low molecular weight water-soluble chitosan (LMWSC) with high reactivity and strong positive charge can be applied as a delivery system having function to carry in the specific tissue the bioactive material like poor solubility drug, or therapeutic gene and developed as a therapeutic system having good therapeutic efficiency. The most important factor for therapy of various diseases is to reveal the antigen or receptor expressed in specific lesion tissue and the antibody and ligand which can bind with antigen is to introduce at the biomaterials for enhancement the therapeutic efficiency. The studies for cationic synthetic polymer as drug or gene delivery have been actively performed, but it has many problems such as toxicity in the body, therapeutic efficiency. From this point of view, this article demonstrated the introduction of functional groups to target the specific tissue and therapeutic strategy using the modification of LMWSC with free-amine group. The development of these delivery system will provide a positive vision for cancer therapy.

• Food Science and Industry
• /
• v.53 no.1
• /
• pp.69-83
• /
• 2020

For the development of the chitosan industry in Korea, the catch of red snow crabs caught on the east coast is rapidly decreasing. Therefore, it is urgent to develop raw materials that can replace the red snow crab as the top priority to solve the supply and demand problems, as well as wastewater treatment costs account for a large proportion of the cost of chitosan. In order to solve the problems, continuous research on biological extraction methods such as enzymatic extraction and microbial fermentation will increase production efficiency and lower unit cost as well as chemical extraction methods. Further efficient manufacturing method can be established. Establishing of novel techniques is indispensable for production of high-purity chitosan and the ability to regulate and separate the molecular weight, as well as joint research with industry, academia and research institute for the research and development of high-functional chitosan derivatives.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.36 no.4
• /
• pp.503-513
• /
• 2007

The obese population has been increasing worldwide and obesity has become one of the socioeconomic problems. Obesity raises more concerns as more studies regarding its direct and indirect relativity to several diseases such as type II diabetes, hypertension, etc. are published. Since leptin, an important signal in the chronic control of food intake and energy expenditure, was discovered in 1994, there has been a great accumulation of knowledge on fighting obesity by facilitating pharmacological and nutritional strategies on the molecular level of the body weight control system. In particular, evidences are accumulating that particular food components affect our physiological function and gene expressions which are associated with body weight control. In this study, we review the four mechanisms for weight control and antiobesity functional agents such as HCA, L-carnitine, CLA, chitosan, calcium supplements capsaicin contained in red pepper, and oriental herbal mixture. We also describe about the efficacy and working mechanism of these functional agents on the basis of antiobesity mechanisms.

• Food Science of Animal Resources
• /
• v.23 no.2
• /
• pp.128-136
• /
• 2003

This study was peformed to evaluate physico-chemical and textural properties, and shelf-life effect of low-fat functional sausages(LFFS) manufactured with sodium lactate(SL), lac color and various molecular weights of chitosans(low=1.5 kDa, medium=30∼40 kDa and high=200 kDa) during storage at 4$^{\circ}C$ for 8 weeks. LFFS had a pH range of 6.39∼6.50, 76∼78% moisture, <2% fat, 14∼15% protein. The combination of SL and low molecular weight(MW) of chitosan improved water holding capacity(WHC), however those of SL and medium MW of chitosan reduced WHC. Vacuum purge(VP) reduced with increased MW of chitosans during refrigerated storage. The addition of chitosans reduced the lightness and yellowness, but increased the redness values, which was comparable to the sodium nitrite concentration between 75 and 150 ppm. LFFS containing SL and medium MW of chitosan increased most texture profile analysis(TPA) values, as compared to controls with 75 and 150 ppm. The addition of SL in LFFS retarded the microbial growth for Listeria monocytogenes, however no synergistic effect with the addition of chitosans were observed. E coli O157:H7 and Salmonella typhimurium reduced during refrigerated storage, regardless of SL and chitosan treatments. Increased storage time increased values for VP, yellowness and textural properties. These results indicated that the combination of SL and various MW of chitosans affected the functional and textural properties, and inhibited the microbial growth for LM effectively. In addition, 0.5% lac color as a replacer for sodium nitrite improved the color development, resulting in similar hunter color values, which was comparable to the sodium nitrite concentration between 75 and 150 ppm.

• Journal of the Korean Society of Food Culture
• /
• v.19 no.3
• /
• pp.359-368
• /
• 2004

The Physicochemical, sensory and cooking properties of functionally fortified rice with dietary fiber and chitosan were compared with regular rice when the rices were cooked with pressure and electric cookers. Moisture content of functional rice before cooking was 11.11%, which was lower than 13.72% in regular rice. Accordingly, moisture contents of functional rice samples cooked both with pressure and electric cookers were lower than those of regular rice. L value showing the degree of lightness of cooked rice was significantly higher in rice samples cooked with pressure cookers. The ${\alpha}$ value, the degree of redness and the b value, the degree of yellowness, were the highest in the functional rice cooked with an electric rice cookers. Textural measurement of hardness using a rheometer showed the highest value in functional rice cooked with a pressure cooker. The degree of gelatinization measured using differential scanning calorimetry (DSC) before cooking showed higher onset gelatinization temperature ($T_0$) and peak gelatinization temperature ($T_p$) in functional rice compared with those in regular rice. The gelatinization enthalpy (${\Delta}H$) of functional rice was lower than that of regular rice, showing that functional foe had lower gelatinization energy compared with regular rice. When the samples were stored in a refrigerator for one week, the DSC showed faster retrogradation degrees in samples cooked with electric rice cooker, having significantly higher enthalpies of regular and functional rice cooked with electric cooked compared to those cooked with pressure cookers. The functional rice samples cooked with pressure cooker had higher consumer acceptance test values compared to those cooked with electric cookers.

• Food Science of Animal Resources
• /
• v.25 no.3
• /
• pp.285-294
• /
• 2005

The objective of this study was to evaluate the physico-chemical properties and flavor compounds of sausages with various levels and molecular weight (MWs) of chitosans, during storage at $4^{\circ}C$. Various MWs (Low: 1.5 kDa; Medium: $30{\sim}50$ kDa; High: 200 kDa) and two levels (0.3 and $0.6\%$) of chiosans were dissolved and measured the viscosity at $4^{\circ}C$, pH values were not affected (p>0.05) by either MWs or levels of chitosans. The addition or high MWs or chitosan into the pork salt soluble protein (SSP) increased the viscosity, whereas no differences were observed in low and medium MWs of chitosan. Textural profile analysis (TPA) was affected by the addition of medium or high MWs of chitosan. As a result, the addition of medium of chitosan increased the hardness, gumminess, chewiness, cohesiveness and springiness values, whereas increased level of chitosan didn't affect TPA values, except few cases. Approximately twenty-nine flavor compounds were identified in the low-fat and regular-fat sausages, however the addition of chitosans didn't impair the flavor composition of the sausages, These results indicated that the addition of chitosans didn't affect the flavor profiles, but affected the textural properties in the sausages, especially MWs higher than 30 kDa.

• Fashion & Textile Research Journal
• /
• v.14 no.2
• /
• pp.320-330
• /
• 2012

The natural dyeing of cotton fabrics with guava leaf extract was investigated. The temperature and time of dyeing are $40^{\circ}C$ and $90^{\circ}C$ for eighty minutes, respectively. In addition, the dyebath has been set at pH 5. Sn pre-mordanted fabrics showed the highest K/S value. Regardless of dyeing temperature, K/S values were high when Al, Cu, Fe-mordanted fabrics were dyed in post-mordanting and Sn-mordanted fabrics were dyed in pre-mordanting. The K/S value of dyeing fabrics could be increased with repetitive dyeing and mordanting. Compared to untreated dyed fabrics, the K/ S values of fabrics which had been treated with soybean milk, chitosan and gall nut tannin were increased. The changed surface colors of fabrics that were treated with soybean milk, chitosan and gall nut tannin were Y, YR and achromatic colors. Fabrics dyed with alkaline water extract showed reddish color. Sn-mordanted fabrics dyed with acidic water extract showed vivid yellowish color, and Cu-mordanted fabrics dyed with ethanol extract showed yellowish green color. In case of Sn-mordanted fabrics, the washing fastness was level 4. The dry cleaning fastness also showed very excellent result with level 4-5. The rubbing fastness was better in dry rubbing than in wet rubbing of the fabrics. For the light fastness, all dyed fabrics showed low fastness. For antibacterial activity, the powder of guava leaf extract and the dyed fabrics with guava leaf extract showed 99.9% of high antibacterial activity. All dyed fabrics showed higher deodorization and UV protection rate than control fabric.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.34 no.2
• /
• pp.291-297
• /
• 2005

Fish sauce is one of the most popular fermented fish products over the world. But it is usually manufactured with high salt concentration (>25%) and long periods of elaboration. In order to increase the consumption of fish sauce, the functional anchovy sauces with low salt concentrations (14 and 17%) were manufactured by adding sea tangle (Kjellamaniealla crassifolia), ume (Prunus mume Sieb. et Zucc), tochukaso (Paecilomyces japonica), and chitosan. On 50 days of storage, pH of all treatments decreased to 5.1, while the amount of lactic acid increased continuously as storage period increased. The amounts of VBN, amino-N, and TBA were highest on 50 days of storage and then kept constantly or decreased a little thereafter. The numbers of total viable cell, lactic acid bacteria, proteolytic bacteria, and fungi increased very slowly as storage period increased.

• Journal of Industrial and Engineering Chemistry
• /
• v.67
• /
• pp.365-372
• /
• 2018

Wounds that heal with excessive scar formation result in poor functional and aesthetic outcomes. To address this, in our study, visible light cured glycol chitosan (GCH) hydrogels containing endothelial growth factor (EGF) and basic fibroblast growth factor (bFGF) were prepared (GCH-EGF, GCH-FGF and GCH-EGF/FGF) and evaluated their efficacies on the improvement of wound healing in vivo. In vitro release test showed that the growth factors were released in a sustained manner along with initial burst for 24 h. In vitro cell proliferation assay of L-929 mouse fibroblast cell line resulted in the superior ability of GCH-EGF/FGF on the rate. In vivo results demonstrated that the growth factor loaded GCHs further enhanced wound healing compared with GCH. In particular, GCH-EGF/EFG showed the most remarkable wound healing effect among the samples.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.32 no.7
• /
• pp.1056-1064
• /
• 2008

Toes socks are used widely for the health of feet. However, discomfort is one of the major complains from toes socks users. The purpose of this study is to determine the effect of functional fibers on the physiological response and wearing sensation of toes socks. For experiment, two different toes socks with cotton/warm fiber(WS) and cotton/chitosan fiber(CS) were knitted automatically by a computer controlled flat knitting machine. The control toes socks with cotton/nylon/polyurethan(TS) were prepared to compare the properties. Experiments were conducted in a climate room of $16\pm2^{\circ}C$, $50\pm5%$ R.H. The results of this study were as follows. The change of heart rate, pulse rate, and mean skin temperature showed no difference among three different socks. However, skin temperature of TS was evaluated higher than that of WS and CS. After exercise wearing WS both instep temperature and sole temperature of women tend to higher compared to men. Wet sensation and overall comfort sensation of toes socks were significantly influenced by different fiber contents. Subjects evaluated WS and CS more comfortable than TS.