Chitosan processing

Most of the early studies on chitosan system processing dealt with the purification of chitosan itself to remove impurities such as proteins, pyrogens, toxic metals, and low molecular weight polysaccharides. Chitosan purification was pursued primarily to allow its use in parenteral pharmaceutical products and/or implantable biomedical devices. Parallel to chitosan purification, a great deal of effort was directed toward chitosan processing into ... 

Ilyina, A. V., Tikhonov, V. E., Albulov, A. I., Varlamov, V. P., Enzymatic preparation of acid-free-water soluble chitosan, Process iochem., 35 (2000), 563-568. 

Demir, A., Aiik, B., Ozdogan, E., Seventekin, N., 2010. The comparison of the effect of enzyme, peroxide, plasma and chitosan processes on wool fabrics and evaluation for antimicrobial activity. Fibers Polym. 11, 989-995. 

However, Park et al. (2004) reported that chitosan process anticoagulant activity was tested in vitro. They hypothesized that blood coagulation factors in the presence of chitosan with a glucosamine structure might be dependent in terms of degree of deacetylation, molecular size, and other physical characters. 

Chatteijee S., 2004. Clarification of fruit juice with chitosan. Process Biochem. 39(12) 2229-2232. 

Wan, YY Du, YM Shi, XW. Immobilization and characterization of laccase from Chinese Rhus vernicifera on modified chitosan. Process Biochemistry, 2006, 41, 1378-1382. 

The thermal treatment of chitosan salt solutions leads, however, to amide formation the process of amidation in films consisting of chitosan formate, acetate and propionate proceeds rapidly in the air at 120 °C. The highest degree of amidation (up to 50%) was reached in chitosan formate. The amidation leads to significant strengthening of the films and reduces their solubility in aqueous media [226]. 

When the films were treated in either an oxygen plasma environment or under UV/ozone irradiation, the rates of oxidation were faster for the plasma process. Irradiation of chitosan solution showed that UV/ozone induces depolymerization. In both plasma and UV/ozone reactions, the main active component for surface modification was UV irradiation at a wavelength below 360 nm [231]. 

Associations can be of physical nature too. Chitosan blends with hydrophilic polymers including polyvinylalcohol, polyethyleneoxide and poly-vinylpyrrohdone, were investigated as candidates for oral gingival delivery systems. Chitosan blends were superior to chitosan alone in terms of comfort, ease of processing, film quality, and flexibihty [325]. 

The efficacy of chitosan in the treatment of leg ulcers stems from its antiinflammatory action and stimulation of epithehahzation. Chitosans stimulate the granulation process and the epidermis formation, thus accelerating heahng, even in the elderly suffering from chronic venous insufficiency, the... 

Chitosan has found many biomedical applications, including tissue engineering approaches. Enzymes such as chitosanase and lysozyme can degrade chitosan. However, chitosan is easily soluble in the presence of acid, and generally insoluble in neutral conditions as well as in most organic solvents due to the existence of amino groups and the high crystallinity. Therefore, many derivatives have been reported to enhance the solubility and processability of this polymer. 

Crini G, Badot PM (2008) Application of chitosan, a natural aminopolysaccharide, for dye removal from aqueous solutions by adsorption processes using batch studies a review of recent literature. Prog Polym Sci 33 399 447... 

The only systems not listed in Tables 2-4 which are also likely to yield walled permeselective capsule are those based on polyvinylamine and chitosan. However, further research is required on the blending and processing of polyvinylamine systems, and the modification of chitosan, to enable the production of mechanically stable capsules which do not rupture catastrophically and slowly degrade as the present systems do under gelling with divalent ions. 

Monoglyceride (MG) is one of the most important emulsifiers in food and pharmaceutical industries [280], MG is industrially produced by trans-esterification of fats and oils at high temperature with alkaline catalyst. The synthesis of MG by hydrolysis or glycerolysis of triglyceride (TG) with immobilized lipase attracted attention recently, because it has mild reaction conditions and avoids formation of side products. Silica and celite are often used as immobilization carriers [281], But the immobilized lipase particles are difficult to reuse due to adsorption of glycerol on this carriers [282], PVA/chitosan composite membrane reactor can be used for enzymatic processing of fats and oils. The immobilized activity of lipase was 2.64 IU/cm2 with a recovery of 24%. The membrane reactor was used in a two-phase system reaction to synthesize monoglyceride (MG) by hydrolysis of palm oil, which was reused for at least nine batches with yield of 32-50%. 

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