An approach to understanding the deacetylation degree of chitosan

High-density chitosan reduces the severity of bacterial spot and activates the defense mechanisms of tomato plants

“…Titration was performed by adding 0.5 mL of NaOH (165 mM) every 20 sec for 13 min (adapted from Alvarenga et al, 2010). Through two inflection points that occur during titration, it was possible to estimate the degree of deacetylation (DD) of the chitosans studied.…”

Characterization and Properties of Chitosan

“…The first rapid descending branch corresponds to neutralization of HCl in excess (A-B), the second segment refers to neutralization of the ammonium group (B-C) and the third to the excess of base (D). The two stoichiometry points are found by intersection of the three lines and the difference between the two points corresponds to the volume of base required to neutralize the ammonium groups (de Alvarenga et al, 2010). The percentage of amino groups represented by the degree of deacetylation (DD) was calculated using formula (3):…”

“…• Elemental analysis (Davies & Hayes, 1988;dos Santos et al, 2009); • Titration (Arcidiacono & Kaplan, 1992;Balázs & Sipos, 2007;de Alvarenga et al, 2010;Hattori et al, 1999;Park et al, 1983;Raymond et al, 1993;Tôei & Kohara, 1976;Zhanga et al, 2011); • Hydrolytic methods (Davies & Hayes, 1988;Nanjo et al, 1991;Niola et al, 1993;Sato et al, 1998;Zamani et al, 2008); • HPLC -Ultraviolet (Aiba, 1986;Muzzarelli & Rocchetti, 1985); • Infrared (Baxter et al, 1992;Duarte et al, 2002;Kasaai, 2008;Miya et al, 1980;Moore & Roberts, 1980;Sannan et al, 1978); • 1 H nuclear magnetic resonance (Brugnerotto et al, 2001;de Alvarenga et al, 2010;Fernandez-Megia et al, 2005;Lavertu et al, 2003;Varum et al, 1991); • CP-MAS 13 C NMR (Heux et al, 2000;Manni et al, 2010;Raymond et al, 1993); • CP-MAS 15 N NMR (Kasaai, 2009;Yu et al, 1999); • Many other methods are described in the literature but with a somewhat smaller appeal. Some of these methods are: steric exclusion chromatography (Brugnerotto et al, 2001), nitrous acid deamination (Sashiwa et al, 1991), thermal analysis (Garcia Alonso et al, 1983), gas chromatography with columns packed with chitin and chitosan (Muzzarelli et al, 1980),...…”

Enhancing Biogas Production and UASB Start-Up by Chitosan Addition

“…and in a system for controlled liberation of medicines (capsules and microcapsules). In addition, chitosan has been used as a flocculant for the removal of metallic and colouring ions from industrial effluents by bonding the micro-floc particles together to form larger, denser flakes that are easier to separate (de Alvarenga et al, 2010;Renault et al, 2009). …”

“…Chitosan is obtained by partial deacetylation of chitin (de Alvarenga et al, 2010). Chitin is a -(1→4)-linked polymer of 2-acetamido-2-deoxy-d-glucose (N-acetyl-d-glucosamine) which exists in the exoskeletons of insects, crustaceans and the cell walls of fungi and algae.…”