Abstract

The effect of alkali/chitin ratio, temperature and reaction time on chitosan obtained from lobster chitin under homogeneous conditions was investigated. Conversion of chitin to chitosan through time was evaluated by means of soluble material determination in acetic acid. Acetylation degree and viscosimetric molecular weight expressed by relative viscosity of chitosans were determined. The best treatment was the one using an alcali/chitin ratio of 140 mL.10 g-1 at 30ºC and six days of reaction time. In addition, chitosan characteristics were compared with a SIGMA reagent product and differences were only appreciated at the desacetylation degree. Antifungal activities of chitosan from the best treatment and SIGMA chitosan were compared and there were not significant differences between them, but with the control treatment.