The effects of temperature and time on certain properties of different molecular weight chitosan powders (both modified and unmodified) are described in this research thus allowing to simulate the conditions at bread baking (temperature in the interval from 100oC to 200oC; time – up to 15 min.). In the same time investigations on the high molecular chitosan film mechanical and barrier properties are carried out in comparison with those of middle and low-molecular chitosan films. Several testing methods, including microscopy, differential scanning analysis, thermogravimetry, stress-strain analysis as well as viscosimetry have been used to carry out the above mentioned investigations.