Structure characterization of chitosan and methylcellulose films

PINOTTI, A.; GARCIA, M.A.; MARTINO, M.N.; ZARITZKY, N.E.

Cork, Irlanda

Conferencia; Conference on Food Structure and Food Quality, AOCS; 2004

AOCS

Films from biopolymers comply with environment concerns and consumer demands for higher quality food products. Chitosan (CH) and methylcellulose (MC) are hydrocolloids with good film forming properties. The objectives were to characterise the filmogenic suspensions (rheological behaviour) and composite film structure (mechanical properties, water vapour permeability, WVP and SEM). Suspensions of 1 and 2 % CH and 1% MC were mixed in different proportions. All suspensions were pseudoplastic; apparent viscosity of the mixtures were higher than those of individual component suspensions. Films were obtained by casting. Barrier and mechanical properties of biofilms depend on its composition and microstructure as seen by SEM micrographs. WVP of biofilms ranged between 9.03 and 7.55 ×10-11 (g/sec m Pa). Desired mechanical properties of films can be obtained by modifying MC-CH ratio. Film flexibility increased with MC content, the higher elongation and lower elastic modulus of composite films indicated the relevance of hydrocolloid interactions.