Effect of amylose:amylopectin ratio and rice bran addition on starchfilms properties

Autores UPV


tThe influence of the amylose:amylopectin ratio on the properties of pea, potato and cassava starch filmsand the effect of the incorporation of rice bran of two different particle sizes were studied. The structural,mechanical, optical and barrier properties of the films were analyzed after 1 and 5 weeks. The high con-tent of amylose gave rise to stiffer, more resistant to fracture, but less stretchable films, with lower oxygenpermeability and greater water binding capacity. Although no changes in the water vapour permeabil-ity values of the films were observed during storage, their oxygen permeability decreased. Throughoutstorage, films became stiffer, more resistant to break, but less stretchable. Rice bran with the smallestparticles improved the elastic modulus of the films, especially in high amylose content films, but reducedthe film stretchability and its barrier properties, due to the enhancement of the water binding capacityand the introduction of discontinuities.