Emulsificantes com diferentes EHL (Equilíbrio hidrofílico-lipofílico) em filmes de amido de mandioca

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

The exhaustion of petroleum world wide reserve and the preoccupation with the enviromental preservation have served as incentive for the development of biodegradable films. Cassava starch is widely produce in the brazilian industry and present characteristics that allow the use of this agropolymer as raw material for this finality. As a way to improve film stability, cassava starch films with addition of emulsifiers span 80 and tween 80 (at 0.5, 1.5 eand 2.0% level) were developed. The films were evaluated with prespect to mechanical, barrier, thermal, optical and microstructural properties. The film containing 2.0% span 80 presented phase separation, with formation of microdroplets, that damaged the homogeneity and integrity of the films. Glass transition temperature decreased with the addition of emulsifiers, from 54 to 43ºC. Isotherms and kinetics showed the behaviour of the films in different relative humidity and addition of the emulsifiers did not modify the hydrofhilicity. The samples did not show diference in water permeability. Mechanical properties (tensile and puncture) showed that film with 2.0% span 80 was less resistant that others. Infrared spectra showed that raw materials and films have the same chemical linkages and interactions. Thus, the addition of span 80 and tween 80 emulsifiers did not improve the barrier properties and stability of the films.

ASSUNTO(S)

amido de mandioca - filmes alimentos - embalagens filmes biodegradáveis - emulsões biodegradable films starch emulsions

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