Effect of starch laurate addition on the properties of mango kernel starch films

Abstract

In this work, starch obtained from mango kernel seeds was applied in the preparation of films in combination with its hydrophobic derivatives. Chemical modification of starch was carried out at two different concentrations of vinyl laurate, in dimethyl sulfoxide, under basic catalysis. The degrees of substitution of the starch laurates were 2.4 and 0.3, respectively. None of the products formed films when dispersed in water. However, blends of starch/starch laurate (degree of substitution = 0.3) formed films after microfluidization of their aqueous suspensions. The blends with up to 15% wt of starch laurate (degree of substitution = 0.3) resulted in films of higher elongation at break, higher opacity and lower tensile strength and elastic modulus. The microfluidization of biopolymer suspensions was crucial to obtain films with lower water vapor permeability. X-ray diffraction results corroborated to the mechanical properties of the films, showing that the incorporation of starch laurate reduced the starch films crystallinity.