Active edible coating for lipid oxidation control in Brazil nuts

Abstract

The aim of this study was to evaluate the effect of adding a lipid antioxidant (tocopherol) and a surfactant (soy lecithin) to carboxymethyl cellulose (CMC) films. CMC film-forming solutions containing sorbitol, soy lecithin, and different tocopherol concentrations (0.125% and 0.250% tocopherol mix) were produced. The solutions were characterized for their rheological, optical, antioxidant, phenolic content, and stability, and were then applied as edible coatings to whole and broken Brazil nuts. The mass gain and degree of lipid oxidation of the coated and control nuts were evaluated. Special emphasis has been given to the antioxidant properties of the solution, as they are decisive for the use of the solutions as a coating to prevent or retard lipid oxidation. The solutions had a pseudoplastic character; the viscosity varied as the temperature changed, and the modules G′ and G″ depended on the applied frequency ranges. The coated nuts showed oxidative stability against the T4 coating formulation during the storage period. It was concluded that the T4 coating has the potential to be used as active packaging for foods with a high lipid content to prevent or delay oxidation processes.