Abstract

The aim of this study was to develop edible coatings containing natural additives incorporated to the matrix of cassava starch, for use in muffins, as well as to evaluate the efficacy of its use in the increase of shelf life and maintenance of the products characteristics. Seventeen film forming formulations were developed following a central composite experimental design (CCD). The influence of independent variables (soluble coffee, cocoa powder and propolis extract) was determined on the sensorial (colour, taste, texture and dissolution) and physical-chemical parameters (water activity, humidity, hardness, chewiness, cohesiveness and elasticity) of the muffins with edible active coatings. Two new formulations were selected for the study of microbiological and physical-chemical stability during the storage. In the sensorial evaluation, it was verified that the variables studied exerted a significant effect (p<0.05) for colour, taste and solubility of the coated product. Regarding the texture, none of the variables showed a significant effect (p>0.05). For colour, the concentrations of soluble coffee and cocoa powder were significantly influenced (p<0.05) both by the tasters and by instrument (L*, a*, and b*). In the shelf life test, the active coating containing soluble coffee (0.76%), cocoa powder (0.22%) and propolis extract (0.82%) increased the shelf life of the muffins in up to six times, when compared with the control. The result was approximately 87 days shelf life in normal storage conditions (25°C). It was evidenced that the additives tested have an antimicrobial action, associated to the preservation of the other stability properties of the product.

Key words: Additives, stability, shelf life, edible coatings.