Bioactive Edible Films Based on Arrowroot Starch Incorporated with Cranberry Powder: Microstructure, Thermal Properties, Ascorbic Acid Content and Sensory Analysis

The growing global awareness about environmental preservation has stimulated the search for alternatives to replace conventional plastics made from fossil sources. One of the advantages is using polymers from renewable sources, such as starch and gelatin, which, in addition to being biodegradable, may also be edible. The incorporation of cranberry into a polymeric matrix can transfer bioactive composite films, colour and flavour to the film, which are characteristic of this fruit, expanding its application to fruit stripes or colourful coatings for specific foods. In this context, the aim of this work was to evaluate the influence of the incorporation of 0, 5, 15, 25, 35, 45 and 55% (solids mass/biopolymer mass) cranberry powder on the microstructure, thermal properties, ascorbic acid content and sensory analysis of gelatin and arrowroot starch films obtained by casting. Scanning electron microscopy (SEM) images showed that the incorporation of cranberry made the film surface rough and irregular. All films presented an X-ray diffraction pattern typical of a semicrystalline material. The glass transition temperature (T(g)) decreased when increasing the concentration of cranberry in films. All films with cranberry presented high ascorbic acid content and were well accepted by the tasters when sensory analysis was performed.