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 (Tg) 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.

Microencapsulation of blackberry pulp with arrowroot starch and gum arabic mixture by spray drying.

This research work aimed to obtain blackberry pulp powder by spray drying and, by an experimental design, evaluated the effect of inlet air temperature (100-150 °C) and blackberry pulp solids:arrowroot starch/gum arabic solids ratio of 1:0.5-1:2 on the physicochemical properties of the powders. Arrowroot starch and gum arabic present glass transition temperature (Tg) values above 100 °C; hence it was possible to employ them as carriers in blackberry pulp spray drying in order to increase Tg of the system. Powder yield and solubility increased with increasing blackberry pulp solids:arrowroot starch/gum arabic solids ratio of 1:0.5-1:2, whereas hygroscopicity decreased. Yield, solubility and hygroscopicity of the powders increased and water activity decreased, with increasing inlet air temperature. The powders presented low moisture content and water activity. Temperature of 143 °C and blackberry pulp solids:arrowroot starch/gum arabic solids ratio of 1:1.78 were the optimal conditions to obtain high yield and blackberry powders that are soluble in water and less hygroscopic.