Development of edible films based on sweet potato (Ipomoea batatas) starch and their application in candy packaging

Recent studies have focused on the generation of biomaterials from natural sources, highlighting the use of starch from different sources to obtain edible films and coatings. In this study, edible films were developed from sweet potato starch, and their potential use in candy packaging was evaluated. Films were prepared by the casting method, and the effects of sweet potato starch (3 %–5 % w/w), glycerol (0.8 %–1.2 % v/v), and calcium carbonate (0.05 %–0.1 % w/w) on the physical, structural, optical, and barrier properties were examined using a completely randomized design. The sweet potato starch presented granules with a spherical appearance and a swelling capacity of 1.33 g/g at 80 °C. ANOVA results showed that starch content and glycerol–calcium carbonate interaction affected the thickness and color parameters. The water vapor permeability and water solubility increased with increasing starch and glycerol concentrations. Fourier transform infrared spectroscopy (FTIR) analysis of film microstructure showed increase in the band intensity, indicating modification of the starch structure. The film with sweet potato starch, glycerol, and calcium carbonate concentrations of 3 %, 0.8 %, and 0.1 %, respectively, used for candy packaging, endowed the product with good sensory acceptance during the 21 days of storage, although the product displayed slight changes in the color.