Comparison of Physical and Functional Characteristics of Biodegradable Smart Films Embedded with Betacyanin-Rich Extracts from Different Sources

This research aimed to develop and compare smart biodegradable chitosan-based films incorporated with betacyanin-rich extracts [Avila-Ospina et al. in J. Exp. Bot. 65:3799-3811, 2014] from beetroot and red-fleshed dragon fruit (RFDF). Beetroot BRE contained two-fold higher betacyanin content than RFDF one, so to prepare the same betacyanin amount added into films, the BRE concentrations from beetroot (3, 5, and 7%, w/w) and RFDF (6, 10, and 14%, w/w) were used. The betacyanin-embedded films exhibited pink-red color with a smoother cross-sectional facade and better flatness than the ones without betacyanin. When betacyanin was involved, no observable variations in the FTIR spectra of these films were noticed. Furthermore, the presence of betacyanin could increase tensile strength, elongation at break, and antioxidant activities of the formulated films, but lessen their light transmittance, moisture content, swelling ratio, and water vapor permeability. Additionally, their thickness, elongation at break, and antioxidant activities intensified along with the raising content of betacyanin, while other optical and physical characteristics diminished. Both types of BRE provided the films a sensitivity towards ammonia but BRE from RFDF resulted in a faster color change, up to 10 min, compared to up to 30 min for BRE from beetroot. This implies the more potential of the former as an indicator in development of smart packaging.