Multivariate exploratory data analysis by PCA of the combined effect of film-forming composition, drying conditions, and UV-C irradiation on the functional properties of films based on chitosan and pectin

The technical features of biodegradable films depend on several manufacturing parameters. Exploiting these films on an industrial basis requires statistical models for the fast and effective evaluation of these parameters. This study analyses the impact of compositional and drying factors on the microstructural and functional properties of films based on chitosan and pectin through a multivariate approach. A total of 32 formulations were developed and the results were analysed through principal component analysis (PCA). Four formulations did not form films due to the photodegradation caused by prolonged UV-C irradiation. Films containing glycerol had a higher elasticity (1.5–39%) than those with propylene glycol or that were not plasticized (1.2–12%). Glycerol increased the thickness of pectin films (56–77 μm). Sodium trimethaphosphate (STMP) enhanced the UV mean absorbance of both pectin and chitosan films (0.7–1.7). In addition, STMP led to an increase of thickness (72–129 μm) and air permeability (38.6 × 103 to 9206.1 × 103 cm3/m2 × day × kPa) of the chitosan films, while CaCl2 led to a decrease of thickness (31–59 μm) and air permeability (23.9 × 103 to 46.8 × 103 cm3/m2 × day × kPa) of the pectin films.