Corn starch and gelatin-based films added with guabiroba pulp for application in food packaging

The guabiroba pulp (GP) has natural antioxidant compounds, such as phenolic compounds and ascorbic acid. The aim of this work was to produce an active biodegradable film based on blends of gelatin (GEL) and corn starch (NCS) and activated with GP, for application as package for extra-virgin olive oil, as a sachet. For that, the effect of blends composition was first evaluated in passive films, and then, a formulation was chosen to produce the active film with guabiroba pulp. The effect of the incorporation of GP on the barrier, mechanical and optical properties of these films was studied, and the antioxidant effect on the storage of extra virgin olive oil was verified in a specific test. Blends with GEL (5 and 10%) and NCS (2 and 4%) were prepared, in the different ratios. The film with 5% GEL and 2% NCS in the 1:1 ratio, was selected for the addition of GP (10 and 20%). The addition of GP caused a reduction in tensile strength and increased elongation values. The film with 10% GP was selected for the preparation of the sachet, due to its lower value of water vapor permeability. At the end of the storage period (15 days), the values of acidity index and peroxide index of the extra-virgin olive oil did not reach the maximum limit allowed by the current legislation. It can be concluded that the results obtained may be useful for future studies and applications using active and biodegradable packaging.