Development and characterization of active edible film with blueberry residue extract ( Vaccinium spp.)

Blueberry ( Vaccinium spp.) processing produces residues high in antioxidant compounds, such as peels, seeds, and stems, which have the potential to be employed in a variety of products. Using extracts containing bioactive components (e.g., polyphenols and anthocyanins) to produce active edible films is an attractive application. In this regard, the objective of this work was the development and characterization of an active edible film with blueberry residue extract. The extracts were obtained by ultrasound-assisted extraction with 60% hydroethanolic solvent (1:10 m/v of residue) for 25 min at 30 ± 2 °C and 80% of total power (132 W) at 40 kHz. The extract was analyzed for total phenolic compounds and antioxidant activity (DPPH). Cornstarch and glycerol were used to formulate the films, which were characterized according to grammage, thickness, moisture, antioxidant activity, color, and visual parameters. The extraction yield was 207.2 mg/g of residue, the IC 50 values ranged from 0.118 to 0.144 mg/mL during 28 days of storage, and the average content of phenolic compounds was 58.18 mg GAE/g dry extract. In the active edible films, the grammage ranged from 0.0131 to 0.0143 g/cm 2 , the thickness was between 0.15 and 0.23 mm, and the moisture content was from 17.19 to 18.00%. The antioxidant activity of the films containing blueberry residue extract ranged from 52.65 to 76.02%, corresponding to extract concentrations of 0.25 and 2.6 mg/mL of filmogenic solution, respectively. The color parameter showed that when the extract was added, the films became less bright, leaning toward red and yellow. In general, the samples demonstrated good integrity, brightness, and clarity.