Optimizing Extraction of Bioactive Compounds from Grape Pomace to Produce an Eco-Friendly Smart Straw

Grape pomace (GP) is a byproduct rich in bioactive compounds. This study optimized the extraction of these compounds using a Central Composite Rotational Design (CCRD 2²), evaluating temperature (41-69 °C) and time (0.8-3.2 h). The optimized extract (GPE) showed high phenolic content (163.99 mg GAE/L), anthocyanins (136.46 mg C3GE/L), and antioxidant activity (69.21% DPPH). GPE was incorporated into babassu mesocarp starch (BS) films, producing an active smart film (GPE-BS) that changed color at extreme pH (2 and 13). The GPE-BS film also showed improved hydrophobicity, antioxidant activity, and elongation at break compared to BS films (control). When tested as a straw for sugar-free cola, the film maintained structural integrity for 2 h. Thus, GPE-BS films are promising for smart food packaging or as edible straws.