INNOVATIVE EDIBLE FILMS BASED ON PEIXINHO DA HORTA AND AGAR-AGAR: DEVELOPMENT AND CHARACTERIZATION

The growing demand for healthy eating has driven the consumption of vegetables, including Unconventional Food Plants such as peixinho-da-horta. However, its limited availability still restricts consumption, which can be expanded through the production of edible films. Within this context, the main objective of this study is the production of edible films based on dehydrated peixinho da horta (PHD) with different concentrations of agar-agar (C_agar-agar). The films were produced with 1 g of PHD and 2 or 2.5 g of C_agar-agar and characterized in terms of visual evaluation, proximate composition, antioxidant activity (ABTS•+, FRAP), total phenolic compound release, and sensory evaluation. It was observed that C_agar-agar did not influence the visual characteristics or the proximate composition of the films, which presented a heterogeneous surface and values that did not significantly differ in terms of moisture (~22 g/100 g w.b.), ash (~2 g/100 g w.b.), lipids (~2 g/100 g w.b.), and proteins (~3.8 g/100 g w.b.), making them a source of protein with a low lipid content. In the ABTS•+ method, the films showed values of 5.09±0.99ᵃ and 4.38±0.59ᵃ μM TE/g of edible film, while in the FRAP assay, values were 20.66±1.81ᵃ and 18.94±2.23ᵃ μM TE/g of edible film for the formulations containing 2 g and 2.5 g of C_agar-agar, respectively. The Peppas and Sahlin model provided the best fit for the release kinetics (R² = 0.91 and 0.93 for 2 g and 2.5 g of C_agar-agar, respectively). The 2.5 g formulation reached 215.89 mg GAE/100 g of edible film (t = 300 min), while the 2 g formulation reached 372.26 mg GAE/100 g of edible film (t = 70 min). Both formulations proved to be a source of antioxidants and total phenolic compounds, with the lower polymer concentration leading to a faster release of these compounds. Regarding sensory analysis, no significant differences were observed in aroma, color, flavor, or overall appearance, with scores ~6. However, increasing the agar-agar concentration reduced the acceptance of the edible films in terms of texture, with scores of 4.89±2.12ᵃ (2g) and 4.51±2.07ᵇ (2.5g). Thus, PHD-based films exhibited similar proximate composition and antioxidant activity among the tested formulations. A lower concentration of agar-agar resulted in a faster release of phenolic compounds, while a higher concentration reduced sensory acceptance in terms of texture. Therefore, the films demonstrated potential as a source of antioxidants and proteins, with overall acceptance by the panelists, making them an innovative product.