Bi-layer gelatin active films with "Pitanga" leaf hydroethanolic extract and/or natamycin in the second layer - Luciano, Carla Giovana; Tessaro, Larissa; Lourenço, Rodrigo Vinicius; Bittante, Ana Mônica Quinta Barbosa; Fernandes, Andrezza Maria; Sobral, Paulo José do Amaral (Journal of Applied Polymer Science, 2021)