Produção de filmes de amido extraído de banana prata verde (Musa sapientum) modificados com plasma DBD em múltiplas etapas

• Ano de defesa: 2021
• Autor(a) principal: Marenco Orozco, Gerald Alberto
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Palavras-chave em Português: Amido de banana; Filmes comestíveis; Descarga de barreira dielétrica; Otimização; Propriedades mecânicas; Molhabilidade
• Link de acesso: http://www.repositorio.ufc.br/handle/riufc/60001

Films from biopolymers have been studied in recent years in order to determine and improve their physical properties of mechanical strength and wettability. This study uses banana starch (Musa sapientum) of Prata variety; for this, it is first determined that the optimal method of extraction of starch granules in the pulp is by means of a solution of sodium bisulphite (NaHSO3), 4% (m/v) at 1:3 ratio (pulp/solution) and subsequent centrifugation, drying and grinding. Therefore, this starch extracted from bananas is used to produce films using the casting method, and a 2k experimental design is applied to study the effects of the dielectric barrier discharge plasma (DBD) in the frequency of 400 Hz and voltage of 20 kV for 15 minutes in three treatment phases: granular phase, filmogenic suspension phase and final phase. Films treated with either plasma treatment had a higher short-range ordered structure degree or crystalline/amorphous ratio (CAR) than untreated films. Scanning electron microscopy (SEM) used in films shows that there are differences in the surface of the films, especially those treated in the suspension phase (PG group) and in the final phase (PF group). Regarding the wettability tests, the PSPGNF and PSPGPF films presented the lowest values of moisture (<9.5%) and solubility (<31.1%). On the other hand, the PSNGPF film has the highest contact angle with water (65.1°) and tensile strength (9.11 MPa), and offers good puncture resistance (0.33 MPa out of a maximum of 0.42 MPa). Neither of the treatments presents significant difference for Young's modulus nor the elongation at break in puncture test. It is concluded that the DBD plasma optimizes, in the initial and in the final phases of film production, the mechanical and hydrophobicity properties necessary for the quality of packaging and food coating.