Development of arabinoxylans-based composite films for food packaging

• Autor(a) principal: Salvada, Joana Sanches
• Data de Publicação: 2022
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10362/133790
• topic: Arabinoxylan; Edible films; Oleic acid; Beeswax; Emulsion; Food packaging; Domínio/Área Científica::Engenharia e Tecnologia::Outras Engenharias e Tecnologias

In the last decades, the overuse of synthetic polymers in the plastic packaging industry has become a serious global environmental problem due to their non-biodegradability. To overcome this issue, industries and researchers have joined efforts to decrease the amount of synthetic materials used by exploring alternatives from renewable resources, aiming at developing biodegradable and biocompatible packaging materials. In this context, edible films and coatings based on biodegradable biopolymers have been gaining a significant importance as they present a promising solution for the issue at hand. In this thesis, the polysaccharide arabinoxylan, extracted from corn fibre by alkaline hydrolysis, was used to produce composite and multilayer edible films. The composite films were produced through an oil-in-water emulsion with different quantities of oleic acid or limonene, while the multilayer films were manufactured by submerging the arabinoxylan films in a beeswax solution. Both films, along with the pure arabinoxylan film, were later characterised in terms of their antioxidant activity, optical and mechanical properties, surface hydrophobicity, and barrier properties against water vapour and Ultraviolet-Visible (UV-Vis) radiation. The emulsified films were found to be heterogeneous and thick, presenting worse water vapour permeability and surface hydrophobicity properties, and a lower antioxidant activity than the pure arabinoxylan films. On the other hand, the multilayer films revealed a smooth and uniform beeswax coating, which enhanced the films’ barrier properties against water vapour and UV-Vis radiation. Moreover, these films showed higher values of water contact angle, tensile stress and Young’s modulus, but lower elongation at break than the composite films. The results suggest that the multilayer films are more advantageous than the emulsified films. Therefore, the production of the developed biopolymeric films will have a positive outcome, contributing to improve sustainability practices in the food packaging sector.