Faba bean foods: Structure and texture : Evaluation of faba bean component behaviours in different product matrices

Sammanfattning: Faba bean (Vicia faba minor) is a cool-climate crop that could serve as a locally sourced sustainable ingredient in transition towards a more plant-based diet in temperate regions. Poor texture is one of the main aversion factors of plant-based foods, so this thesis characterised the functionality of faba bean components and their effect on structure and texture in different food matrices. The main aim in this thesis was to increase the knowledge on structure-texture relationship in increasingly complex faba bean food prodcuts.Isolated faba bean fractions (starch, protein and fibre) were studied. Faba bean starch was physiochemically characterised and microscopic and macroscopic properties were correlated. Different ratios of starch and protein were then combined to create mixed gels. Faba bean starch formed a relatively viscous paste due to long branch-chains, high amylose content and larger granule size. Addition of protein perturbed starch network formation, delaying and reducing associated pasting and gel viscosities in mixed systems. For food model systems, two prototypes were designed: i) a combination of faba bean starch, protein and fibre to produce edible ink for 3D-printed foods and ii) faba bean protein films reinforced with cellulose nanocrystals (CNC) for use as bio-degradable edible packaging. For the 3D samples, fibre appeared to have a stabilising effect on structure, improving ink printability while also ensuring that 3D-printed objects retained their shape. Carbohydrate-rich 3D-printed objects had a more porous structure that required less force to compress than structurally more compact protein-rich objects. Addition of CNC resulted in stronger, stiffer and more opaque films with improved barrier properties.Thus faba bean fractions in different combinations and processing approaches yield different textures. Using the basic knowledge of component functionalities in simple systems obtained in this thesis, intra- and intermolecular factors influencing product texture in more complex systems can be assessed.