Effect of a new microwave-dried orange fibre ingredient vs. a commercial citrus fibre on texture and sensory properties of gluten-free muffins

Orange by-products are an important source of dietary fibre. The objective of this study was to compare two gluten-free muffins formulated with two different orange fibres: one obtained by hot air coupled with microwave drying (HAD + MW) of orange peels and the other commercially available. Physico-chemical and rheological properties of the fibre dispersions were analysed and compared to commercial citrus fibre. Texture profile (TPA) and sensory analysis were carried out on both muffins. Total dietary fibre, water retention capacity, viscosity and viscoelastic properties (G' and G") were higher for HAD + MW fibre. The development of stronger gel-like structures during HAD + MW drying could explain higher hardness and chewiness values found during muffins TPA. However, these differences were not negatively perceived by panellists, as they all preferred HAD + MW muffins due to their attractive colour, flavour, texture and chewiness. HAD + MW drying resulted in a potential technology for obtaining improved dietary fibre ingredients for gluten-free bakery. Industrial relevance: This work represents an approach to simultaneously solve and improve two current issues with gluten-free muffins: (1) to improve their nutritional and sensory properties and (2) to develop new processes for applying orange by-products as improved functional ingredients in bakery.