Biscuits Enriched with Dietary Fibre Powder Obtained from the Water-Extraction Residue of Maize Milling by-Product.

A maize milling by-product was defatted by aqueous extraction and the residue was dehydrated, comminuted and sieved to obtain two powders differing in particle size and having a very high fibre content. The powders were then incorporated into the structure of short-dough biscuit, at two wheat flour substitution levels (10 and 20%), aiming at the development of a nutritionally improved product. Their impact on biscuit dough properties and the quality and sensory characteristics of the final products was evaluated. As it was revealed, powders' addition altered dough consistency and alveograph indices mainly due to interactions between wheat flour proteins and polysaccharides and enhanced the nutritional profile of the biscuits by inducing a 4- to 6-fold increase of their fibre content. Additionally, it influenced only to a limited extent the degree of some of the final product characteristics, e.g., protein and fat content, spread ratio, breaking strength, depending both on the level of incorporation and the particle size of the residue. On the whole, products' sensory quality was not negatively influenced, suggesting that it is possible to use both powders for the fortification with fibre of biscuits and possibly other bakery products.