Extruded flour as techno-functional ingredient in muffins with berry pomace

Blackcurrant pomace is a by-product from fruit juice production, which is rich in polyphenols and dietary fibre. When added to bakery products, its high fibre content has detrimental effects on dough/batter viscosity and on the texture and the structure of the final product. In this study, wheat flour extruded at different temperatures was used to replace 50% of wheat flour in a muffin formulation to counteract these detrimental effects. In addition, the effect of blackcurrant on the glucose release during in vitro digestion was analysed. The extrusion treatment of the flour caused a disruption of the starch granules, and affected starch characteristics such as water binding capacity and swelling. Its incorporation in muffins did not produce important differences in texture, nor in consumer acceptance, compared to a standard formulation. Moreover, the addition of blackcurrant counteracted the hyperglycaemic effect of pre-gelatinised starch. •Flour extrusion increased water binding capacity and glucose release.•The use of extruded flour modified structure and rheology of the batters.•No changes in muffins acceptance were detected when extruded flour was used.•Berry pomace counteracted the increase in glucose release caused by gelatinized starch.