We also observed significant differences in volume increase during baking (see Table 4). Muffin volume was 90 mL for REF and as low as 71 mL when FA was used as filler. Muffin height varied from 45.4 to 48.2 mm, and muffin diameter from 63.4 to 71.8 mm. This indicates that lateral expansion during baking contributes to volume increase to a larger extent than the increase in height. Product density, calculated from mass and volume after baking,was 0.39 g/mL for muffin IF, 0.41 g/mL for REF, and 0.42 g/mL for PD and MD. Highest density values were obtained for muffins FP (0.49 g/ mL) and FA (0.51 g/mL). As cake density is inversely related to the amount of air in the batter (Indrani & Rao, 2008), this indicates that either foaming capacity or foam stability during baking is negatively affected by these fibres.