Study the influence of waxy wheat flour, inulin and guar gum on quality and microstructure of Pita and Tandoori breads: response surface methodology aids functional food development.

A diet high in dietary fibre (DF) is thought to help reduce cholesterol levels, may control blood glucose levels and reduces gut transit time. However, people often fail to consume the recommended quantity of DF. The aim of this study was to supplement two types of bread with some novel functional food ingredients; waxy wheat flour (WF), inulin (IN) and guar gum (GG) to develop products rich in DF. Response surface methodology (RSM) was employed to study the effect of DF on two different breads. Breads were assessed using Cryo-SEM for its microstructure pattern, and physical attributes (pita; springiness, chewiness and hardness, Tandoori; hardness and elasticity). The results showed that, for pita bread, the outcome showed that IN and GG alone significantly increased hardness and chewiness and decreased springiness. WF addition only decreased springiness. GG linearly increased pita height and volume, but it quadratically increased weight loss. Moreover, IN increased volume and height in a quadratic way. Regarding Tandoori bread, IN reduced bread toughness, but showed no effect on extensibility. WF alone increased volume and diameter. The microstructure also showed that the novel ingredients modified starch gelatinisation and gluten-starch matrix in both pita and Tandoori breads differently. Therefore, the influence of the three functional ingredients alone and in combinations influenced quality parameters dissimilarly.