Recent market developments raised the need for alternatives to hydrocolloids as texture improver in gluten-free bread. Chickpea exerts several physicochemical properties (water- and oil-binding, emulsifying and foaming) that might address this need. Therefore, the effect of processing on chickpea functionality was tested on low ingredient dose, comparably to that of common hydrocolloids. Control bread was small, hard and with low gas retention ability as shown by microscopy, depicting holes inside crumb pores. Addition of chickpea flour in low dose (2% w/w) enhanced loaf volume by 20% and reduced crumb hardness by 40%, due to increased gas retention (no holes within pores) and superior homogeneity of the starch-protein network. On the contrary, chickpea paste deleteriously affected bread quality due to loss of solubility upon cooking. Interestingly, both soaking and cooking water significantly reduced crumb hardness, although to a lower extent than the flour. More homogeneous crumb structure and gas retention were observed in the micrographs, possibly due to the emulsifying activity of flavonoids and saponins (soaking) and insoluble fibre (cooking). Chickpea ingredients are promising substitute of hydrocolloids such as xanthan gum for texture improvement of gluten-free bread, although acting with different mechanisms.
Keywords: Bakery products; digital image; food ingredients; food texture; legumes.