Effects of dispersing media and heating rates on pasting profiles of wheat and gluten-free samples in relation to their solvent retention capacities and mixing properties

Four commercial wheat flours and two commercial GF bread mixtures were investigated in this study. The main aim was to find time-, cost- and sample-saving methods able to determine the quality characteristics of these materials in relation to their end-use and to the interactions taking place in the various systems. Samples were mainly characterized by Solvent Retention Capacity (SRC) and Rapid Visco-Analyser (RVA) tests. Mixogram and Confocal Laser Scanning Microscopy were adopted to investigate dough networking. In particular, RVA tests were performed adopting various heating rates and dispersing media, to: 1) investigate how different heating/cooling rates could affect samples' pasting properties; ii) evaluate the role of alpha-amylase activity in controlling RVA profiles; iii) determine the contribution of proteins to RVA profiles. Interesting results were obtained in particular from SRC and RVA, suggesting that going beyond their conventional use as standard methods was feasible and very profitable. In fact, both the approaches well differentiated not only common and durum wheat flours but also the GF mixtures (e.g. WRC values ranged from 53.7 +/- 0.1 to 152.1 +/- 0.8 g/100 g db, and peak viscosity - measured at a heating rate of 3 degrees C/min - from 682 +/- 72 cP to 4026 +/- 11 cP).