Pizza under the toppings: macro and microstructure of different Italian pizza types

Various kinds of pizza, different for dough base preparation, sauces and topping, are available according to the customs and traditions. Differences in dough preparation likely affect product structure. This work aimed at investigating the macro and microstructure of the most widespread pizza styles in Italy: Neapolitan Pizza (NP) and Romana Pizza (RP) with a doughy crust, and “Pizza al Piatto” (PP) with a crispy crust. Flour with high proteins (14%) and farinograph stability (8 min) was used for all the samples. Pizza-making processes differed for hydration, mixing, leavening, and baking conditions. The thickness and the honeycomb structure of both the outer edge and the internal disk bread were evaluated by Image Analysis and Light Microscopy. NP - which is defined as Traditional Specialty Guaranteed (TSG) food by the European Commission (Council Regulation 97/2009) - exhibited a high outer edge (about 25mm) where the large alveoli (>3mm²) represented more than the 80% of the porous area even if their number was less than 10%. This organization was similar to that of RP and very different to that of PP, where small (<1mm²) and medium (1-3mm²) alveoli represented more than 25% of the porous area. The long home-made dough preparation (30min) and the long proofing step (12h at 25°C) of NP promoted the development of large alveoli and a network with thick protein strands (>200-300 micron) that were able to expand while baking in the wood-fired oven. Whereas, the mechanical kneading used for PP promotes the development of thin proteins strands (50-100micron) which were responsible for a less porous structure and a more crispy crust. In conclusion, dough-making process greatly affected pizza structure. Differences in structure between NP and PP lead us to investigate their digestibility.