Development of bakery formulation for sprayable cake preparation

The aim of this work was to create an innovative sprayable bakery mix for foam-style cake preparation. The main goal was to obtain a batter liquid enough to be easily and quickly dosed in a spray system but maintaining its structure during baking. A commercial liquid batter was selected, and its recipe modified to fit in a spray system. The commercial bakery mix was characterized in terms of physical-chemical, thermal, and rheological attributes. The product was then diluted with milk or whipping cream at a 3:1 (gproduct/gdiluent) ratio to modulate its viscosity to be sprayed in a nitrous oxide loaded siphon system. All the prepared samples were characterized in terms of physicochemical properties at different stages of cake production (before and after spraying, and after baking) to investigate the effect of dilution on rheology and spray-ability and on the texture of final cake. Before cooking, the dilution determined an increase of water content and activity and a remarkable difference in colour coordinates compared to the reference. However, the differences in physicochemical parameters were minimized after baking due to water content reduction and non-enzymatic browning phenomena. Despite that, the diluent type affected thermal characteristic peaks linked to fat melting and starch gelatinization phenomena, respectively. In fat melting, whipping cream addition maintained enthalpy values similar to control due to the high lipid content balancing the dilution effect. Instead, the greatest water amount in milk contributed to fat reduction and enthalpy reduction. In starch gelatinization, both milk and cream addition determined a reduction of the associated total energy due to a starch dilution effect. From a rheological point of view, a significant decrease in viscosity enabled the diluted batter to be sprayed. All samples displayed shear rate dependent and shear-thinning behaviour. When the batter was sprayed the values of apparent viscosity suddenly increased, probably due to a reduced droplet size, minor average interparticle distance and the interaction of foaming agents and proteins. After baking, sprayed samples showed firmness and springiness comparable to the control cake. However, the cakes from both the diluted batters presented some cooking defects typical of an incorrect leavening process enforced by yeast dilution and lack in aeration stability during baking.