CLSM study of layers in laminated dough: Roll out of layers and elastic recoil

• The median thickness of fat measured was close to the theory above 3 sheeting steps.
• Fat with higher melting point did not reach the theoretical thickness value.
• The quantity of dough was 20–90% higher than the target due to elastic recoil.
• There was no significant effect of a harder fat consistency on elastic recoil.
• The higher the amount of fat in the sample, the less the elastic recoil of dough.

It has been thought that all fat and dough layers in laminated dough had the same thickness at the end of lamination. Moreover dough rheology (taking into account elastic recoil) is too complex to generalize calculation of the final thickness of the dough after lamination. Confocal laser scanning microscopy can differentiate the fat from the dough when combined with fluorophore staining (Nile Red and Alexa), and an algorithm was applied to quantify their respective thicknesses. When fat consistency was close to that of dough, the median thickness of fat was fairly close to theoretical values. Successive sheeting steps resulted in homogenization of layer thicknesses. The surface area of fat in relation to paste was greater than expected, especially for low numbers of sheeting steps, and also for samples with higher numbers of sheeting steps, presenting an exceptionally thick layer of fat (including that produced by back flow). Elastic recoil was between 20 and 90% higher than the targeted roll out; no significant effect of a harder fat consistency was found. Elastic recoil was less when the amount of fat in the sample was greater.