Inflation, squeezing and collapse in wheat flour dough during baking: effects of flour quality and oven temperature

LUCAS, TIPHAINE; VANIN, FERNNANDA ; URETA M. MICAELA; CHALLOIS, S; DIASCORN, YVES; SALVADORI VIVIANA O.; GRENIER, DAVID

JOURNAL OF CEREAL SCIENCE (PRINT)

ACADEMIC PRESS LTD-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2020

0733-5210

An existing method to assess variations in local gas fraction (Wagner et al. 2008, J. Cereal Sci. 27(4), 577?585) wasfurther developed and successfully adapted to real bakery products (pan bread, baguette). Local inflation was found tobe temperature-dependent for as long as cells remained closed. Collapse in unbalanced dough was monitored byMRI, showing that local inflation at the core occurred simultaneously with a pronounced overall decrease in the doughsection. Maximal inflation in unbalanced dough is maximal while crust is still deformable (not set)did not coincide withcrust setting but occurred when core inflation counterbalanced the collapse of the peripheral dough layers. Crustsetting occurred later, during the overall decrease in the dough section. The formation of a rigid shell halted collapseand led to a slope reduction in the dough-section decrease which then continued at the pace of the shrinkage of theporous structure upon dehydration. Squeezing occurred in the peripheral crumb layers when the rapid expansion ofthe dough core encountered the limitations in overall expansion introduced by crust setting; consistent with this view,squeezing started when the overall rate of dough inflation slowed (causing a break in the slope), and finished at thecessation of core inflation. The slow rate of decrease in overall dough area (<1% per min) was associated with thedownward and upward displacement of the upper and lower dough surfaces respectively and was assigned todehydration-induced shrinkage. Calculations of local strain and strain rates confirmed a preponderance of large strains(0.20-0.30) and low strain rates whether in extension or compression (10-3 s-1).