CHANGES IN SIZE OF GAS CELLS IN DOUGH AND BREAD DURING BREADMAKING AND CALCULATION OF CRITICAL SIZE OF GAS CELLS THAT EXPAND

Abstract

ABSTRACT Microscopic observation showed that a group of small air cells entrained during the early stage of mixing is the original cause of cell structure of bread. At the beginning of fermentation, about 3 × 10 8 /m 2 gas cells with diameters between 3 × 10 −6 and 8 × 10 −4 m were entrained in the dough. The distribution curve of cell size was approximately normal on a logarithmic scale. During fermentation and proofing, a great portion of carbon dioxide was released into cells larger than about 10 −4 m in diameter that was equivalent to a few percentages of total number of gas cells. After baking, gas cells smaller than 10 −4 m in diameter were not observed and the total number of cells in baked bread reduced to about 10 6 /m 2 with diameters between 10 −4 and about 5 × 10 −3 m. The critical cell size to expand generally agreed with the calculated value using an equation, rc’= 3s/E (re': critical radius to expand, s: surface tension, E: elasticity), and cited value of s and E.