Effect of gaseous acetic acid on dough rheological and breadmaking properties

Breads baked from wheat flours (protein contents 14.1-16.5% at 14.0% mb) that were pretreated with 2-3 mt of gaseous acetic acid per kg of wheat flour, showed maximum bread height and specific volume (cm(3)/g). Flour-water suspension and the crumb pH values were gradually decreased with increased amounts of acetic acid. Gas generation and dough expansion tests with bread dough showed that the addition of the same amount of acetic acid, which achieved maximum specific volume, also showed the highest rate of gas generation and dough expansion. However, increasing acetic acid decreased these values. Scanning electron microscope (Cryo-SEM) observation showed that the bread dough made from the same acetic acid-treated flour indicated continuum and no cracks in the dough matrix. Evaluation of mixograms showed the decrease of mixing stability with increased acetic acid levels. Viscosity and water binding capacity of flour-water suspensions were sharply increased by the addition of acetic acid at pH 5.0-3.5.