Influences of baking and thawing conditions on quality of par-baked French bread

We examined the effects of baking time and temperature for the preparation of par-baked French bread, and of thawing and second baking conditions on the characteristics of bread prepared from par-baked bread. Par-baked French bread with loaf volume and crumb structure comparable to fully baked bread (control) was obtained with ≥6 min baking at 218°C, which increased the crumb temperature to 97°C. Freezing, thawing, and second baking of par-baked bread decreased loaf volume by ≥100 mL. The second baking time of par-baked bread, which was adjusted to have the bread crumb subjected to 97°C for 14 min based on the crumb temperature profile, produced a darker crust of bread compared with the control. The par-baked bread with 6 min of initial baking at 218°C and frozen at -30°C required 12 min of second baking after thawing for 180 min to ≈20°C to produce crust color, crumb moisture, and firmness comparable to that of the control. When thawing time of par-baked bread was shortened from 180 to 0 min, the second baking time required to yield crust color similar to the control increased from 12 to 16 min. The crumb moisture content was higher in bread baked for 16 min without thawing par-baked bread than those baked after thawing for 45 or 180 min. Lowering the initial baking temperature of par-baked bread from 246 to 163°C with the adjustment of baking time from 4 to 12 min decreased crumb firmness of the re-baked (218°C, 16 min) bread from 2.5 to 1.5 N at 2 hr after baking and from 9.8-10.3 to 6.2-6.3 N at 48 hr.