On food and cooking the science and lore of the kitchen ( PDFDrive ) 1026

time and settle A kind of settling and strengthening also takes place among the starch molecules in bread, but these have toughening effects that are undesirable, at least for bread to be eaten fresh Stale toughened bread does have its uses (see box, p 542) The majority of starch molecules, the branched amylopectins within the granul, also retrograde But thanks to their irregular structure, they form crystalline regions and expel water much more slowly, over the course of several days This is the process responsible for the undesirable firming in texture after the bread has become sliceable For some reason, both the rate and the extent of staling are lower in lighter, less dense breads Certain emulsifying agents have been found to retard staling substantially and for this reason have been added to mass-produced bread doughs for about 50 years True buttermilk (p 50) and egg yolks are rich in emusifiers and have the same effect It’s thought that these substances complex with starch or in some other way interfere with water movement, thereby inhibiting recrystallization Reheating Reverses Staling As long as much of the water released by the starch granules remains in the surrounding gluten — that is, as long as the loaf isn’t too old, or has been wrapped and refrigerated — staling can be reversed by heating the bread above the gelation temperature of wheat starch, 140ºF/60ºC Once more the crystalline regions are disrupted, water molecules move in between the starch molecules, and the granules and amylose gels become tender again This is why toasting sliced bread makes the interior soft, and why a loaf of bread can be refreshed by heating it in the oven Storing Bread: Avoid the Refrigerator ... water movement, thereby inhibiting recrystallization Reheating Reverses Staling As long as much of the water released by the starch granules remains in the surrounding gluten — that is, as long as the loaf isn’t too old,... or has been wrapped and refrigerated — staling can be reversed by heating the bread above the gelation temperature of wheat starch, 140ºF/60ºC Once more the crystalline regions are disrupted,... molecules move in between the starch molecules, and the granules and amylose gels become tender again This is why toasting sliced bread makes the interior soft, and why a loaf of bread can be refreshed by heating it in the oven