On food and cooking the science and lore of the kitchen ( PDFDrive ) 1162

they lend a cloudiness and distinct “cereal” flavor to starch-water mixtures Light that passes right through a gelated mesh of pure starch and water is scattered by tiny starchlipid or starch-protein complexes, producing a milky, impenetrable appearance Grain starches contain a high proportion of moderately long amylose molecules that readily form a network with each other, and so make sauces that quickly thicken and congeal when cooled Wheat Flour Wheat flour is made by grinding wheat grains and sieving the bran and germ from the starch-rich endosperm(p 528) Wheat flour is only about 75% starch, and includes about 10% by weight of protein, mainly the insoluble gluten proteins It’s therefore a less efficient thickener than pure cornstarch or potato starch; it takes more flour to obtain the same consistency A common rule of thumb is to use 1.5 times as much flour as starch Flour has a distinct wheat flavor that cooks often transform by precooking the flour before adding it to a sauce (p 617) The suspended particles of gluten protein make flour-based sauces especially opaque and give their surface a matte appearance, unless the sauce is cooked for hours and skimmed to remove the gluten Cornstarch Cornstarch is practically pure starch and so a more efficient thickener than flour Cornstarch is manufactured by soaking the whole maize grain, milling it coarsely to remove the germ and hull, and grinding, sieving, and centrifuging the remainder to separate the seed proteins The resulting starch is washed, dried, and reground into a fine powder consisting of single granules or small aggregates During this wet processing, the starch granules absorb odors and develop their own when their traces of lipids are oxidized, so cornstarch has a distinctive flavor ... manufactured by soaking the whole maize grain, milling it coarsely to remove the germ and hull, and grinding, sieving, and centrifuging the remainder to separate the seed proteins The resulting starch... dried, and reground into a fine powder consisting of single granules or small aggregates During this wet processing, the starch granules absorb odors and develop their own when their traces of lipids... that cooks often transform by precooking the flour before adding it to a sauce (p 617) The suspended particles of gluten protein make flour-based sauces especially opaque and give their surface