Experimental cookery

Cracker flour is milled from soft winter wheat. Micka states that be- cause it constitutes nearly 90 per cent of the cracker it is largely responsible for the general character of the finished product. A desirable cracker flour differs from bread flour in color, absorption, and fermentation capacities. Because of the long fermentation period the inside color of crackers is quite uniform but the color of the flour affects the outside color and bloom of the cracker. A cracker flour has a lower water-absorbing capacity than bread flour and, since little sugar is added, the flour must itself furnish the necessary fermentative material. The geographical areas in which the different classes of wheat are grown determine to a great extent the type of flour that predominates in local retail markets in these areas. For example, in Iowa it is very difl&cult to obtain soft-wheat flour, except in the specially prepared cake flours, the bread and all-purpose hard-wheat flours being found on the local markets. In Alabama it is just as difficult to obtain hard-wheat flours. In some sec- tions or states both soft- and hard-wheat flours are readily obtainable. Bleaching of flour. Bleaching can occur through aging or gradual oxida- tion of the carotene, but a large portion of flour is bleached at the mills in a short time. Nitrogen peroxide or chlorine, benzoyl peroxide or nitrogen trichloride, or a combination of two of these, is used for bleaching. Rye Flour The Service and Regulatory Announcements define rye flour as "the fine-ground product made by bolting rye meal, and contains not more than 13.5 per cent moisture, not less than 1.36 per cent nitrogen, and not more than 1.25 per cent ash." Bailey has reported formulas and methods for testing the use of rye flour in bread. There are five classes of rye flour, based largely on the color: white, light, medium, dark, and extra dark. Composition of Flour Flour contains pigments, enzymes, cellulose, moisture, fat, mineral salts, carbohydrates, and proteins. All the constituents of flour are important in DIASTASES 397 that all affect the baking qualities of the flour and thus the product in which the flour is used. Color of Flour Bailey states that the color of flour is due to five factors : ( 1 ) Granula- tion or size of flour particles, which affects the appearance of the flour and not that of the dough. Large granules appear darker than small ones. (2) Color changes due to mixing with water in contact with air at ele- vated temperatures are caused by enzymes found principally in the bran. (3) Dirt and foreign matter, as weed seeds, if highly pigmented, may become pulverized and color the flour. (4) A reddish-brown pigment is present in small quantities in flour made from "red" wheats. Highly re- fined flours from those wheats show less of these small bran particles containing the pigments. (5) Carotinoid pigments. Flour contains the pigment carotene which gives it a creamy or yellow tint, the depth of color depending upon the amount of the pigment present. Because of the fineness of division of the flour particles its bulk includes a large proportion of air. The carotene is bleached by oxidation ; thus, in aging, natural bleaching of the flour occurs. Markley and Bailey have reported that flour contains the following fat- soluble pigments: carotene, xanthophyll, and an unknown pigment.