CHEMICAL AISTALYSIS OF WHEAT-FLOUR SUBSTITUTES. 3 



•until thoroughly dry and brittle, and then passing the dried product 

 through a small hand-power mill. For the banana flour, large 

 green fruit was used. It was peeled by hand, sliced, dried, and 

 ground into a flour. 



Of those prepared in the Plant Chemical Laboratory the chestnut, 

 dasheen (peeled and unpeeled), rice (poHshed and brown), millet, 

 bean, pea, chick-pea, and soy bean were first thoroughly cleansed and 

 then ground in a hand mill, while rye, feterita, kafir, milo, and 

 kaoliang were scoured and then ground in an experimental mill 

 to give the desired flours. To obtain the peanut meal, roasted 

 peanuts were crushed with a rolhng pin. 



The potato flakes employed in these experiments were obtained 

 from Germany several years ago. The boiled potatoes were prepared 

 in the laboratory by boiling potatoes in their skins, after which 

 they were cooled, peeled, and mashed. 



BREAD. 



All the breads analyzed in this investigation were made from 

 mixtures of flour, in the proportion of 25 per cent of substitute to 

 75 per cent of standard wheat flour.^ 



METHODS OF ANALYSIS. 



The methods for the analysis of cereal foods adopted by the 

 Association of Ofiicial Agricultural Chemists ^ were used for all the 

 determinations made, with the exception of the fat determination. 

 As it is impossible to obtain accurate results for the estimation of 

 fat in bread by the usual method of extraction, the Polenski method ^ 

 was employed for this determination. The carbohydrates were 

 obtained by difference. The calories per pound were calculated by 

 multiplying the sum of the carbohydrates and protein by 1,860, and 

 the fat by 4,220, and then adding the two results thus obtained.* 



RESULTS OF THE ANALYSIS. 



Table 1 gives the composition of the standard flour and of the 

 substitutes. The composition of the breads, as analyzed on the 

 air-dry basis, is given in Table 2, and, as calculated on the basis of 

 an assumed average moisture content of 35 per cent, in Table 3. In 

 a general way, the data in these three tables have been arranged in 

 the order of the protein content of the flour. Those showing a low 

 protein content come first, being followed in turn by those pre- 

 pared from grains and cereals, then by those made from legumes, 

 and, finally, by those from certain by-products. Besides giving 

 the composition of the various flours and breads studied, the tables 



1 The bread was made according to the directions given in U. S. Dept. Agr. Farmers' Bui. 955. 



2 Jour. A. O. A. C, Aug. 15, 1916, Vol. II, No. 2, part 2: 187. 



3 Zt. Anal. Chem. 1911, 50: 655. 



4 The calories were ea2eulated by Rubner's factors. 



