Experimental cookery

"Higher saturated fatty acids (which may occur in small amounts in any wheat product as a result of hydrolysis of the triglycerides) have only a very slight 'shortening' effect on the flour-water curves. Unsaturated fatty acids (oleic, linolic, and linolenic) cause a decided change in the shape of the curves and produce 'short' tough glutens when added to patent flour. These unsaturated acids, however, are only slightly detrimental to the baking quality of a flour. The bake is not harmed as much as one would expect from the feeling of the gluten." 400 FLOUR AND BREAD The effect of unsaturated fatty acids on flour is in direct correlation with their' increasing number of double bonds. The oxidation products of these unsaturated fatty acids have a significant damaging effect on the baking quality of flour. In addition, these investigators have shown that extracting fat from flour with ether injures the baking quality of both strong and weak flours. The addition of flour fat brought the quality of the ether-extracted flour back to normal but the addition of germ fat did not. They concluded that this indicated that flour fat contains some constituent or groups of compounds necessary for good baking quality of flour, which are absent in the germ lipoids. The Ash Content o£ Flour Sullivan found that the total ash content of wheat averaged 1.86 per cent. In general the ash content of a flour increases as more of the wheat kernel is used. Whole-wheat flour contains all the ash of the wheat, and patent flour contains the smallest percentage of total ash. Patent flour may contain as low as 0.25 to 0.3 per cent of total ash. Sullivan gives the inorganic constituents present in relatively larger quantities in flour as shown in Table 45 : TABLE 45 Inorganic Constituents Present in Relatively Larger Quantities in Wheat, Patent Flour, and Bread (Sullivan) Inorganic constituent Wheat^ % Patent flour % Bread % Total ash 1.86 0.571 0.428 0.194 0.173 0.055 0.048 0.009 0.006 0.45 0.168 0.113 0.165 0.029 0.051 0.016 0.003 0.005 2.77 Potassium Phosphorus . 0.200 0 140 Sulfur Magnesium 0.192 0.040 Chlorine Calcium Sodium . 1.005 0.080 0.660 Silicon 0.005 Calculated to dry basis. Phosphorus is found in inorganic combination and in organic combina- tion in phytin, nucleic acid, and lipoids. Sullivan states that potassium probably has some direct bearing in the ASH CONTENT OF FLOUR 401 translocation of sugars and starch formation and that a potassium deficiency influences the respiration rate of plants and may have some role in the activity of diastatic enzymes. Magnesium is found in excess of calcium in plants, whereas the reverse is true of animal tissues. It is present in chlorophyll and Sullivan states that it takes some part in the transfer of phosphoric acid through plant tissues. It may exist in the wheat pericarp as the magnesium salt of inositiol phos- phoric acid. It is found in larger quantity in stronger wheats than in weaker wheats, and there is a correlation between the percentage of mag- nesium and protein content.