This section is from the book "Experimental Cookery From The Chemical And Physical Standpoint", by Belle Lowe. Also available from Amazon: Experimental cookery.
1 Calculated to dry basis.
Phosphorus is found in inorganic combination and in organic combination in phytin, nucleic acid, and lipoids.
Sullivan states that potassium probably has some direct bearing in the 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 phosphoric acid. It is found in larger quantity in stronger wheats than in weaker wheats, and there is a correlation between the percentage of magnesium and protein content.
Calcium is essential for the growth of plants. It is present in both inorganic and organic combination. Sullivan states plants deficient in calcium are unable to assimilate nitrates and accumulate carbohydrates in large quantities. Sullivan and Near have reported the potassium, calcium, magnesium, and phosphorus content of glutens in three grades of flour. Their investigation shows that the calcium content is highest in glutens of highest strength, and potassium and magnesium increase as the tenacity of the gluten decreases.
Calcium acid phosphate is often added to soft-wheat flour and sometimes to high grades of flour. This practise is very common in the South. A great deal of this flour is used in quick breads like biscuits. The addition of the calcium acid phosphate is said to improve the volume, quality of crumb, texture, and color of biscuits.
Sullivan states that the inorganic constituents - iron, manganese, copper, zinc, boron, cobalt, iodine, flourine, and nickel - all play a significant role in plant physiology. The addition of certain of these rare minerals, in as little concentration as one part per million, to nutrient solutions in which plants are grown permits normal growth and production, although too great a concentration of some of these elements has undesirable effects.
Gericke studied the effect on bread scores of supplying to wheat grown in liquid media the following salts during the latter part of the growth period: NH4NO3, Ca(N03)2, KNO3, Mg(NO3)2, and NaNO3. He decided the physical state of the protein was determined by the nature of the salt solution surrounding the protein during its synthesis and translocation in the grain. Quality in bread varies with the quantity and quality of the protein in the flour. Bread from flour of wheat grown in Ca(NO3)2 scored exceptionally high. The order in decreasing desirability of scores for bread was: Ca(NO3)2, KNO3, NaNO3, Mg(NO3)2, and NH4NO3, though there was little difference between sodium and magnesium. However, the ammonium nitrate was definitely the lowest-scoring bread.
Gericke found that the effect of chloride salts supplied to wheat grown in liquid media on bread scores was in the following order, the highest being given first: CaCl2, NaCL, MgCl2, and KC1. The best bread was obtained from the wheat supplied with NH4C1, but this was the only salt supplying nitrogen and hence the only wheat which gave a flour with a high protein content.