Cereal Chem 44:383 - 391.  |  VIEW ARTICLE
Relation of Starch Damage and Related Characteristics to Kernel Hardness in Australian Wheat Varieties.

P. C. Williams. Copyright 1967 by the American Association of Cereal Chemists, Inc. 

A simple test, the particle size index (PSI) test, is described. Its principle depends on the breakdown of wheat kernels under a standard grinding procedure. The test gives a consistent measure of kernel hardness. Over a very wide range of wheat varieties, grown under different environmental conditions in Australia, kernel hardness as measured by this test has been shown to be closely related to the damaged-starch content of flour milled from the wheat by a standardized milling procedure, and to be associated with characteristics of water absorption, diastatic activity, and gassing power. Regression formulas are presented for computation of these factors from PSI data. The PSI test may also be used to assess the degree of alpha- amylase activity of a flour before milling. Evidence is presented to show that the starch of hard wheat flours is apparently more susceptible to attack by diastatic enzymes than is starch from soft wheat flours. Furthermore, under Australian conditions there appears to be little or no relation between the distribution of starch granules of different sizes within and between varieties, with regard to damage incurred during milling.