MICRO TESTS OF ALIMENTARY PASTES: III. THE DIFFERENTIAL RESPONSE OF VARIETIES TO PROCESSING METHODS

The differential response of durum wheat varieties to processing methods, used in the micro test, was studied in a factorial investigation involving four varieties and 27 methods representing the factorial combinations of three absorption levels, three mixing times, and three pressures. Changes in the quality of the micro disks of alimentary paste were measured in terms of the optical absorption coefficient (opacity), colour characteristics (black, yellow, red, and white), and pigment content. Significant interactions between varieties and the three processing factors were demonstrated; different processing methods placed the semolinas in different orders with respect to most of the quality characteristics. It is concluded that it will be difficult to devise a standard micro test for alimentary pastes that will be widely accepted. However, larger interactions with methods will not occur with all pairs of varieties, and it will generally be possible to demonstrate consistent differences between most varieties with respect to at least one or two quality characteristics.