Cereal Chem. 71:383-391 | VIEW
Instrumental Measurement of Bread Crumb Grain by Digital Image Analysis.
H. D. Sapirstein, R. Roller, and W. Bushuk. Copyright 1994 by the American Association of Cereal Chemists, Inc.
An instrumental system has been developed for direct quantitative assessment of bread crumb grain using digital image analysis technology implemented on a personal computer. Software was developed for comprehensive measurement of crumb grain features including cell area, cell density (cells/cm2), cell wall thickness, cell total area ratio, crumb brightness, and uniformity of cell size. The system is completely objective in all respects, including the critical step of crumb cell detection where an adaptation of the K- means algorithm was used for image segmentation by thresholding. Typical spatial resolution of the system using a conventional macroviewing lens was approximately (80 micrometers)2 crumb per pixel. Image processing time to compute the crumb cell structure for a single bread slice (307,200 pixels per image) was about 10 sec. The precision and accuracy of the system were tested by analysis of results of experimental breadmaking with and without oxidants (control). Compared with control loaves, bread crumb containing oxidants was determined to be 6% brighter and had, on average, 21% more cells/cm2, 17% smaller cells in cross-sectional area, 13% thinner cell walls, and 16% more uniform grain. These values were consistent with the finer crumb grain of bread containing oxidants, as observed visually. The proportion of crumb comprising gas cells for control and oxidized bread was precisely identical (46%). The equivalence provides objective evidence that the predominant difference in the crumb structure of bread prepared with and without oxidants relates almost exclusively to the degree of subdivision or coalescence of gas cells.