345 A new high-resolution digital imaging system for at-line measurement of crumb grain of baked goods.

H. D. SAPIRSTEIN and R. Roller. Dept. of Food Science, Univ. of Manitoba, Winnipeg, MB R3T 2N2.

A new digital video imaging system has been developed to facilitate the measurement of crumb grain of laboratory- and commercial-scale bread and cake products. The personal computer based system is configured around an electronically shuttered high-resolution (2048 × 10 bit) monochrome line scan camera interfaced to an image frame grabber with digital signal processing capability. Bread or cake slices, up to 17 cm wide, are mechanically transported to the camera on a conveyer. The latter comprises a seamless belt, variable-speed DC motor, digital tachometer for monitoring motor speed, and a high-resolution encoder to accurately measure belt movement and synchronize image acquisition. Illumination is provided by two DC regulated fiber optic light lines and a quartz halogen source. Resolution is ~155 pixels/mm(^2) for commercial size bread and much higher for pup-sized products. Crumb grain analysis software was adapted from previous work (Sapirstein et al 1994, Cereal Chem. 7:383). Measurements include crumb brightness, mean cell size and distributions, crumb grain fineness and uniformity, cell wall thickness, void fraction, crust thickness, and an overall bread score dependent on user-established weightings for selected parameters. The prototype imaging system provides rapid, objective, accurate and comprehensive analysis of crumb grain, and a package that can be commercialized with few modifications.