Evaluation of ultrasonic wave propagation to measure chilling injury in tomatoes

Chilling injury was induced by storing tomatoes at 3degreesC. Texture changes related to chilling injury were evaluated by acoustic firmness measurements and ultrasonic wave propagation. Because of the very high attenuation of the ultrasonic waves it was not possible to measure through a whole tomato. The ultrasonic transducers were fitted with beam focussing probes that were driven into the tomato flesh so that both the end of the transmitter and receiver probes were spaced 10 mm apart. The attenuation of 50 kHz ultrasonic waves increased when chilling injury developed, but only when the tomatoes were harvested at a mature stage. Time of flight of ultrasonic waves, texture attributes such as firmness or taste attributes (soluble solids content, pH) could not be used unambiguously to measure chilling injury in tomatoes. (C) 2003 Elsevier B.V. All rights reserved.