The objective of this study was to determine the crispiness of microwave-expanded imitation cheese and compare the results with sensory evaluation. Three cheeses were manufactured with 36%, 19%, or 15% protein; all three with 0% fat, a fourth cheese had 4% fat and 19% protein. After 3 and 9 days of storage at 5 C, the cheeses were subjected to rnicrowaving and the volumetric expansion, mechanical, acoustic and sensory crispiness of the expanded products was determined. The expansion and crispiness increased with increasing heating time and decreased with decreasing protein content. The expanded cheese with the highest protein (36%) and the cheese with 4% fat were considered the most and the least crispy respectively by mechanical, acoustic and sensory evaluation. Crispiness of the microwave-expanded imitation cheese was influenced by the protein content and the degree of plasticisation of the cheese matrix. (C) 2011 Elsevier Ltd. All rights reserved.