Last week we began measurements on McVitie’s Digestive biscuits and carrots. We steamed the samples for different periods of time in order to modify their moisture content. We chose these two foods because of their very different structures. We want to probe how the moisture dependencies of acoustic and mechanical parameters are influenced by structure.
We steamed biscuits for 30, 45 and 60 seconds and carrots for 1,2,3,4 and 5 minutes in a steam oven. The acoustic data was consistently limited for different steam-time samples in both foods and failed to give any useful information. However, the force-deformation curves were more successful for both foods and we were able to identify parameters in each that showed a dependency on steam time. For both biscuits and carrots (first and second graphs below, respectively), the maximum force was seen to decrease with increasing steam time. We will now investigate these variations in more detail to probe the underlying structural mechanisms.
