Cutting forces in foods: experimental measurements

Cutting forces for cheese decreased with increasing temperature and increased with cutting speed. The relatively homogeneous nature of the samples resulted in consistent and repeatable measurements. For bacon, variable salt content gave rise to different ice contents and thus hardnesses in samples at the same 'frozen' temperatures. Layers of fat and muscle boundaries also produced marked deviations from the average forces. Force results were therefore scattered but increased with decreasing temperature. The effect of cutting speed was not consistent for all forces, but higher speeds generally produced higher forces. For beef, there was a marked difference between frozen and unfrozen samples but little difference between samples at different unfrozen temperatures. In unfrozen samples, cutting speed had little effect on forces, whereas faster cutting speeds produced higher forces in frozen samples. The proportion of total cutting forces made up by friction was found to be consistent over all temperatures and speeds for cheese and bacon, but markedly higher in the frozen beef samples compared to the unfrozen samples.