The cutting force of the extrudates was negatively correlated with the expansion ratio (r 1⁄4 0.628, p 1⁄4 0.007) and positively correlated with the density (r 1⁄4 0.726, p 1⁄4 0.001), given that extrudates presenting greater expansion or lower density may be structurally more fragile or have lower mechanical strength (Yuliani et al., 2009).