The instrumental forces derived from the cut tests were corre- lated with the sensory attributes of texture (Table 4). Hardness cor- related positively with both cut tests, although the correlation coefficient for the cut test with a ‘‘V’’ shape probe (r = 0.718) was higher than for the cut test with a guillotine (r = 0.687). The adhe- siveness of the snacks correlated positively with the cut test using a ‘‘V’’ shape probe (r = 0.763) and chewiness correlated positively with the cut test with a guillotine, although the correlation coeffi- cient was only 0.662. Similarly to hardness, fracturability corre- lated positively with both cut tests, although the correlation coefficient was higher for the cut test with a guillotine (0.776). Cor- relation coefficient about of 0.70 indicates fairly strong correlation according to Rayner (1969) cited by Leighton et al. (2010). No sig- nificant correlation was found with crispness.
Varela et al. (2009) evaluated the crispness of two types of ex- truded snacks (wheat crusts and cheese balls) by means of com- pression and puncture tests and by using a sensory panel, who bit the snacks with the incisor teeth and chewed them with the back molars. These authors reported that the ratings from the bit- ing and chewing tests were very similar and that the results ob- tained from the sensory evaluation were similar to the instrumental results, although no correlation analysis was performed.