The term "firmness" may be preferable to "hardness" in
describing food texture so as not to conflict with mechanical
engineering definitions (14); however, Boyd and Sherman (6)
report that consumers' use of the term hardness does not correspond with the usage by material scientists but agrees with the
definition of the General Foods sensory texture profile CIO), i.e.,
force required to compress a solid substance between molar
teeth. Sensory toughness is manifested by high, persistent re-
sistance to breakdown on mastication (15) and should relate to
rupture energy in mechanical tests (14). Although it has been
proposed (18, 19) that crispness is an acoustical phenomenon,
crispness often has been related to mechanical characteristics.
For example, in sensory analysis of almonds (16), crispness
tended to follow sensory hardness or fracturability. depending
on the panelist.