The texture of potato chips was evaluated using a novel method. Four kinds of potato chips with different
thicknesses and crispness were fractured by a probe and the corresponding acoustic vibrations were
detected by a piezoelectric sensor. The vibration signals were filtered into 19 frequency bands. The texture
index (TI) was calculated for each band, using data from three selected parts of the time-domain signals:
the anterior part from the probe contact point to a major fracture, the major fracture part, and the
full texture signals. The TI was the lowest for the anterior part at all bands. The TI of the major fracture
part was the highest in all frequency bands except for 100–140 Hz. The new analysis method revealed
that the TI above 1600 Hz reflected the crispness of potato chips.