The texture of apple pieces was measured using a TA-XT2
Texture Analyzer (Stable Micro Systems Ltd., England, UK) by
measuring the maximum penetration force required for a 4-mmdiameter
probe to penetrate into apple cylinders (20 mm high) to a
depth of 10 mm at a speed rate of 5 mm s1. Apple pieces were
placed perpendicularly to the probe to allow the penetration in
their geometric center.