Non-destructive determination of the optimum eating ripeness of pears and their texture measurements using acoustical vibration techniques

Taniwaki Mitsuru

Hanada Takanori

Tohro Minami

Sakurai Naoki

Postharvest Biology and Technology

We investigated the time-course changes in the elasticity index (El) and texture index (TI) of pears (Pyrus communis L. cv. La France) during the postharvest period. EI was determined using a formula EI = f(2)(2)m(2/3), where f(2) is the pear sample's second resonance frequency and m is the sample mass. A non-destructive vibrational method using a laser Doppler vibrometer (LDV) was used to measure the pears' second resonance frequency (f(2)). Changes in the EI of the pears showed bi-phasic decay. Along with sensory testing, we determiner) the period of optimum eating ripeness of the pears in terms of their EI to be 8.1 x 10(4)-1.5 x 10(5) kg(2/3) Hz(2). Pre-determined EI of pears enables consumers to predict the time range of optimum eating ripeness. An improved device for texture measurement was used for measuring time-course changes in the texture of pears. The texture was quantified with TI, which was determined for 18 frequency bands through integration of squared amplitudes of texture signals multiplied using a factor of a frequency band. The TI declined gradually over a wide frequency range as the pear samples ripened.

Fruit ripening

Storage

Laser Doppler vibrometer

Piezoelectric sensor

Botany [ 470 ]

eng

Elsevier Science BV

Copyright (c) 2008 Elsevier B.V.

[ISSN] 0925-5214

[DOI] 10.1016/j.postharvbio.2008.08.004

[NCID] AA10838952

[DOI] http://dx.doi.org/10.1016/j.postharvbio.2008.08.004