Mechanical resonance method for evaluation of peach fruit firmness

An investigation was carried out to establish the basic relationship between mechanical resonance, firmness, chemical composition and ethylene production during the maturity time and the ripening time of peach fruit. The stiffness factor calculated by a non-destructive frequency response technique was compared with biological properties obtained by measurement of chemical composition, firmness and ethylene production in the internal atmosphere of tested fruit. The correlation between the biological multifunction and the mechanical resonance frequency of peach fruit can be expressed by an exponential relationship. Multifactorial index seems to describe the rupture point that for peach fruit coincides with the beginning of climacteric developmental stage, detected by ethylene production.