Effect of vehicle vibration on the mechanical and sensory properties of avocado (Persea Americana Mill. Cv. Hass) during road transportation

The vibration that occurs in vehicles during road transport has an important effect on the damage experienced by agricultural products, such as fruit. Young's modulus and Poisson's coefficient are critical mechanical properties of fruit, and alterations may indicate damage during transportation. This work studied the effect of vibration on mechanical damage in avocados (Persea americana Mill. cv. Hass) during a road trip of over 25 km in distance between the farm to avocado packing house. Chemical and mechanical properties were evaluated during twelve postharvest days at 23 degrees C and 65% relative humidity. Once avocadoes reached full maturity, sensory tests were performed according to Colombian Technical Standards NTC 5328 and NTC 3932. Results obtained from field data are presented as power spectral density (PSD) functions to facilitate the interpretation of the exposure of produce to vibration energy during transportation. The highest intensity of these vibrations was recorded at a frequency of 2.5 Hz for frequency intervals of 0 Hz-5 Hz at the rear of the vehicle. The chemical analysis, includingmoisture content, protein, ash and ethereal extract, showed no statistically significant differences (p > .05) between the protected fruit (PF) and unprotected fruit (UF). The mechanical damage demonstrated a statistically significant difference (p < .05) in Young's modulus between the PF and the UF. Sensory analysis also showed that the mechanical damage caused by the vibration levels affected the integrity of lenticels by means of the external appearance and pulp color descriptors of the fruit, which contributed to the subsequent darkening of the skin and the softening of the fruit.