Effect of Stage of Ripening on Mechanical Damage in Tomato Fruits

Abstract

Mechanical damage is the major cause of postharvest losses and among the perishable crops tomato is susceptible to mechanical injury considrably. By conducting a series of impact tests (from 0.18 to 2.88 J) by a pendulum impact apparatus, occurance of damage, in the form of rupture and latent damage, were investigated as affected by stages of ripening (pink, ripening, maturity and Plasmolism) and variety (Super Bta and Petoerly-ch). According to the results at any treatment of variety and stage of ripeness, falling of tomatoes from maximum height of 59 cm does not occure any rupture in fruit, causes injury in tomatos as degradation as a kind of latent damage. However, the minimum energy required for rupture injury was about 1.58 J and 0.84 J in first and third stages of ripenening, respectively. According to the results of ANOVA, there are no differences between two varieties based on rupture injury, whereas, impact energy and especially stage of ripeness had significant effect on all types of mechanical damage in tomato fruit. Also, the results showed that the severity and rate of latent damage increase progressively, through 24 to 72 hours of storage of fruits in natural conditions. Ripenenning stage is the major factor affect severity of latent damage through 72 hours after impact.