Abstract
The physical behavior under drop impact of the fruits of tomato for processing was investigated to elucidate the resistivity of the fruits against impact load.
1. Impact force and impact energy accompanied by the dropping increased with increasing drop height or fruit weight. The impact energy was relatively large in the varieties of oblate fruits (H-1409, Kagome 70, ES-58) and the smallest in those of pear-shaped fruits (Super Roma V.F., Chico) among the examined varieties.
2. The hardness of the fruits was decreased by suffering the drop impact, and the decrease in the hardness became pronounced with an increase in impact. The degree of deformation accompanied by impact was distinguished in the varieties of round or oblate fruits, whereas it was not distinguished in those of pear-shaped or lengthy fruits.
3. The frequency of occurrence of injured fruits increased with increasing drop height. The damage index of the fruits increased with increasing fruit-shape index and fruit weight.
The critical impact energy for the occurrence of injured fruits was comparatively high in Chico, AT 70/24, and Super Roma V. F. among the examined varieties. Accordingly, the resistivity against impact load was higher in the varieties of pear-shaped or lengthy fruits than in those of oblate or round ones.
The resistivity of each variety decreased with a progress in maturity of fruits.
