3.2. Firmness
Firmness of cherry tomatoes stored in modified atmosphere
package (MAP) for 25 days at 5 C is shown in Fig. 2. The
compressive force decreased over storage for samples stored under
MAP and the control. For 10% deformation, there was a reduction of
1.19 N in compressive force for samples stored in packs containing
5% O2, 5% CO2, and 90% N2 for 25 days, while the control samples
showed a reduction of 2.09 N in compression force during the
storage period. These results indicate that the modified atmosphere
reduced fruit softening and maintained
firmness throughout
storage compared to the control.
The effect of modified atmospheres on the maintenance of fruit
firmness is usually related to the control of weight loss. In this
work, the samples with the highest weight loss (control) showed a
greater reduction in texture. Fruit softening occurs due to
deterioration in the cell structure, cell wall composition, and
intracellular materials (Seymour et al., 1993). These biochemical
processes involve the direct suppression of the activities of pectin
esterase and polygalacturonase enzymes leading to postharvest
softening of fruit structure or blockage of the synthesis of ethylene