Bruising

In order to enable the mechanical harvest of table olives, it is also necessary to prevent external fruit colour change or bruising.

The bruising process after induced mechanical injury was characterised in various cultivars. Some cultivars are resistant to browning and do not show any brown spot three hours after application of pressure. The different response to mechanical damage shown by the cultivars could be mainly due to genetic differences. Mesocarp cells in the fruits of the sensitive cultivars are damaged and lack a cell wall as a result of the applied pressure. The cuticles of resistant cultivars are thicker compared to those of susceptible cultivars. The bruising process is enzymatic. Figure 5 shows resistant versus sensitive cultivars.

Figure 5: Photographs of 5 fruits from each of the most susceptible (left) or resistant (right) cultivars to bruising, three hours after induced mechanical pressure.