were accompanied by decreasing acceptability levels
from A (freshly harvested) to E (overripe). Firmness
values of both varieties decreased with decreasing acceptability
level. This reduction was between A and D
acceptability level for ‘‘Liberto’’ while between A and
C acceptability levels for Criterium. In both varieties,
there was a higher variation between maximum and
minimum firmness values at A and B acceptability
levels. Those variation levels were smaller in the acceptability
C, D and E levels. The variation between
minimum and maximum values of fruits which had A
and B acceptability levels (very firm) is slightly higher
than the variations of other acceptability levels. This
variation might be due to some difficulty in categorisation,
especially of fruits which had A and B acceptability
levels. All fruits were very firm when touched by
hand. It is very difficult to determine the texture of the
inner structure of the fruits by hand but it is possible to
determine the firmness of the fruits by very sensitive
machines. The Instron machine gives accurate values
which were varied, but all of the fruits were very firm.
Categorisation was easier for softer (C, D and E)
fruits by touch.
On the basis of objective firmness evaluation it was
found that the minimum acceptable levels or marketability
scores of tomato firmness at which an individual
tomato fruit could be acceptable for sale at retail level is
about 1.45 and 1.46 Nmm1 for Liberto and Criterium
varieties of tomatoes respectively. However, the
firmness values of the tomatoes generally used at home
is about 1.28 and 1.22 Nmm1, for tomatoes that had
60% (C) acceptability score for the Liberto and Criterium
varieties, respectively. Those tomatoes could be
also marketable even in supermarkets and they were
capable to being sliced easily. If the firmness values of
tomatoes are below 1.22 or 1.28 Nmm1, they are very
difficult to sell in the supermarket and very difficult to
slice or to use them for making salads. If the firmness
values of tomatoes are higher than 1.28 Nmm1
(slightly soft) they could be used for making salads especially
if their firmness is above 1.46