Weight loss was determined by using Tefera et al. (2007) method.
Fruit firmness was measured on two opposite peeled sides using a
pressure meter (OSK 10576 CO., Japan) fitted with an 8 mm
diameter flat tip. The firmness considered as an average peak force
of 10 fruits and expressed as kg. Total soluble solid in the juice was
determined with a hand- refractometer (NC-1, Atago Co., Japan) at
room temperature and expressed as a percentage.
Titratable acidity was determined by titration an aliquot (20 ml) of
the juice to pH 8.2 with 0.1N NaOH and the result was expressed
as a percentage of malic acid.TSS/TA ratio was evaluated as the
TSS/TA ratio (that is, ratio increasing with maturity) (Schirra et al.,
2004). PH of the juice was measured using a pH meter (Jenway,
3020).