EFFECT OF HOT WATER DIP TREATMENTS ON REDUCING CHILLING INJURY AND DECAY AND KEEPING QUALITY OF NON-ASTRINGENT CHOCOLATE PERSIMMONS DURING COLD STORAGE

The experiment was carried out during 1997 and 1998 seasons on Chocolate
persimmons (Diospyros kaki L.) to study the effect of some prestorage heat treatments
through hot water dips (dipping in hot water at 60°C for 10 min; 55°C for 20 min; 50°C
for 30 min; 45°C for 40 min or 40°C for 50 min) on reducing chilling injury and decay and
keeping quality of the fruits under test during storage at O°C and 85-90% RH.
Either heat treated or non treated fruits remained 50 days of storage. The
unmarketable fruits of all treatments appeared for the first time at the end of storage
period. The best treatment for reducing decay was at 40°C for 50 min, while the best
one for reducing chilling injury was at 55°C for 20 min. However, the differences were
insignificant among unmarketable fruits of all treatments.
As the storage period advanced weight loss % increased, while firmness,
tannines and malic acid % decreased. TSS% and vitamin C content increased at the
start of storage period then, TSS % decreased while vitamin C content tended to remain
constant and thereafter increased. Hot water dip, had no significant effect on weight
loss and firmness. Slight differences in TSS , vitamin C,tannines and malic acid
contents between heat treated and untreated fruits were noticed.