160 Papaya
and then subsequently rubbed away mechanically. Finally, the fruits are sorted again
to remove any blackened pieces, bits of peeling, seeds, and so on. The peeled fruit
can be cut into a variety of shapes, according to type. The shape of the cut fruit must
be given on the can (slices diced, pieces, etc.). The cut pieces are now filled into jars
or cans and covered with syrup. Additional information must be given on the can
such as the sugar content of the syrup. Sugar concentration of the syrup is described
on the can, namely, very lightly sugared (9%–14%), lightly sugared (14%–17%), sug-
ared (17%–20%) and strongly sugared (>20%), vacuum sealed and pasteurised or
sterilised. After the jars or cans have been vacuum sealed, they are either pasteurised
(temperatures >80°C) or sterilised (temperatures >100°C). After the heating process,
the canned fruits are first cooled to 40°C and then subsequently down to storage
temperature.
14.4.5 Jelly...........................................................................
Mix 1.0 kg grated pulp of fully mature peeled, but somewhat, raw fruits and 1.0 kg
ripe papaya pulp with 2.5 L of water and 10.0 g citric acid. Boil for 30 min, cool and
allow settling for 2 h. Separate the supernatant and filter. Formation of single clot
with small quantity of ethyl alcohol added to test samples indicates high pectin con-
tent. Concentrate further, if necessary, to obtain single clot. Cook gently the extract
with equal quantity of sugar to obtain the end point indicated by the formation of
sheet. For packing of hot jelly, cover with a layer of melted wax and close the lid for
safe storage (Medina et al. 2003).
14.4.6 Fruit Pulp
Juice found in the peel should not be allowed to mix with pulp. The multitudinous
and highly active enzymes should be inactivated during processing. All machine
parts that come into contact with the pulp must be constructed out of stainless steel
to prevent discolouring. In order to make papaya marmalade, only fresh, ripe and not
mouldy fruits should be used. After harvesting, the fruits are then sorted and washed
in a water bath at 50°C for 20 min. Next, they are sent through a steam tunnel, where
they are treated with steam (100°C) in order to prevent latex from oozing out of the
peel; to deactivate the enzymes in the peel; to clean the surface of the fruit; to reduce
the number of micro-organisms, and to soften the outer parts of the fruit in order to
increase the amount of pulp produced. The fruit is then cooled down with water jets
for 3–4 min, subsequently peeled, and then fed into a strainer (0.6 mm screen) to
remove the kernels. Afterwards, the pulp is generally treated with a 50% citric acid
solution in order to lower the pH value to 3.0–3.5. Another strainer (<0.5 mm screen)
removes the fine fibres and particles, before the pulp is heated to 93.0–96.0°C in a
heat exchanger for 2 min. The papaya pulp can now be filled (up to 5.0 kg) into tin
(lead-free) cans whilst still hot, whereby the cans are sealed while being steamed,
the temperature is maintained for 5 min, and then rapidly cooled down. At tempera-
tures of around 15°C, the pulp can be stored for up to 1 year. After pasteurising, the
pulp can also be cooled down and filled into polyethylene bags placed in 50–200 kg
barrels. It is then rapidly frozen and can be stored at −18°C for 18 months. Pulp that