1. Label the top of the four test
tubes using a marker pen. A suitable code would be
as follows:
P, A,
P+A, W.
2. With a micropipette, measure
1 ml of pectinase
into the first test tube. Into the
second
test tube, place 1 ml of
amylase. Add
a mixture of 0.5 ml
of pectinase
and 0.5
ml of amylase
to the third tube. Finally, add 1 ml
of distilled water
to the
remaining tube.
3. Stir the apple juice well to
distribute any suspended particles evenly through it. To
each test tube
add 10 ml of
apple juice.
4. Agitate or stir the contents of the tubes to mix the enzymes throughout the juice.
5. Put all the tubes into the water bath.
6. Observe the tubes and record
the appearence of their contents at 5 minute
intervals
over a
half hour period.
7. Further clearing may occur if
the tubes are left to stand overnight
at room
temperature.
Although the enzymes used in this protocol are food grade,
the concentrations suggested
are far greater than are normally
used for clarifying fruit juice. Therefore even if the
work is carried out in a food preparation area using
clean equipment, the fruit juice
produced should not
be consumed.