Aim – to what extent does enzyme pectinase affect the
production of juice from apples
RQ- how does a change
in pH influence the activity of enzyme pectinase in the production of apple
juice from apple pulp.
Independent variable –
pH values to be used
14-13, 10-9, 7, 3-4, 1-2
Dependant
variable
Volume of
the apple juice produced
Intensity
of colour of apple juice formed
Controlled
variables
Temperature
Volume of
water
Mass of
apple
Concentration
of pectinase
Time
Funnel size
Type of
filter paper
Apparatus
Pectinase
Distilled
water
3xapples
tweezers
1xpeeler
1xgrater
1xbowl
1xspatula
Glass rods
Pipette
Balance
Measuring
cylinder (50)
6xbeaker
(100ml)
Incubator
stopwatch
30x25ml
beaker
30x10ml
measuring cylinder
30x 20ml
measuring cylinder
30x glass
funnels
30x filter
paper
Procedure
1.label five 25ml
beakers with 0 and either A, B, C, D and E. Repeat for measures: 2, 3,7,10 and
13. Label the 20ml measuring cylinders in the same way.
2. Peel the rind
off of the apples using the vegetable peeler and then grate the pulp into a
bowl, avoiding the stalk and seeds.
3. Measure 5g
of apple pulp into each of the 25ml beakers. Use tweezers and spatulas to get the
accuracy of 5.00g.
4.
Prepare the pectinase solution. Weigh 10g
of Pectinase according to percentage concentration into a 100ml beaker and pour
Distilled Water into a 50ml measuring cylinder until it reaches 50ml. Add
a little water from the 50ml measuring cylinder to the 100ml beaker to dissolve
the powder, while stirring vigorously with a glass rod. Pour back into the 50ml
measuring cylinder and add until the solution is 50ml in volume. Divide into
five 10ml measuring cylinders using a funnel and the pipette
5. Pour
pectinase solution into five 25ml beakers, stir to make sure each shaving of apple
is fully submerged. Incubate immediately at 40 degree celcius for 25 minutes.
6. Remove and pour
contents of each into a filter-papered funnel inside a 20ml measuring cylinder
7. Measure
the volume of juice produce for every 5,10,15 mins.
