Pectinase Lab
South Carolina Biology Standard
2.8
Background
• Pectinases are enzymes that breakdown the
polysaccharide pectin that is located primarily
in the middle lamella of cell walls. Pectin
compounds are widely distributed in plant
tissues- especially in fruits.
• Commercially prepared pecitnase can be
added to prepared fruits to speed up the
release of juice.
Hypothesis
• If pectinase is added to applesauce, then
______________________________
Materials and Safety
•
•
•
•
•
•
•
•
Graduated cylinder
Beakers
Pipettes
Stirring rods
Applesauce
Distilled water
Pectinase
Filter paper
Safety
-Goggles
-closed toe shoes
-long pants
Procedure
• Place approximately 25 ml of applesauce into
each of the two beakers
• Add 1ml of distilled water to one beaker
• Add 1 ml of pectinase to the other beaker.
• Stir the contents of each- being careful not to
use the same stirring rod and contaminate the
other beaker
• Let stand 5 minutes
continued
• Fold a filter paper into 4s
• Place on top of the graduated cylinder
• Using your stirring rod, pour the contents of
each beaker into separate graduated cylinders
• Record the amount of juice collected
Results
Applesauce with water
Applesauce with Pectinase
Total juice collected (ml)
Day 2.
• Today we will manipulate the temperature
and the pH of the applesauce to see if has any
effect on the production of apple juice.
• The pectinase is kept in the refrigerator so
let’s heat up the applesauce/pectinase
mixture.
• The pH of room temperature applesauce is
___. Let’s lower the pH a little more.
Next• Add 1 ml of pectinase to room temperature
applesauce. Place in a hot water bath for 5
minutes- stirring occasionally.
• Repeat using 1 ml of water. Heat for 5
minutes- stirring occasionally.
• After 5 minutes- pour both of the applesauce
mixtures into a filter and allow to sit on top of
a graduated cylinder for 5 minutes.
• Draw a new table to record today’s results.
Then….
• Get 2 more samples of applesauce- 25 ml.
• Add 5 ml of pH UP to both samples.
• Add 5 ml of pectinase to one sample, 5 ml of
water to the other sample.
• Let sit 5 minutes, then filter as before.
Results
Applesauce w/pectinase
Heated 5 minutes
Juice produced- ml
Applesauce w/out
pecitnase
Heated 5 minutes
Juice produced-ml
Applesauce w/ pectinase
pH up to
Juice produced- ml
Applesauce w/out
pectinase
pH up to
Juice produced- ml
conclusion
• Support or reject your hypothesis
• How much difference was there between the
amount of juice collected with the water and the
pectinase?
• Compare the change in pH and the change in
temperature to your room temperature resultswhat do you find?
• Do you think pH and temperature had any effect
on pectinase and the amount of juice produced?
• Do you think this would work with any other
fruits?