South Carolina Biology Standard 2.8 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 Safety Beakers -Goggles Pipettes -closed toe shoes Stirring rods -long pants Applesauce Distilled water Pectinase Filter paper

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 Total juice collected (ml) Applesauce with Pectinase

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 Juice produced-ml Applesauce w/ pectinase pH up to Applesauce w/out pectinase

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 results- what 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?