Suzy S. Student

November 5, 2007

Problem: Which enzyme, or combination of enzymes, maximizes juice production? Which enzyme is most cost effective in the production of apple juice?

Hypothesis: If pectinase, cellulase, and a combination of pectinase and cellulase are used, then pectinase will produce more apple juice because pectinase breaks down the sugar pectin in the apple.

Variables: The independent variable in this lab is the type of enzyme used. The dependent variable is the amount of juice produced.

Procedure:

  1. Place a measuring cup on a balance and hit the zero button. Fill the cup with 30 mL of apple sauce and record the weight of the apple sauce in the data table.
  2. Obtain a funnel and a piece of filter paper. Fold the filter paper in half twice to make a funnel. Place the filter paper in the funnel and wet lightly so it will stay in place.
  3. Place the funnel on top of a graduated cylinder.
  4. Pour the apple sauce into a plastic cup. Obtain 20 drops of pectinase.
  5. Add the pectinase to the apple sauce and stir until mixed.
  6. Place the apple sauce into the funnel and begin the stopwatch. Time for 3 minutes
  7. After 3 minutes, measure the volume of apple juice in the graduated cylinder and record this volume in the data table.
  8. Repeat steps 1-7 but use 20 drops of cellulase in place of pectinase
  9. Repeat steps 1-7 but use 10 drops of pectinase and 10 drops of cellulase
  10. Repeat steps 1-7 but use 20 drops of water, this is a control.

Results:

Table 1: Apple sauce used and juice produced

Amount of apple sauce used / Liquid added / Group results/ mL of juice produced / Class average/ mL of juice produced
Pectinase / 30 g / 20 drops pectinase / 5.5 mL / 4.65 mL
Cellulase / 30.5 g / 20 drops cellulase / 4.2 mL / 3.4 mL
Pectinase & Cellulase / 30.3 g / 10 drops pectinase and 10 drops cellulase / 5.0 mL / 4.6 mL
Water / 30.2 g / 20 drops water / 4.2 mL / 3.3 mL

Conclusion: The problem in this lab is to determine which enzyme of combination of enzymes maximizes juice production. Also, which enzyme is most cost effective.

The hypothesis was proven correct. Pectinase produced more juice than cellulase or the combination of cellulase and pectinase.

The data table shows that pectinase produced the most juice, 5.5 mL for the group and 4.65 mL of juice for the class average. Cellulase alone only produced 4.2 mL of juice for the group and 3.4 mL for the class average. The combination of enzymes, pectinase and cellulase, produced 5.0 mL for the group and 4.6 mL for the class average. Water, the control, produced 4.2 mL for the group and 3.3 mL for the class average.

Pectinase costs $50 per liter and cellulase costs $100 per liter. Due to the fact that pectinase produced more juice, and costs less, pectinase is the most cost effective enzyme to use.

In this lab, the amount of sauce was controlled, using 30 mL each time. There was however a slight difference in the weight of the apple sauce. Also, each trial was timed for three minutes and 20 drops of liquid were added each time.

If this lab could be repeated, the number of times the enzyme is stirred with the apple sauce should be controlled. Also, while the class average was calculated, repeating each trial three times would increase the validity of the experiment.