Effect of pectinase on jucie production

[umah11]

Hello,

I am doing my biology project on juice production.
I am investigating the efect of diffrent enzymes on apple juice production.
I read a guide on this website and would like to know: do you have to put enzyme + apple in a waterbath?

I wait for your reply.

Thank you very much

[donnahardy2]

Hi,

Welcome to Science Buddies! This is a great project. I assume you are doing a version of the following project:

https://www.sciencebuddies.org/science- ... p010.shtml

In this project, the apples are chopped into very small 5 mm pieces and the enzyme is added to the sample with a small amount of water. The procedure does suggest using a 40 degree Centigrade water bath; however, you could certainly use a different temperature. Since it sounds like you are going to try different enzymes, then the enzyme will be your independent variable and the amount of juice will be the dependent variable. In this experiment, the temperature should be one of your controlled parameters and should be the same for all samples. Do you know what the optimum temperature for pectinase is? What about the other enzymes you will be using?

Do you have any other questions?

Donna Hardy

[umah11]

Thank you very much for your reply.

This is the problem. I dont know what temperatures i have to put the enzymes in?

I am using different enzymes but I know that some enzymes may be denatured at 40 degrees so do I have to find out all optimum tempretures for each enzyme ?

Another website I found recommended not putting the enzyme + apples into the water bath. Should I maybe do this? Because if I do change temperature I do not want the enzyme to get denatured.

Thank you very much for your help

[donnahardy2]

Hi,

Here’s a report that, although, not published in a scientific journal, appears to confirm that 40 degrees Centigrade is the optimum temperature for pectinase:

http://www.123helpme.com/view.asp?id=122363

And the optimum pH is 4.5 to 5.5:

http://en.wikipedia.org/wiki/Pectinase

Here’s a really good source of information on pectinase from one of the references on the Wikipedia article:

http://pec.biodbs.info/

A warm water bath would definitely speed up the reaction compared to ambient temperature.


What other enzymes were you planning to use? It would probably be best to use the optimum temperature and pH for each enzyme.

Donna Hardy

[umah11]

Hello,

Hope you had a happy new year.

thank you for the reply.

The enzymes i am using are: Amylase, Cellulase & Pectinase

I am investigating the effect of enzymes on juice produiction so i would assume that all factors have to be kept the same. So would it be better if i do not heat the enzymes at all?

[donnahardy2]

Hi.

Amylase has an optimum temperature of 40 degrees C, pectinase has an optimum of about 37degrees C, and cellulase has an optimum between 40 and 50 degrees Centigrade. So you would probably get faster results if you heated the samples to at least 35 degrees Centigrade. The general rule is there enzyme activity will double with every 10 degree C increase in temperature. If you can’t maintain a constant elevated temperature for all samples, however, it would be better to keep everything at ambient temperature, but you should record the temperature when you do the experiment.

Donna Hardy

[umah11]

Hello,

I have decided that I will keep the temperature for all enzymes around 35C.

The part I found difficult was finding the optimum temperature as so many websites had different temperatures so I didn't know which temperature I would use.

Thank you very much for your help.

Umamah

[donnahardy2]

Hi,

The problem with finding the optimum temperature for these enzymes is that there are many sources for each enzyme, and each specific enzyme has its own optimum temperature. For example, here is a paper that reports the study of cellulase from two difference organisms, with an optimum temperature of 40 degrees C and the other with an optimum of 45 degrees C.

http://www.hindawi.com/journals/btri/2011/810425/

There are also cellulases with optimum temperatures of 90degrees C. Your could verify the optimum temperature of the enzymes you will be using by asking your supplier what organism the enzymes were purified from. I think it is reasonable for you to use 35 degrees C for your experiment. Another way to do it would be to use the specific optimum temperature for each enzyme. This is a challenging experiment to design.

Donna Hardy

[umah11]

Hello,

Would it be better if I put all the enzymes at 35C or should I find out the optimum from the supplier and then put each one according to the optimum?

Sorry for asking spammy questions.

[donnahardy2]

Hi,

You have a very good question and I don’t know the answer. If you had time and materials for a pilot experiment, you could do a preliminary experiment and find out what difference it would make. Ideally, I think you would want to set up the experiment using the specific optimum conditions for each enzyme, however, if this would make the experiment too hard to do, you could just use 35 degrees Centigrade and perhaps let the experiment run for an extended period of time to ensure that using a slightly suboptimum temperature would not limit the enzyme activity. If you don’t have time for two experiments, then just choose one set of conditions. I think you will have some interesting results either way.


Donna Hardy

[umah11]

Thats fine. I'll ask my teacher and see what she says.

Also do I have to dilute the enzyme? I read on a another website that you don't have to dilute.

[donnahardy2]

Hi,

Another good question. I just checked the product available from Carolina Biologicals, and it is a liquid, but there are no instructions available on the website. Where did you get your pectinase and did it come with any instructions? How are you going to make sure you use an equivalent amount of each enzyme in your experiment? If possible, can you post the brand and source of each of you enzymes? You definitely need more information. If written information did not come with each enzyme, then check the website of the supplier and look for information on the source of the enzyme, the activity of the enzyme, and directions for use.

Enzymes are usually measured by enzyme activity or specific activity.

http://en.wikipedia.org/wiki/Enzyme_assay

Donna Hardy

[umah11]

I have not started my investigation yet but I can ask the technician AT my school and hopefully they can tell me the suppliers and the instructions

I will use a 4ml syringe to measrure the volume of enzyme.

Thank you very much for your help.