Related Experiment Videos
Separation of thermostable pectinmethylesterase from marsh grapefruit pulp
1Department of Food Science and Technology, University of Georgia, Athens, Georgia 30602, USA.
Journal of Agricultural and Food Chemistry
|October 29, 2000
Summary
A new ion-exchange method efficiently isolates thermostable pectin methylesterase (TS-PME) from grapefruit. Optimal conditions yielded high enzyme activity, suggesting separation of a protective factor.
Area of Science:
- Biochemistry
- Enzymology
- Food Science
Background:
- Pectin methylesterase (PME) is crucial in fruit processing.
- Thermostable PME (TS-PME) offers advantages for industrial applications.
- Efficient isolation methods for TS-PME are needed.
Purpose of the Study:
- To develop a rapid ion-exchange method for isolating TS-PME from Marsh grapefruit pulp.
- To optimize extraction and purification conditions for TS-PME.
- To evaluate the yield and specific activity of isolated TS-PME.
Main Methods:
- Selective extraction of TS-PME using 1 M NaCl at low pH.
- Ion-exchange chromatography without precipitation or dialysis.
- Testing different NaCl concentrations (0.1, 0.25, 0.5 M) during column loading.
Main Results:
- High yields (up to 70%) achieved at 0.1 M NaCl, with specific activity >400 U/mg protein at 0.5 M NaCl.
- TS-PME activity in loaded fractions was higher than in heated crude extracts.
- Loss of thermostability observed in some fractions loaded at lower NaCl concentrations.
Conclusions:
- The developed ion-exchange method rapidly isolates active TS-PME from grapefruit.
- Loading at 0.5 M NaCl maximizes TS-PME activity and suggests separation of a protective factor.
- This method holds potential for industrial enzyme purification.