Importance of peroxide value testing
At its core, peroxide value testing helps you determine if your raw materials or food products are fresh or rancid. Having this information helps ensure that you consistently deliver quality products.
Why measure peroxides? Lipid peroxides are the primary product of oxidized oils or fats and are an indicator of off-flavors and off-odors (rancidity). This helps explain why peroxide value testing is the most commonly used assay for evaluating the level of oxidation in fats and oils.
Principles of the peroxide value test
MP Bio’s Peroxide Test Kit is designed to provide rapid analysis of lipid peroxides in any type of oil or complex sample using microanalytical and membrane separation principles. The Peroxide Test Kit quantitates peroxide value (PV) by transferring a free electron to a metal-chromogen complex whose visible spectrum then changes and is read using the SafTest analyzer.
The Peroxide Test Kit can be used for testing solubilized dry and wet matrices by extracting lipid fat from the sample matrix using MP Bio’s preparation reagent and employing mechanical mixing and warming techniques.
This results in significantly shorter sample preparation (~15 minutes), allowing for data to be obtained in under 30 minutes. The kit contains all reagents, calibrators, and controls required for testing approximately 100 samples.
The Peroxide Test Kit offers a fast, easy, non-toxic means of obtaining peroxide values in almost any sample type.
Correlation with AOCS method
We’ve developed our rancidity tests to be accurate and reproducible. MP Bio’s Peroxide Test Kit is in alignment with AOAC and is designed to replace AOCS extraction and titration testing methods.
Peroxide value testing samples
There are several sample types you can test for peroxide values, including:
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No matter the sample type you are working with, there are consistent sample handling guidelines we suggest when using our SafTest methods. Prepare your samples based on our Sample Preparation Quick Card and Peroxide Test Kit Protocol.
Sample Handling Guidelines:
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Calibration Range: |
0.00 – 0.20 MEQ/kg |
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Optimal Working Range: |
0.05 – 50 MEQ/kg |
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Sample Preparation Time Requirement: |
1 – 20 minutes |
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Analysis Time: |
~10 minutes |
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Minimum sample size: |
>1mL or 4g |
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Sample Preparation: |
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Protips for generating calibration curves
When you receive a new kit, you must first run a calibration curve. If it’s your first time setting up a calibration curve, or if you simply need a refresher, check out our Peroxide Test Kit Protocol to get a step-by-step guide on how to properly set up a calibration curve for your peroxide value test.
The SafTest™ analyzer will use the Calibrators to calculate the lipid peroxide content as milliequivalents of peroxides per kilogram of sample. Adjust the instrument results by taking into account the dilution factor. For example:
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Dilution Factor |
SafTestTM Results |
Dilution x Results |
Final Results |
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1:10 |
0.08 MEQ/kg |
10 x 0.08 MEQ/kg |
0.8 MEQ/kg |
The final result can be calculated into milliequivalents of peroxides per kilogram of fat by taking the percent fat into consideration when performing your calculation. For example, with a sample that is 10% fat and yields a final result of 0.8 MEQ/kg:
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Final Result |
Result / (%Fat/100) |
Final Result |
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0.8 MEQ/kg |
0.8 / (10/100) |
8 MEG/kg of fat |
Calibration Protips:
- Use a new tip for each Calibrator and Control
- The same tip can be used if running a duplicate
- Remove all air bubbles from the tip before drawing the final sample
ProTips for troubleshooting your SafTestTM peroxide value test
- If the sample value is greater than the value of the highest calibrator, the instrument will flag the results as “HI.” The sample must be prepared at a higher dilution and retested; see Additional Dilutions Quick Card.
- If the sample value is less than the value of the lowest calibrator, the instrument will flag the results as “LO”. Values that are flagged “LO” should be reported as “< value of the lowest calibrator.”
- Check the instrument printout for flags or error messages before reporting results. The coefficient of variation (%CV) should be less than 10%. Higher variations will be flagged, in which case you should repeat the test.
- EXCEPTION – A large %CV is expected with samples that are measured at the low end of the calibration curve. For such measurements, do not repeat the test.
- If the slope, intercept, or correlation coefficient guidelines are not met, recalibrate the instrument.
- The range for the Control is found on the Peroxide Control Package Insert. Your test value for the Control should approximate this range. If it does not, rerun the test.
Summary of Advantages of SafTestTM Test Kits
- Six different reagent kits for the analysis of quality in human and pet foods, oils, cosmetics and biodiesel
- Requires only small amount of the sample (10 – 50 μL)
- Results that meet the standards set by AOCS and or ASTM
- Obtain quality data in 20 – 30 minutes as opposed to traditional methods that take 8 hours
- Designed for ease-of-use and convenience
- Each kit contains up to 120 tests and comes pre-packaged with all the reagents, calibrators and controls
- All reagents are non-toxic
Related Articles and Resources:
Peroxide Test Kit
Accurately measure peroxide value of solid or liquid samples within 30 minutes.
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