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Home » Food diagnostics » Analysis » Polyphenols/oil stability index in olive oilPolyphenols/oil stability index in olive oil
The antioxidant power of polyphenols has an important role for olive oil stability since there is a correlation between the total polyphenols value and the oxidation resistance time.Furthermore Polyphenols have an important role in protecting not only oil but also the cells of human body because they fight against the negative effects of free radicals.
Polyphenols value decreases during oil extraction and therefore polyphenols/antioxidant activity test can be used for optimizing the transformation process in the oil-mill.
The official method to determine oil oxidative stability, i.e. the relative resistance of oil to oxidation, is the so-called Rancimat method (induction time). A study published in the Journal of AOAC International [Vol. 91, No 4, 2008] and carried out by Asteriadis S.A. and Minerva S.A. enterprises in partnership with the University of Athens, examined the OxiTester photometric method for the determination of olive Oil Stability Index (OSI) and polyphenol content, and compared it with the Rancimat official testing method. Said study validated the simple and fast OxiTester method as a valid alternative to Rancimat.
Furthermore, the OxiTester system requires shorter testing times compared to Rancimat to evaluate Oil Stability Index (OSI)
OxiTester about 6 minutes
Rancimat 12 hours
Key Points about Polyphenols OxiTester method
- It detects the total amount of polyphenols in a faster and easier way compared to the Folin-Ciocalteau method
- It does not require any calibration, unlike the Folin-Ciocalteau method.
- It represents a valid alternative to the Rancimat method to determine oxidative stability.
- Test results are available in 6 minutes, while 12 hours are the schedule foreseen in the Rancimat method.
For more information about Poliphenols/OSI analysis and OxiTester, please contact us
Instruments to Use
Reagents
R (pre-filled in cuvette): alcohol mixture, cromogenic
Test method
Test type: End Point
Colour reading at 505 nm
Test time: 5 minutes
It is possible to carry out several test sessions with a maximum of 14 samples. Calibration can be performed by aligning the test to reference values.
Test principle
The polyphenols, when in contact with a coloured complex in an alcohol solution, become oxidized and develop a violet colour whose intensity, measured at 505 nm, is indirectly proportional to the concentration of polyphenols in the sample. The Foodlab method is the most indicative, in respect to other methods, to evaluate the antioxidant power of the polyphenols because it reproduces in the test tube the actions that come about spontaneously in oil and in the human body between polyphenols and free radicals.
In addition the Foodlab method simplifies and speeds up the official procedure, and thanks to the microquantity of the samples utilized permitting to analyze the oil contained in few pressed olives (cold extract system CDR) to monitor the maturation process.
Sample
Oil as is
Reagent Kits
The reagents are provided in sealed bags, each containing 10 cuvettes. They have a 12 months duration, starting from the production date. Stocking requirements are described on the bag label.
Reagents do not contain dangerous solvents and are ready for use.
For more information about Poliphenols/OSI analysis and OxiTester, please contact us
| KIT CODE | SAMPLE VOLUME | RANGE |
| *300478 (10 Test) *300475 (100 Test) |
10 µL | 10 – 900 mg/Kg gallic acid |
| Reagent developed by CDR s.r.l | ||||
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Quality System certified ISO 9001 Ed. 2008 |
