Total Polyphenols test in olive oil/Stability index
The antioxidant capacity of polyphenols plays an important role in the stability of olive oil, as there is a correlation between the amount of total polyphenols and resistance to oxidation over time. The polyphenols have a protective action not only on oil but also on cells of the human body because they oppose the negative effects of free radicals. The amount of polyphenols decreases during oil extraction so the test can be used to optimize the processing.
The oxidative stability index of olive oil is directly proportional to the antioxidant capacity (polyphenols). It is calculated on the basis of the comparison, performed by Minerva SA e Asteriadis SA in collaboration with the University of Athens, between CDR method and AOCS official method Cd 12b-92 (Rancimat), which estimates the time of induction, expressed in hours.
Method
End point test.
Test time: 5 minutes.
Analysis sessions with multiple samples are possible up to a maximum of 4 tests for CDR OxiTester and 3 tests for CDR OxiTester Junior.
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Sample treatment
Use oil as is.
Principle of the test
The polyphenols, in contact with a chromogenic compound in an alcoholic solution, are oxidized and decrease the color of the compound. The decreasing of color, read at 505 nm, is directly proportional to the concentration of polyphenols in the sample, expressed as mg/kg of tyrosol.
Calibration curve
The new Total Polyphenols (Biophenols) analysis used by the CDR OxiTester has been calibrated with the reference method IOC / T.20 / Doc. n. 29: 2009, by the Commodity Chemical Laboratory of Chamber of Commerce of Florence, Italy. They confirmed that the results of the Total Polyphenols of olive oil analysis, obtained with the CDR OxiTester, are compliant with the reference method.
CDR OxiTester method shows a very good correlation with OIC (International Olive Council) method.
Download the complete report of the Commodity Chemical Laboratory of Chamber of Commerce of Florence: Technological methods for the rapid biophenol assay of olive oils.
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Reagent test Kits
Measuring range
| Analyses | Measuring range | Resolution | Repeatability |
|---|---|---|---|
| Polyphenols - Stability index | 200 - 1000 mg/Kg tyrosol | 1 mg/Kg tyrosol | 34 mg/Kg tyrosol |
Analyzers for quality control of olive oil
CDR OxiTester
Complete analysis panel, supplied already configured
Up to 16 determinations simultaneously
Possibility of carrying out analyses of the same sample
Integrated printer
Full connections (LAN - USB - Bluetooth barcode/QR code reader)
CDR OxiTester Jr
Partial analysis panel, customisable configuration
Up to 3 determinations simultaneously
Wireless connection to external printer
USB connections