Color‐pigment correlation in virgin olive oil

Abstract

The chlorophyll and carotenoid content of virgin olive oils from five varieties harvested at varying degrees of ripeness were determined. Colors were evaluated from the chromatic ordinates L*, a*, b* of the absorption spectrum.Oil color changes for different varieties or stages of ripeness are directly related to pigment content and a* and b* values. The statistical study made on both series of parameters proves that there is a good correlation between them. The carotenoid content and b* have one of the best correlation coefficients (r) and is easily measured. This methodology evaluates chlorophyll and carotenoid content, an additional attribute for evaluation of virgin olive oil quality.

Geographical Discrimination of Virgin Olive Oils from the Tunisian Coasts by Combining Fatty Acids and Phenolic Acids Profiles within a Multivariate Analysis

“…Chlorophyll and carotenoid concentrations of the samples were determined colorimetrically as previously described by Minguez-Mosquera et al in 1991 14 . The olive oil sample 7.5 g was dissolved in 25 mL of cyclohexane and the absorbance of the samples at 470 and 670 nm, which are associated with carotene and chlorophyll, respectively, were measured with a UV spectrophotometer Shimadzu UV-1601 Spectrophotometer, Japan .…”

Agronomic and Technological Factors Affecting Tunisian Olive Oil Quality

“…Carotenes and chlorophylls pigments were determined by measuring the absorbance at 470 and 670 nm, respectively. The results were expressed as mg of pheophytin "α" and lutein per kg of oil, respectively [8].…”

“…The total pigment content of olive oils is an important quality parameter, in addition to its involvement in the mechanisms of auto-oxidation and photo-oxidation [8] [34]; it is correlated with the color, which is a basic attribute for olive oil quality assessment. In our study the chlorophyll pigment content was not affected by the extraction system.…”

Chemical composition of virgin olive oils from the Chemlali cultivar with regard to the method of the olive tree propagation

“…Chlorophyll and carotenoid contents were determined colorimetrically as previously described (Mínguez-Mosquera et al, 1991). The maximum absorption at 670 nm is related to the chlorophyll fraction, while the maximum absorption at 470 nm is related to the carotenoid fraction.…”