Journal of the American Oil Chemists' Society

, Volume 86, Issue 7, pp 627–636

Color Measurements in Blue-Tinted Cups for Virgin-Olive-Oil Tasting

  • M. Melgosa
  • L. Gómez-Robledo
  • R. Huertas
  • L. F. Capitán-Vallvey
  • M. J. Moyano
  • F. J. Heredia
Original Paper

DOI: 10.1007/s11746-009-1387-2

Cite this article as:
Melgosa, M., Gómez-Robledo, L., Huertas, R. et al. J Am Oil Chem Soc (2009) 86: 627. doi:10.1007/s11746-009-1387-2

Abstract

Color measurements have been performed using eighteen virgin-olive-oil tasting cups with ten different commercial virgin olive oils, positioned in a color cabinet with a D65 source. Three geometries (spectroradiometer tilted 0°, 30°, and 60°) were employed, simulating different positions of the taster’s eye. Our main goal was to test whether traditional blue-tinted cups effectively conceal the color of virgin olive oils, as desired in sensorial analyses. None of the cups employed had all their geometrical dimensions within the standardized values, despite being cups used in official sensorial analyses. Measuring a magnitude similar to the spectral transmittance, we found substantial differences among the glasses of the eighteen tasting cups. Comparing color variability for one virgin olive oil in different tasting cups, and one tasting cup with different virgin olive oils, we discovered that: (1) variability was higher in the case of one virgin olive oil in different cups; (2) in both cases the variability increased with the tilt of the spectroradiometer; (3) even when the variability was lowest (i.e., 0° measurements for two oils in the same cup), the average color difference was above typical visual thresholds in simultaneous comparison experiments. In the most usual case of a successive comparison between two oils in the same tasting cup, it is expected that in most cases tasters will perceive color differences between the oils when their eyes are tilted 60° with respect to the horizontal, but not when they observe the cup in the horizontal direction. In summary, blue-tinted olive-oil-tasting cups reduce, but do not completely conceal, oil color. The use of opaque tasting cups with black walls is suggested.

Keywords

Virgin olive oil Oil tasting Color measurement Color differences Standard oil-tasting cups 

Copyright information

© AOCS 2009

Authors and Affiliations

  • M. Melgosa
    • 1
  • L. Gómez-Robledo
    • 1
  • R. Huertas
    • 1
  • L. F. Capitán-Vallvey
    • 2
  • M. J. Moyano
    • 3
  • F. J. Heredia
    • 4
  1. 1.Departamento de Óptica, Facultad de CienciasUniversidad de GranadaGranadaSpain
  2. 2.Solid Phase Spectrometry Research Group, Departamento de Química Analítica, Facultad de CienciasUniversidad de GranadaGranadaSpain
  3. 3.Almazara Experimental del Instituto de la GrasaCSICSevillaSpain
  4. 4.Grupo de Color y Calidad de Alimentos, Facultad de FarmaciaUniversidad de SevillaSevillaSpain