Affiliation: | (1) Departmento de Psicología Evolutiva y de la Educación, Facultad de Psicología, Universidad de Granada, 18071 Granada, Spain;(2) área de Nutrición y Bromatología, Facultad de Farmacia, Universidad de Sevilla, 41012 Sevilla, Spain;(3) Almazara Experimental del Instituto de la Grasa, Consejo Superior de Investigaciones Cientificas (CSIC), 41012 Sevilla, Spain;(4) Departamento de óptica, Facultad de Ciencias, Campus de Fuentenueva s/n, Universidad de Granada, 18071 Granada, Spain |
Abstract: | A new color scale was developed from a broad data set of 1700 virgin olive oil samples over four crop seasons, which can be considered highly representative of the whole color range of virgin olive oils available in Spain. This color scale provides a new set of 60 color standards, improving the results achieved by the old 60-color standards proposed by the bromthymol blue method. Seeking the greatest possibility of including a near match between colors of virgin olive oils and proposed standards, we developed our new color scale using a recent uniform color space, with standards placed in a regular rhombohedral lattice like the one employed by the Uniform Color Scales of the Optical Society of America. The average color difference between each of the 1700 virgin olive oils and its nearest standard is reduced from 8.17 CIELAB units, using the bromthymol blue standards, to 3.99 CIELAB units using the new standards. Within a color tolerance of 7.0 CIELAB units, 93.2% of our virgin olive oils can be classified with the new standards, but only 59.1% with the bromthymol blue ones. In the interest of future adoption, the performance of the new color standards should be tested by industry and researchers. |