The Color Space of Foods:  Virgin Olive Oil

Abstract

The CIE 1976 (L*, a*, and b*) color space for virgin olive oil was determined. Such a space encompasses any acceptable sample of this type of oil irrespective of the agronomic treatment that the olives have undergone because its color is due to two types of pigments, a systematic combination of which provides the whole range of theoretically possible colors. Color is quantified from the visible spectra for pure samples. Therefore, the pigment spectra, which were the averages of those for several samples, were determined in a medium highly similar to the source oil following application of a photochemical method. A combination of the pigment spectra provided 651 spectra for virtual samples, the colors of which spanned the entire color space for virgin olive oil. The positions of more than 100 Spanish olive oil samples of diverse origins in the color space were also determined, and the results were examined in relation to oil type and quality. Similar color spaces can be obtained for other foods, which can thus be characterized in terms of an additional physical property.

Impact assessment of mechanical harvest on fruit physiology and consequences on oil physicochemical and sensory quality from ‘Manzanilla de Sevilla’ and ‘Manzanilla Cacereña’ super‐high‐density hedgerows. A preliminary study

“…Chlorophylls and carotenoids are the main pigments responsible for the colour of VOO, and carotenoids display an antioxidant action . Mechanical harvesting did not affect the chlorophyll content in either cultivar (Table ).…”

The Color of Olive Oils: The Pigments and Their Likely Health Benefits and Visual and Instrumental Methods of Analysis

“…Olive oil is an important component of the praised Mediterranean diet, which is attracting increasingly the interest of scientists due to the health benefits it can provide (Visioli and Galli 2002; Pérez‐Jiménez 2007; Pérez‐Jiménez and others 2007). As is the case for foodstuffs in general (Francis 1995), the color of olive oil is very related to its perceived quality and therefore to its acceptability (Ranalli and others 1997; Boskou 1998), hence this parameter is being paid much attention in recent years, above all in Spain (Mínguez‐Mosquera and others 1991; Escolar and others 1994, 2007; Moyano and others 1999, 2001, 2008a, 2008b; Melgosa and others 2000, 2001, 2004, 2005; Romero and others 2001; Criado and others 2008).…”

“…Anyhow, several studies on the objective specification of this attribute have come out in the last few years, it is important to stress the need to define unambiguously the different attributes related to color (lightness, hue, chroma, for example) (Escolar and others 1994, 2007; Moyano and others 2001, 2008a, 2008b; Melgosa and others 2004, 2005).…”

A comprehensive study on the colour of virgin olive oils and its relationship with their chlorophylls and carotenoids indexes (II): CIELUV and CIELAB uniform colour spaces

“…Among many other foodstuffs, the colour of olive oils, a food staple in the Mediterranean basin and a major component of the praised Mediterranean diet, have been the subject of a myriad of studies in the last years (Ceballos, Moyano, Vicario, Alba, & Heredia, 2003;Escolar et al, 1994;Escolar, Haro, & Ayuso, 2007;Moyano et al, 2001;Moyano, Melgosa, Alba, Hita, & Heredia, 1999), which is connected with the renewed interest in such products due to the wholesomeness and the likely beneficial effects stemming from their chemical composition (Cunha, Amaral, Fernandes, & Oliveira, 2006;Lee, Thurnham, & Chopra, 2000;Ranalli, Cabras, Iannucci, & Contento, 2001;Tura et al, 2007). Food Research International 41 (2008) [513][514][515][516][517][518][519][520][521] Contents lists available at ScienceDirect In this study, we have assessed objectively the colour and the total pigment contents of 1700 samples of Spanish olive oils (with different composition and obtained from olives from different geographical areas and at three different stages of ripeness) with diverse objectives, ranging from the thorough characterization of their colour in two different globally-accepted uniform colour systems (CIELUV and CIELAB) to the establishment of statistical relationships between their colour parameters and pigment contents.…”