Identification of color optima of commercial tomato catsup

Color is an important quality feature of foods which, in many cases, determines consumer choice and selection. This is particularly true in case of products which are used only as additives to various foods and dishes such as tomato catsup. A screening of commercially available catsup showed a large variation in color properties expressed in terms of CIE-Lab parameters (L* = 30.7-35.8, C* = 18.7-30.1, and h(ab) = 32.0-39.0). Sensory preference tests revealed that mainly lightness and hue are responsible for consumer preference of catsup. Generally, catsup with a hue angle > 35, corresponding to a more orange appearance, was less preferred. It was also observed that within the preferred samples some consumers significantly preferred brighter catsup (L* similar to 34), whereas another group of consumers showed an attitude towards darker catsup samples (L* similar to 32). Color difference scores between the two groups of catsups ranged between 3.7 and 7.2. These samples differed only slightly in hue underlining the importance of lightness and chroma. Several one-dimensional color parameters were related to preference data and judged with respect to applicability.