Colour Retention of “High Colour” Lines of Tomatoes Canned As Juice

Abstract

Crimson (ogc), recombinant (ogc+ hp), and to a slightly lesser extent high pigment (hp), lines of tomatoes made a deeper, more intensered juice than did normal colour (r+) lines. Hunter Colour Difference Meter values expressed as a/b and bL/a were used in assessing colour. Differences between colour lines that existed before canning were maintained during the canning operation and continued to exist throughout storage in the can. With all lines, heat treatment involved in canning caused some initial loss, after which colour remained stable.The results show that the promising high colour lines now being used by plant breeders maintain their colour superiority over normal colour lines after canning and storage. The results also provide reassurance that colour evaluations of raw, “cold-press” juice (common practice when evaluating breeding material) reliably indicate processed colour, even wiiere different colour lines and their respective pigment systems are concerned.Characteristic structure of the red (lycopene) and yellow (beta-carotene) pigment bodies determining tomato colour is shown in light and electron micrographs.