The extent to which instrumental colour determinations by FOPu (light scatt
ering), Gofo (reflectance) and Labscan II (CIE L*, CLE a* and CIE b*, hue a
nd chroma) are related to the Japanese colour grades was studied. Additiona
lly, four on-line methods: pH1, FOP1, PQM1 (conductivity) and DDLT (Double
Density Light Transmission, analogous to Capteur Gras/Maigre), were evaluat
ed for their ability to predict subjectively and objectively colour. One hu
ndred and twenty samples of m. longissimus thoracis et lumborum, from anima
ls of different genotypes, were analysed. Of the instrumental colour determ
inations, CIE L* (r = -0.82), FOPu (r = -0.70) and Gofo (r = 0.70) were bes
t correlated with the Japanese colour scores. The Japanese colour grades co
uld be predicted by the on-line instruments, pH1, FOP1, PQM1 and DDLT, with
determination coefficients between 15 and 28%. Ultimate meat colour, deter
mined by Japanese colour standards, FOPu, Gofo and CIE L*, was better predi
cted by DDLT than by the classic on-line instruments: FOP1, pill and PQM1,
although the standard error of the estimate was similar for all instruments
. This means that DDLT, although originally designed for estimating lean me
at percentage, can additionally give information about meat quality, in par
ticular colour. However, it must be stressed that the colour estimate by DD
LT refers to a population of animals, rather than to individual pigs, becau
se of the number of erroneously assigned samples. (C) 1999 Elsevier Science
Ltd. All rights reserved.