Measurement and prediction of pork colour

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.