Differences between observers in assessment of meat colour.

Abstract

Animal Production in Australia Vol. 1.5 DIFFERENCES BETWEEN OBSERVERS IN ASSESSMENT OF MEAT COLOUR T.G. TRUSCOTT*, J.E. HUDSON* and S.K. ANDERSON* Meat colour is considered by retailers In order to consumers when choosing meat. beef of three large retail meat traders, the three supermarket chains (A, B and C) was as of the 317 electrically stimulated steer car Melbourne Agricultural Show. The colour of the 1. dorsi at the 10th scored using a 15 point scale. A score of light colour, 6 to 10 an acceptable colour colour. Each carcass was observed between from 3.5 to 4 hr after quartering. The 1. 26 and 30 hr post slaughter. to be of prime importance to compare preferences for colour of senior meat buyer from each o f ked to visually score meat col our casses presented at the 1982 rib on one side of each carcass was 1 to 5 indicated an unacceptably and 11 to 15 an unacceptably dark 21 and 25 hr post slaughter and dorsi pH was measured in situ between The mean (5S.D.) colour score for observers A, B and C was 10.6+1.3, 7.7k1.3 and 9.4k2.3, respectively. The variance of C's scores was significantly (P<O.O5) greater than the variances of A's and B's scores, indicating that C used the colour scoring scale in a different manner. Although the variances of A's and B's scores were the same, A scored carcasses significantly (P<O.OOl) higher than B. Observers' scores were only moderately correlated (r AB=0.66; rAC=0.56; rBC=0.68). Shorthose (1980) suggests that consumers purchasing pasture-fed beef will consider meat with an ultimate pH greater than 5.8 to be dark. The mean (2S.D.) pH of the 317 carcasses was 5.6kO.13 with only 14 (4.4%) above pH 5.8. The observers, however, varied significantly (P<O.OOl) in the percentage scored as unacceptably dark (54.3%, 2.5% and 23.3% by A, B and C, respectively). Only observer A indicated that any carcasses (4) had unacceptably light meat. Age as well as pH is known to affect muscle colour. However, either alone or in combination, age (scored by dentition) and pH explained only low levels of variation in observers' scores of meat colour (Table 1). Even so, age plus pH explained significantly (PcO.01) more variation in B's scores than in the scores of A or C. The results suggest that observer B was better than the other two observers in perception and description of variation in meat colour associated with age and pH. TABLE 1 Correlation coefficients for the relation of dentition and pH with observers' meat colour scores Overall, this study showed that three experienced meat retailers varied significantly in their description of meat colour and in what they considered acceptable for their marketing requirements. SHORTHOSE, W.R. (1980). III Symposio National de Ciencia y Technologia de Carnes. Buenos Aires, November 1980 * Department of Agriculture, G.P.O. Box 4041, Melbourne, Victoria, 3001. 762