Effects of rigor attainment temperature on meat blooming and colour on display

This paper describes the colour properties of seven hot-boned, unstimulated beef striploins during rigor attainment at 9, 14 and 24 degrees C, during blooming at 4 degrees C, and after storage at -1 degrees C for 0, 2 and 8 weeks. Immediately after rigor attainment (0 weeks of storage) full blooming, as judged by L* and chroma, took at least 12 h. After 2 and 8 weeks storage, blooming was complete within about 4 h. The exponential equations describing blooming were different for O weeks compared with 2 and 8 weeks. This difference can be explained in terms of oxygen consumption by meat freshly in rigor. At O weeks, meat that entered rigor at 24 degrees C had the best bloomed colour, whereas at 2 and 8 weeks the 9 degrees C treatment had the best and the 24 degrees C the worst. The data set, which spanned a range of ultimate pH values and three rigor attainment temperatures, was used to estimate the value of early colour measurements (first 24 h post-rigor) in predicting colour during display several weeks later. As judged by correlation coefficients, early measurements of hue were the only ones useful. L* and chroma were poor predictors. This result, together with the knowledge that blooming is slow in the first 24 h post-rigor, casts doubt on the value of subjective or objective colour assessments made in chillers. Temperature of rigor attainment between 9 and 24 degrees C did not affect the time of browning onset, nor the rate of browning. It was confirmed that meat with lower pH had higher chroma before and after blooming. (C) 1999 Elsevier Science Ltd. All rights reserved.