The significance of cooling rate on water dynamics in porcine muscle from heterozygote carriers and non-carriers of the halothane gene―a low-field NMR relaxation study

摘要

The post mortem changes in the chemical/physical state distribution of water were followed in pig muscle (M. longissimus dorsi) from heterozygote (n= 12) and non-carriers (n= 12) of the halothane gene exposed to two different cooling profiles using continuous low-field NMR relaxation measurements. T_2 relaxation data were analyzed using distributed exponential fitting analysis. Independent of genotype post mortem changes were observed in the two water populations characterizing water within the myofi-brillar space (T_(21)) and the extra-myofibrillar space (T_(22)), respectively, as a function of chilling regime. The effect was most pronounced in samples from heterozygote carriers of the halothane gene. The obtained results strongly suggest that improved water-holding capacity of muscles upon fast chilling can be ascribed to a reduced accumulation of extra-myofibrillar water in the meat post mortem, and it is hypothesized that differences in the accumulation of extra-rnyofibrillar water post mortem can be ascribed largely to the time at which disruption of cell membrane integrity takes place.