POSTMORTAL CHANGES IN PH VALUE OF CHICKEN MUSCLES

The study was aimed at evaluation of the dynamics of pH in breast and thigh muscles of chickens from the ordinary agricultural production an d slaughtered in a large-scale processing enterprise. Eight groups of chickens, randomly selected, were appraised during three months. Ten c hickens were included in each group of evaluated chickens. Actual time of slaughtering and pH values was measured post mortem in the large b reast muscle and in the biceps thigh muscle in time intervals from 30 to 300 minutes. Average pH values for the whole set (n = 80) were as f ollows: [GRAPHICS] The differences found between average pH values in the breast and thigh muscles in comparable times are higher than the d ata reported in literature. This can be explained by operational condi tions of observations in which thigh muscle of chickens is more exerte d during pre-slaughter period, glycogen is mostly exhausted and result ing pH of meat is relatively high. Great differences between different groups (Figs. 1 and 2) may be caused by different pre-slaughter condi tions of different groups of chickens. Relatively great variability in pH values was found in ten-membered sets of values in appropriate mus cle and appropriate time (Tabs. I and II). This may be explained by a great variability of action of pre-slaughter effects and in their diff erent action on individual chickens. This apparent great variability o f values is considered as normal and natural. It caused that only extr emely different groups of chickens in view of the course of pH values in the breast and thigh muscle exhibited significantly different value s (Tabs. III and IV); the differences between all the other groups to each other were insignificant.Too high variability of pH values in the muscles of slaughtered chickens, some of them have neutral pH value, indicates non-standard pre-slaughter conditions. Some of them lead to the physical exhaustion of chickens and finally, to high values of mea t pH value, undesirable in view of hygiene, as such meat is very susce ptible to microbial spoilage. Considerate and generous treatment are r equired during preslaughter handling with slaughter chickens.