The use of infrared thermography for pork quality prediction.

Based on the close association between muscle temperature rise and early post-mortem pH fall rate, infra-red thermography (IRT) has been applied to detect the temperature increase in pigs in response to pre-slaughter handling with the ultimate objective to predict meat quality variation. Two experiments were carried out with the objective to determine whether IRT body temperature as measured either on dorsal or orbital regions immediately before slaughter can be used to explain variation in pork quality. In experiment 1, fore-back IRT (IRFBT) body temperature readings were taken on 133 pigs in the stunning chute while in experiment 2, 258 pigs were scanned at the ocular region (IROT) in the restrainer. Meat quality was assessed in the longissimus dorsi (LD) and semimembranosus (SM) muscles. No significant correlations were found between IRFBT and meat quality parameters in experiment 1, whereas, in experiment 2, IROT temperature recordings were correlated with pH1 (r = − 0.18; P = 0.03) and drip loss (r = 0.20; P = 0.02) in the LD muscle and with pH1 in the SM muscle (r = − 0.20; P = 0.02). These results indicate that the higher the body and muscle temperature are before slaughter, the faster is the rate of early post-mortem meat acidification. The poor prediction rate of IRFBT body temperature may be explained by the presence of dirt, hair and humidity on pig skin interfering with the temperature readings. The measurement of IRT body temperature in the ocular region may be a promising technique to predict the variation of important meat quality traits.