During the conversion of muscle to meat, the rate and the extent of pH decline are able to influence the final quality of meat. The ultimate pH (pHu) value reached at 24h post mortem varies inter- and intra-species and essentially depends on muscle’s glycolytic potential. However, also the concentration of buffering compounds (i.e. anserine and carnosine) might play a role [1]. Thus, a study was performed in order to investigate the post mortem acidification pattern in chicken breast (Pectoralis major), thigh (Extensor Iliotibialis lateralis) and drumstick (Peroneus longus) muscles, characterized by a different in vivo energy metabolism. For this purpose, 12 carcasses were selected immediately after evisceration and samples from each muscle were collected at 15 min, 2, 4, 8 and 24h post mortem, instantly frozen in liquid nitrogen and stored at -80°C in order to evaluate pH and R-value. Then, at 24h post mortem, fiber-typing, total heme pigments and concentration of histidine compounds were also assessed. The findings evidenced that leg muscles had a more rapid pH decline and a significantly higher pHu, if compared with breast. Accordingly, R-value data confirmed the same trend. Drumstick muscle exhibited the highest content of total heme pigments, whereas no differences were found between pectoral and thigh muscles, which showed similar fiber composition. Moreover, if compared to leg muscles, breast presented a remarkably higher concentration of histidine compounds (anserine and carnosine). In conclusion, muscles with a different fiber composition exhibit a dissimilar acidification pattern during post mortem time, which can be partially explained by the different concentration of anserine and carnosine having a strong buffering capacity. These results might also give a reason for the higher pHu of chicken breast, if compared to other meats with similar fiber composition (i.e. pork and rabbit loin). 1. Decker A., The role of histidine-containing compounds on the buffering capacity of muscle, Proceedings of the 54th Reciprocal Meat Conference, 2001.
Post mortem acidification pattern in chicken breast and leg muscles
Giulia Baldi;Francesca Soglia;Maurizio Mazzoni;Luca Laghi;Samer Mudalal;Claudio Cavani;Massimiliano Petracci
2018
Abstract
During the conversion of muscle to meat, the rate and the extent of pH decline are able to influence the final quality of meat. The ultimate pH (pHu) value reached at 24h post mortem varies inter- and intra-species and essentially depends on muscle’s glycolytic potential. However, also the concentration of buffering compounds (i.e. anserine and carnosine) might play a role [1]. Thus, a study was performed in order to investigate the post mortem acidification pattern in chicken breast (Pectoralis major), thigh (Extensor Iliotibialis lateralis) and drumstick (Peroneus longus) muscles, characterized by a different in vivo energy metabolism. For this purpose, 12 carcasses were selected immediately after evisceration and samples from each muscle were collected at 15 min, 2, 4, 8 and 24h post mortem, instantly frozen in liquid nitrogen and stored at -80°C in order to evaluate pH and R-value. Then, at 24h post mortem, fiber-typing, total heme pigments and concentration of histidine compounds were also assessed. The findings evidenced that leg muscles had a more rapid pH decline and a significantly higher pHu, if compared with breast. Accordingly, R-value data confirmed the same trend. Drumstick muscle exhibited the highest content of total heme pigments, whereas no differences were found between pectoral and thigh muscles, which showed similar fiber composition. Moreover, if compared to leg muscles, breast presented a remarkably higher concentration of histidine compounds (anserine and carnosine). In conclusion, muscles with a different fiber composition exhibit a dissimilar acidification pattern during post mortem time, which can be partially explained by the different concentration of anserine and carnosine having a strong buffering capacity. These results might also give a reason for the higher pHu of chicken breast, if compared to other meats with similar fiber composition (i.e. pork and rabbit loin). 1. Decker A., The role of histidine-containing compounds on the buffering capacity of muscle, Proceedings of the 54th Reciprocal Meat Conference, 2001.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
