Maintaining muscles at a high post-mortem temperature induces PSE-like meat in turkey C. Molette, H. Re´mignon*, R. Babile´ Ecole Nationale Supe´rieure Agronomique de Toulouse, BP107, Avenue de l’Agrobiopole, 31326 Castanet Tolosan Cedex, France Received 16 November 2001; received in revised form 26 April 2002; accepted 10 May 2002 Abstract The aim of the present study was to validate an experimental model which surely generates pale, soft, exudative (PSE) turkey meat. Immediately after exsanguination, Pectoralis major (n=15) were kept at various temperatures (4, 20 or 40  C) for 6 h. All the muscles were then stored at 4  C for 9 days. They had the same rate of pH fall. L* values were higher in the 40  C treatment muscles than in the two other treatment muscles between 1 and 9 h. Drip loss of the 40  C treatment muscles was higher than in the two other treatment muscles. However, thawing and cook loss were not significantly different between treatments. Cooked meat from the 40  C treatment muscle was tougher than the two other treatment muscles. Napole yield was lower for these muscles. Myofi- brillar protein extractability was lower in the 40  C treatment muscle whatever the considered time. We showed that the 40  C treatment muscles were similar to PSE muscles. # 2002 Elsevier Science Ltd. All rights reserved. Keywords: Turkey; PSE; Protein extractability; Water-holding capacity; Colour; Shear force; Meat quality 1. Introduction The pale, soft, exudative (PSE) syndrome leads to meats, which have a paler colour, a higher toughness and a lower water-holding capacity. In pork, this phe- nomenon is well known whereas, in turkey and chicken, it appeared recently. Observations in slaughterhouse (especially in the United States) have shown that PSE meat could represent from 5 to 30% of the slaughtered turkeys (Barbut, 1996, 1997; McCurdy, Barbut, & Quinton, 1996). The default was detected using the instrumental measurement of the colour. As a con- sequence, Barbut (1993, 1996 and 1998) suggested to classify as PSE every turkey breast meat with L* values higher than 52 at 24 h post-mortem. Warris and Brown (1987) have reported that early post-mortem pH decline from 30 min to 1 h was the most important factor which determined the degree of exudation in pork meat. Early studies by Bendall and Wismer-Pedersen (1962) have also revealed that rigor development in pork muscles at elevated post-mortem temperatures of 37  C always resulted in PSE meat characteristics. It is generally accepted that pHu values, measured at 24 h post-mortem, of PSE meat are similar to those of ‘‘normal’’ meat. So, the rate of pH fall seems to be the major factor, which determines the sev- erity of problems associated with PSE meat. The inter- relationship between temperature and pH in the development of PSE characteristics is also important and well-established (pork: Fernandez, Forslid & Torn- berg, 1994; turkey: McKee & Sams, 1998). McKee and Sams (1998) have subjected turkey car- casses to high temperature. They have performed sev- eral measurements during the 4 h post-mortem when carcasses were kept at high temperature. In their study, carcasses kept at 40  C presented the PSE char- acteristics. The aim of our study was to validate a simi- lar model, which could surely generate PSE turkey meat to better understand the biochemical mechanisms of the syndrome apparition. For this purpose, turkey pector- alis major (PM) muscles were subjected immediately after slaughter to high temperature for 6 h. As a con- sequence, both high temperature and low pH would be encountered. Possible origins of the meat defaults would also be suggested along our study. 0309-1740/03/$ - see front matter # 2002 Elsevier Science Ltd. All rights reserved. PII: S0309-1740(02)00114-6 Meat Science 63 (2003) 525–532 www.elsevier.com/locate/meatsci * Corresponding author. Tel.: +33-5-62-19-39-12; fax: +33-5-62- 19-39-01. E-mail address: remignon@ensat.fr (H. Remignon).