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RESEARCH ARTICLE

Quantifying the rate of pH and temperature decline in lamb carcasses at three abattoirs in New South Wales

E. S. Toohey A D , D. L. Hopkins A , B. M. McLeod B and S. G. Nielsen C
+ Author Affiliations
- Author Affiliations

A The Australian Sheep Industry Cooperative Research Centre, NSW Department of Primary Industries, Centre for Sheep Meat Development, PO Box 129, Cowra, NSW 2794, Australia.

B NSW Department of Primary Industries, Glen Innes Agricultural Research and Advisory Station, Private Mail Bag, Glen Innes, NSW 2370, Australia.

C NSW Department of Primary Industries, Orange Agricultural Institute, Forest Road, Orange, NSW 2800, Australia.

D Corresponding author. Email: edwina.toohey@dpi.nsw.gov.au

Australian Journal of Experimental Agriculture 46(7) 875-878 https://doi.org/10.1071/EA05324
Submitted: 18 November 2005  Accepted: 17 March 2006   Published: 8 June 2006

Abstract

The aim of this work was to benchmark the rate of pH and temperature decline in lamb carcasses (particularly the temperature at pH 6.0) at 3 commercial abattoirs across New South Wales. In total, 1197 carcasses were monitored over 13 months for pH and temperature decline. The lambs were sourced from a variety of regions, either direct from the paddock or from sale yards. Carcass weight was not significantly (P>0.05) different between abattoirs or seasons. There was a significant (P<0.05) interaction between abattoir and season for carcass fat depth at the 12th rib (GR) when adjusted to the same hot carcass weight, such that as carcass weight increased so did GR with changes in the relationship between seasons and abattoirs. The predicted pH at 3 h was significantly different between abattoirs, with abattoirs A and B having a significantly (P<0.05) higher pH than abattoir C. All abattoirs were different (P<0.05) for predicted temperature at 3 h, with abattoir A having the lowest and C having the highest temperature. Predicted pH at both 25 and 18°C were significantly different (P<0.05) between abattoirs, with abattoir C having the lowest and abattoir A having the highest pH at both temperatures. Abattoir A and B were not different for predicted temperature at pH 6.0, but abattoir C had a significantly higher temperature (P<0.05). Over all abattoirs only 18.8% of sampled carcasses complied with the recommended pH–temperature window of 18–25°C at pH 6.0. Of the carcasses sampled, 79.4% had a slow rate of pH decline and did not reach the onset of rigor (pH 6.0) by 18°C.

Keywords: lamb, pH, temperature.


Acknowledgments

The study was funded by NSW Department of Primary Industries, Meat and Livestock Australia and the Australian Sheep Industry Cooperative Centre. The valuable support and assistance of the management and staff of all 3 meat processing companies who took part in this benchmarking study was paramount to the successful completion of this work and this is recognised.


References


Anon. (1992) ‘AUS-MEAT language’. 4th edn. (Authority for Uniform Specification Meat and Livestock Australia: Sydney)

Anon. (1995) Australian standard for hygienic production of meat for human consumption. SCRAM Report No. 54. (CSIRO Publishing: Melbourne)

Devine CE, Wahlgren NM, Tornberg E (1999) Effect of rigor temperature on muscle shorting and tenderisation of restrained and unrestrained beef M. longissimus thoracicus et lumborum. Meat Science 51, 61–72.
Crossref | GoogleScholarGoogle Scholar | open url image1

Devine CE , Hopkins DL , Hwang IH , Ferguson DM , Richards I (2004) Electrical stimulation. In ‘Encyclopedia of meat sciences’. (Eds W Jensen, C Devine, M Dikeman). pp. 413–423. (Elsevier: Oxford)

Geesink GH, Bekhit AD, Bickerstaffe R (2000) Rigor temperature and meat quality characteristics of lamb longissimus muscle. Journal of Animal Science 78, 2842–2848.
PubMed |
open url image1

Genstat 2004: ‘Genstat 7.1.’ 6th edn. (Lawes Agricultural Trust: Rothamsted Experimental Station)

Gilmour AR , Cullis BR , Gogel GJ , Welham SJ , Thompson R (2002) ‘ASReml user guide release 1.0.’ (NSW Agriculture: Orange)

Hopkins DL, Gilbert KD, Saunders KL (1990) The performance of short scrotum and wether lambs born in winter or spring and run at pasture in Northern Tasmania. Australian Journal of Experimental Agriculture 30, 165–170.
Crossref | GoogleScholarGoogle Scholar | open url image1

Hopkins DL , Jacobs RH , Toohey ES , Pearce KL , Pethick DW , Richards I (2006) Electrical stimulation and hydration to optimise meat quality. In ‘Wool meets meat — tools for a modern enterprise. Proceedings of the 2006 Australian Sheep Industry CRC conference’. pp. 154–159. (NSW Agriculture: Orange)

Hwang IH, Thompson JM (2001) The interaction between pH and temperature decline early post-mortem on the calpain system and objective tenderness in electrically stimulated beef longissimus dorsi muscle. Meat Science 58, 167–174.
Crossref | GoogleScholarGoogle Scholar | open url image1

McGeehin B, Sheridan JJ, Butler F (2001) Factors affecting pH decline in lambs after slaughter. Meat Science 58, 79–84.
Crossref | GoogleScholarGoogle Scholar | open url image1

Polidori P, Lee S, Kauffman RG, Marsh BB (1999) Low voltage electrical stimulation of lamb carcasses: effects on meat quality. Meat Science 53, 179–182.
Crossref | GoogleScholarGoogle Scholar | open url image1

Shaw FD, Baud SR, Richards I, Pethick DW, Walker PJ, Thompson JM (2005) New electrical stimulation technologies for sheep carcasses. Australian Journal of Experimental Agriculture 45, 575–583.
Crossref | GoogleScholarGoogle Scholar | open url image1

Spooncer WF (1993) Options for hot boning. In ‘Meat 93, The Australian Meat Industry Research Conference’. pp. 1–6.

Strydom PE, Frylinck L, Smith MF (2005) Should electrical stimulation be applied when cold shortening is not a risk? Meat Science 70, 733–742.
Crossref | GoogleScholarGoogle Scholar | open url image1

Thompson JM, Hopkins DL, D’Souza DN, Walker PJ, Baud SR, Pethick DW (2005) The impact of processing on sensory and objective measurements of sheep meat eating quality. Australian Journal of Experimental Agriculture 45, 561–573.
Crossref | GoogleScholarGoogle Scholar | open url image1

Tornberg E (1996) Biophysical aspects of meat tenderness. Meat Science 43, 175–191.
Crossref | GoogleScholarGoogle Scholar | open url image1

Young OA, Hopkins DL, Pethick DW (2005) Critical control points for meat quality in the Australian sheep meat supply chain. Australian Journal of Experimental Agriculture 45, 593–601.
Crossref | GoogleScholarGoogle Scholar | open url image1