Benchmarking Lamb Eating Quality

Summary

Consumers perceive Iamb to be unreliable with regard to eating quality. The eating quality of lamb is influenced by a number of factors from conception to cooking including:

• breed, environment,
• on-farm practices,
• slaughter and post-slaughter treatments and
• cooking methods employed by consumers.

Improving consistency in eating quality of Iamb particularly tenderness, has the potential to increase both consumer satisfaction and consumption levels of Iamb, in both domestic and export markets. Previous research identified variability in the tenderness of Iamb while a more recent study conducted amongst retailers, wholesalers and boning rooms in Melbourne from July 1991 to June 1993 found that tenderness of Iamb was inconsistent. Lamb eating quality was influenced by season, with lamb being less tender in late autumn and winter. Post-slaughter management practices such as carcass ageing was also shown to significantly affect lamb eating quality.

his project examined tenderness of Iamb in capital cities in Australia where Branded lamb Alliances have been functioning. To provide a valid comparison, the quality of Iamb traded through normal marketing channels in the 'generic' industry was monitored in this study in four Australian capital cities. The Warner-Bratzler shear force test, sometimes in combination with trained panel or consumer sensory evaluations, was the standard test used in this study to define the toughness/tenderness of Australian lamb.

In this project, retail butchers and supermarkets in Melbourne, Sydney, Canberra and Perth handling 'generic' Iamb were visited in December 1997, March 1998, June 1998 and October 1998. Retail outlets handling Iamb marketed through two established Alliances were also visited in December 1997, March 1998, June 1998 and October 1998 on the same day as 'generic' outlets.

Lamb mid loins from different Iamb carcasses were purchased from each store, then de-boned and de-fatted prior to freezing on the day of purchase. All denuded loins were then sent to the Victorian Institute of Animal Science, Werribee. Loins were thawed and muscle pH and tenderness, using a Warner-Bratzler shear force blade fitted to an Instron Universal Testing Machine, was measured on each loin.

This research identified that no significant differences in average WB shear force values were found for Iamb due to season of purchase, with average WB values ranging from 3.49 kg in December 1997 to 3.72 kg in June 1998.

​Significant differences in WB shear force values were, however, found between Iamb mid loins purchased at the retail level in the four different capital cities and in the two Alliances. Overall, Iamb purchased from stores involved in Alliance B had a significantly higher average WB shear force value (4.65 kg) compared with Iamb purchased in Alliance A (3.24​ kg), Sydney (3.07 kg) and Canberra (3.07 kg). lamb purchased in Melbourne (3.91 kg) and Perth (4.30 kg) was intermediate in terms of average WB values.

Generally, muscle pH was not found to explain high WB shear force values obtained for lamb assessed in this study. Only 5% of lamb purchased from Alliance B stores in March and June 1998 recorded muscle pH greater than 5.8, whilst in December 1997 and October 1998 no lamb sourced from this Alliance had a high muscle pH. In June 1998, 45% of lamb midloins purchased in Canberra had an ultimate pH greater than 5.8. The results of this study are very encouraging for the Australian lamb industry as the majority of lamb achieved an acceptable level of tenderness.