Validation Trials

MLA and B+LNZ have commissioned both laboratory and in-plant based validation trials of the meat quality benefits of SmartStretch.

Early in-plant trials in November 2008 using an early 'Boa' prototype were carried out on beef striploins. These compared stretched primals against achilles hung ('Tenderstretch' and 'Superstretch') carcasses and demonstrated the benefits of stretching against ageing.

In 2009, laboratory based stretching trials on four key primals (cube roll, strip loin, topside, eye round and abductor) from New Zealand prime beef, bull and cow animal types were carried out by an independent meat science laboratory in New Zealand, Carne Technologies.

The results of this trial can be summarised as follows: 

• Stretching significantly improved the shear force at 24 hours in all cuts tested although the effect tended to be greatest in the topside and eye round muscles compared to the cube roll and adductor. 
• Irrespective of muscle and stretch, the greatest benefits of stretching are demonstrated in cuts from bulls, whereas cows and then prime beef show less of an effect.  
• A minimum level of stretch is necessary to produce an effect on tenderness (20% was found to be a representative value in previous work). 
• A relationship between the extent of the stretch and shear force values at 24 hours was not found i.e. stretching more than the minimum level did not appear to increase tenderness any further. 
• Stretching exerted its greatest effect on muscles whose controls had a high shear force at 24 hours; if the unstretched controls had a lower shear force (already tender), then the benefit from stretching was minimal or absent. 
• Stretching reduces the variability in toughness of key muscles between carcasses, irrespective of stretch level.

While current work is focussed on SmartStretch beef applications, the technology can also be successfully applied to sheep primals.  Earlier laboratory and in-plant work has demonstrated shear force improvements for sheep primals, and further in-plant validation of this is planned for later in 2010.

Results have been published in July 2008 under

'Accelerated tenderness of sheep topsides using a meat stretching device'

as well as the December 2009 project milestone report

'Accelerated processing sheep/beef meat'

More recent results from trials include a hot boning trial on topsides, that confirmed that stretching over a minimum threshold value did not further increase tenderness.

Not all trial results achieved so far have been consistent as regards tenderness (shear force) improvements, given the variability caused by machine operation, primal type and animal types. 

Further in-plant validation trials are underway or planned for both sheep and beef primals and these will provide additional guidelines on the commercial use of SmartStretch.