Spray chilling increases venison return
Venison exports contribute over $200 million a year to the New Zealand economy. A research project carried out for the New Zealand deer industry confirmed that using a different chilling process would considerably improve the returns for both the processor and supplier and encouraged more deer processors to take up the process.
Meat exported in chilled form has a higher market value than meat that is exported frozen. To chill the meat, hot carcasses are normally placed in a chiller room that brings the meat temperature down to around 2°C. During this process, water evaporates from the carcass surface, resulting in a loss of weight.
AgResearch scientist, Dr Katja Rosenvold, says that spray chilling is an alternative process that is widely used in the meat processing industry.
“It involves intermittently spraying water onto the carcasses during the chilling process to reduce the net loss of water through evaporation from the carcass. As well as reducing the water lost from the meat, maintaining evaporation from the carcass throughout chilling cools the carcass more quickly, just as people feel colder as water evaporates off their skin.”
However, uncertainty about the impact of spray chilling on a number of important meat attributes made some processors reluctant to adopt spray chilling.
“In this project, the deer industry wanted to understand if the reduced water loss achieved with spray chilling was evenly distributed between the different meat cuts or whether water was lost from some but added to others” says Dr Rosenvold.
“The project found that the traditional air chilling process lost approximately a kilogram of water (2% of carcass weight) per deer carcass while there was no loss from the spray-chilled carcasses.”
“Reducing the weight loss during chilling equates to a significant increase in yield when the venison is processed, thereby increasing export revenues,” says Dr Rosenvold.
DEEResearch and the Foundation for Research, Science & Technology invested $65,000 in this research project. The outcome has encouraged two additional venison processing plants to take up spray chilling since 2010. Based on a conservative estimate of a 1.5% weight saving in those plants, AgResearch estimates that the impact was about $370,000 of additional exports per year since 2010. In comparison, on the same basis, use of spray chilling by all venison processors would be worth $3.1 million of exports per year.
Approximate economic analysis
For the 12 months to May 2012 , venison slaughter was 413,074 animals, comprising 23,188 tonnes. For the season to the end of May 2012, the average carcass weight was 56.3kg. For the twelve months to May 2012, the FOB export value was $207.5 million and the export volume was 15,249 tonnes, giving an export value of $13.61/kg.
Although the 2% weight saving was achieved in the project, it would be conservative to estimate that a 1.5% weight saving would be realistic in practice. A 1.5% saving in exported weight is therefore worth about 1.5% of the export value, or about $3.1 million if applied to the total value of venison exported.
To estimate the impact of this project, we would have to know what fraction of this added export value was due to this project. This can be estimated as follows:
We are aware that:
a) Some venison plants were already using spray chilling before this project was carried out, and
b) It is not clear that all venison plants are now using spray chilling.
However, one company was encouraged to install spray chilling as a result of the DEEResearch/FRST project and they have two out of 17 plants that are licensed to slaughter deer for the EU . The volume of deer slaughtered in each plant is commercially confidential but if we might make a rough assumption that those plants’ throughput is approximately average for deer slaughter plants. In that case, they would have processed about two seventeenths of the total exported value of venison, of which the 2% saving due to spray chilling would come to about $366,000 per year, which we have rounded to $370,000 per year, given the uncertainties involved in this estimate.
This figure is therefore an overall estimate of the value to the New Zealand economy. If we were assessing the value of this project to venison producers and processors, it would be necessary to subtract the capital and operating costs of the spray chilling equipment. These costs are commercially sensitive figures that are not available to AgResearch, however we expect that venison processors would have required that installing spray chilling equipment was financially viable, so the benefits to the processors (at least) would have outweighed the costs.