Spray Chilling
Description
Spray chilling is the intermittent spraying of carcases with water during the early stages of the cooling of hot sides. The aim is to reduce the weight loss (shrink) of up to 1- 2% due to evaporation of moisture from the surface tissue.
Benefits
Previous research by by Hippe et al[i], Greer et al[ii] and Lee et al[iii] has shown that spray chilling can reduce evaporative weight loss in beef chillers by 0.5-1.5%, 2% and 1.3% respectively.
In 2008 the Australian industry produced close to 2.2 million tones of beef and veal. Using an average beef sales price of $5.06 per kilogram results in a cost to the industry of evaporative losses as shown in the following table.
More information
Beef carcases are normally chilled for 16 to 20 hours prior to boning into primal cuts and trimmings which are packed for further cooling and dispatch. During this carcase chilling process, carcases can lose 1 to 2% of their hot weight which is a potential loss of revenue for the processor. Spray chilling has been widely used in the USA for many years to reduce this weight loss (or shrink) but the practice has been used little in Australia. Spray chilling is the intermittent spraying of carcases with water during the first few hours of the chilling phase followed by a drying period prior to loadout and boning.
The limited application of spray chilling in Australia is thought to be due to concerns that it may result in a decrease in the shelf life of vacuum-packaged meat for which Australia has a high reputation in export markets. Spray chilling has been shown to reduce weight loss during overnight chilling to about 0.4% to 0.5% (Jones & Robertson, 1988, Strydom & Buys, 1995, Greer & Jones, 1997).
However, there is little information in the scientific literature regarding the effect of spray chilling on the yield of saleable meat from the boned carcase. Greer & Jones (1997) showed that spray chilling had no detrimental effect on the shelf life of vacuum-packed beef up to 6 weeks, but Australian processors require vacuum packaged storage life of 10 weeks or more.
Although there is some published literature relating to meat industry spray chilling systems' water spray rates, most relate to studies conducted in either the US or Canada. As such there is no definitive data available as to what the optimal spray rates are in order to minimise the side shrinkage losses under typical Australian Meat Industry production conditions while still meeting all of the relevant Australian Meat Industry Standards & Regulations.
The following final reports from MLA projects on spray chilling are available:
[i] Hippe, C L, Field, R A, Ray, B and Russel, W C, ‘Effect of spray chilling on quality of beef from lean and fatter carcasses'. University of Wyoming 7th July 1990.
[ii] Greer, G G, Jones, S D, ‘Quality and bacteriological consequences of beef carcass spray-chilling: Effects of spray duration and boxed bee storage temperature'. Meat Science, Vol. 45m No. 1, pp 61-73, 1997
[iii] Lee, L M, Hawrysh, Z J, Jeremiah L E and Hardin, R T, ‘Shrouding, spray chilling and vacuum-packaged aging effects on process and eating quality attributes of beef'. Journal of Food Science, Vol. 55, No. 5, pp1270-1273 ,1990.