The shelf-life of Australian frozen red meat

Summary

• Commercially produced Australian frozen beef and lamb was transported to the UK under standard commercially used conditions and then stored at -12°C, -18°C, and -24°C and instrumental, chemical, microbiological, and sensorial analyses conducted on the meat over a 38 calendar month period.

• Clear changes with time were found in chemical measures of rancidity that can be related to meat composition, packaging, and storage temperature. However, these changes do not appear to correlate clearly with the taste panel results in this study. Whereas the Peroxide Value (PV) and Thiobarbituric acid reactive substances (TBARS) levels (both signs of lipid oxidation/rancidity) show a clear relationship with storage temperature over time at different holding temperatures, this does not appear to be reflected in the taste panel assessment.

• While sensory degradation (a drop in mean scores of some characteristics) occurred over time in all meat samples, this did not appear to be affected by storage temperature, but occurred at all storage temperatures, and the meat remained palatable after 38 months.

• While -18°C has become established as the standard temperature for the storage of frozen foods, red meat of the type examined, appears able to be stored successfully for many months or years at a temperature warmer than this threshold. Providing the meat is of sufficient hygienic quality when frozen and handled under controlled hygienic conditions, no food safety hazards exist with frozen meat that has been held at, or reached a temperature between -10°C and -18°C. Sensory degradation occurs only slowly at these temperatures and no food safety hazards arise.

Objectives

There were three overall objectives for this research project:

• To determine the shelf-life of frozen Australian beef and lamb loin (strip loin and eye of loin, respectively), beef trim of 65CL, 85CL, and 95CL, and lamb trim of 65CL, 85CL, and 90CL (Chemical Lean).

• To determine the correlation of frozen end of shelf-life (determined by taste panel) to any measurable parameters, such as oxidative rancidity (PV and TBARS).

• To determine the rate of oxidation or development of rancidity in frozen Australian beef and lamb meat stored at -12°C, -18°C (Control), and -24°C.

Key findings

While -18°C has become established as the standard temperature for the storage of frozen foods, red meat of the type examined appears able to be stored successfully for many months or years at a temperature warmer than this threshold. Providing the meat is of sufficient hygienic quality when frozen and handled under controlled hygienic conditions, no food safety hazards exist with frozen meat that has been held at, or reached, a temperature between -10°C and -18°C. Sensory degradation occurs only slowly at these temperatures and no food safety hazards arise.

Benefits to industry

• Australia exported more than 1.13 million tonnes of frozen beef and sheepmeat in 2020, with the bulk of shipments spread across North Asia, Southeast Asia, North America, the Middle East and Europe.

• There is a lack of comprehensive scientific data to support the shelf-life for Australian frozen red meat for up to 36 months of storage. These data will provide evidence-based shelf-life claims for Australian product to respond to restrictive regulations in some importing countries and customer requests for substantiation. In 2020, 6.4 million tonnes of frozen red meat were exported around the world, the second highest volume on record and a trade worth US$28.2 billion.

• This work will contribute to increased growth and improve market access of Australian meat.

MLA action

Communicate the information with industry.

Future research

This study demonstrated that if held at, or around, -18°C, frozen beef and lamb can be stored without significant sensory degradation for a period of over 36 months. Providing the meat is of sufficient hygienic quality when frozen and handled under controlled hygienic conditions, no food safety hazards arise. Mandated shorter frozen shelf-life requirements (such as 12 months) should be reviewed to reflect this evidence.