The practical storage life of Australian frozen boxed beef and lamb

There is little data on the practical frozen shelf life of commercially produced meat that has been stored beyond 12 months, and how frozen storage temperature affects eating quality. Commercially produced Australian boxed beef and lamb (loin and trim with low and high fat content) was processed and frozen under standard commercial conditions and shipped (by sea and air, respectively) to the UK. In the UK, products were stored at -12 °C, -18 °C and -24 °C, and instrumental and sensorial analyses conducted over a 38-month period from processing. No clear relationships or trends between sample type, storage temperature, and the time of storage were apparent in instrumentally measured quality parameters (colour, cook loss, texture, or microbial quality) apart from those relating to lipid oxidation (peroxide value (PV) and assay of thiobarbituric acid reactive substances (TBARS)). Some changes were found in characteristics assessed by a sensory panel. Lipid oxidation was observed in all products at all temperatures but not at levels that would be expected to be detected by sensory assessment, which was confirmed by the sensory panel. This study shows that commercially produced, vacuum packed, Australian boxed frozen beef and lamb loin and beef trims shipped by air or sea can be subsequently stored at -12 °C, -18 °C, or -24 °C without significant sensory degradation for a period of over 36 months. Frozen boxed lamb wrapped in plastic did not degrade significantly in meat flavour or lamb odour intensity or frequently produce unacceptable sensory scores until more than 28 months of frozen storage.