Extended shelf-life evaluation of sliced lamb shoulders

Summary

​Several Australian sheep and lamb processors export vacuum packed lamb shoulders to Japan, where they are sliced, packed in overwrap trays and distributed to various supermarket outlets.
In this trial lamb shoulders, typical of product destined for the Japanese market, were vacuum packed and stored for 78 days at 0°C.
On five occasions during this period, lamb was sliced to a thickness of 4-5 mm, packed in overwrap trays and stored under retail conditions for zero and two days.
Aerobic plate and lactic acid bacteria counts were obtained from vacuum packed product directly after opening and from sliced lamb. Sensory evaluations of sliced product were undertaken using an untrained Japanese sensory panel.
The microbiological flora on the sliced product consisted predominantly of lactic acid bacteria.
Stationary phase was reached after about 50 days of storage.
Freshly sliced product had between 0.8 and 1.9 log10 cfu/g lower microbiological levels than stored sliced lamb.
Sensory scores for appearance, colour, smell, taste, texture and overall impression were consistent across the 78 day storage period.
Only retail storage of sliced lamb appeared to impact all sensory attributes - freshly cut product scored between one quarter and half of a score higher than stored retail product.
However, no relationship between microbiology and sensory score was found and despite the high bacteria levels, product after 78 days was still in very good condition.