Vacuum-packaging of bovine edible offal

Edible offals are relatively perishable and may be frozen before leaving the abattoir, commanding a lower price on the wholesale market than fresh offals. Investigations are described in which a range of offals was vacuum-packaged in an effort to extend the shelf-life of the fresh material. Several visits to two abattoirs revealed that their offals after chilling were generally of rather poor microbiological quality, partly due to handling practices and, in one abattoir, to inadequate chilling. Reductions in the initial microbial load on hearts and tongues were achieved by immersion in water at 90°C, or with 100 ppm free chlorine or 1 % (v/v) lactic acid. However, these treatments offered no advantage over good production methods in extending the safe storage period in the vacuum-package. When offals produced under normal conditions were vacuum-packaged a storage period of 2-3 weeks at 1°C ± 1° was achieved which allowed a subsequent shelf-life of 3-4 days in air at 4°C. Offals produced with low initial numbers of contaminants gave the possibility of 1-2 weeks longer in the vacuum-package. A detailed investigation of the organisms growing on vacuum-packaged liver showed that a lactic flora developed during storage, but this did not inhibit potential spoilage organisms such as Pseudomonas or Alteromonas.