Use of lactatae at different pH for preservation of fresh sausages

Traditional Italian fresh sausage was manufactured with 3 different formulations: no sodium lactate; 1.5% sodium lactate at pH 7.0; or 1.5% sodium lactate at pH 5.5. Sausages were packaged in trays with a gas permeable sealing film or modified atmosphere packaged (in an 80% O 2/20% N 2 atmosphere at a product:gas ratio of 1:3) with a gas-impermeable sealing film. All the packaged samples were stored at 6°C. Physicochemical properties (pH, a w, drip formation), microbiological quality (psychrotrophic bacteria, coliforms and lactic acid bacteria) and sensory properties were assessed after 3, 6 and 9 days of storage for the conventionally packaged samples and after 5, 10 and 15 days for the modified atmosphere packaged samples. Overall, sodium lactate reduced microbial growth and improved shelf life of fresh sausages; use of sodium lactate at pH 7.0 gave the best inhibition of microbial growth. pH had no significant effect on the action of sodium lactate on retention of sensory properties during storage. Modified atmosphere packaging gave better shelf life then conventional packaging, except for a slightly higher incidence of drip formation on the surface of the sausages.