Cooked and brined shrimps packed in modified atmosphere have a shelf-life of >7 months at 0 °C, but spoil in 4-6 days at 25 °C

Summary Spoilage and safety of cooked, brined and modified atmosphere packed shrimps were studied at 0, 5, 8, 15 and 25 °C. Shrimps from two sources, cold and warm waters, were brined in a sodium–chloride brine containing benzoic, citric and sorbic acids. Shelf‐life was above 7 months at 0 °C but only 4–6 days at 25 °C.

Apparent activation energy for the effect of temperature on shelf‐life was > 100 kJ mol‐1. This pronounced effect of temperature was explained by changes in spoilage microflora at different storage temperatures. Simple and empirical mathematical models for rates of spoilage were developed for the prediction of shelf‐life at different temperatures.

To evaluate safety, products were challenged with Listeria monocytogenes and spores of Clostridium botulinum. Above 5 °C growth responses of L. monocytogenes followed the square root model with a Tmin‐value of +0.2 °C. Cl. botulinum produced toxin at the time of spoilage at 25 °C but only in shrimps with < 3% water‐phase salt.