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

Spoilage and safety of cooked, brined and modified atmosphere packed shrimp s were studied at 0, 5, 8, 15 and 25 degrees C. Shrimps from two sources, c old and warm waters, were brined in a sodium-chloride brine containing benz oic, citric and sorbic acids. Shelf-life was above 7 months at 0 degrees C but only 4-6 days at 25 degrees C. Apparent activation energy for the effec t of temperature on shelf-life was > 100 kJ mol(-1). This pronounced effect of temperature was explained by changes in spoilage microflora at differen t storage temperatures. Simple and empirical mathematical models for rates of spoilage were developed for the prediction of shelf-life at different te mperatures. To evaluate safety, products were challenged with Listeria mono cytogenes and spores of Clostridium botulinum. Above 5 degrees C growth res ponses of L. monocytogenes followed the square root model with a T-min-valu e of +0.2 degrees C. Cl. botulinum produced toxin at the time of spoilage a t 25 degrees C but only in shrimps with < 3% water-phase salt.