Effect of steam- and hot-water post-process pasteurization on microbial and physical property measures of fully cooked vacuum-packaged chicken breast strips

The microbial inactivation was conducted using fully cooked chicken breast strips that were surface-inoculated with Listeria innocua (10(7) colony forming unit per gram product), vacuum packaged, and treated by steam or hot water at 88 degreesC for 10 to 35 min. The studies for physical properties were conducted using uninoculated products that were treated for 25 to 35 min. Both steam and hot water treatments were effective in inactivating L. innocua in the packaged products. No significant difference was found on the survivors of L. innocua between steam and hot water treatments. No significant difference was found on water activity and shear force among the treated and untreated products. However, significant difference was found on expressible and total moisture among treated and untreated products. This study showed that post process pasteurization with hot water or steam lowered microbial populations but affected the water purge from the products.