Package systems and storage times serve as postlethality controls for Listeria monocytogenes on whole-muscle beef jerky and pork and beef smoked sausage sticks.

Abstract

To validate how packaging and storage reduces Listeria monocytogenes on whole-muscle beef jerky and smoked pork and beef sausage sticks, four packaging systems (heat sealed [HS] without vacuum, heat sealed with oxygen scavenger, nitrogen flushed with oxygen scavenger [NFOS], and vacuum) and four ambient temperature storage times were evaluated. Commercially available whole-muscle beef jerky and smoked pork and beef sausage sticks were inoculated with a five-strain L. monocytogenes cocktail, packaged, and then stored at 25.5 °C until enumerated for L. monocytogenes at 0, 24, 48, and 72 h and 30 days after packaging. The interaction of packaging and storage time affected L. monocytogenes reduction on jerky, but not on sausage sticks. A >2-log CFU/cm(2) reduction was achieved on sausage sticks after 24 h of storage, regardless of package type, while jerky had <2-log reductions for all packaging types. At 48 h, log reductions were similar (P. 0.05) for all types of jerky packaging, ranging from 1.26 to 1.72 log CFU/cm(2); however, at 72 h, mean L. monocytogenes reductions were >2 log CFU/cm(2), except for NFOS (1.22-log CFU/cm(2) reduction). Processors could package beef jerky in HS packages with oxygen scavenger or vacuum in conjunction with a 24-h holding time as an antimicrobial process to ensure a >1-log CFU/cm(2) L. monocytogenes reduction or use a 48-h holding time for HS- or NFOS-packaged beef jerky. A >3-log CFU/cm(2) mean reduction was observed for all beef jerky and sausage stick packaging systems after 30 days of 25.5 °C storage.