The Effect of Salt Reduction on the Microbial Composition and Quality Characteristics of Sliced Roast Beef and Turkey

This study analyzed the effects of salt reduction on microbiological composition and quality characteristics of deli-style turkey breast and roast beef. Turkey breast and roast beef were manufactured with four different salt concentrations: 1.0%, 1.5%, 2.0%, and 2.5% on a meat block basis in addition to sugar, phosphate, and water. Samples were cooked, chilled overnight, sliced, and packaged. On the day of slicing, samples were evaluated for water activity, cooking yield, proximate composition and percent salt. Samples were evaluated throughout 18w of refrigerated storage for pH, texture profile analysis, aerobic plate count (APC), and anaerobic plate count. Bacterial communities were analyzed by 16S rRNA gene sequencing. Beef with 2.5% salt had the lowest APC. Aerobic plate count increased until week 6 and then reached a plateau. Family Pseudomonadaceae was the dominant flora on all samples. Relative abundance of Pseudomonadaceae was 46.4% of all sequences in beef samples and 36.0% in turkey samples after slicing, and increased at week 2 for the remainder of storage time. Salt reduction negatively impacted cooking yield and increased water activity. Beef samples had a lower pH than turkey, and 1.5% salt had a lower pH than all other salt concentrations. Decreasing salt concentration increased hardness. In beef, gumminess and cohesiveness increased as salt decreased. In turkey samples, the greatest gumminess and cohesiveness was observed with 1.5% salt while turkey with 2.5% salt had the least gumminess and cohesiveness. Beef samples with 1.0% salt had the greatest chewiness, followed by beef with 1.5% salt. Turkey samples with 2.5%, 2.0%, and 1.0% had the lowest chewiness values. Salt reduction decreased springiness, and turkey samples had lower values than beef. These results show that bacterial population dynamics of cooked deli meat may be more dependent on initial load than salt concentration. Furthermore, reducing salt alters the textural properties of cooked deli meats, changes the proximate composition of cooked meat products, and reduces cooking yields. Advisor: Gary A. Sulliva