Total Aerobic and Coliform Counts in Beef-Soy and Chicken-Soy Patties During Refrigerated Storage

Three commercial texturized soy proteins (TSP-A, TSP-B, TSP-C) and one commercial soy protein concentrate (SPC) were each added to raw ground beef or chicken at a 10% or 30% level to form patties which were stored at 4 C. During storage up to 8 days, aerobic plate counts of beef were significantly higher with than without the TSP's. Coliform counts were higher with the beef containing TSP-B and TSP-C. During storage up to 10 days chicken patties containing TSP-A or TSP-C exhibited higher aerobic plate counts than controls, whereas patties with TSP-B or SPC did not. No increases occurred in coliform counts. In beef-soy mixtures, the counts were higher for the 30% than for the 10% level but the reverse was true in chicken-soy mixtures. Coliforms were identified by the Analytab Products, Inc. System. In the beef control and beef-soy mixtures, Serratia was the predominant genus at 0 and 8 days of storage. In the chicken control, Escherichia was the predominant genus at 0 day of storage, but Enterobacter was predominant in the control and in chicken-soy mixtures after 10 days of storage.