Effect of Meat Binding Formulations on Thermal Inactivation of Escherichia coli O157:H7 Internalized in Beef

摘要

This study evaluated the effects of meat binding or restructuring formulations, including salt/phosphate, algin/calcium, Activa (TM) RM, and Fibrimex (R), with or without 0.27 (wt/wt) lactic acid, on thermal inactivation of internalized Escherichia coli O157:H7 in ground beef, serving as a model system for restructured products. Ground beef batches ( 700 g; approximately 5 fat) were mechanically mixed with a 5-strain composite of E. coli O157:H7 (7 log CFU/g) and then with the restructuring formulations. Product portions (30 g) were extruded into plastic test tubes (2.5 x 10 cm) and stored at 4 degrees C ( 18 h), before heating to 60 or 65 degrees C in a circulating water bath to simulate rare or medium-rare doneness of beef, respectively. Cooking to 60 or 65 degrees C reduced (P 0.05) among all treatments and the control. At 65 degrees C, greater ( P 0.05) to that of the control. Cooking weight losses were lower (P < 0.05) in salt/ phosphate samples (< 1) compared to other formulations and the control (7.4 to 15.9). Findings indicated that, under the conditions examined, restructuring of beef with salt/ phosphate, algin/calcium, Activa (TM) RM, or Fibrimex (R) did not affect inactivation of internalized E. coli O157: H7 in undercooked (60 or 65 degrees C) samples, whereas inclusion of lactic acid (0.27) in nonintact beef products enhanced pathogen destruction at 65 degrees C.