Fate of Escherichia coli O157:H7 During Production of Snack Sticks Made from Beef or a Venison/Beef Fat Blend and Directly Acidified with Citric or Lactic Acid

Abstract

The effectiveness of a typical production process for eliminating Escherichia coli O157:H7 in directly acidified snack sticks made with beef or a venison/beef fat blend was evaluated for formulations of different fat content (10% and 25%) and type of direct acidulant (encapsulated citric or lactic acid). Raw batter inoculated with E. coli O157:H7 to an initial level of approximately 7.1 log CFU/g was stuffed into 21‐mm casings and processed according to a thermal‐processing schedule typical of those used commercially for directly acidified sausage products (maximum internal product temperature of 68.3 °C, followed by drying and cooling). For both beef and venison/beef fat blend snack sticks, log reductions ranged from 6.2 to > 6.6 CFU/g at the end of processing. Although moderate reductions (1.5 to 2.0 log CFU/g) were achieved as a result of processing to internal product temperatures of 68.3 °C, latter stages of the process (during which products were dried and cooled) factored prominently in the overall lethality of the process, and were essential in achieving the 5‐log reduction required by the U.S. Dept. of Agriculture, Food Safety and Inspection Service. The efficacy of the process was not affected (P≤ 0.05) by fat content (10% or 25%) or by the type of direct acidulant used (encapsulated citric or lactic acid). Phenol red sorbitol agar was more effective for recovering heat‐ and acid‐injured E. coli O157 than MacConkey sorbitol agar was and, therefore, provided a more conservative estimate of process lethality.

Evaluation of Brining Ingredients and Antimicrobials for Effects on Thermal Destruction of Escherichia coli O157:H7 in a Meat Model System

“…In our study, fat level (type of beef) had no effect ( P ≥ 0.05) on microbial (total and E. coli O157:H7) counts, with few exceptions where this effect was negligible and had no practical significance (Table 7 and 8). Overall, our findings agree with those of Stoltenberg and others (2006) who reported that fat content (10% or 25%) did not affect E. coli O157:H7 counts during the production of beef snack sticks.…”

Validation of Heating Conditions in Production of Direct Acidified Venison With Beef Fat Summer Sausage for Elimination of Escherichia Coli O157:h7

“…(2007) study, no differences in log reductions were determined between fat contents for all‐beef or venison with beef fat summer sausages. This similar trend also was observed by Stoltenberg et al . (2006) for a thermal process used to control E. coli O157:H7 populations in snack sticks with 10 and 25% fat levels.…”

“…Therefore, our study demonstrates the ability to achieve lethality with a high RH during the thermal process. To achieve a lower MPR, a drying step could be implemented similar to one described by Stoltenberg et al . (2006).…”

“…In addition, Stoltenberg et al . (2006) observed no significant differences in E. coli O157:H7 populations when validating a thermal process for snack sticks containing either encapsulated citric or lactic acid.…”

Effect of milk fat content on the performance of ohmic heating for inactivation ofEscherichia coliO157:H7,Salmonella entericaSerovar Typhimurium andListeria monocytogenes

“…15% fat) subjected to a circulating water bath (75°C). Kotrola and Conner (1997) and Stoltenberg et al (2006) also reported that fat content had no significant effect on the inactivation of E. coli O157:H7 when processed by thermal treatment. Inactivation of E. coli O157:H7, salmonellae, Campylobacter jejuni, Listeria monocytogenes and Staphylococcus spp.…”