Traditional processing of summer sausage applies lower fermentation pH values (≤4.6) and higher thermal treatments after fermentation to meet U.S. Department of Agriculture’s Food Safety and Inspection Service (FSIS) performance standards for E. coli O157:H7 lethality (5D process; decimal reduction dose). Fermentation of summer sausages to lower pH values, along with higher cook temperatures following fermentation, have changed traditional summer sausage quality (texture and flavor). While alternate approaches were not available when the performance standards were mandated, the emergence of high-pressure processing (HPP) technology and its use in meat processing have provided an alternate, non-thermal processing technology to achieve pathogen reduction with minimal impact on product quality. Our goal is to evaluate the use of HPP subsequent to mild fermentation and lower than traditional thermal processing to augment the pathogen reductions achieved during fermentation and mild cooking and to meet FSIS performance standards.
In a previous article we wrote for this publication (November 2018), we discussed the ability to maintain summer sausage texture and color after HPP. While that article focused on product quality, the main goal of using HPP was its ability to reduce or eliminate pathogenic microorganisms that could survive mild fermentation and heat treatment or process deviations during manufacture of ready-to-eat (RTE) summer sausage. To help ensure microbiological safety, it is recommended that RTE meat products containing beef should achieve a 5D reduction of E. coli O157:H7 and Shiga-toxin producing E. coli (STEC). Processors using mild fermentation with a low degree of thermal processing currently operate under in-plant validations because of a lack of scientific literature validating alternative procedures to achieve a 5D process.