“There are numerous factors that contribute to a food product’s shelf life,” he said. “In addition to microbial suppression and pathogen control, prepared food products, including meat and poultry, must be formulated for color stability and flavor protection, yield and moisture management, and maintenance of texture and stability. Factors that impact these attributes include temperature abuse, exposure to light, compromised packaging and more.”
Ready-to-eat meats, namely luncheon meats and cooked sausages, are a challenging category to manage. One reason is that Listeria monocytogenes, a pathogenic microorganism, is ubiquitous in the environment.
“Listeria survives and persists in the food manufacturing environment, as well as in the service deli counter and salad bars,” Smith said. “Listeria is responsible for most food safety recalls of ready-to-eat foods.”
As the name suggests, these foods are ready to eat and do not typically undergo a cook step that would destroy the pathogen. Thus, other precautionary steps should be taken to ensure their safety throughout shelf life.
Further, many of today’s ready-to-eat meats are much more susceptible to microbial breakdown because of their healthier, clean-label compositions, Smith explained. This includes being lower in sodium (salt being a natural preservative), higher in moisture (to replace fat content – moisture and fat are inversely related in meat composition) and void of shelf life-extending additives considered artificial.
“There are three categories of microbial management systems,” Smith said. “These are biological, chemical and physical.”
Historical techniques in these three categories are the use of honey or spices (biological); salt or vinegar (chemical); and drying or smoking (physical). Modern intervention technologies include, respectively, bacteriocins or bacteriophage; organic acids/salts or oxidants; and thermal processing or high-pressure pasteurization.
“The chemical category includes antimicrobial agents that are added to the meat or poultry to suppress, inhibit or destroy pathogenic and spoilage microorganisms,” Smith said.
Many traditional, and highly effective, chemical antimicrobials are not considered clean-label options. Examples are lactates and propionates, as well as other organic acids and salts. Newer clean-label options include buffered vinegar-based solutions, cultured sugar systems, celery juice powder and cherry juice powder.
“Smoke and smoke-type ingredients are another clean-label option, as are essential oil fractions of various botanicals,” Smith said.
There are many technologies available to meat and poultry processors to manage product shelf life and ensure food safety. Product claims, market positioning and economics all come into play when evaluating options.