For a TCS food (Food Code “TCS” =Temperature Control for Safety), the default refrigerated food shelf life is 7 days.  This is based mostly on the potential for the growth of Listeria monocytogenes (a cold loving foodborne illness bacteria).  Food manufacturers desiring a shelf life greater than 7 days must provide evidence for the safety of their food now called an extended shelf life refrigerated food.  Examples are deli meats, processed meat, seafood, egg, and vegetable salads, fresh pasta and pasta sauces, other sauces, soups, entrees, complete meals, and uncured meat and poultry items. Cook-chill or sous vide foods, cooked inside a hermetically sealed plastic package under vacuum, are also included.

There are several foodborne illness psychrotrophic (cold loving) bacteria of concern in ESRFs including Listeria monocytogenes, non-proteolytic Clostridium botulinum, and Yersinia enterocolitica.  There are a plethora of quality spoilage microorganisms including lactic acid bacteria, yeasts, molds, Pseudomonads, and Bacillus species.  The keys to the safety and quality of these ESRFs are hurdles and barriers to both foodborne illness bacteria and spoilage microorganisms. The palette of hurdles/barriers can include: heat (pasteurization), salt, low Aw, low pH, lower refrigerator temperatures (even freezing), and the use of antimicrobials.