Food safety and basic principles for control
The safety of chilled foods with respect to pathogens must be designed into the product using formulation, processing parameters and preservation factors. This must be validated, taking into account:
- Any variability in the finished product (e.g. pH, aW) and processing, considering worst-case possibilities,
- Appropriate hygiene during manufacture
- Expected storage conditions
- Usage instructions.
- All of these factors must be taken into account for a safe shelf life to be assigned.
Heat treatment is customarily used to reduce pathogens and spoilage organisms to an acceptable level. In heat-treated chilled food it is common practice to aim for a Log 6 reduction of either Listeria monocytogenes (this treatment will also control other vegetative pathogens) or cold growing Clostridium botulinum (this treatment will not control other spore-forming pathogens such as Bacillus cereus). The choice of heat treatment is part of the product and process design.
Intrinsic Preservation Factors
Individual hurdles, such as reduced water activity, pH, preservatives, and others, or a combination thereof can be used to control pathogen growth, toxin formation and/or spoilage during storage and distribution. In preserving foods, generally more than one factor is relied upon to prevent spoilage and/or food-borne disease. The combination of several hurdles to control microbial growth may be synergistic. In such cases the overall hurdle effect is stronger than the addition of individual ones.
During the evaluation and assessment of their effectiveness it must be ensured that the chosen hurdle system will not cause unwanted side effects. For example, the use of a modified atmosphere to inhibit aerobic microorganisms (in particular moulds) may favor other undesirable anaerobic organisms, resulting in a potentially hazardous product.
Expected Storage Conditions, Shelf life and Usage Instructions
Chilled foods are prepared foods that for reasons of safety and/or quality rely on storage at refrigeration temperatures throughout their entire life. Having considered product safety the potential for presence and subsequent growth of spoilage organisms must also be taken into account when deciding on the target shelf life and specifying usage instructions. Knowledge of chill chain performance, in terms of temperature and time, as well as reasonable consumer handling, must be taken into account when designing chilled products and establishing their shelf life.
Reference: RECOMMENDATIONS FOR THE PRODUCTION OF PREPACKAGED CHILLED FOOD, ECFF Recommendations December 2006