1. RTE food in which growth of Listeria monocytogenes can occur Detected in 25g Potentially hazardous Post-processing or post-harvest contamination or inadequate process control. Higher levels in product in the marketplace may be due to poor temperature control during storage and/or distribution or inappropriate length of life. Product disposition action required to assess safety and determine if disposal or product recall is required. Vulnerability of population to be considered. An investigation should be undertaken of: the raw materials used; adequacy of cleaning and sanitising of premises and equipment, particularly of preferred such as drains adequacy of construction and maintenance of premises the effectiveness of processing controls the adequacy of process flow. Increased sampling, including environmental sampling. Not detected in 25g Satisfactory 2. RTE food in which growth of Listeria monocytogenes will not occur >102 Potentially hazardous Post-processing or post-harvest contamination or inadequate process control. Product disposition action required to assess safety and determine if disposal or product recall is required. Vulnerability of population should be considered. An investigation should be implemented as above. Detected but ≤102 Satisfactory if a listericidal process has not been applied. Marginal if a listericidal process has been applied. Indicates better process control required. While regulatory limits are met, the presence of L. monocytogenes should be investigated in the case of a food that has received a listericidal process. For foods that have not, ongoing trend analysis should be used to monitor levels. Product disposition action may be required to assess safety and determine if disposal or recall is required. Vulnerability of population should be considered. Absent in 25g Satisfactory
the adequacy of processing used (e.g. adequate cooking, pH, water activity) the adequacy of measures implemented to prevent the likelihood of cross contamination the effectiveness of cleaning and sanitising equipment (e.g. blenders, vitamisers, other processing equipment) the adequacy of time and temperature controls used. The adequacy of health and hygiene practices may also require investigation if an infected food handler is suspected. Confirmation of identity, serotyping, phage typing required where cases of foodborne illness suspected. Not detected in 25g Satisfactory Table 2. Interpreting results for testing of in ready-to-eat foods Indicator Result (cfu/g) Interpretation Likely Actions (includes coliforms) >104 Unsatisfactory For processed foods indicates that contamination has occurred post processing (cross contamination from food contact surfaces, raw products or food handlers) or there has been inadequate processing. Poor temperature time control may also be a contributing factor. Review: processing controls used (such as cooking temperatures) cleaning and sanitising practices for premises and equipment food handler hygiene time and temperature control. Additional food or environmental samples may be required for investigation.
102 –104 Marginal Some contamination or inadequate processing indicated. Proactive investigation to ensure processing and hygiene controls are being implemented. Results may need to be compared with other food samples from the production environment for interpretation. <102 Satisfactory >102 Unsatisfactory For raw and processed foods indicates potential for there to have been contamination of faecal origin from poor hygienic practices (cross contamination from food contact surfaces, raw foods or food handlers) or there has been inadequate processing. For RTE foods that have not been processed (e.g. fresh produce), contamination from the primary production environment should be considered. Review: processing controls used (such as cooking temperatures) cleaning and sanitising practices for premises and equipment food handler hygiene time and temperature control primary production controls (e.g. harvest practices, water quality, fertilizers, other inputs as appropriate). Additional food or environmental samples may be required for investigation and testing for enteric pathogens considered if appropriate. 3 - <102 Marginal low levels may occasionally be found in RTE food, widespread detection in several foods or areas of the food production environment suggests poor hygienic practices. Proactive investigation to ensure processing and hygiene controls are being implemented. <3 Satisfactory Listeria spp. (other than L. monocytogenes) >102 Unsatisfactory Detection of Listeria spp. at this level signifies that conditions may also be favourable for L. monocytogenes to be present. This may be due to poor food handling controls or cross contamination. Higher levels may also suggest poor temperature control or inappropriate length of shelf life. An investigation should be undertaken of: the raw materials used; adequacy of cleaning and sanitising of premises and equipment adequacy of construction and maintenance of premises the effectiveness of processing controls. Additional sampling, including environmental sampling should be considered (including specific testing for L. monocytogenes).
≤102 Marginal Indicates that food handling controls or contamination may become a problem. Proactive investigation to ensure production, processing and hygiene controls are being implemented as intended. Consider additional sampling of the environment and food products. Not detected in 25g Satisfactory Table 3. Interpretation of results for (MAB) colony count (at 30°C) in RTE foods Food Category Examples Result (cfu/g) Satisfactory Marginal Unsatisfactory Category 1 Applies to cooked immediately before consumption Hot takeaway food such as pizza Whole cooked bakery products such as pies, sausage rolls, quiches ready to eat cook/chill and cook/freeze meals. < 103 103 - <105 ≥105 Category 2 Applies to RTE foods in which all components of the foods have been cooked but there is some handling before sale or consumption. Bakery products such as cakes (without fresh cream) Fully cooked bakery products (pies, quiches etc.) that are chilled/portioned/further handled. < 104 104 - <106 ≥106 Category 3 Applies to RTE foods which contain some components that have been cooked and then further handled (stored, sliced or mixed) before preparation of the final food or where no cooking process has been used. Dips such as hummus, tzatziki etc. Bakery products containing cream Sandwiches Sliced meats Sushi rolls <106 106 - <107 ≥107
intestinal contents or bile staining (intestinal tearing). Appropriate animal welfare outcomes. Ensure that condemned and inedible carcases aren’t entering the washing process. Minimise contamination of wash and improve reduction of microbial load. Enable timely corrective actions to be implemented in order to minimise the amount of product affected. Enable sufficient process control for microbiological hazards to ensure that the wash/chill system operates effectively and does not increase microbiological loads on carcases. Enable timely responses to be implemented in the event of to ensure adequate process control is maintained and minimal product is affected. Enable sufficient process control during further processing and handling of product. Enable timely responses to be implemented in the event of to minimise the amount of product affected. Corrective action Withhold from slaughter (e.g. feed detected in crop/<8hrs feed withdrawal; chemical residue suspected). Removal and humane slaughter of injured/diseased birds (disposal). Removal of dead birds (disposal). Isolation of suspect/diseased flocks. Notify relevant authority when required. Adjust equipment to allow for correct operation appropriate to carcase size. Identify and re-train relevant operational staff. Isolate and re-work affected product within appropriate timeframes. Adjust/service/repair equipment to manufacturer’s specification. Halt killing process and clean and sanitise evisceration equipment prior to restarting Notify relevant authority when required. Ensure correct operation of spin chiller (e.g. overflow) and adjust sanitiser and/or pH levels to return to within operational parameters. Adjust automatic dosing equipment. Identify and re-train relevant operational staff. Notify relevant authority when required. Adjust operational temperature of chilling system (e.g. add ice to spin chiller). Seal cold storage rooms to maintain temperature and monitor via data logging. Halt further stunning/killing process and hold in-process carcasses in chilling system. Identify alternative storage arrangements. Isolate/freeze/test-and-hold potentially affected product. Condemn affected product where temperature exceeds 5°C for a period of time that may compromise the wholesomeness of the product, and the product isn’t compromised to the point where remedial processing wouldn’t ensure the product is still acceptable for human consumption.
The primary control for C perfringens in foods is maintaining temperatures that prevent multiplication of vegetative cells in cooked foods. The optimum growth temperature for C. perfringens is generally between 43°C to 47°C. Because of its fast doubling time, cooked foods prepared in advance need to be cooled rapidly to limit the time at these temperatures. Clause 7(3) of Standard 3.2.2 of the Code (Australia only**) specifies cooling requirements for cooked potentially hazardous foods which require cooling from 60°C to 21°C to be achieved within 2 hours*. Cooling from 21°C to 5°C should occur within a further 4 hours. Once cooled, cooked foods should be stored at 5°C or below. Reheating previously cooked foods also needs to be rapid to minimise the time the food is kept at optimal growth temperatures. Reheating to above 70°C will kill vegetative cells of C. perfringens present. pH and water activity The growth of C. perfringens is inhibited pH 5.5 and the minimum water activity for growth is 0.97. * Standard 3.2.2 provides for an alternative cooling process to be used where it can be demonstrated that the microbiological safety of the food will not be adversely affected. **Similar time-temperature requirements for the cooling of foods are also included in New Zealand legislation. Resources J & Bodnaruk, P (2003) Clostridium perfringens. Ch 15 In: Hocking AD (ed) Foodborne microorganisms of public health significance. 6th ed, Australian Institute of Food Science and Technology (NSW Branch), Sydney, p479-542 (1996) Microorganisms in Foods 5: Microbiological specifications of food pathogens. Chapman & Hall, London. http://www.foodsafety.govt.nz/elibrary/industry/Clostridium_Perfringens-Associated_With.htm Listeria monocytogenes Description Listeria monocytogenes is a Gram-positive, forming bacterium that is widespread in the natural environment and carried by many domestic and wild animals. It has been isolated from soils and vegetation, animal feeds such as silage, as well as surface and marine waters as a result of contamination from sewerage or run off.