res are less heat resistant than Type I spores but can grow at temperatures as low as 3ºC. Both types of Cl.botulinum do not thrive in the presence of air and are therefore considered strict anaerobes.
How does nitrite prevent botulism?
Nitrite, in combination with salt and pH, is used in cured meats to ensure their safety with respect to a number of pathogens including Cl. botulinum. To cause illness, spores of Cl. botulinum have to be able to germinate and then grow in the meat product until a point at which botulinum toxin is produced by the bacteria. Nitrite exerts a concentration-dependent antimicrobial effect in meat products, including inhibition of the outgrowth of spores of Cl. botulinum. The antimicrobial effect is also pH-dependent, increasing ten-fold for each unit fall in pH. In its review of nitrite, the EFSA Biohazard Panel in 2003 concluded that between 50-150 mg/kg nitrite is necessary to inhibit the growth of Cl. botulinum. The panel concluded that the ingoing amount of nitrite into the product was the important preservation factor.
What must I do to satisfy the competent authorities that my product is safe and labelled correctly, if I remove the sodium or potassium nitrite/nitrate from my meat product and replace it with an alternative ingredient that is also a source of nitrite/nitrate?
The competent authorities are the government bodies charged with ensuring compliance with the food law. Where sodium or potassium nitrite/nitrate has been removed from the meat product and replaced by an alternative ingredient that is also a source of nitrate/nitrite, the competent authority will require the food business operator to prove that the alternative ingredient is not having a preservative effect in the final product. The competent authority may request inter alia:
(a) Full analytical results showing the levels of nitrate/nitrite in the meat product at the start and end of shelf life and the variability in those levels over several batches
(b) Demonstrable evidence that the alternative ingredient is not providing a preservative effect and is not being added for the purposes of colouring the final meat product
If (b) above is demonstrated to the satisfaction of the competent authorities the food business operator (FBO) will also be required to provide at least the following information to verify that the reformulated meat product is still safe and can be produced safely on a consistent basis:
(c) A full documented hazard analysis showing the major chemical, biological and physical hazards relevant to the product. If sodium or potassium nitrite/nitrate is removed from a meat product then Cl. botulinum must be one of the hazards considered
(d) A full documented validation study to support the safety of the product throughout the applied shelf-life, taking into account all the hazards including Cl. botulinum and any anticipated levels of consumer abuse, like storage of chilled meats in domestic refrigerators at temperatures above 5ºC. The FSAI's Guidance Note No.18 - Validation of Product Self-life (Revision 2), pg 27 Section 126.96.36.199, has further information on establishing the study conditions.
(e) Identification of Critical Control Points at the production steps critical to ensuring the safety of the food, establishment of suitable critical limits based on the validation data used for shelf life determination and application of appropriate corrective actions to ensure food safety should the critical limits be exceeded
(f) Full monitoring data to verify the functioning of the HACCP system
(g) Documentation relating to the HACCP system
Last reviewed: 6/2/2015