Nitrates and nitrites in cured ham: legal limits and production without nitrifying agents

In previous articles, we explained what nitrates and nitrites in cured ham are, their function, and how they are incorporated during the production of hams and shoulders. This third part concludes the series by addressing three key issues from the perspectives of technology and food safety: applicable legal limits, the potential formation of nitrosamines, and the requirements for producing cured ham without added nitrates or nitrites.¿Cuáles son las dosis máximas de nitratos y nitritos permitidas por la legislación?

What are the maximum levels of nitrates and nitrites permitted by legislation?

The maximum dosage of nitrates and nitrites is regulated by Regulation (EC) No 1333/2008 on food additives, along with its subsequent amendments—including Regulation (EU) 2023/2108, which updates the conditions of use for nitrites and nitrates in certain foods. This legislation establishes the positive list of additives permitted in the EU, the food categories in which they may be used, and the authorized maximum limits.

The residual amount refers to the nitrite and nitrate content remaining in the final product—ready for marketing—at the end of the production process and throughout its shelf life.

Residual limits applicable to cured ham at the end of the production process.

Internal control, HACCP, and compliance verification.

Compliance with these limits must be guaranteed by the manufacturing company itself. To this end, it must be incorporated into its HACCP (Hazard Analysis and Critical Control Points) system, including the recording of quantities added during formulation and periodic analyses of residual nitrate and nitrite levels in the final product.

Additionally, there is oversight by the competent authorities, who must verify compliance with the limits established in Regulation 1333/2008 through checks, inspections, and product analysis.

What are nitrosamines?

Some nitrosamines (specifically N-nitrosamines) are compounds that have been classified by the IARC as possible carcinogens. They can form through the reaction between nitrites and amines, primarily in acidic media or under specific temperature and time conditions.

N-nitrosamines can be generated via two main pathways: endogenous and exogenous.

Endogenous formation of nitrosamines

Endogenous formation occurs naturally within our own bodies—in the saliva, the stomach, and, to a lesser extent, the intestine.

This process is promoted by a high dietary nitrate load (from vegetables, water, meat products containing nitrates and nitrites, etc.) and by stomach acidity.

In this regard, many vegetables—especially leafy greens—have a nitrate content far higher than that of cured ham; however, this comparison must be interpreted with caution, as the food matrix differs:

Nitrate content in vegetables:

Maximum residual limit for nitrates in cured ham: <205 mg/kg expressed as NaNO₃

Exogenous formation of nitrosamines

The exogenous pathway occurs within the food itself—during processing or storage—particularly in meat products containing nitrates and nitrites. It is promoted by high temperatures and the presence of amines and nitrites in the food; consequently, it is of little significance regarding the routine consumption of uncooked cured ham.

How is the formation of nitrosamines in cured ham prevented?

The prevention of nitrosamine formation in cured ham relies on various technological and process control measures:

• Limited use of nitrites in accordance with legislation.

• Production of ham without nitrifying agents.

• Use of inhibitors such as certain antioxidants (ascorbate, erythorbate, etc.)

• Cured ham is not subjected to high temperatures (unlike other products, such as cooked ham, where formation levels may be higher).

• Water activity is low, which reduces chemical reactions.

Mechanism of action of nitrates and nitrites during curing

As mentioned in previous articles, nitrates (NO₃⁻) are reduced to nitrites (NO₂⁻) during the curing process through the action of reducing bacteria.

Nitrite converts to nitrous acid (HNO₂) in an acidic medium, and this is reduced to nitric oxide (NO). The NO reacts with muscle myoglobin to form nitrosylmyoglobin, a stable pigment that gives cured ham its characteristic red color.

Can hams be produced without nitrates and nitrites?

Yes, it is possible to produce hams without nitrates or nitrites, but strict measures must be taken to ensure food safety by preventing the growth of pathogenic microorganisms.

Eliminating these preservatives entails removing one of the barriers against the growth of certain pathogenic microorganisms, such as *Clostridium botulinum*, while maintaining product quality.

Technological requirements for producing ham without nitrifying agents

To produce hams without added nitrates or nitrites, companies must adapt and validate their production processes to ensure product safety. Therefore, it is essential to reinforce other control measures throughout the curing process. This approach requires:

• Reformulation of the technological process, including the adjustment of parameters such as salt content, pH, aw, temperature, and humidity across the various stages.
• Scientific and technical validation of the process, which must be based on HACCP, feasibility studies, challenge tests, and documentation justifying the system’s efficacy.
• A control system that includes parameter monitoring and microbiological verification of the final product in its various presentations.

Monte Nevado: cured ham made without added additives

After many years of research and development, all Monte Nevado brand products are now made without any additives. The only ingredients used in Monte Nevado products are ham and sea salt.

This production method requires deep knowledge of the curing process, precise management of each phase, and a control system capable of ensuring food safety and the quality of the final product without resorting to added nitrifying agents.

Signed

Alejandro Olmos

Quality and R&D&i Director