Upholding the Highest Standards in UK Food Production- Analysed, Verified, Trusted - The Promise of UK Food Producers
Maintaining the safety and quality of food including meat and dairy products is underpinned by strict regulatory standards and consumer expectations. There is increasing public awareness of health risks linked specifically to elevated nitrate and nitrite levels. The association with potential carcinogenic nitrosamine formation means that UK producers and laboratories are committed to delivering products that are both safe and compliant. To achieve this, the sector employs a blend of rapid, objective testing technologies and robust laboratory validation frameworks using internationally recognised quality assurance practices.
Sources of Nitrates in Meat and Dairy Products
These come from two broad categories: natural or environmental sources and processing-related additives. Natural sources include nitrates taken up from animal feed and water. For example, widely used nitrate-rich fertilisers can leach into soil and groundwater, contaminating pastures and drinking water for livestock.
Common additive sources are curing agents and processing aids. Nitrates (E251/E252) and nitrites (E249/E250) are added to cured meats (bacon, ham, salami, sausages) and some cheeses. These compounds serve as antimicrobial preservatives (notably against botulism) and colour/flavour fixatives. For example, the Food Standards Agency (FSA) notes that sodium nitrate/potassium nitrite are used in “bacon, ham, corned beef and other cured meats” to inhibit bacterial growth.
In the UK, any labelling claims such as “no added nitrites” usually mean synthetic nitrite isn’t added – although the meat may still absorb nitrate from plant feed which then converts to nitrite during curing.
Screening During Food Production
Rapid and reliable screening is essential, in practice, the food industry often employs rapid in-line tests for nitrate/nitrite. The simplest are dip-and-read test strips: paper or plastic strips impregnated with reagents that change colour upon reaction with nitrate/nitrite.
Test strips are extremely easy to use (just dip into a prepared sample and compare to a colour chart) and give results in under 2 minutes. They are widely used by field labs and quality auditors for rapid pass/fail checks. However, this semi-quantitative test is subjective, and whilst it has good quality control value, more objective analytical information is often required.
Latest Developments in Rapid Nitrate/Nitrite Analysis
A major development is the integration of Macherey-Nagel's RELAX/QUANTOFIX® system within food production and laboratory environments. Unlike traditional subjective colorimetric test strips that rely on human interpretation, the RELAX reflectometer provides digital, objective analysis of QUANTOFIX® test strips, for fast and reliable quantification of nitrates and nitrites.
Key Benefits:
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Objective analysis: The RELAX reader measures test strip colour intensity using photometry, eliminating user bias or lighting variability.
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Rapid turnaround: Results are available within minutes, allowing real-time decision-making on the production floor.
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Ease of implementation: The system’s portability and simple operation make it ideal for factory laboratories, quality control checkpoints, and even pre-shipment batch testing.
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Data integrity: Results can be stored and exported for traceability and audit purposes, supporting compliance with UK Food Standards Agency (FSA) guidelines and food safety standards.
By embedding rapid, automated screening with the RELAX/QUANTOFIX® system, UK food producers can significantly reduce the risk of non-compliance and ensure only safe, verified products proceed to market.
Functionality:
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A sample (e.g., meat extract or dairy serum) is prepared—usually by homogenisation and dilution with water.
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The appropriate QUANTOFIX® strip (e.g., QUANTOFIX® Nitrate/Nitrite) is dipped into the prepared sample.
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After a standard reaction time (30–120 seconds), the strip is inserted into the RELAX® device.
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The RELAX® reflectometer measures the reflectance and converts it into a quantitative result (e.g., mg/L nitrate or nitrite), based on its stored calibration curves.
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The result can be saved, printed, or exported via USB.

Key Advantages:
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Speed: Results typically within 2–5 minutes.
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Ease of Use: Minimal technical skill and training are required, ideal for routine checks.
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Reduced subjectivity: Unlike visual strip readings, RELAX® standardises interpretation.
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Portability: Useful for in-process control on the factory floor or in decentralised labs.
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Traceability: Some models allow data export for audit and regulatory documentation.
Incorporating RELAX/QUANTOFIX® into Laboratory Testing Procedures
In a UK food quality laboratory (especially for meat and dairy products), the RELAX/QUANTOFIX® system is typically used in 3 roles:
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Rapid screening: As a first-tier test to check compliance before more detailed laboratory assays are performed. For example, before final packaging of bacon, batches can be quickly tested for residual nitrite.
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Pre-laboratory triage: To prioritise samples for full ion chromatography (IC) analysis. Only samples approaching or exceeding action limits would proceed to full IC quantification.
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Batch release control: Especially in "natural" cured meat production where nitrate levels from vegetable extracts must be checked batch-to-batch.
The system does not replace full IC-based regulatory testing, but it complements it by providing fast, documented QC assurance at earlier production stages.
Enhancing Laboratory Confidence: ESSLAB’s certified reference materials (CRMs) and PT Schemes
ESSLAB provides certified reference materials (CRMs) and proficiency testing (PT) schemes specifically designed to support nitrate and nitrite analysis.
How CRMs and PTs Strengthen Analytical Quality:
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Certified Reference Materials (CRMs):
Ensure calibration accuracy, method validation, and measurement traceability against known standards.
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Proficiency Testing (PT) Schemes:
Benchmark laboratory performance anonymously against peers, validate methods, and demonstrate ongoing competency to accreditation bodies such as UKAS under ISO/IEC 17025 standards.
Particularly for advanced techniques such as ion chromatography (IC), these tools are vital for demonstrating analytical rigour, enhancing data reliability, and reinforcing industry-wide trust in food testing results.
The Result: UK Food Production That Leads the World
By combining rapid, non-subjective screening with certified laboratory validation, UK food producers deliver food products that are safe, trusted, and fully compliant with the world’s most demanding regulations.
This layered quality assurance approach — incorporating real-time testing, CRMs, and PT schemes — exemplifies the UK's enduring commitment to scientific excellence, consumer safety, and global leadership in food quality.