Overview
ISO 16634-2:2016 sets out an internationally recognized method for determining the total nitrogen content and calculating the crude protein content in cereals, pulses, and milled cereal products. Using the Dumas principle of combustion, this standard offers an alternative to the Kjeldahl method for protein analysis in food products. The Dumas method is favored for its speed and avoidance of hazardous chemicals, making it increasingly popular in quality control and analytical laboratories within the food industry.
This standard is essential for manufacturers, laboratories, and regulatory bodies seeking accurate, reproducible, and comparable results for nitrogen and protein determination in cereal-based food products.
Key Topics
- Total Nitrogen Determination: Utilizes combustion (Dumas principle) to convert all nitrogenous compounds in the sample into nitrogen gas, which is then quantified.
- Crude Protein Calculation: The total nitrogen content is converted to crude protein content using product-specific conversion factors.
- Sample Preparation: Emphasizes obtaining homogenous samples and proper moisture determination using referenced ISO methods (e.g., ISO 712, ISO 6540, ISO 24557).
- Calibration and Quality Control: Outlines the need for frequent calibration using compounds of known nitrogen content and daily performance checks.
- Precision and Repeatability: Includes guidance on interlaboratory reproducibility, repeatability limits, and reporting uncertainty.
- Test Reporting: Specifies data and procedural details required in the analytical report for traceability and comparability.
Applications
ISO 16634-2:2016 has widespread practical applications for those engaged in food analysis, quality assurance, and regulatory compliance:
- Food Industry Laboratories: For routine monitoring of protein content in raw materials and finished products like wheat flour, pulses, barley, and maize.
- Regulatory Compliance: Assists in meeting national and international labeling requirements for protein content in cereal-based foods.
- Research & Development: Supports product development and nutritional research by providing a standard, validated approach to measuring protein content.
- Third-Party Testing Providers: Enables contract laboratories to deliver consistent, ISO-compliant results for clients in the grain and food processing sectors.
- Trade and Export: Facilitates fair commercial transactions by providing comparable analytical results, reducing trade disputes over product composition.
Related Standards
For reliable and standardized results, the following related ISO standards are often referenced alongside ISO 16634-2:2016:
- ISO 16634-1 - Food products - Determination of total nitrogen content by combustion (Dumas method) - Part 1: Oilseeds and animal feeding stuffs
- ISO 712 - Cereals and cereal products - Determination of moisture content - Reference method
- ISO 6540 - Maize - Determination of moisture content (on milled and whole grains)
- ISO 24557 - Pulses - Determination of moisture content - Air-oven method
- ISO 24333 - Cereals and cereal products - Sampling
Employing ISO 16634-2:2016 improves the reliability and credibility of protein measurement in cereals and pulses, ensuring consistent quality and meeting global market expectations. By adhering to this method, food producers and analytical laboratories demonstrate a commitment to best practices and regulatory alignment in food analysis.
Open preview (PDF)Food products — Determination of the total nitrogen content by combustion according to the Dumas principle and calculation of the crude protein content — Part 2: Cereals, pulses and milled cereal products