GIFSQ Tools · Module 5 — Cereal, Grain, Flour & Milling Technology · Tool 86 of 500
Wheat protein from nitrogen by ICC 105/2. Enter the nitrogen content and the moisture to get protein as-is, on a dry basis, and at the standard 12 % moisture basis used in wheat trading.
Try sample values — fills the form with the worked example below.
Leave the factor blank to use 5.7 for wheat. Use 6.25 only for a general food protein calculation (see Tool 4).
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Protein, as-is (%)
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Protein, dry basis (%)
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Protein, 12 % moisture basis (%)
Equation: Protein % (as-is) = nitrogen % × factor. Protein % (dry basis) = protein % (as-is) × 100 ÷ (100 − moisture %). Protein % (12 % moisture basis) = protein % (dry basis) × 0.88.
Method: ICC 105/2 (determination of crude protein in cereals and cereal products for food and for feed — Kjeldahl method) and ICC 105/1 for the Dumas combustion variant; nitrogen is determined by Kjeldahl or Dumas and converted with the wheat factor 5.7.
Assumptions: all nitrogen in the sample is protein nitrogen; the factor 5.7 matches wheat protein composition; moisture is the ISO 712 value for the same sample.
Limitations: non-protein nitrogen (for example, from fertiliser residue) inflates the result; the factor is species-specific, so do not use 5.7 for other grains; the Kjeldahl titration itself is covered by Tool 5.
Rounding: protein to 2 decimal places. Intermediate values are not rounded.
This is a calculation aid, not a laboratory report — confirm against your accredited method before citing a value.
Method: ICC 105/2 (determination of crude protein in cereals and cereal products for food and for feed — Kjeldahl method) and ICC 105/1 for the Dumas combustion variant; nitrogen is determined by Kjeldahl or Dumas and converted with the wheat factor 5.7.
Assumptions: all nitrogen in the sample is protein nitrogen; the factor 5.7 matches wheat protein composition; moisture is the ISO 712 value for the same sample.
Limitations: non-protein nitrogen (for example, from fertiliser residue) inflates the result; the factor is species-specific, so do not use 5.7 for other grains; the Kjeldahl titration itself is covered by Tool 5.
Rounding: protein to 2 decimal places. Intermediate values are not rounded.
This is a calculation aid, not a laboratory report — confirm against your accredited method before citing a value.
Worked example: Nitrogen 2.10 %, moisture 13.0 %. Protein (as-is) = 2.10 × 5.7 = 11.97 %; protein (dry basis) = 11.97 × 100 ÷ 87 = 13.76 %; protein at 12 % moisture basis = 13.76 × 0.88 = 12.11 % — bread-wheat strength.
Enter values above to see results.
The wheat nitrogen-to-protein factor is 5.7 (not the general 6.25). Protein at 12 % moisture basis is the trading figure; dry-basis protein is the laboratory figure. Tool 86 of 500 — GIFSQ Tool 86 of 500 — GIFSQ
