Uglich, Russian Federation
Uglich, Russian Federation
Uglich, Russian Federation
Formol titration is a familiar method for determining the mass fraction of protein in milk. However, it needs to be adapted to new instruments and modern metrology. The current methodology presented in State Standard GOST 25179-2014 requires a complex procedure to establish the alteration, which is often neglected by commercial laboratories and milk producers. This research clarified the formula for converting formol titration data into protein mass fraction without having to perform a variable correction. By processing 413 measurement results, the authors came up with two formulas: Y = 0.5X and Y 0.48X + 0.10, where Y is the mass fraction of protein (%) and X is the volume of sodium hydroxide spent on titration after adding formaldehyde to milk (cm3). Both formulas provided results close to those obtained by the Kjeldahl method, the correlation coefficient being ≥ 0.99. The conversion formulas made it possible to adapt the formol titration method to modern automatic potentiometric analyzers, thus optimizing the procedure and increasing its accuracy.
protein in milk, formol titration method, conversion factor, metrological characteristics
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