Affiliation:
1. All-Russian Scientific Research Institute of Buttermaking and Cheesemaking – Branch of V.M.Gorbatov Federal Research Center for Food Systems RAS
2. All-Russian Scientific-Research Institute of Butter- and Cheesemaking — Branch of V. M. Gorbatov Federal Research Center for Food Systems of RAS
3. All-Russian Scientific Research Institute of Butter- and Cheesemaking – Branch of V.M. Gorbatov Federal Research Center for Food Systems
Abstract
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.
Publisher
Kemerovo State University
Reference5 articles.
1. Тепел, А. Химия и физика молока / А. Тепел. – Пер. с нем. под ред. С.А. Фильчаковой. – СПб.: Профессия, 2012. – С. 321., Tepel, A. Himiya i fizika moloka / A. Tepel. – Per. s nem. pod red. S.A. Fil'chakovoy. – SPb.: Professiya, 2012. – S. 321.
2. Лепилкина, О. В. О проблемах определения белка в молоке методом формольного титрования / О. В. Лепилкина, А. Ю. Гусева // Молочная промышленность. 2022. № 4. С. 20–22. https://doi.org/10.31515/1019-8946-2022-04-20-22; https://elibrary.ru/ovxmyt, Lepilkina, O. V. O problemah opredeleniya belka v moloke metodom formol'nogo titrovaniya / O. V. Lepilkina, A. Yu. Guseva // Molochnaya promyshlennost'. 2022. № 4. S. 20–22. https://doi.org/10.31515/1019-8946-2022-04-20-22; https://elibrary.ru/ovxmyt
3. Castillo, L. S. Comparison of Orange G Dye, Formol Titration, and Kjeldahl Methods for Milk Protein Determinations / L. S. Castillo, G. W. Trimberger, C. R. Henderson [et al.] // Journal of Dairy Science. 1962. Vol. 45. № 9. Р. 1079–1082. https://doi.org/10.3168/jds.S0022-0302(62)89562-9, Castillo, L. S. Comparison of Orange G Dye, Formol Titration, and Kjeldahl Methods for Milk Protein Determinations / L. S. Castillo, G. W. Trimberger, C. R. Henderson [et al.] // Journal of Dairy Science. 1962. Vol. 45. № 9. R. 1079–1082. https://doi.org/10.3168/jds.S0022-0302(62)89562-9
4. Gomaa, M. New method for determination of protein content of goats milk and compared with different methods / M. Gomaa, M. E. Abdel-Aziz, E. H. Hafez, I. Salama Samar // Journal of Food and Dairy Sciences. 2014. Vol. 59, № 5 (2). Р. 95–101. https://doi.org/10.21608/jfds.2014.52745, Gomaa, M. New method for determination of protein content of goats milk and compared with different methods / M. Gomaa, M. E. Abdel-Aziz, E. H. Hafez, I. Salama Samar // Journal of Food and Dairy Sciences. 2014. Vol. 59, № 5 (2). R. 95–101. https://doi.org/10.21608/jfds.2014.52745
5. Shagufta, F. Determination of chemical composition of milk marketed in Quetta, Pakistan / F. Shagufta, S. Ashif, K. Muzaffar [et al.] // International Journal of Advanced Research in Biological Sciences. 2016. Vol. 3. № 5. Р. 98–103, Shagufta, F. Determination of chemical composition of milk marketed in Quetta, Pakistan / F. Shagufta, S. Ashif, K. Muzaffar [et al.] // International Journal of Advanced Research in Biological Sciences. 2016. Vol. 3. № 5. R. 98–103