Asian Journal of Dairy and Food Research, volume 39 issue 4 (december 2020) : 278-285

Effect of Fat on Protein Estimation in Milk and Its Correlation with Lactose in Different Milk Types: A Small-Scale Study

Sweekruthi A. Shetty, Melissa F. Young, Sunita Taneja, Kannan Rangiah
1<div>Institute of Bioinformatics, Discoverer Building, International Tech Park, Whitefield, Bangalore-560 066, Karnataka, India.&nbsp;</div>
Cite article:- Shetty A. Sweekruthi, Young F. Melissa, Taneja Sunita, Rangiah Kannan (2020). Effect of Fat on Protein Estimation in Milk and Its Correlation with Lactose in Different Milk Types: A Small-Scale Study. Asian Journal of Dairy and Food Research. 39(4): 278-285. doi: 10.18805/ajdfr.DR-1567.
Background: Estimation of macronutrients like protein and lactose is important to assess the quality of milk. To estimate these two macronutrients, ten raw milk samples obtained from each group of different animals (cow, goat, buffalo), ten pasteurized cow milk and ten human milk samples were analysed. 
Methods: Bicinchoninic acid (BCA) method was used to estimate protein from different milk samples. Four different sample preparation protocols were compared to check the effect of fat on BCA based protein estimation: dilution (D), fat removal-protein precipitation (FR&PP), fat removal-dilution (FR&D) and dilution-fat removal (D&FR). For lactose quantification, ultrahigh-performance liquid chromatography-mass spectrometry-selected reaction monitoring (UHPLC-MS/SRM) method was developed and validated using 13C6 lactose as internal standard (ISTD).
Result: Among these four different protocols, D&FR method showed consistent data for total protein content in animal milk (cow-3.16%, goat-3.21%, buffalo-3.81%, pasteurized-2.98%) and FR&PP showed consistent data in human milk samples (1.2%). Though BCA method is simple to use, proper sample preparation protocol has to be applied prior to protein estimation to avoid the interference due to fat or lactose. In case of lactose, inter-day validation showed the accuracy ranging from 97.13 to 100.54%, coefficient of variation varying between 0.1 to 1.53%, correlation R2=0.999. Lactose is in the range of 4.1 to 4.8% in animal milk and 6.6% in human milk samples. The internal ratio of lactose/protein (1.28 to 1.55 in animal milk and 5.33 in human milk) will be useful to differentiate human milk from animal milk type and to assess the milk quality.
  1. Bar³owska, J., Szwajkowska, M., Litwi`nczuk, Z., Kr`o, J. (2011). Nutritional Value and Technological Suitability of Milk from Various Animal Species Used for Dairy Production. Comprehensive Reviews in Food Science and Food Safety. 10: 291-302. 
  2. Beijers, R.J. Graaf, F.V., Schaafsma, A., Siemensma, A.D. (1992). Composition of premature breast-milk during lactation: constant digestible protein content (as in full term milk). Early Human Development. 29: 351-356. 
  3. Bergqvist Y., Karisson, L., Fohlin, L. (1989). Total Protein Determined in Human Breast Milk by Use of Coomassie Brilliant Blue and Centrifugal Analysis. Clin. Chem. 35: 2127-2129.
  4. Fangmeier, M., Kemerich, G.T., Machado, B.L., Maciel, M.J., de Souza, C.F.V. (2019). Effects of cow, goat and buffalo milk on the characteristics of cream cheese with whey retention. Food Sci. Technol, Campinas. 39:122-128.https://doi.org/10.1590/fst.39317. 
  5. Food and Agriculture Organization of the United Nations, Statistics Division, http://www.fao.org/faostat. 1945, Accessed on May 20, 2019. 
  6. Fusch, G., Choi, A., Rochow, N., Fusch, C. (2011). Quantification of lactose content in human and cow’s milk using UPLC-tandem mass spectrometry. Journal of Chromatography B. 879: 3759-3762. 
  7. Garballo-Rubio, A., Soto-Chinchilla, J., Moreno, A., Zafra-Gómez, A. (2018). Determination of residual lactose in lactose-free cow milk by hydrophilic interaction liquid chromatography (HILIC) coupled to tandem mass spectrometry. Journal of Food Composition and Analysis. 66: 39-45. 
  8. Giuffrida, F., Austin, S., Cuany, D., Sanchez-Bridge, B., Longet, K., Bertschy, E., Sauser, J., Thakkar, S.K., Lee, L.Y., Affolter, M. (2019). Comparison of macronutrient content in human milk measured by mid-infrared human milk analyzer and reference methods. Journal of Perinatology. 39: 497-503. 
  9. Giuffrida, F., Austin, S., Cuany, D., Sanchez-Bridge, B., Longet, K., Bertschy, E., Sauser, J., Thakkar, S.K., Lee, L.Y., Affolter, M. (2019). Comparison of macronutrient content in human milk measured by mid-infrared human milk analyzer and reference methods. Journal of Perinatology. 39: 497-503. 
  10. Hibberd, C.M., Brooke, O.G., Carter, N.D., Haug, M., Harzer, G. (1982). Variation in the composition of breast milk during the first 5 weeks of lactation: implications for the feeding of preterm infants. Archives of Disease in Childhood. 57: 658-662. 
  11. Horowitz, I.W. (2005a). Fat, lactose, protein and solids in milk. Mid-infrared spectroscopic method, method no. 972.16, Gaithersburg, MD, USA: AOAC International.
  12. Horowitz, I.W. (2005b). Lactose in milk, Polarimetric method, method no. 896.01, Gaithersburg, MD, USA: AOAC International.
  13. Horowitz, I.W. (2005c). Lactose in milk. Gravimetric method Munson-walker, method no. 930.28. Gaithersburg, MD, USA: AOAC International. 
  14. Kamizake, N.K.K., Goncalves, M.M., Zaia, C.T.B.V., Zaia, D.A.M. (2003). Determination of total proteins in cow milk powder samples: a comparative study between the Kjeldahl method and spectrophotometric methods. Journal of Food Composition and Analysis. 16: 507-516. 
  15. Kanwal, R., Ahmed, T., Mirza, B. (2004). Comparative Analysis of Quality of Milk Collected from Buffalo, Cow, Goat and sheep of Rawalpindi/Islamabad Region in Pakistan. Asian Journal of Plant Sciences. 3: 300-305. 
  16. Kapadiya, D.B., Prajapati, D.B., Jain, A.K., Mehta, B.M., Darji, V.B., Aparnathi, K.D. (2016). Comparison of Surti goat milk with cow and buffalo milk for gross composition, nitrogen distribution and selected minerals content. Vet World. 9: 710-716. 
  17. Keller, R.P. Neville, M.C. (1986). Determination of Total Protein in Human Milk: Comparison of Methods. Clin. Chem. 32: 120-123.
  18. Kjeldahl, J. (1883). Neue Methode zur Bestimmung des Stickstoffs in organischen Körpern. Fresenius’ J. Anal. Chem. 22: 366-382.
  19. Kulkarni, C.P. (2017). Analysis of casein precipitation from the various milk samples available in market. International Journal of Food Science and Nutrition. 2: 215-216.
  20. Lactose content, standard no. ISO 22662 (IDF 198) Milk and milk products - Determination of lactose content by high-performance liquid chromatography (Reference method), Geneva, Switzerland: International Organisation for Standardisation, 2007.
  21. Layman, D.K., Lonnerdal, B., Fernstrom, J.D. (2018). Applications for á-lactalbumin in human nutrition. Nutrition Reviews. 76: 444-460. 
  22. Linn, J.G. (1988). Chapter: Factors Affecting the Composition of Milk from Dairy Cows, Book: Designing Foods: Animal Product Options in the Marketplace Committee on Technological Options to Improve the Nutritional Attributes of Animal Products. National Academy Press Washington, D.C. 
  23. Lubetzky, R., Sever, O., Mimouni, F.B., Mandel, D. (2015). Human Milk Macronutrients Content: Effect of Advanced Maternal Age. Breastfeed Med. 9: 433-436. 
  24. Lynch, J.M., Barbano, D.M. (1999). Kjeldahl nitrogen analysis as a reference method for protein determination in dairy products. J. AOAC Int. 82: 1389-1392.
  25. Mayuri, M., Garg, V., Mukherji, C., Aggarwal, D., Ganguly, S. (2012). Bovine milk usage and feeding practices for infants in India. Indian J. Public Health. 56: 75-81. 
  26. Milk facts. Nutritional components in milk. http://milkfacts.info/Nutrition%20Facts/Nutritional%20Components.htm. Accessed on 3 Sep 2019.
  27. Miller, EM., Aiello, M.O., Fujita, M., Hinde, K., Milligan, L., Quinn, E.A. (2013). Field and laboratory methods in human milk research. Am. J. Hum. Biol. 25: 1-11. 
  28. Moran-Lev, H., Mimouni, F.B., Ovental, A., Mangel, L., Mandel, D., Lubetzky, R. (2015). Circadian macronutrients variations over the first 7 weeks of human milk feeding of preterm infants. Breastfeed Med. 10: 366-370. DOI: 10.1089/bfm. 2015.0053.
  29. Muehlhoff, E., Bennett, A., McMahon, D. (2013). Milk and Dairy Products in Human Nutrition, Food and Agriculture Organization of the United Nations. https://doi.org/10. 1186/1471- 2458-11- 95.
  30. National Dairy Development Board, India. https://www.nddb.coop/ccnddb/milk-facts, 1965, Accessed 5 September 2019.
  31. Park, Y.W., Haenlein, G.F.W. (2007). Goat Milk, Its Products and Nutrition. In: Handbook of Food Products Manufacturing. Y.H. Hui, Ed. John Wiley & Sons, Inc., New York, NY. 447-486.
  32. Shetty SA., Young MF., Taneja S., Rangiah K (2020). Quantification of B-vitamins from different fresh milk samples using ultra- high performance liquid chromatography mass spectrometry/ selected reaction monitoring methods. J. Chromatogr A. 1609: 460452.
  33. Wahid, H., Rosnina, Y. (2011). Buffalo: Asia. In: Encyclopedia of Dairy Sciences, 2nd edn (Ed. by J.W. Fuquay, P.F. Fox & P.L.H. McSweeney), pp. 772-779. Academic Press, Oxford.
  34. WHO (2011). Exclusive breastfeeding for six months best for babies everywhere. https://www.who.int/mediacentre/news/statements/2011/breastfeeding_20110115/en/.
  35. Zhou, L., Tang, Q., Iqbal, M.W., Xia, Z., Huang, F., Li, L., Liang, M., Lin, B., Qin, G., Zou, C. (2018). A comparison of milk protein, fat, lactose, total solids and amino acid profiles of three different buffalo breeds in Guangxi, China. Italian Journal of Animal Science. 17: 873-878.

Editorial Board

View all (0)