Food Analytical Methods

, Volume 12, Issue 11, pp 2555–2561 | Cite as

A New Method to Distinguish the Milk Adulteration with Neutralizers by Detection of Lactic Acid

  • Alessandra Aiello
  • Fabiana PizzolongoEmail author
  • Nadia Manzo
  • Raffaele Romano


A liquid chromatographic method based on determining of the amount of lactic acid was developed to detect milk adulteration with neutralizers. The developed method can be applied to milk with pH values within the regular range of 6.5–6.7 that is suspected of being neutralised. Determination of lactic acid was carried out in milk acidified with lactic acid and neutralised with sodium hydroxide to simulate the adulteration. The validation parameters showed high linearity (R2 > 0.99), good precision (relative standard deviation ≤ 0.123%) and high sensibility (limit of detection 0.1 mg/L and limit of quantification 1 mg/L). The proposed method was applied to bacterially acidified and subsequently neutralised milk and detected a content of lactic acid of approximately 40 mg/100 mL in milk slightly acidified to pH 6.4. The developed method is simple, fast, precise and suitable for detecting the addition of hydroxides in sour milk.

In parallel, the sodium content was determined in the same sodium hydroxide neutralised samples, but the addition of a small amount of this alkali does not affect the natural variation of sodium in milk.


Milk adulteration Sodium hydroxide Lactic acid Neutralizers 


Compliance with Ethical Standards

Conflict of Interest

Alessandra Aiello declares that she has no conflict of interest. Fabiana Pizzolongo declares that she has no conflict of interest. Nadia Manzo declares that she has no conflict of interest. Raffaele Romano declares that he has no conflict of interest.

Ethical Approval

This article does not contain any studies with human participants or animals performed by any of the authors.

Informed Consent

Not applicable.


  1. Aaku E, Collison E, Gashe B, Mpuchane S (2004) Microbiological quality of milk from two processing plants in Gaborone Botswana. Food Control 15:181–186CrossRefGoogle Scholar
  2. Ahmad S, Gaucher I, Rousseau F, Beaucher E, Piot M, Grongnet J, Gaucheron F (2008) Effects of acidification on physico-chemical characteristics of buffalo milk: a comparison with cow’s milk. Food Chem 106:11–17CrossRefGoogle Scholar
  3. Alais C. (2000) Scienza del latte (Tecniche Nuove, Milano)Google Scholar
  4. Ayub M, Ahmad Q, Abbas M, Qazi IM, Khatta IFA (2007) Composition and adulteration analysis of milk samples. Sarhad J Agric 23:4Google Scholar
  5. Cunniff P (1995) Official methods of analysis of AOAC international. Washington, DC: Association of Official Analytical ChemistsGoogle Scholar
  6. De Marchi M, Fagan C, O’Donnell C, Cecchinato A, Dal Zotto R, Cassandro M, Penasa M, Bittante G (2009) Prediction of coagulation properties, titratable acidity, and pH of bovine milk using mid-infrared spectroscopy. J Dairy Sci 92:423–432CrossRefGoogle Scholar
  7. Gaucheron F (2005) The minerals of milk. Reprod Nutr Dev 45:473–483CrossRefGoogle Scholar
  8. Hantsis-Zacharov E, Halpern M (2007) Culturable psychrotrophic bacterial communities in raw milk and their proteolytic and lipolytic traits. Appl Environ Microbiol 73:7162–7168CrossRefGoogle Scholar
  9. ISO (2005) ISO 8069; in Dried milk - determination of content of lactic acid and lactatesGoogle Scholar
  10. Jayarao B, Henning D (2001) Prevalence of foodborne pathogens in bulk tank milk. J Dairy Sci 84:2157–2162CrossRefGoogle Scholar
  11. Jensen RG (1995) Handbook of milk compositionCrossRefGoogle Scholar
  12. Ling ER (1951) The determination of lactic acid in milk. J Sci Food Agric 2:10CrossRefGoogle Scholar
  13. Lucey J, Gorry C, OKennedy B, Kalab M, TanKinita R, Fox P (1996) Effect of acidification and neutralization of milk on some physico-chemical properties of casein micelles. Int Dairy J 6:257–272CrossRefGoogle Scholar
  14. Maheswara Reddy D, Venkatesh K, Venkata Sesha Reddy C (2017) Adulteration of milk and its detection: a review. Int J Chem Stud 5:5Google Scholar
  15. Noel L, Carl M, Vastel C, Guerin T (2008) Determination of sodium, potassium, calcium and magnesium content in milk products by flame atomic absorption spectrometry (FAAS): a joint ISO/IDF collaborative study. Int Dairy J 18:899–904CrossRefGoogle Scholar
  16. Regulation (2008) EC Regulation n.1333Google Scholar
  17. Ribani M, Bottoli C, Collins C, Jardim I, Melo L (2004) Validation for chromatographic and electrophoretic methods. Quim Nova 27:771–780CrossRefGoogle Scholar
  18. Sharma R, Rajput YS, Barui AK, Naik NL (2012) Detection of adulterants in milk - a laboratory manual (NDRI publication)Google Scholar
  19. Singuluri H, Sukumaran M (2014) Milk adulteration in Hyderabad, India – a comparative study on the levels of different adulterants present in milk. J Chromatogr Sep Tech 5:3CrossRefGoogle Scholar
  20. Verdier-Metz I, Coulon J, Pradel P (2001) Relationship between milk fat and protein contents and cheese yield. Anim Res 50:365–371CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Department of Agricultural SciencesUniversity of Naples Federico IIPorticiItaly

Personalised recommendations