Discrimination of bovine milk from non-dairy milk by lipids fingerprinting using routine matrix-assisted laser desorption ionization mass spectrometry

Sci Rep. 2020 Mar 20;10(1):5160. doi: 10.1038/s41598-020-62113-9.

Abstract

An important sustainable development goal for any country is to ensure food security by producing a sufficient and safe food supply. This is the case for bovine milk where addition of non-dairy milks such as vegetables (e.g., soya or coconut) has become a common source of adulteration and fraud. Conventionally, gas chromatography techniques are used to detect key lipids (e.g., triacylglycerols) has an effective read-out of assessing milks origins and to detect foreign milks in bovine milks. However, such approach requires several sample preparation steps and a dedicated laboratory environment, precluding a high throughput process. To cope with this need, here, we aimed to develop a novel and simple method without organic solvent extractions for the detection of bovine and non-dairy milks based on lipids fingerprint by routine MALDI-TOF mass spectrometry (MS). The optimized method relies on the simple dilution of milks in water followed by MALDI-TOF MS analyses in the positive linear ion mode and using a matrix consisting of a 9:1 mixture of 2,5-dihydroxybenzoic acid and 2-hydroxy-5-methoxybenzoic acid (super-DHB) solubilized at 10 mg/mL in 70% ethanol. This sensitive, inexpensive, and rapid method has potential for use in food authenticity applications.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Benzaldehydes / chemistry
  • Cattle
  • Gas Chromatography-Mass Spectrometry / methods
  • Gentisates / chemistry
  • Lipids / analysis*
  • Milk / chemistry*
  • Nuts / chemistry
  • Soy Milk / chemistry
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / methods*

Substances

  • 2-hydroxy-5-methoxybenzaldehyde
  • Benzaldehydes
  • Gentisates
  • Lipids
  • 2,5-dihydroxybenzoic acid