Discrimination of milk fermented with different starter cultures by MALDI-TOF MS and REIMS fingerprinting

Fermented milk products are valued by consumers and the food industry for their nutritional properties, pleasant taste, and texture. To rapidly discriminate the peptide and small molecular fingerprints of fermented milk with different flavour characteristics, we assessed the suitability of high-throughput protocols for the screening of these samples using rapid evaporative ionisation mass spectrometry (REIMS) and matrix-assisted laser desorption ionisation–time-of-flight mass spectrometry (MALDI-TOF MS). With minimal sample preparation, we can distinguish between different fermented milk produced from different bacterial strains. These techniques can aid in quick and cost-effective fingerprinting to screen for new and interesting fermented products and bacterial cultures. Furthermore, we have demonstrated for the first time the suitability of REIMS for the measurement of liquid dairy samples.