Utilization of MALDI-TOF Mass Spectrometry for microbiological evaluation of milk and dairy products

Abstract

Milk and its derivatives are foods that are distinguished by their high nutritional value. This characteristic allows a wide variety of microorganisms to be found in such products, including those considered desirable and undesirable. In addition, a large volume of milk has been produced worldwide, demanding more practical and accurate methods, such as MALDI-TOF mass spectrometry, to be applied for the microbiological evaluation of dairy products. This methodology is based on the ionization and desorption of microbial proteins, which are then accelerated in a vacuum tube. According to the time-of-flight along the tube of the different ionized particles composing the sample, characteristic spectra are formed and compared to the spectra present in the database, allowing the identification of the microorganism. Many scientific studies have demonstrated that the identification by MALDI-TOF of distinct microorganisms isolated from dairy products (milk, cheeses and fermented milks) w compatible with the result obtained by genetic sequencing methods (16S rRNA gene), which is considered the gold standard method for microbial identification. Although this is a new method and requires considerable investment to acquire the device, its performance has been satisfactory and promising. Therefore, there is a great future perspective that its use will be more effective for the identification of dairy microorganisms.

Keywords

• microbiologia de leite
• análise proteômica
• identificação microbiana.