Identification of spoilage by Alicyclobacillus bacteria in tomato-based products by UHPLC-MS/MS

In recent years, there have been some cases of alteration of tomato derivatives by Alicyclobacilli spp. The spoilage was reported by consumers who felt odors and abnormal tastes ("bad") of products. In this work, an untarget approach with Q-Exactive™ Quadrupole-Orbitrap Mass Spectrometer has been used to identify metabolites associated with the alteration of tomato puree by Alicyclobacillus bacteria. The study was carried out on tomato puree found positive for the presence of Alicyclobacillus spores. The germination and growth of native spores were induced through incubation at 65°C under static conditions for 5 days. For microbial concentration below 100 ufc/mL, negative growth was considered. The samples arising from incubation were submitted to UHPL-HRMS/MS analysis. To find compounds related to microbial growth, data obtained by UHPLC-MS/MS analysis were processed with Thermo Fisher Compound Discoverer™ 2.0 software. We compared samples grouped according to microbial growth: positive growth vs negative growth. Five compounds were identified and confirmed by analysis performed on authentic standards. To other compounds, we have assigned a putative identity. The HRMS approach using Q-Exactive™ Quadrupole-Orbitrap Mass Spectrometer has proven to be an important and powerful tool for identification of compounds which could be used as marker molecules in cases of suspected spoilage by Alicyclobacillus bacteria in tomato derivatives.