MALDI mass spectrometry imaging of fresh and processed food: constituents, ingredients, contaminants and additives

Mass Spectrometry imaging (MS imaging) provides spatial information for a wide range of compound classes in different sample matrices. We used MS imaging to investigate the distribution of components in fresh and processed food, including meat, dairy and bakery products. The MS imaging workflow was optimized to cater to the specific properties and challenges of the individual samples. We successfully detected highly nonpolar and polar constituents such as beta-carotene and anthocyanins, respectively. For the first time, the distribution of a contaminant and a food additive was visualized in processed food. We detected acrylamide in German gingerbread and investigated the penetration of the preservative natamycin into cheese. For this purpose, a new data analysis tool was developed to study the penetration of analytes from uneven surfaces. Our results show that MS imaging has great potential in food analysis to provide relevant information about components distributions, particularly those underlying official regulations. HighlightsO_LIInvestigation of fresh and processed food by MALDI mass spectrometry imaging C_LIO_LIVisualization of different compound classes in plant and meat-based food C_LIO_LIDevelopment of data processing tool for penetration/diffusion analysis (in food) C_LIO_LINatamycin penetration in cheese, first visualization of food additive by MS imaging C_LIO_LIAcrylamide in gingerbread, first visualization of contaminant by MS imaging C_LI