Production process defects of Mixi beverage detected by neutral desorption-extractive electrospray ionization mass spectrometry

Process defects in the model production process of Mixi beverage, a typical example of extremely viscous food products have been successfully detected using neutral desorption extractive electrospray ionization mass spectrometry (ND-EESI-MS) without sample pretreatment. We employed statistical analysis to explore the correlation between process defects in the production and metabolite ions in the fingerprints of MiXi samples with diverse qualities, which were acquired using ND-EESI-MS. Abnormal signals of analytes such as the appearance of heavy metal ions or pesticides, as well as changes in beneficial ingredients (eg. D-glucose) observed in the fingerprints could serve as indicators of defects encountered in the production. Meanwhile, we quantitatively analysed the concentrations of heavy metals and pesticide residues in Mixi beverage, and the results showed a strong linear relationship (R2 > 0.99) between heavy metals and pesticide residues in the concentration range of 0.50-200.00 μg L-1, with the limit of detection (LOD) of 0.04-1.44 μg L-1 and the limit of quantification (LOQ) of 0.12-4.36 μg L-1 with RSD of 0.39-3.66%. Furthermore, in contrast to previous methods, the concealed defects occurring in the manufacturing process, including raw material screening, soaking, extracting, etc., can be directly detected by terminal product analysis, reflecting ND-EESI-MS was a promising tool for quality control in viscous beverage and tracing defects in the production process.