Abstract
The capacity of a direct injection mass spectrometer based on proton transfer reaction (PTR-MS) to monitor the transient changes of the volatile organic compounds (VOCs) during dulce de leche production was investigated. We found a correlation between the mass fingerprint and some physio-chemical properties of the dulce de leche samples. The intensity of the selected mass fragments related to VOCs was positively correlated with the changes of solids content but negatively with that of water activity. Rheological and textural changes were also highly correlated with the intensity observed for several mass fragments. Hence, this relationship could be useful to predict the textural and rheological changes during heating a complex fluid. Although not all the correlations between physical changes and VOCs formation reflected a direct cause–effect relationship, but those results demonstrated the suitability of the PTR-MS technique to monitor the quality changes even in complex food mixture during thermal processing.