Milk process authentication by vitamin B 6 as a novel time temperature integrator

As raw cow's milk possesses a limited shelf-life and can also pose a threat to the consumer's health, thermal preservation techniques are customary nowadays. A range of compounds can be used for the assessment of successfulness of such treatments, so-called time temperature integrators (TTIs). Although most water-soluble vitamins are known to be depleted during heat exposure in milk, their application as TTI hasn't been investigated yet. Especially vitamin B6 with its various possible vitamers (chemical different forms that exhibit vitamin activity) might be a suitable system for a new vitamin-based TTI. Therefore, the applicability of B6 vitamers in cow's milk as a TTI system was to be evaluated in this study. A recently developed ultra-high performance liquid chromatography method for the simultaneous assessment of all relevant B6 vitamers in cow's milk was used to characterize the status and composition of B6 vitamers in a market survey (n = 78) from Austria, Germany and Czech Republic, comprising milk produced by various thermal and non-thermal preservation techniques such as pasteurization, extended shelf life, ultra-high temperature (UHT). Examining generated data using classification and regression decision trees, discrimination of UHT milk from other preservation techniques, based on the ratio of B6 vitamers was possible. Hence, representing the first report for process authentication of cow's milk based on the composition of minor nutrients (B6 vitamers).