Kinetic modelling of anthocyanins and vitamin C degradation in a maqui-citrus beverage during storage for different sweeteners and pasteurization treatments

Kinetic models to describe the degradation of anthocyanins (first-order model) and vitamin C (system of ordinary differential equations) in a novel beverage, has been used as a tool to identify the most relevant variables for the degradation kinetics and to support shelf-life estimation. The models were based on an empirical dataset, accounting for the effect of a prior processing treatment (HHP at 400 MPa- 180s; HHP at 600 MPa-180s; thermal treatment at 85ºC for 15s), storage temperature (4 or 20ºC), and the use of two different sweeteners (sucralose or stevia). Using model selection (based on AIC), we conclude that the degradation kinetics depends on a complex combination of process and product parameters. A strong temperature dependence on anthocyanins and vitamin C was observed during pasteurization. Products treated by HHP resulted in higher vitamin C concentrations during storage than those thermally treated. Finally, an interaction with the sweetener resulted in a slight stabilization of bioactive compounds. In conclusion, this study demonstrates the the complexity of the degradation process of bioactive compounds in these beverages, advocating that nonlinear kinetic models serve as a tool to identify the most relevant parameters, ultimately supporting product formulation and shelf life estimation