Beetroot juice is a source of polyphenols and betalains. Betalains serve both as colourants and bioactive compounds, and are known to be sensitive to temperature. Conventional thermal treatments can significantly affect the visual appearance and the nutritional quality of beetroot juice and, in consequence, the ultimate consumer acceptance. Our aim is therefore to evaluate the effects of an alternative high pressure processing on the physicochemical, nutritional, sensory and microbiological quality of a beetroot juice. The results showed that a high pressure-processed beetroot juice (600 MPa, RT, 3 min) retained the physicochemical and nutritional properties (bioactive compounds and antioxidant properties) of the freshly squeezed juice with no clearly differentiated sensory quality. The microbiological shelf-life of the juice was established at 21 days, under refrigerated conditions, observing only minor nutritional losses throughout storage. The promising results of high pressure processing for the preservation of betalain-rich juices therefore suggests that the technique represents a useful alternative to conventional thermal treatments.
