Quality Changes and Shelf-Life Prediction of a Fresh Fruit and Vegetable Purple Smoothie

© 2017, Springer Science+Business Media, LLC.The sensory, microbial, and bioactive quality changes of untreated (CTRL) and mild heat-treated (HT; 90 °C/45 s) smoothies were studied and modelled throughout storage (5, 15 and 25 °C). The overall acceptability was better preserved in HT samples being highly correlated (hierarchical clustering) with the flavour. The sensory quality data estimated smoothie shelf-life (CTRL/HT) of 18/55 (at 5 °C), 4.5/12 (at 15 °C) and 2.4/5.8 (at 25 °C) days. The yeast and mould growth rate was lower in HT compared to CTRL while a lag phase for mesophiles/psychrophiles was observed in HT-5/15 °C. HT and 5 °C storage stabilised the phenolic content. Ferric reducing antioxidant power reported the best correlation (R2 = 0.94) with the studied bioactive compounds, followed by ABTS (R2 = 0.81) while DPPH was the total antioxidant capacity method with the lowest adjustment (R2 = 0.49). Conclusively, modelling was used to estimate the shelf-life of a smoothie based on quality retention after a short-time, high-temperature heat treatment that better preserved microbial and nutritional quality during storage.