Influence of thin-film evaporation and different storage conditions on beetroot juice concentrate: a study on storage stability, betalains degradation kinetics and color stability.

UNLABELLED: Beta vulgaris L. (Beetroot) juice was concentrated from 5°Brix to ~ 60°Brix via thin-film evaporator (TFE) and stored for 90 days at room (25 ± 2 °C temperature, and 60-70% relative humidity) and elevated (37 ± 2 °C temperature and 90% relative humidity) storing environments. Quality attributes, including physicochemical and microbiological parameters, were evaluated periodically. Minimal changes were observed in pH, TA, and TSS throughout the storage. Betalains and antioxidant activity declined progressively with time and temperature, with pigment loss of 7.58% and 17.23% at room and elevated storage conditions, respectively, after 90 days. Browning and HMF increased more at 37 °C but remained within acceptable limits. Degradation of betalains followed first-order kinetics. Generally, TFE proved effective in concentrating beetroot juice while maintaining acceptable stability, suggesting its potential for producing colorant-grade beetroot concentrates with extended shelf life. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at https://doi.org/10.1007/s10068-026-02244-3.