Emerging technology approach for extractability and stability of betalains from the peel of beetroot (Beta vulgaris L.)

Abstract Betalains are natural color compounds with high water affinity, unstable, and fragile; hence, understanding their thermal tolerance is always beneficial either in manufacturing them or in their application in betalain-rich functional foods for better handling. In our study, the extractability of betalains via microwave-assisted extraction (MAE) from the peel of beetroot was implemented at 100–800 W for 30–150 s with four different solvents. Among the maximum amounts of total betalains (202.08 ± 2.23 mg/100 g FW), betacyanin (115.89 ± 1.08 mg/100 g FW) and betaxanthin (86.21 ± 1.16 mg/100 g FW) were generated by pure water solvent after 150 s of MAE at 800 W. Alternatively, the susceptibility of beetroot peel extracts to processing conditions was investigated by heating them at 30–70 °C, and the thermal instability of betalains was evaluated by half-life (t 1/2 ), temperature quotient (Q 10 ), and activation energy (E a ), using the Arrhenius equation. The resulted retention percentage (R%) proved that ascorbic acid improved the R% of total betalains from 22 to 51% and betacyanin from 3 to 29% and in contrast reduced R% of betaxanthin from 56 to 40% after the heat treatment at 70 °C for 5 h.