Ultrasound assisted extraction of hibiscus (Hibiscus sabdariffa L.) bioactive compounds for application as potential functional ingredient

The ultrasound assisted extraction (UAE) of total anthocyanins (TA) and total phenolic compounds (TP) from hibiscus calyces was evaluated with the intention of using the extract in future food products. The Box-Behnken Design was used for the extraction evaluating sonication time, solvent concentration and temperature. Final results suggest that 45 min, 65 degrees C and 25% ethanol can be considered the best region for UAE extraction. The relative area of the peaks identified by UPLC-MS/MS in the extract obtained by the UAE are superior in 2 or even 4 times those obtained by conventional extraction, for all the compounds, suggesting that the UAE method is more effective in the extraction of bioactive compounds. The extract obtained was used to make jelly and submitted to in vitro digestion and colonic fermentation. Loss of TP, TA and antioxidant activity in the jelly with addition of extract was lower when compared to extract loss itself, showing that it is feasible the hibiscus extract application in food products.