OPTIMIZATION OF DEHYDRATION AND EXTRACTION OF PHENOLIC COMPOUNDS FROM MANGO PEEL

Mango peel, a by-product obtained from the industrialization of this fruit, is a promising and inexpensive source of phenolic compounds. In the present study, both the drying of the mango peel and the extraction of phenolic compounds were optimized using the response surface methodology. In this sense, temperature and charge/area ratio were selected as depend variables to drying process. Instead, for the ultrasonic assisted extraction (UAE) the temperature, ethanol-water concentration and time were optimized. For both processes, the total phenolic content (TPC) and mangiferin concentrations were the response variables. The TPC and the xanthone concentration were determined by the Folin-Ciocalteu method and HPLC-ESI-IT-MSn, respectively. The optimal conditions for the dehydration process were 54 °C and 2.3 kg m-2, reaching a TPC of 21.7 ± 1.6 mg GAE g-1 dw and a concentration of mangiferin of 1.94 ± 0.22 mg g-1 dw. Regarding to UAE, the optimum conditions were 51 °C, 50% ethanol and 71 min. Under these conditions, the TPC was 19.5 ± 0.8 mg GAE g-1 dw and the mangiferin concentration corresponded to 1.50 ± 0.13 mg g-1 dw. Additionally, 38 compounds were identified in the extract obtained under optimal conditions.