<i>Spondias tuberosa</i> Seed as a Source of Bioactives by an Optimized Microwave-Assisted Green Extraction

Umbu (<i>Spondias tuberosa</i>Arruda) is a native Brazilian Caatinga fruit. The pulp is the main product of its agroindustrialization; however, depulping generates approximately 25% of residue. This study aimed to recover bioactive compounds from umbu seed through a more sustainable approach, using propylene glycol as a solvent in microwave-assisted solid-liquid extraction. Additionally, the study evaluated the chemical profile, photoprotective action, and <i>in vitro</i> toxicity. An experimental design using percentage of propylene glycol (15-85%) and temperature (59-201 °C) as independent variables was adopted. Total phenolic content (TPC) and antioxidant capacity by DPPH^•, ABTS^•+, and FRAP were evaluated as responses. The highest response values were observed at 201 °C and 60% propylene glycol. Adjusting the extraction time to 15 min resulted in a 41% increase in TPC. According to UPLC-HRMS/MS analysis, the optimized extract is mainly composed of phenolic compounds. It showed a sun protection factor of 13 at 30 mg/mL. Furthermore, the 25% extract showed no toxicity in the <i>G. mellonella</i> model. Therefore, the use of propylene glycol as a green solvent in microwave-assisted extraction favored the recovery of bioactive compounds from umbu seed, enabling the production of a bioproduct with potential cosmetic application.