Recovery of ascorbic acid, phenolic compounds and carotenoids from acerola by-products: An opportunity for their valorization

Ascorbic acid, phenolic compounds and carotenoids were extracted from acerola (Malpighia emarginata DC.) by-products using gas-expanded liquids (GXLs) based on carbon dioxide expanded ethanol at 40 °C and 7 MPa. The by-products generated in the processing of acerola: bagasse (seed and peel) and non-pomace (from the juice clarification step), were studied separately. The overall extraction yields obtained were 3.8 and 12.9 g/100 g for bagasse and non-pomace, respectively. Ascorbic acid was not detected in the bagasse extract, while 158.2 mg/gextract was found in non-pomace extract, and 193.7 mg/g was found in the acerola juice powder. The higher the concentration of ascorbic acid, the higher the antioxidant activity of the extracts. The phytochemical profile obtained by LC-Q-TOF-MS/MS showed a higher number of phenolic compounds (hydroxycinnamic acids and flavonoids) in the bagasse and non-pomace extracts when compared to acerola juice. In addition, GXL promoted the extraction of a pool of carotenoids (lutein and β-carotene), pheophytin and chlorophyll derivatives detected by LC-APCI-MS/MS. The obtained extracts, rich in bioactive compounds, open an opportunity for the valorization of acerola by-products, meeting the current demand for natural nutraceuticals rich in vitamin C and polyphenols.
The authors are grateful to CAPES-PRINT, project number 88887.310560/2018-00472 (Brazil) and Project AGL2017-89417-R (MINECO, Spain).