Integrated green-based methods to recover bioactive compounds from by-product of acerola processing

This study aimed to recover bioactive compounds from by-product of acerola processing. Firstly, hydrothermal treatment was carried out to extract the compounds, and later, it was concentrated by nanofiltration (NF). Central Composite Rotational Design associated with response surface methodology was applied to maximize the extraction. The optimal conditions were 15 min and a liquid-solid ratio of 22 mL/g (water/non-pomace). The optimized extract was concentrated in NF by a volumetric factor of 13-fold to provide a concentrated product with characteristics compatible with acerola juice. The concentration resulted in the following retentions (R%) and concentration factors (CF): 94.9% and 9.2 for total phenolic content (TPC), 91.6% and 4.9 for ascorbic acid (AA), 99.0% and 8.0 for antioxidant compounds, respectively. NF membrane also showed retention higher than 90.0% for catechin, caffeic acid, ferulic acid, and rutin. TPC and antioxidant activity found in the concentrated extract was 1.3 and 1.5-fold higher than the acerola juice, respectively. The AA content in the extract was below the value found in the juice, 7.9 and 9.1 mg/mL, respectively. Finally, the hydrothermal treatment resulted in higher extraction of phenolic compounds compared to conventional extraction, and its integration with NF resulted in a high content of bioactive compounds.
The authors are grateful to CAPES-PRINT project number 88887.310560/2018-00472 and DINTER/CAPES 1955/2016 process number 23038.021515/2016-97.