Evaluation of supercritical atomization assisted (SAA) to obtain phenolic compounds from microparticles of beet leave extracts

The production and processing of beet generates a large amount of by-product, where the leaves are discarded as waste. Beet leaves contain valuable compounds, such as phytochemicals and bioactive compounds, which have the potential to be applied as food additives and/or nutraceuticals. This work aimed to recover phenolic compounds from microparticles obtained from beet leave extract using supercritical assisted atomization (SAA). The solvent used for the extraction was ethanol, at a concentration of 70%, in a ratio of 1:40 (1g of sample to 40mL of solvent), for 2h. The operating conditions for each test applied to the SAA were 30/35/40 seg of CO₂ flow; 50/50/60 seg of solvent flow and ratios of 1:10, 1:20, and 1:30 (extract/polymer) for SAA 1, SAA 2 and SAA 3, respectively. The Folin Ciocalteu method was used to measure total phenolic compounds (TPC). It was noted that the recovery of phenolic compounds from the extract encapsulated with PVP (polyvinylpyrrolidone) was higher when compared to the extract alone. The results showed that the conditions used in the SAA 3 test obtained the best yields of TPC, with around 18 mg GAE g^-¹. This result suggests that a higher proportion of polymer contributes to a higher recovery of TPC. This is confirmed by the results of the other tests carried out, in which TPC recovery increases as the ratio of polymer grows. Thus, it can be concluded that assisted supercritical atomization is a promising process, contributing to the recovery of bioactive compounds and the management of agro-industrial waste.