Multi-response optimal hot pressurized liquid recovery of extractable polyphenols from leaves of maqui (Aristotelia chilensis [Mol.] Stuntz)

Multi-response optimization of hot pressurized liquid extraction (HPLE) was applied for the first time to obtain maqui (Aristotelia chilensis [Mol.] Stuntz) leaf extracts. The total polyphenol content (TPC), the antioxidant capacity (AC) as well as the total polyphenol purity of the maqui leaf extracts were accurately predicted (RSD < 8%) at the evaluated extraction scales. The optimum HPLE conditions that prioritized TPC and AC equally (OPT1) recovered ~3 times more TPC (205.14 mg GAE/g leaves) than maqui leaf extracts obtained by maceration, while the extract that prioritized purity over TPC and AC presented the highest purity (36.29%) and an EC₅₀ ~3 times lower than currently reported values. It was found by multi-response optimization that maqui leaves and HPLE are among the best natural sources and extraction techniques, respectively, to recover protocatechuic acid, quercetin, and catechin.