Multi-response Optimization of a Solvent System for the Extraction of Antioxidants Polyphenols from Jambolan Fruit (Syzygium cumini (L.) Skeels)

The identification of bio-polyphenols from jambolan fruit is of great interest and requires extraction conditions that preserve their bioactivities. This study aimed to optimize a solvent system for the extraction of polyphenols from jambolan fruit pulp using a simplex-centroid design with axial points. We evaluated various proportions of water, ethanol, and acetone to quantify the total polyphenol content and determine antioxidant activity. Polyphenols in the optimized extracts were identified using high-efficiency liquid chromatography and mass spectrometry. The optimal yield was obtained with a binary mixture of water and acetone (0.5:0.5, v/v), which produced more than 90% of the maximum multi-response values. The identification of bio-polyphenols showed that gallic, quinic, and protocatechuic acids; glycosylated anthocyanins; myricetin isomers; and proanthocyanidins as epigallocatechin trimers were the main compounds responsible for the antioxidant activity of jambolan. In conclusion, a binary mixture of water and acetone in equal proportions was effective in extracting polyphenols with antioxidant activity, thus establishing jambolan as a potential source of bioactive compounds. Graphical Abstract