EXTRACTION AND SPECTROPHOTOMETRY QUANTIFICATION OF TOTAL POLYPHENOLIC CONTENT IN ONION

A various organic solvents were tested (methanol, ethanol, ethyl acetate and acetone) and their different concentrations (20, 40, 60 and 80%) in order to establish optimum solvent concentration for extraction of polyphenols from onion. RESULTS AND DISCUSSION This study evaluated total polyphenolic content (TPC) after optimization of extraction of polyphenols from onion using different concentration of conventional organic solvents (methanol, ethanol, acetone and ethyl acetate) and different times. According to the literature the Folin-Ciocalteu assay is used for TPC determination in different fruits and vegetables, as it is case in the work of Llupa and coworkers (2022). [...]of reaction of polyphenolic compounds with Folin-Ciocalteu reagent blue complex was formed with absorption maximum in the visible region around 760 nm, and it can be quantified by visible spectrophotometry (Kamboj et al, 2015).