Subcritical water extraction of red cabbage regarding cholinesterase and tyrosinase inhibitory activity

Abstract

Pressurized high-temperature processing of water where polarity can be regulated has been an advanced extraction technology considering sustainable management and efficient use of natural resources. In this study, subcritical water extraction of red cabbage and its enzyme inhibitory potential were investigated using response surface methodology. Spectrophotometric quantification was utilized for total phenol, flavonoid, and anthocyanin contents, while dominant anthocyanin molecules were identified with UPLC-DAD, ESI-MS/MS. The 200 bar-120°C-30 min-30 solvent:solid ratio extract was determined with the highest total anthocyanin content (2.33 mg Cya3GluE/g), where cyanidin-3-sophoroside-5-glucoside, cyanidin-3-(sinapoyl)-sophoroside-5-glucoside, and cyanidin-3-(sinapoyl)(sinapoyl)-sophoroside-5-glucoside were identified as the dominant anthocyanins (1.15 mg Cya3GluE/g). IC50 values for acetylcholinesterase, butyrylcholinesterase, and tyrosinase inhibitory activities were found to be 0.058 mg/ml, 0.215 mg/ml, and 0.86 mg/ml, respectively (tenfold superior to solvent extract). Despite the well-known high-temperature lability of phenolic compounds, subcritical water proved to be useful as a more selective system for extracting red cabbage bioactives with enzyme inhibitory activity when appropriate process conditions could be determined.