Optimisation of the extraction of phenolic compounds from apples using response surface methodology

•The best condition for methanolic extraction was 84.5% for 15min at 28°C.•The best condition for extraction with acetone was 65% at 10°C for 20min.•Acetone solution extracted more bioactive compounds than methanol.•Chlorogenic acid and phloridzin had better yields with methanolic extraction.•Acetone solution extracted most catechin. The extraction of phenolic compounds from apples was optimised using response surface methodology (RSM). A Box–Behnken design was conducted to analyse the effects of solvent concentration (methanol or acetone), temperature and time on the extraction of total phenolic content, total flavonoids and antioxidant capacity (FRAP and DPPH). Analysis of the individual phenolics was performed by HPLC in optimal extraction conditions. The optimisation suggested that extraction with 84.5% methanol for 15min, at 28°C and extraction with 65% acetone for 20min, at 10°Cwere the best solutions for this combination of variables. RSM was shown to be an adequate approach for modelling the extraction of phenolic compounds from apples. Most of the experiments with acetone solutions extracted more bioactive compounds, and hence they had more antioxidant capacity, however, chlorogenic acid and phloridzin had higher yields (32.4% and 48.4%, respectively) in extraction with methanol.