OPTIMISATION OF ANTHOCYANIN RECOVERY FROM ONION (ALLIUM CEPA) SOLID WASTES USING RESPONSE SURFACE METHODOLOGY

An experimental setup based on a 23-full factorial, central composite design was implemented with the aim to optimising recovery of anthocyanin recovery from onion solid wastes. In order to allow for the establishment of a sustainable process, reusable and non-toxic solutions composed of water/ethanol/citric acid were employed as extracting media. The factors considered were (i) the pH of the medium, (ii) the extraction time and (iii) the ethanol concentration. The 2nd order polynomial equation obtained after elaboration of the experimental data indicated that extraction time mostly affected the extraction yield.