Optimization and Modeling of Solid-liquid multivariable extractor (SoLVE): a new solution for tomato waste valorization

In this work, a new extraction technique and a new modeling approach were proposed for the simultaneous recovery of hydrophobic (carotenoids) and hydrophilic (polyphenols) antioxidants from industrial tomato waste. SoLVE (Solid-Liquid multiVariable Extractor), is an extractor characterized by high versatility. The effects of pressure (50-200 bar), solvent composition (ethanol 20-100%), temperature (25-95 degrees C), and time (0-40 min) were experimentally evaluated on lycopene and total polyphenol yields, antioxidant activity, and kinetic parameters. Indeed, Peleg's model for the description of the extraction over time was applied and completely integrated with response surface modeling to assess and also predict the dependences on the selected process variables of initial extraction rate and yields at infinite time of all the kinetic curves observed for lycopene and total poly phenol yield and extract antioxidant activity. Results showed better performances of SoLVE (60.2 +/- 4.1 mu g/gDB of lycopene and 6.52 +/- 0.01 mgGAE/gDB of polyphenols) compared to ultrasound-assisted extraction (36.7 +/- 0.9 mu g/gDB of lycopene and 1.3 +/- 0.04 mgGAE/gDB of polyphenols), both carried out on the same biomass and using the same solvents, showing the potential of this new extraction method for the valorization of tomato waste, even without using ultrasounds which SoLVE is equipped with. (C) 2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.