###### Abstract
The high degree of conjugation makes this carotenoid one of the most powerful natural antioxidants, with a singlet-oxygen quenching ability twice as high as that of \(\beta\)-carotene and ten times higher than that of \(\alpha\)-tocopherol [14]. Its beneficial properties for human health suggest including this compound as a functional ingredient in various formulations, such as enriched beverages, food supplements, as well as in cosmetic and pharmaceutical applications. Lycopene is industrially produced by chemical synthesis or extracted from vegetable sources, mainly tomatoes. Clinical studies have shown that dietary supplements made with natural lycopene are more effective than those containing its synthetic form, probably for the presence of other bio-active molecules co-extracted from natural sources, which synergize with lycopene in promoting positive effects on human health [15]. Its antioxidant activity is synergistically enhanced by the presence of other tomato phytochemicals including \(\beta\)-carotene, phytoene, and phytofluene [16]. Large amounts of lycopene and other carotenoids are contained in tomato by-products, equivalent to 40% of the raw material. During fruit ripening, lycopene accumulates in the skins, where its concentration results to be above five times higher than in the pulp [17], while tomato seeds contain an oil with high nutritional quality, due to its high amounts of phytosterols and antioxidants [18]. Lycopene is insoluble in water and soluble in highly toxic organic solvents, such as benzene, chloroform, and dichloromethane, but it decomposes easily during storage. Supercritical CO\({}_{2}\) (sc-CO\({}_{2}\)) extraction, currently used for a large range of applications, such as decaffeination, refining of lubricant oils, and extraction of natural products from vegetable matrices, represents a way to overcome the drawbacks associated with the use of conventional organic solvents, as their toxicity, difficulties of separation from the extract, and presence of traces into the exhaust solid and the extracts. Several studies were focused on the optimization of sc-CO\({}_{2}\) extraction conditions by varying temperature, pressure, and flow rate and by adding organic co-solvents [19; 20; 21]. In particular, the adoption of high pressures (up to 500 bar) allowed to reach considerable extraction yields at the expense of a lower selectivity [22]. Supercritical fluid extraction has been successfully used also in combination with pressurized liquid extraction, which ensures high process selectivity toward target metabolites of interest for several industrial applications [23]. Moreover, the use of vegetable oils as co-solvents has been demonstrated to improve the extraction yields, contributing to avoiding the degradation of the lycopene during the extraction process [24]. The addition of an oleaginous co-matrix with the tomato matrix, as a source of an oily co-solvent, can enhance the lycopene sc-CO\({}_{2}\) extraction yield and preserve its stability [25; 26]. Many authors [19; 26; 27; 28; 29; 30; 31] investigated the effect of the extraction conditions on the lycopene and \(\beta\)-carotene recovery from tomato peels in the presence of tomato seeds through an sc-CO\({}_{2}\) extraction technique. The results reported in literature are within a wide range of variability due to the different matrices and experimental conditions tested and the different scale of the extraction reactors used. [PERSON] et al. [32; 33] showed the feasibility of extracting lipid fractions from food waste, such as bilberry seeds and spent coffee grounds, respectively, using a hydrofluorocarbon solvent, namely Norflurane, at moderate pressures (5-8 atm). Norflurane or R134a is a haloalkane refrigerant, GRAS (\"Generally Recognized As Safe\") certified by the FDA (\"Federal Food, Drug, and Cosmetic Act\"). It is usually used as a propellant for inhalers and extinguishing agents, and in recent years has found interesting applications also as a solvent.