*Article* **Sustainable Drying and Green Deep Eutectic Extraction of Carotenoids from Tomato Pomace**

**Celeste Lazzarini 1, Enrico Casadei 1, Enrico Valli 1,2,\*, Matilde Tura 3, Luigi Ragni 1,2, Alessandra Bendini 1,2 and Tullia Gallina Toschi 2,3**



**Abstract:** The extraction of molecules with high added value plays an important role in the recovery of food waste. This work aimed to valorize tomato pomace, a by-product composed of skin and seeds, through extraction of carotenoids, especially lycopene and β-carotene. The tomato pomace was dried using three different methods (freeze-drying, heat drying, and non-thermal air-drying) to reduce its weight, volume, and water activity and to concentrate the carotenoid fraction. These drying approaches were compared considering the extractive potential. Three solvent mixtures were compared, a traditional one (*n*-hexane:acetone) and two green deep eutectic solvent mixtures (ethyl acetate:ethyl lactate and menthol:lactic acid) in combination with different drying procedures. The extract obtained using ethyl acetate:ethyl lactate with non-thermal air-drying showed the highest contents of lycopene and β-carotene (75.86 and 3950.08 μg/g of dried sample, respectively) compared with the other procedures.

**Keywords:** tomato pomace; lycopene; β-carotene; extraction; sustainability; food by-products; deep eutectic solvents; non-thermal drying
