A Box–Behnken model and three-dimension (3D) response surface were also used for information. As can be seen, in general, the best results in terms of extraction yield were obtained working at the highest temperature and relatively high pressure and flow rate (31.25 µg/g on raw tomato skin in run four and 30.27 µg/g of raw tomato skin in run eight). In general, the validity of the model could be judged by the lack of fit to check the adequacy of the model.