Table 1 shows the experimental design and the lycopene yields
obtained under different testing conditions. A Box–Behnken model
and three-dimension (3D) response surface (Fig. 1A–C) 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
lg/g on raw tomato skin in run four and 30.27 lg/g of raw tomato
skin in run eight).