Lycopene and compositions comprised thereof, for example tomato plant extracts, are uniquely suited for treating, preventively andor curatively, cutaneous signs of aging, in particular inhibiting damage to the skin andor mucous membranes via inhibition of collagenases. In this case, detector elements arranged at the edge of array are provided, whose scintillators have an extent transversely with respect to the edge of the array which is larger than is necessary for encompassing the detection zone. The aerationbackwash device adapted to at least partially surround a portion of said membrane module and including a communication chamber having spaced through-openings in fluid communication with the chamber and the membrane module. The densitometer determines the successive tones corresponding to a plurality of step areas of a toner pattern for each image frame.