red beets or prickly pears can give a startling
but harmless tinge to the urine. The red
betains contain a phenolic group and are good
antioxidants; yellow betaxanthins don’t and
aren’t.
The three major kinds of plant pigments. For
the sake of clarity, most hydrogen atoms are
left unlabeled; dots indicate carbon atoms.
T o p : Beta-carotene, the most common
carotenoid pigment, and the source of the
orange color of carrots. The long fat-like
carbon chain makes these pigments much
more soluble in fats and oils than in water.
Bottom left: Chlorophyll a, the main source of
the green in vegetables and fruits, with a
heme-like region (p. 133) and a long carbon
tail that makes chlorophyll more soluble in