Similar reports about the isomerisation of lycopene in tomato samples
during thermal processing above 75 C (Cocero et al., 2003),
and the decrease in the trans- to cis-isomer ratios from 90:10 to
40:60 after heating at 140 C (Mayer-Miebach et al., 2005) have already
been demonstrated. The decreased antioxidant activity of
each unit of lycopene extract, which correlated with the content
of trans-lycopene and trans/cis ratio, might indicate that trans-lycopene
has a high stability and exhibits higher antioxidant activity
than do the cis-isomers.