Why 13-cis lycopene more stable than 7-cis and 11-cis?

Answer 1

Because the molecular energy is higher in the 13-cis than 7 & 11-cis.

Answer 2

13-cis lycopene is more stable than 7-cis and 11-cis because it has a more extended conjugated system, making it less prone to isomerization and oxidation. The increased delocalization of electrons in 13-cis lycopene results in higher stability compared to 7-cis and 11-cis isomers.