Chemical cleavage of fucoxanthin from Undaria pinnatifida and formation of apo-fucoxanthinones and apo-fucoxanthinals identified using LC-DAD-APCI-MS/MS.

•Chemical oxidation of fucoxanthin follows the first- or second-order kinetic models.•Apo-fucoxanthins are detected as the predominant fucoxanthin cleavage products.•Three apo-fucoxanthinones and 11 apo-fucoxanthinals are identified successfully.