Identification and quantification of metallo-chlorophyll complexes in bright green table olives by high-performance liquid chromatrography-mass spectrometry quadrupole/time-of-flight.

Five different samples of table olives, two regular Spanish table olives and three "bright green table olives", have been analyzed by HPLC-MS/MS to determine their pigment profile. Typical pigment profiles of almost all table olives show primarily chlorophyll derivatives lacking metals (e.g., pheophytin a/b and 15(2)-Me-phytol-chlorin e(6)). Bright green table olives have a unique profile including metallo-chlorophyll complexes (Cu-15(2)-Me-phytol-chlorin e(6) with 26-48% and Cu-pheophytin a with 3-18%) as their major pigments. New tentative structures have been identified by MS such as 15(2)-Me-phytol-rhodin g(7), 15(2)-Me-phytol-chlorin e(6), 15(2)-Me-phytol-isochlorin e(4), Cu-15(2)-Me-phytol-rhodin g(7), Cu-15(2)-Me-phytol-chlorin e(6), and Cu-15(2)-Me-phytol-isochlorin e(4), and new MS/MS fragmentation patterns are reported for Cu-15(2)-Me-phytol-rhodin g(7), Cu-15(2)-Me-phytol-chlorin e(6), Cu-pheophytin b, Cu-pheophytin a, Cu-pyropheophytin b, and Cu-pyropheophytin a. The presence of metallo-chlorophyll derivatives is responsible for the intense color of bright green table olives, but these metallo-chlorophyll complexes may be regarded as a "green staining" defect that is unacceptable to consumers.