Pigment profiling of ‘QN Orange'scallop and ‘Bohai Red’ scallop adductor muscles by liquid chromatography coupled with triple quadrupole mass spectrometry

Two new scallop strains, the 'QN Orange' scallop and the 'Bohai Red' scallop, were selected from the hybrid cohort between the bay scallop (Argopecten irradians irradians) and the Peruvian scallop (Argopecten purpuratus) to improve the bay scallop stock, which has suffered from significant inbreeding depression characterized by poor growth and high mortality. Although both strains were originated from the same hybrid cohort, the 'QN Orange' scallops possess orange adductor muscles while the 'Bohai Red' scallops have white adductor muscles. To explore the pigment profiles of adductor muscle coloration in these two scallop strains, an optimized method based on liquid chromatography coupled with triple quadrupole mass spectrometry (HPLC-QqQ-MS) with atmospheric pressure chemical ionization (APCI) was established to determine chlorophyll (chlorophyll a and chlorophyll b) and carotenoids (including α-carotene, β-carotene, ε-carotene, γ-carotene, ζ-carotene, lutein, fucoxanthin, zeaxanthin, canthaxanthin, pectenoxanthin, and pectenolone). The results showed that the total contents of carotenoids in the adductor muscle, gill, and mantle of 'QN Orange' scallops were 82.68, 105.49, and 100.49 μg g−1, which were 49.88, 3.26, and 4.18 times higher than those in the 'Bohai Red' scallops, respectively. In particular, the contents of the pigments pectenolone, pectenoxanthin, fucoxanthin, zeaxanthin, and lutein in the 'QN Orange' scallops were 171.58, 61.67, 3.87, 22.16 and 23.27 μg g−1, which were 6.92, 3.38, 27.64, 15.75, and 13.00 times higher than those in the 'Bohai Red' scallops, respectively. These results suggest that the orange coloration in the 'QN Orange' scallops might be caused by the accumulation of carotenoids.