Characterization of vitamin B12 compounds from commercially available fish roe products

Although fish roes (or the egg-laden ovary) are seafood products with high nutritional value and are considered abundant in vitamins including vitamin B₁₂, nevertheless, the detailed properties of vitamin B₁₂ have not been fully elucidated in fish roe products. Vitamin B₁₂ content was determined using C18-reversed-phase high-performance liquid chromatography after purification of samples from immunoaffinity columns. Salmon egg-laden ovary products (sujiko), salmon roe products (ikura), dried mullet roe products (bottarga), and white sturgeon roe products (caviar) were found to contain substantial levels of vitamin B₁₂ (more than approximately 15 µg/100 g wet weight). Interestingly, high levels of vitamin B₁₂ per 100 g wet weight have been measured in pollack roe products (tarako) and flying fish roe products (tobiko). Liquid chromatography–electrospray-ionization/tandem mass spectrometry analysis revealed that vitamin B₁₂ was the predominant corrinoid in the evaluated fish roe products examined, while no inactive corrinoid compounds were identified. These results suggest that commercially available fish roe products could be an important source of vitamin B₁₂ for use as a dietary product for humans.