Vitamin B₁₂ Carboxylic Acid Characterization in the Viscera Edible Portions of Lobster, Crayfish, Crab, and Shrimp

The vitamin B₁₂ content of lobster, crayfish, crab, and shrimp viscera was determined using a microbiological assay based on Lactobacillus delbrueckii subsp. lactis ATCC7830. These viscera contained high vitamin B₁₂ levels (7.2–118.6 μg/100 g of wet weight). We purified vitamin B₁₂ compounds from the extracts of these viscera using an immunoaffinity column. Corrinoid compounds were identified using liquid chromatography-electrospray ionization tandem mass spectrometry. The viscera tested contained vitamin B₁₂-b-, -d-, and -e-monocarboxylic acids and vitamin B₁₂-be-dicarboxylic acid, modified with peripheral propionamide side chains of the corrin ring. These vitamin B₁₂ carboxylic acids are specifically located in the viscera edible portions of lobster, crayfish, crab, and shrimp.