Vitamin B<sub>12</sub> Carboxylic Acid Characterization in the Viscera Edible Portions of Lobster, Crayfish, Crab, and Shrimp
Kyohei Koseki, Naho Okamoto, Yui Ito, Tomohiro Bito, Atsushi Ishihara, Yukihiro Umebayashi, Fumio Watanabe
Abstract
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.