Abstract
Vitamin B 12 content of various edible shellfish was determined by both Lactobacillus leichmannii ATCC 7830 microbiological and intrinsic factor-chemiluminescence methods. The values determined by the microbiological method were 1.2-19.8 (M/C ratio) fold greater in the shellfish than the values determined by the chemiluminescence method. Vitamin B 12 compounds were purified from most eaten shellfish, oyster (M/C, 1.5), mussel (M/C, 1.2), and short-necked clam (M/C, 2.7), and partially characterized. TLC and HPLC patterns of each red-colored vitamin B 12 compound (M/C, 1.0-1.2) purified from these shellfish were identical to those of authentic vitamin B 12. Although the higher values in the determination of vitamin B 12 by the microbiological method may be due to the occurrence of vitamin B 12 -substitutive compounds, the edible shellfish would be excellent vitamin B 12 sources judging from the values (≧ 6 μ g/100g) determined by the chemiluminescence method.