Occurrence of Vitamin B₁₂ in Green, Blue, Red, and Black Tea Leaves

抄録

Vitamin B₁₂ contents of green (0046-0263 and 0, 125-0535μg/ 100g dry weight), blue (0.068-0.081 and 0.525-0.528μg/100g dry weight), red (0.061 and 0.663μg/100g dry weight), and black (0.104-0.859 and 0.305-1.20μg/100g dry weight) tea leaves were obtained by intrinsic factor-chemiluminescence and microbiological methods, respectively. Although vitamin Bit was found in all tea leaves tested by both assay methods, the higher values by the microbiological method were not due to occurrence of both deoxyribosides and deoxynucleotides (known as an alkali-resistant factor), but may have been due to that of inactive corrinoid compounds for mammals in the tea leaves.