Author(s)

Fei Teng, Tomohiro Bito, Shigeo Takenaka, Yukinori Yabuta, Fumio Watanabe

Department of Veterinary Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka, Japan.
Division of Applied Bioresources Chemistry, The United Graduate School of Agricultural Sciences, Tottori University, Tottori, Japan.

We determined vitamin B₁₂ content of Chinese black tea leaves using a microbiological assay based on Lactobacillus delbrueckii ATCC 7830. Trace levels (0.25 - 0.69 μg/100g dry weight) of vitamin B₁₂ were detected in Pu’er, Fu, and Brick tea leaves. However, vitamin B₁₂ content (0.06 - 1.37 μg/100g dry weight) of Ryubao tea leaves significantly varied. To determine whether Chinese black tea leaves contain vitamin B₁₂ or other corrinoid compounds that are inactive in humans, corrinoid compounds were purified from Ryubao tea by an immunoaffinity column chromatography and vitamin B₁₂ was identified by liquid chromatography-electrospray ionization/tandem mass spectrometry. Vitamin B₁₂ content in the tea drink prepared from Ryubao tea leaves was very low (0.8 ng/100mL). Our results indicate that Chinese black tea is usually not a good source of B₁₂, although Ryubao tea leaves with the highest B₁₂ content may be utilized as a source of this vitamin for vegerarians.

Chinese Black Tea Leaves, Cobalamin, Ryubao Tea, Vitamin _B12

Teng, F. , Bito, T. , Takenaka, S. , Yabuta, Y. and Watanabe, F. (2014) Determination of Vitamin B₁₂ in Chinese Black Tea Leaves. Food and Nutrition Sciences, 5, 1326-1332. doi: 10.4236/fns.2014.514144.