Determination of water-soluble vitamins using a colorimetric microbial viability assay based on the reduction of water-soluble tetrazolium salts

Tadayuki Tsukatani; Hikaru Suenaga; Munetaka Ishiyama; Takatoshi Ezoe; Kiyoshi Matsumoto

doi:10.1016/j.foodchem.2010.12.130

Determination of water-soluble vitamins using a colorimetric microbial viability assay based on the reduction of water-soluble tetrazolium salts

Food Chem. 2011 Jul 15;127(2):711-5. doi: 10.1016/j.foodchem.2010.12.130. Epub 2011 Jan 8.

Authors

Tadayuki Tsukatani¹, Hikaru Suenaga, Munetaka Ishiyama, Takatoshi Ezoe, Kiyoshi Matsumoto

Affiliation

¹ Biotechnology and Food Research Institute, Fukuoka Industrial Technology Center, Kurume 839-0861, Japan. Electronic address: tukatani@fitc.pref.fukuoka.jp.

PMID: 23140724
DOI: 10.1016/j.foodchem.2010.12.130

Abstract

A method for the determination of water-soluble vitamins using a colorimetric microbial viability assay based on the reduction of the tetrazolium salt {2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium, monosodium salt (WST-8)} via 2-methyl-1,4-napthoquinone (NQ) was developed. Measurement conditions were optimized for the microbiological determination of water-soluble vitamins, such as vitamin B(6), biotin, folic acid, niacin, and pantothenic acid, using microorganisms that have a water-soluble vitamin requirement. A linear relationship between absorbance and water-soluble vitamin concentration was obtained. The proposed method was applied to determine the concentration of vitamin B(6) in various foodstuffs. There was good agreement between vitamin B(6) concentrations determined after 24h using the WST-8 colorimetric method and those obtained after 48h using a conventional method. The results suggest that the WST-8 colorimetric assay is a useful method for the rapid determination of water-soluble vitamins in a 96-well microtiter plate.