Analysis of eight water soluble vitamins in ricebean (Vigna umbellata) varieties from NE India by reverse phase-HPLC

A simple, quick, and sensitive HPLC procedure for simultaneous quantification of eight water-soluble vitamins (WSVs) in 11 ricebean (Vigna umbellata) varieties (JCR-08-7, JCR-08-8, JCR-08-10, JCR-08-12, JCR-08-15, JCR-08-16, JCR-08-32, JCR-13-11, JCR-13-13, JCR-50 and Nagadal) is described. The method includes enzymatic digestion followed by clean-up with solid phase extraction column and then analysis of extracted compounds by reverse phase column using UV-detector. The optimum conditions revealed that the method had an excellent linearity with good regression coefficient (r > 0.993), precision (0.3–2.77%), and accuracy (83–124%), and relatively short analysis time (13 min). The detection and quantification limits for all WSVs ranged 0.1470–1.1583 µg/mL and 0.4456–3.51 µg/mL, respectively. The average content (mg/100 g) of WSVs in 11 ricebean varieties was—B1: 0.579 ± 0.22, C: 2.111 ± 0.86, B3: 2.292 ± 1.15, B6 (pyridoxal-5-phosphate): 7.002 ± 1.31, B6 (pyridoxine hydrochloride): 2.79 ± 3.23, B5: 6.163 ± 3.35, B9: 0.289 ± 0.14, and B2: 0.163 ± 0.06. Principal components analysis showed that Nagadal belongs to third group which had the highest amount vitamin B1, vitamin B3, vitamin B5, and vitamin B2.