DETERMINATION OF THE AVERAGE MOLECULAR-WEIGHT OF BARLEY BETA-GLUCAN WITHIN THE RANGE 30-100K BY THE CALCOFLUOR FIA METHOD

A new methodology for the determination of β-glucan average molecular weights within the range 30-100k has been developed. It was found that, when the amount of β-glucan was determined by the Calcoflour flow-injection analysis (Calcoflour-FIA) method with two eluants, one of high ionic strength (0·02 g/l Calcoflour in aqueous 0·1 M Tris, pH 11, 0·17 M NaCl), which fully detects β-glucan of molecular weight (MW) higher than approximately 10k, and the other of very low ionic strength (0·02 g/l Calcoflour in aqueous 0·1 M Tris, pH 11), which fully detects only high MW (> 150k) β-glucan, the ratio of the amounts detected by the two eluants was correlated with the average molecular weight of β-glucan. When compared with the high-performance size-exclusion chromatography with post-column detection by Calcoflour-FIA (HPSEC-FIA) method, both methods gave similar results within the range of applicability of the new method. © 1993 Academic Press Limited.