A RAPID AND SIMPLE METHOD FOR THE DETERMINATION OF STARCH AND Β-Glucan IN BARLEY AND MALT

Abstract

A simple and precise method suitable for the routine determination of starch and p-glucan in barley and malt is described. Perchloric acid (50 mM) was used to effect rapid (3 min) and exhaustive extraction of both glucans which were then measured directly from this single extract by specific enzymic hydrolysis of the individual glucans to glucose. The glucose was also measured enzymically. Little or no acid hydrolysis of starch or p-glucan was observed under the extraction conditions used; most or all of the free glucose could be attributed to hydrolysis of sucrose. Complete solubilisation of the gum and hemicellulosic components of p-glucan was achieved. Preincubation of the acid extracts with protease prior to amyloglucosidase digestion resulted in higher measure ments (approximately 4% w/w) of starch. The method was used to measure the levels of starch and p-glucan in five varieties of barley with contrasting malting quality, in micro-malts prepared from these samples and in commercial lager and ale malts.

Comparison of Different Types of NIR Instruments in Ability to Measure β‐Glucan Content in Naked Barley

“…Using best fit of wavelength search, the analysis at 2234, 2374 and 2500 nm yielded reasonable R 2 = 0.85 but with an unacceptable SEE (standard error of estimate) of 0.68%. These results are not surprising, considering that the authors used the reference βglucan determination method described by Ahluwalia and Ellis (1984). This reference method normally yields an accuracy of ±0.25%, a result considerable higher than the ±0.1% characteristic for currently used AACC McCleary Method.…”

Measurement of (1 → 3),(1 → 4)‐β‐D‐glucan in barley and oats: A streamlined enzymic procedure

“…Several methods for the measurement of (1 --+3),(1+4)-P-glucan, hereafter referred to as P-glucan, have been developed and reported (Gill et a1 1982;Bamforth 1983;Ahluwalia and Ellis 1984;Aman and Hesselman 1985;McCleary and Glennie-Holmes 1985;Henry and Blakeney 1988;Jorgensen and Aastrup 1988). Two of these methods, the enzymic method developed by us (McCleary and Glennie-Holmes 1985;McCleary and Nurthen 1986) and the Carlsberg calcofluor method (Jorgensen and Aastrup 1988), have been subjected to interlaboratory evaluation and shown to be accurate and reliable (Munck et al 1989).…”

RELATIONSHIP BETWEEN ACID EXTRACT VISCOSITY AND TOTAL SOLUBLE AND INSOLUBLE Β-Glucan CONTENTS OF HULLED AND HULLESS BARLEY

“…Several methods have been reported in the literature for the measurement of p-glucan content of barley and malt (Fleming et al 1974 (Martin and Bamforth 1981), and in perchloric acid (Ahluwalia and Ellis 1984 (Henry 1984) The procedure used was essentially that of Greenberg and Whitmore (1974) Table 4 are based on single analysis. A ratio similar to one obtained in the present study between 65oC water-soluble and waterinsoluble B-glucan in barley ofdiverse origins was reported by Anderson et al (1978), It is apparent the ratio between the two fractions will largely depend on the method of extractlon.…”