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Starch determination in some dietary fiber sources

Author:
Dintzis, F.R., Harris, C.C.
Source:
Cereal chemistry 1981 v.58 no.5 pp. 467
ISSN:
0009-0352
Subject:
starch, carbohydrate content, dietary fiber, wheat bran, corn bran, soybean hulls, food analysis, enzymatic hydrolysis, alpha-amylase, glucan 1,4-alpha-glucosidase, gas chromatography, sugars, glucose
Abstract:
Commercially available and relatively inexpensive enzymes, single glucoamylase preparations and a high-temperature, dual dystem of .alpha.-amylase plus glucoamylase, were used successfully to determine starch in dietary fiber sources such as some cereal brans that contain large amounts of cellulose and hemicellulose. Gas chromatography was used to measure neutral sugars released by the enzyme preparations, glucose oxidase-peroxidase to measure released glucose only, and optical rotation to directly measure starch content in CaCl2 or dimethyl sulfoxide solution. Incubation of autoclaved substrate with glucoamylase at 50.degree. C for 2 h or use of high temperature .alpha.-amylase (75.degree. C for 20 min) plus glucoamylase (65.degree. C for 35 min) appeared to minimize the effects of suspected hemicellulase and cellulase impurities. Both enzyme systems and methods of detecting glucose yielded similar starch contents of bran materials. Starch values obtained by optical rotation for wheat brans were lower than those measured by enzyme methods.
Agid:
26306
Handle:
10113/26306