ISSN:0038-9056    

DOI:10.1002/star.19870390202

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

摘要:

AbstractX‐ray analysis of starch isolated from yellow corn, sorghum (Giza 3 and 114) sordan 79 and pearl millet was carried out. The calculated “d” spacing reinforced the pattern of diffraction as “A” type. The general pattern of the X‐ray diffraction of the tested samples showed symmetric configuration with a specified diffracting angle for each sample. While no significant difference between the “d” spacing of the two types of sorghum Giza 3 and 114 was noticed, a sharp diffraction angle at “d” spacing of 5.9111 Å was o

ISSN:0038-9056    

DOI:10.1002/star.19870390203

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

摘要:

AbstractStarch from the seed ofC. edulisis isolated, purified and its physicochemical properties are compared with maize starch. Scanning electron microscopy of the granules show that they are either smaller round or polygonal in shape. It has low phosphorus and amylose content and water binding capacity while methanol soluble lipids and proteins are more than in maize starch. Galatinization temperature and swelling power ofC. edulisstarch is almost comparable, but it has less solubility when compared with maize starch. Brabender viscosity shows high peak forC. edulisstarch and lesser retrogradation.

ISSN:0038-9056    

DOI:10.1002/star.19870390204

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

摘要:

AbstractScanning electron microscopy of swollen starch granule systems is valuable for interpretation of structural changes, but the results obtained must be interpreted with caution. The two major drying systems used, solvent exchange and lyophilization, both produce artefacts but of different types. The presence of pores on specimens prepared by lyophilization has often been interpreted as a true feature of the granule structure, but our experience suggests that this is incorrect. Furthermore, we consider that the fibrillar structure present in preparations of lyophilized starch solubles results from ice crystal formation effectively concentrating, in the remainder of the solution, solute which is subsequently preserved as a dry web.

ISSN:0038-9056    

DOI:10.1002/star.19870390205

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

摘要:

AbstractThe analysis of alkaline degradation products of monosaccharides has been performed by13C NMR spectroscopy. The13C chemical shifts of several carboxylic acids produced by alkaline degradation of monosaccharides have been determined. The application of these data to the identification and quantification of products in an alkaline degradation mixture ofD‐glucose is presented. Carboxylic acid products up to 6 carbon atoms have easily been identified in such complex reaction mixtures. Furthermore, information on the different functional groups present in the oligomeric reaction products has been obtained from the alkaline degradation of 1‐13C‐D‐

ISSN:0038-9056    

DOI:10.1002/star.19870390206

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

摘要:

AbstractIn order to elucidate acceptor molecule of starch synthase bound to starch granules, the enzyme from sweet‐potato roots was reacted with ADP‐ and UDP‐[14C]‐glucose, and the reaction products were structurally characterized. The radioactivity of the products was released as [14C]‐maltose by β‐amylase. The [14C]‐glucose incorporation was found to be mostly in amylopectin component. However, approximately 30 and 20% of total radioactivity transferred from ADP‐ and UDP‐[14C]‐glucose, respectively, were also present in a molecule with a lower molecular weight than that of amylose component. The radioactivity was incorporated into the much longer unit‐chains of amylopectin than into the usual chains. These results indicate that starch synthase bound to sweet‐potato starch granules transfers glucose from ADP‐ and UDP‐glucose into specific outer chains of amylopectin component, and that the incorporation of the glucose into a short‐chain amylose molecule is simultaneously cata

ISSN:0038-9056    

DOI:10.1002/star.19870390207

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

摘要:

AbstractCarbamatstärken sind Ester der Carbamidsäure. Sie enthalten, gebunden an die Glucoseeinheiten der Molekülkette, Carbamoyl als funktionelle Gruppe. CONH2ist durch Hydrolyse vom Stärkemolekül abspaltbar. Das dabei äquivalent freigesetzte Ammoniak wird mit Wasserdampf in vorgelegte Borsäure destilliert und mit 0,05‐MSchwefelsäure titrimetrisch bestimmt. Aus dem Analysenergebnis kann der durchschnittliche Substitutionsgrad und Veresterungsgrad des Derivates berechnet werden.Die Wirksamkeit der Analysenmethode wird an zwei Urethanen, einer Carbamatstärke und einer Carbamatphosphatstärke dargelegt, die Reproduzierbarkeit durch den Wiederholstreubereich g

ISSN:0038-9056    

DOI:10.1002/star.19870390208

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

摘要:

AbstractGlucose isomerase was produced fromStreptomyces phaeochromogenesby aerobic fermentation at 28°C for 24 h. The crude enzyme was obtained by disintegrating the harvested cells. Ammonium sulphate at a saturation of 0.65 gave the maximum enzyme recovery 89.4%) from the crude extract, while acetone gave 66.4% at a concentration of 3/1 (v/v). The crude enzyme extract was purified by concentration, dialysis, precipitation with ammonium sulphate, passing through a column of Amberlite, and then the eluate was treated with acetone to precipitate the enzyme. The kinetic behavior was studied and it was found that optimumD‐glucose concentration was 0.8‐M. No change in Kmvalue was observed, while Vmaxwas affe

ISSN:0038-9056    

DOI:10.1002/star.19870390209

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

摘要:

AbstractMaltulose precursors are produced due to chemical isomerization of the reducing end glucose units during enzyme liquefaction and autoclaving of starch in the enzyme‐enzyme process of glucose manufacture. The precursors are hydrolyzed during subsequent saccharification with amyloglucosidase to form maltulose as one of the products. Temperature, pH and DE of the liquefied starch during autoclaving and α‐amylase treatment are important factors in controlling precursor formation, low temperature, low pH and low DE resulting in less maltulose formation. Acid liquefaction prior to saccharification does not result in maltulose precursor formation. Blocking of the reducing end glucose unit by hydrogenation to sorbitol prevents the formation of maltulose; maltitol is produced ins

ISSN:0038-9056    

DOI:10.1002/star.19870390210

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

ISSN:0038-9056    

DOI:10.1002/star.19870390211

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY