摘要:

AbstractCharacterization of Potato Phosphorylase by Ultracentrifugation and Gel Permeation Chromatography.Potato phosphorylase was characterized by ultracentrifugation and gel permeation chromatography. The sedimentation constant was determined by sedimentation transport measurements at protein concentrations of 2 to 20 mg/ml. Using the equation of Scholtan the molecular weight of phosphorylase was found to be 200 000. The same value was obtained by gel permeation chromatography.In all experiments the phosphorylase behaved as a homogeneous component, whereas the measurements of sedimentation equilibrium showed a concentration dependence of the molecular weight indicating dissoziation of the phosphorylase protein into two components with a molecular weight of each 90 000. As the dissoziation of the phosphorylase into two subunits didn't bring about either an inactivation or a change of the specific activity the existence of an enzymatically active protein with a molecular weight of 90 000 is to be assumed.

ISSN:0038-9056    

DOI:10.1002/star.19720240202

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY

摘要:

AbstractIn the course of a series of thermo‐analytical investigations on amylose, attention has been focused on the acid salt catalysts. Studies on the sequence and nature of the chemical changes occuring in amylose during heating have been carried out by using differential thermal analysis (DTA) and thermogravimetric analysis (TGA).A strongly exothermic reaction, with some nitrate salts, was observed accompained by a rapid weight loss, not characteristic of any one of the substances in the mixtures. The exothermic decomposition could be explained as an oxidative attack of NO2on amylose, the former being produced by thermal decomposition of the nitrate salt. The kinetic parameters obtained from DTA are in accord with the results derived from TGA for the catalytic decomposition of amylos

ISSN:0038-9056    

DOI:10.1002/star.19720240203

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY

摘要:

AbstractDetermination of Phosphate in Starch Phosphates.The knowledge of the total, free and bound phosphate is needed for an exact characterization of starch phosphates. For the determination of the total amount of phosphate, the decomposition of the sample is carried out with ethylene glycol and sodium peroxide in a micro‐steelcylinder under pressure. The determination of the free phosphate is made by the transformation of the excess of pyrophosphate and metaphosphate into orthophosphate with a separate weighed portion. The photometric determination of phosphorus in both cases takes place with vanadate‐molybdate‐reagent. The bound phosphate corresponds to the difference (Ptotal—Ptree) and is related to the average degree of substitution and esterification of the

ISSN:0038-9056    

DOI:10.1002/star.19720240204

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY

摘要:

AbstractNinteen promising strains of fodder sorghum were selected for the present study. The starch content in the seed varied from 42.68 to 68.31%, total sugars from 3.13 to 7.81%, mineral matter from 1.12 to 4.09%. The amylose content was approximately in the range of 12 — 13% and amylose : amylopectin ratio was 1:4 to 1:10. The tannin content ranged from 0.23 to 3.73 mg/g of seed and it was high in non sweet varieties and low in sweet varieties. There was not much difference in the sugar content of sweet and non sweet varieties. The protein content of the seed varied from 8.31 to 14.41%. Starch content of seed was significantly negatively correlated with tannin and mineral matter content of the seed (−0.595 and −0.491) but tannin content was positively correlated with mineral matter content and was significant ( + 0.581). A genetic manipulation of breeding material can bring about high amylose and protein vari

ISSN:0038-9056    

DOI:10.1002/star.19720240205

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY

摘要:

AbstractThe starches of the species of Dioscorea that have been studied are composed of granules of different sizes and shapes. The average iodine affinity is 4.6% so, the amylose content is not very high. The values of the free‐swelling power and solubility and the quick and progressive solubilization in DMSO suggest a heterogeneous structure, with weak linking forces and a low degree of association inside the granules. The Brabender viscosity curves are very similar to the ones of the bread‐fruit starch, exception made to the cold paste viscosity. The properties of the starches of those species of Dioscorea suggest useful applicati

ISSN:0038-9056    

DOI:10.1002/star.19720240206

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY

摘要:

AbstractThe Absolute and the Relative Gelatinization Characteristics of Starches.Part. 2. Relative Measuring of Viscosity by Special Wing Stirrer and the Influence of Amylolytic Enzymes on the Viscogram. The procedure of relative viscosity measurings of starches in the steeping and gelatinization phase by means of a special wing stirrer are described and the measuring results are discussed regarding the viscograms of potato, maize and wheat starch. Examples are given for the viscosimetric measuring of enzyme action. Especially the influence of α‐ and β‐amylase, of amyloglucosidase and papain on the relative viscograms of potato, maize and wheat starch is exa

ISSN:0038-9056    

DOI:10.1002/star.19720240207

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY

ISSN:0038-9056    

DOI:10.1002/star.19720240208

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY

ISSN:0038-9056    

DOI:10.1002/star.19720240209

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY

ISSN:0038-9056    

DOI:10.1002/star.19720240210

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY

ISSN:0038-9056    

DOI:10.1002/star.19720240212

出版商:WILEY‐VCH Verlag GmbH    

年代:1972

数据来源: WILEY