摘要:

AbstractThe starch granules of buffalo gourd contained 30.5% apparent amylose, showed a high swelling power and gelatinised over 57‐70.8°C with an enthalpy of 4.26cal·g−1. The starch pastes had a stable peak viscosity with a resistance to fragmentation intermediate to those of cassava and potato starches during holding at 95°C. The starch gels displayed a higher storage modulus (G′) than that of corn starch and a viscous character similar to that of potato starch. These properties differ from the maize‐like characteristics reported for this type

ISSN:0038-9056    

DOI:10.1002/star.19950471102

出版商:WILEY‐VCH Verlag GmbH    

年代:1995

数据来源: WILEY

摘要:

AbstractIsolation, carbohydrate make‐up and rheological characteristics of galactomannan of the sesbania seeds have been investigated. The galactomannan gum yield was 36.5±1.5%, on whole seed basis. The galactomannan had [a]D30+46.5°, on acid hydrolysis yielded galactose and mannose in the proportion of 1.2:2.2. Rheological properties of aqueous solutions of the galactomannan were investigated over a wide range of shear rates. The power law model, T=KDn, was employed to describe flow behaviour of the galactomannan. The magnitude of flow behaviour index ‘n’ values lower than 1.0, and found to decrease as the concentration increased, indicating pseudoplastic flow. Similarly, consistency index (K) values were increased with increased concentrations of galactomannan. Thus, the galactomannan exhibited good thickening c

ISSN:0038-9056    

DOI:10.1002/star.19950471103

出版商:WILEY‐VCH Verlag GmbH    

年代:1995

数据来源: WILEY

摘要:

AbstractResearch over the past three decades has greatly increased our understanding of the biochemical genetics of various waxy (wx) alleles of maize, but our knowledge about the structure and physicochemical properties of endosperm starches obtained from the wx alleles is still incomplete. We further investigated the structure and physicochemical properties of endosperm starches from a wx allelic series and their normal counterparts in the Oh43 inbred background.Starch granules were prepared from mature kernels of wx mutant alleles; wx‐C31, wx‐R, wx‐90, wx‐a, wx‐B3, wx‐m‐1, wx‐m‐8, and wx‐S5, and their respective normal counterparts in the inbred Oh43 maize background. Measurements of absorption spectra of starch‐iodine complexes and by gel permeation chromatography of Pseudomonasisoamylase‐debranched starches showed that all of the starches from the wxallelic series were uniquely waxy type in characteristics, and their normal counterparts were characteristically normal type. Pasting characteristics of starch granules and retrograded starches of the wxallelic series and their respective normal counterparts were investigated by differential scanning calorimetry (DSC). The peak temperature (Tp) and conclusion temperature (Tc) values from starches of the wxallelic series were slightly higher than those of their respective normal counterparts and the ΔHs of starches of the wxallelic series were greater than those of their respective normal counterparts. The onset temperature (To), Tp, and Tc of all retrograded starches were very similar, however, the ΔHs of the retrograded starches of the wxallelic series were greate than those of their respective normal counterpart. Starch granules of the wxallelic series were hydrolyzed more rapidly than those of their respe

ISSN:0038-9056    

DOI:10.1002/star.19950471104

出版商:WILEY‐VCH Verlag GmbH    

年代:1995

数据来源: WILEY

摘要:

AbstractThe influence of shear rate and concentration on the viscosity of solutions of native potato starch in water was investigated. The concentration dependence of viscosity was expressed by the Huggins equation with shear rate independent intrinsic viscosity. On the other hand the Huggins parameter is strongly influenced by the shear rate and decreases with the reciprocal square root of increasing shear rate in the range from 50.1/s to 1000‐1/

ISSN:0038-9056    

DOI:10.1002/star.19950471105

出版商:WILEY‐VCH Verlag GmbH    

年代:1995

数据来源: WILEY

摘要:

AbstractPotato starch has been hydrolysed lowering the molecular mass. The influence of starch molecules mass on the mechanical properties of thermoplastic starch has been investigated. Acid hydrolysis was performed with hydrochloric acid in various concentrations and time spans. Acid hydrolysis of the granular potato starch decreased both the molecular mass of amylose and amylopectin. The thermoplastic materials have been made by extrusion processing of the various starches with fixed amounts of water and glycerol.The stress‐strain properties showed to be influenced by molecular mass. The materials were rubbery at 20°C and 60% relative humidity. Although the tensile stress did not change significantly, the elastic modulus increased with an decrease in molecular mass. This increase was explained by differences in starch structure and morphology. The higher of the low molecular mass materials could result in a more rapid starch structural ordering. The elongation and tearing energy increased with incrasing molecular mass. Theses effects were explained by the higher amylose chain length and amylopectin endgroups chain length resulting in a more entangled polymer matr

ISSN:0038-9056    

DOI:10.1002/star.19950471106

出版商:WILEY‐VCH Verlag GmbH    

年代:1995

数据来源: WILEY

摘要:

AbstractBy reaction of phosphorylase with D‐glucal and inorganic phosphate instead of the natural substrate α‐D‐glucosyl phosphate novel 2‐deoxy‐maltooligosaccharides could be synthesized. Their properties and characterization by NMR spectroscopy, mass spectrometry and HPLC are described. Under similar conditions, except a higher phosphate concentration, 2‐deoxy‐α‐D‐glucosyl phosphate is obtained. This can also serve for the enzymatic elongation of the primer with 2‐deoxy‐glucosyl residues. The unnatural 2‐deoxy‐maltooligomers could be applied successfully as substrates for the exo‐cleaving enzym

ISSN:0038-9056    

DOI:10.1002/star.19950471107

出版商:WILEY‐VCH Verlag GmbH    

年代:1995

数据来源: WILEY

摘要:

AbstractThis paper reviews the main features of glucoamylase research describing essentially more recent developments on microorganisms, production and properties of glucoamylases. It is an important industrial enzyme and is widely used in starch saccharification, brewing and distilling industry. Glucoamylase can be derived from a wide variety of sources including plants, animals and microorganisms. Most of the production techniques essentially, however, are based on microbial sources. It is an extracellular enzyme and has got second place (next to proteases) in world's distribution and sales among industrial enzymes. Most of the production of glucoamylase is carried out using liquid fermentation process. Technique of solid state fermentation, however, have also been employed for its production and recently this technique is gaining renewed interest from researchers for its production. The paper also describes aspects related with the purification and characterization of glucoamylase enzyme.

ISSN:0038-9056    

DOI:10.1002/star.19950471108

出版商:WILEY‐VCH Verlag GmbH    

年代:1995

数据来源: WILEY

ISSN:0038-9056    

DOI:10.1002/star.19950471109

出版商:WILEY‐VCH Verlag GmbH    

年代:1995

数据来源: WILEY

ISSN:0038-9056    

DOI:10.1002/star.19950471110

出版商:WILEY‐VCH Verlag GmbH    

年代:1995

数据来源: WILEY

ISSN:0038-9056    

DOI:10.1002/star.19950471111

出版商:WILEY‐VCH Verlag GmbH    

年代:1995

数据来源: WILEY