摘要:

AbstractDuring a screening programme for amylase producing microorganisms a strain ofBacilluswas isolated which produced a maltogenic amylase which had possible industrial potential. Unlike the microbial β‐amylases fromB. cereus, B. megaterium, B. polymyxaandB. circulansthis enzyme was characterized by being stable at 60–70°C at pH 4.5.‐5.5. Unfortunately the microorganism proved to be difficult to cultivate. Using recombinant‐DNA techniques it was possible to transfer the gene, which coded for the enzyme, to a host organism which was easier to cultivate, thus making industrial production a viable proposition. The enzyme is suitable for producing high maltose syrups from liquefied starch. When used together with an amylopectin debranching enzyme such as pullulanase, more than 75% maltose can be obtained at

ISSN:0038-9056    

DOI:10.1002/star.19840361202

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

摘要:

AbstractSubject is a glucose isomerase immobilized on a SiO2‐carrier of defined structure which achieves a productivity of 1: 22000 (22 t TS [42% fructose] per kg enzyme) on standard process conditions. The process parameters (degree of isomerization, temperature, pH‐value, cofactors) as well as inhibitors will be discussed with regard to activity and productivity. The process example shows, that reactors only with a very small column volume are needed because of the high productivity in the isomerization plant. The process is suited for a large‐scale production of isoglucose

ISSN:0038-9056    

DOI:10.1002/star.19840361203

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

摘要:

AbstractThe method by which methanol is added to precipitate saponified starch‐g‐polyacrylonitrile (HSPAN) from an alkaline saponification mixture will influence the particle size of the polymer and thus the properties of the absorbent. Slow methanol addition, coupled with thorough mixing to ensure complete absorption of methanol by the reaction mass, will separate individual micron‐sized fragments of HSPAN gel and will yield a product with a small enough particle size to produce a smooth, tree‐flowing gel dispersion when added to water. This product is perhaps more suitable as a thickener than as a water absorbent. More rapid addition of methanol results in incomplete absorption by the reaction mass and causes individual gel fragments to coalesce to form millimeter‐sized chunks of water‐swollen HSPAN. Subsequent dewatering with excess methanol produces a granular product with good absorption properties. Gel‐blocking was reduced by adding either stearic acid or poly(vinyl acetate) to methanol‐pre

ISSN:0038-9056    

DOI:10.1002/star.19840361204

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

摘要:

AbstractThe relative contributions of cultivar, year and location to variation in wheat starch pasting properties were determined by pasting 44 undried prime starches, in the absence of amylases, at three concentrations using the “Minipaster”. The pasting parameter chosen for discrimination and the starch concentration used determined which factors appeared to determine variation. Various pasting ratios, intersection points and concentration response expressions were found no more useful in discriminating starches than were the simple pasting parameters usually measured. Overall, analyses of variance showed that cultivar was most important in determining variation in wheat starch pasting properties, and that year and location equally affected variation to a smaller degree. Differences due to year and location could be ascribed to unusual stresses on the growing wheat c

ISSN:0038-9056    

DOI:10.1002/star.19840361205

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

摘要:

AbstractDer Einfluß von Rindergülle in Kombination mit mineralischen Düngemitteln auf Knollenertrag, Trockensubstanzgehalt, Ertrag und Gehalt an Stärke sowie auf die Qualität der Stärke von Kartoffeln wurde untersucht. Alle Varianten, bei denen der Rindergülle noch N, P, K zugesetzt wurden, waren vom technologischen Standpunkt für die Erzeugung von Stärkekartoffeln mit gutem Knollenertrag und gutem Stärkegehalt geeignet. Die beste Variante war die einer Kombination aus Stroh und Rindergülle mit zugesetzten N‐, P‐, K‐Düngemitteln. Die Problematik der Wahl der besten Variant

ISSN:0038-9056    

DOI:10.1002/star.19840361206

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

摘要:

Abstractβ‐Cyclodextrin is an inclusion complexing agent produced on industrial scale. The low solubility of its complexes is a serious disadvantage in many cases. Substituted β‐Cyclodextrin derivatives are characterized by much higher solubility. Among methylated derivatives the heptakis‐di‐O‐methyl‐β‐Cyclodextrin deserves special attention. In its aqueous solutions many poorly soluble or practically insoluble compounds can be dissolved, whereas the solubility enhancement factor is between 3 and 1 200 depending on the substance. Aqueous injectable solutions can be prepared from highly lipophilic compounds, enzymatic reaction rate of lipophilic substrates can be strongly accelerated, biological absorption of drugs or fat‐soluble vitamins can be enhanced and vaccine production can be augmented up to 100‐fold. Methylated cyclodextrins are able to act as solvents by forming watersoluble inclusion complexes and as phase‐transfer catalysts at free radical polymerization. Low molecular cyclodextrin‐polymers with molecular weight between 2 000 and 10 000 behave similarly. They are very well soluble, retaining their complexing ability. On account of the macromolecular character the diffusion of dissolved and complexed substances is considerably decelerated. By including into a chiral cavity the entrapped molecules become optically active oriented, and therefore their reactions a

ISSN:0038-9056    

DOI:10.1002/star.19840361207

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

摘要:

AbstractA polarographic assay of cyclodextrins in turbid dextrin mixtures is described. The method is based on the ability of cyclodextrins to form complexes with linoleic acid and on the inability of soybean lipoxygenase to oxidize the complexed acid. The degree of complexation is measured with a simple Clark's electrode as a reduced rate of oxygenation of linoleate. Cyclodextrin concentrations down to 0.02–0.04‐mM can be assayed. The method is rapid to carry out because several successive samples can be added into a single lipoxygenase assay mixture. The method was applied to analyses of immobilized cyclodextrins as well as cyclodextrins in complex mixtures of starch and starch degrading enzymes. The conditions for spectrophotometric measurement of the reaction are also descri

ISSN:0038-9056    

DOI:10.1002/star.19840361208

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

ISSN:0038-9056    

DOI:10.1002/star.19840361209

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

ISSN:0038-9056    

DOI:10.1002/star.19840361210

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

ISSN:0038-9056    

DOI:10.1002/star.19840361211

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY