摘要:

AbstractStarch xanthates of 0.11‐0.55 degree of substitution (D.S.) were reacted with low‐molecularweight polyamines – hydrazine, diaminoalkanes, stearylpolyamines, polyethylenamines, and polyethylenimines – to produce thiourethans. The progress of the reaction was followed by observing spectral absorption and viscosity changes. In many cases the reaction produced a gel with viscosity of 10,000‐60,000 cP. The magnitude of the viscosity varied directly with increasing xanthate D.S. Increased amino‐ to xanthate‐group ratios were necessary in the reactions with xanthates at the low end of the D.S. range to achieve much viscosity development as compared to the xanthates of highest D.S. The basicity of the amines was a factor in the rate and extent of reaction, the stronger amines being less reactive than the weaker ones.Solid products were precipitated from the gels by ethanol. Nitrogen and sulfur analyses and infrared and ultraviolet spectra were made with these solids. From those data the D.S. and amount of crosslinking in the products were calculated. The thiourethans had a D.S. that was approximately one‐half of the D.S. of the starting

ISSN:0038-9056    

DOI:10.1002/star.19700220802

出版商:WILEY‐VCH Verlag GmbH    

年代:1970

数据来源: WILEY

摘要:

AbstractStarch granules were labeled by exposure to tritium atoms produced by thermal dissociation of tritium gas at a tungsten filament. Activity was shown by α‐amylase etching experiments to be confined to the surface of the granule. Dextrins and low molecular weight compounds could be partially resolved on Sephadex G‐75. The dextrin produced during tritiation had an elution volume corresponding to dextrin of 20–35 glucose units and was hydrolyzeable by α‐amylase. Labeled starch was hydrolyzed first with ß‐amylase and the limit dextrin hydrolyzed further with α‐amylase. A comparison of the specific activities of the maltoses produced by the two enzymes demonstrated that labeling was more heavily concentrated in outer brunches than in inner branches. Amylose obtained from labeled potato starch was purified by crystallization and on DEAE‐Sephadex columns. The ion‐exchange purified potato amylose was hydrolyzed with ß‐amylase with 50% of the activity retained in maltose. Tritium was found to be concentrated at the nonreducing ends of the amylose molecules. These results suggest that starch molecules are organized in granules with nonreducing ends o

ISSN:0038-9056    

DOI:10.1002/star.19700220803

出版商:WILEY‐VCH Verlag GmbH    

年代:1970

数据来源: WILEY

摘要:

AbstractStarch pyrolysis was carried out in a hot gas stream to establish optimum conditions for the production of levoglucosan. Helium, nitrogen, and steam were used. Steam was most effective and convenient because of its high heat capacity and because it is easily condensed. Yields of levoglucosan increased as pressures decreased. The effect of temperature, feed weight, gas flow rate, reduced air pressure, and catalyst on the yield of levoglucosan is reported. Optimum operating conditions for the acid‐catalyzed process were established. A maximum yield of 44.5% levoglucosan was obtained from cornstarc

ISSN:0038-9056    

DOI:10.1002/star.19700220804

出版商:WILEY‐VCH Verlag GmbH    

年代:1970

数据来源: WILEY

摘要:

More Recent Results of our Research on Starch.The authors most important research results of the last decade have been compiled. Among those there are first of all works on the course of the starch degradation process as well as on the method for measuring molecular distribution, which had been specially designed for this purpose. As to the processes involved in hydrolytic starch degradation by acid, respectively amylases, mainly the different cleavage probabilities of the glucoside bonds have been examined. Determination of the kinetic constants during amylolytic degradation of starch added to elucidate the molecular degradation mechanism. Especially the ß‐amylolysis of a special amylose marked by14C has been examined more closely.The second research field consisted of the determination of the functional groups of potato phosphorylase, of the functional groups of the substrate as well as possible binary and ternary enzyme substrate complexes. On the basis of this theoretical enzyme research an enzymatic brewing technology has been developed, which is already being applied in several production plan

ISSN:0038-9056    

DOI:10.1002/star.19700220805

出版商:WILEY‐VCH Verlag GmbH    

年代:1970

数据来源: WILEY

摘要:

AbstractSodium disulphite (Na2S2O5) has a less active effect on the extraction of corn colloids. The crude protein content of the colloids amounts to a total of 35%.On the Question of Using Sodium Disulphite instead of Sulphurous Acid in Corn Starch Production.1Comparative examinations have been carried out on the composition of extracts, which had been abtained by steeping of corn in sulphurous acid, sodium disulphite solution and water, respectively.2It was found that the presence of chemical reagents in the solution used for the steeping of corn, increases the diffusion of extractive substances (especially of the high‐molecular ones) from the corn kernel into the steeping water. The most active reagent in this action is sulphurous acid because of its reducing properties and its faculty of increasing the permeability of the cell walls.1A certain difference in the effect of sulphurous acid and sodium disulphite solution on the colloidal matter of the corn kernel has been found. The highest total amount of colloidal matter extracted from the corn kernel occurred in the presence of sulphur dioxide. About 50% of the dry matter of the colloids (calculated as crude protein) consists of nitrogenous substances.Test data show that some more high‐molecular non‐nitrogenous substances are extracted from the corn in the presence of sodium disulphite (= sodium pyrosulphite or sodium metabisulphite).4It has been found that the positive effect of lactic acid during evaporation of the extracts consists not only in the formation of soluble lactates, but also in the fact that the high molecular nitrogenous substances are degraded to low‐molecular substances which do not precipitate during thickening of the extract.5Results of the technological testing of sodium disulphite showed that during the manufacturing of starch from corn it is possible to replace sulphur dioxide by this reagent in the steeping process according to the technological structure of th

ISSN:0038-9056    

DOI:10.1002/star.19700220806

出版商:WILEY‐VCH Verlag GmbH    

年代:1970

数据来源: WILEY

摘要:

Economical Methods of Constructing Drying Equipment for the Starch Industry.As the conditions that must be met in drying starch are well known, certain types of dryers are generally accepted in the starch industry. The various dryer designs and their operating criteria are discussed. The main subject of this paper ist the modern methods now employed in constructing dryers. Drying plants are composed of standardized assembly parts allowing manifold possibilities of combination and making the plant highly adaptable to requirements. The standardized assembly parts of the Flash Dryer and of a new type of contact dryer, the Solidaire, are presented. The system of preassembled units permits a differentiated allocation of tasks within the engineering divisions of machinery and equipment manufacturers. When handling a project the process engineer, with preassembled units at his disposal, will need only a minimum of creative design capacity for those parts which require adaptation to given conditions. The engineering division is thus free to dedicate itself to development work. The construction of a drying plant is standardized by a program of construction phases for which the impulse is given from the sales division. This way of handling projects has its bearing on prices and delivery periods to the advantage of both customers and manufacturers.

ISSN:0038-9056    

DOI:10.1002/star.19700220807

出版商:WILEY‐VCH Verlag GmbH    

年代:1970

数据来源: WILEY

ISSN:0038-9056    

DOI:10.1002/star.19700220808

出版商:WILEY‐VCH Verlag GmbH    

年代:1970

数据来源: WILEY

ISSN:0038-9056    

DOI:10.1002/star.19700220809

出版商:WILEY‐VCH Verlag GmbH    

年代:1970

数据来源: WILEY

ISSN:0038-9056    

DOI:10.1002/star.19700220814

出版商:WILEY‐VCH Verlag GmbH    

年代:1970

数据来源: WILEY

ISSN:0038-9056    

DOI:10.1002/star.19700220816

出版商:WILEY‐VCH Verlag GmbH    

年代:1970

数据来源: WILEY