摘要:

AbstractDefiniert aufgebaute Modellsubstanzen können zum Verständnis der Eigenschaften der Stärke beitragen. Geeignete lineare und verschiedenartig verzweigte Produkte mit Amyloseketten einheitlicher Länge werden durch phosphorolytische Synthese mit freien und trägergebundenen Maltooligomeren als Starter hergestellt.Der erste Teil dieser Arbeit gibt einen Überblick, in welcher Weise Löslichkeit, Retrogradation und Gelbildung durch Kettenlänge, Kettenlängenverteilung und Verzweigungsdichte beeinflußt werden, und welche Folgerungen sich für die speziellen Beiträge der natürlichen Stärkekomponenten ergeben.Im zweiten Teil wird über Untersuchungen an reinen Maltooligomeren berichtet, die die synthetischen Modelle im kurzkettigen Bereich ergänzen. Die Röntgen‐Pulveraufnahmen der aus wäßriger Lösung ausgefallenen Proben zeigen den B‐Typ im Bereich DP 20 bis 13, den A‐Typ im Bereich DP 12 bis 10. Die Grenze zur Retrogradation und Kristallisation scheint bei DP 8 bis 9 zu liegen. Bei diesen reinen Substanzen wird der C‐Typ nicht beobachtet. Die Ergebnisse lassen vermuten, daß zwischen der Länge der Amylopektinzweige, die von den Clusterregionen ausgehen, und dem Röntgentyp ein möglicher Zusammenhang besteht. – In Gegenwart von Amylose werden aus iodidfreier Iodlösung langsam I3‐‐Ionen gebildet. Entsprechende Untersuchungen an der Serie von Maltooligomeren zeigen, daß die I3‐‐Bildung korreliert ist mit der Tendenz zur Helix‐Bildung, wie zu erwarten war. In dieser Reihe nimmt Maltotriose eine Sonderstellung ein und verhält sich ähnlich aktiv wie α‐Cyclodextrin. Dieser Befund legt nahe, daß beide Substanzen in

ISSN:0038-9056    

DOI:10.1002/star.19860381202

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY

摘要:

AbstractA number of explanations for the melting behavior of starch in excess and limited water have been offered, none of which appears to be totally satisfactory. Most explanations do not account for the fact that gelatinization starts at the hilum and proceeds to the exterior of the granule. In limited water, starch gives two melting peaks with the differential scanning calorimeter. This has been explained on the basis of the granule limiting water to the crystallites. However, it was found that amylopectin crystallized from soluble material also gave a two‐peak melting pattern in low water very similar to that found with total starch. Thus, the granule structure is not responsible for the two‐peak melting of sta

ISSN:0038-9056    

DOI:10.1002/star.19860381203

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY

摘要:

AbstractThermal analysis (TG, DTG and DTA) was carried out on wheat, rye and maize starch at low rate of temperature increase. The measurements are conducted in the air as well as under argon. Results are discussed together with those formerly published for potato starch. Differences in behaviour of starch depend on its origin and atmosphere applied.

ISSN:0038-9056    

DOI:10.1002/star.19860381204

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY

摘要:

AbstractThe location of amylose and amylopectin components and/or the degree of branching at the exterior of starch granules may influence the binding of F. I. T. C. labelled Concanavilin A. Waxy Maize starch granules and small starch granules from barley have a higher affinity for lectin than starch granules isolated from normal maize or large starch granules isolated from barley kernels. The binding of Concanavilin A to starch granules is shown to be cooperative and reversible.

ISSN:0038-9056    

DOI:10.1002/star.19860381205

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY

摘要:

AbstractIt was found that steeping of corn grains by circulating the corn grains with the steeping liquor is more efficient for removing the water‐soluble components and decreasing the steeping period compared to the usual counter‐current met

ISSN:0038-9056    

DOI:10.1002/star.19860381206

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY

摘要:

AbstractFrom pilot experiments (0,3–3,6 m3) and full scale application (300 m3) it is shown that the improved anaerobic fluid bed technology represents a very reliable and compact high‐rate technology for the purification of highly fluctuational industrial wastewater. A two‐stage process (acidification/methanation) appeared to have advantages with respect to process stability as well as purification capacity. On full scale the average purification capacity, reached six months after start‐up, was 28 kg COD/m3day (based on the volume of the methane reactor), with peaks of 50 kg COD/m3day. Further increases in capacity may be expected in the

ISSN:0038-9056    

DOI:10.1002/star.19860381207

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY

摘要:

AbstractEnzyme preparation obtained cultivatingAspergillus ustuson rice straw‐wheat bran mixture (7:3) possessed cellulase,D‐xylanase, β‐D‐glucosidase, α‐amylase, amyloglucosidase and pectinase activities. Used at 2% level with tapioca starch residue (TSR) slurry gelatinized at 80°C or pressure cooked, it yielded 45–60% reducing sugar and degraded 52–65% of the fiber material. Enhanced saccharification (72%), fiber degradation (75%) could be achieved by pretreating the substrate with mineral acid. Fermentation of the hydrolysates withSaccharomyces cerevisiaeproduced 29–36 ml alcoholper100 g of sun dried TSR. Data on TSR hydrolysis by α‐amylase and amyloglucosidase,A. ustusenzyme preparation individually and in combination with amyloglucosidase, in acid pretreated or untrea

ISSN:0038-9056    

DOI:10.1002/star.19860381208

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY

摘要:

AbstractMixed linkage β‐glucane and pentosanes (mainly arabinoxylanes) are the major endosperm cell‐wall polysaccharides of barely and wheat respectively. These polysaccharides, although minor components of the whole grain, significantly affect the industrial utilization of these cereals. The modification of barley corns during malting requires the dissolution of the β‐glucane in the cell‐wall of the starch endosperm. High β‐glucane concentration in wort and beer effect the rate of filtration and can also lead to precipitate or gel formation in the final product. In a similar manner, pentosane is thought to cause filtration problems with wheat starch hydrolysates by increasing viscosity and by producing gelatinous precipitate which blocks filters. Ironically, it is this same viscosity building and water binding capacity which is considered to render pentosanes of considerable value in dough development and bread storage (anti‐staling functions). In the current paper, some aspects of the beneficial and detrimental effects of pentosanes and β‐glucane in the industrial utilization of wheat and barley are discussed. More specifically, enzymic methods for the preparation, analysis and identification of these polysaccharides and for the removal of their functional properties, are de

ISSN:0038-9056    

DOI:10.1002/star.19860381209

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY

ISSN:0038-9056    

DOI:10.1002/star.19860381210

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY

ISSN:0038-9056    

DOI:10.1002/star.19860381211

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY