摘要:

AbstractThe quantity variations and the structural changes of the α 1,4 —α 1,6 glucopolysaccharides contained in the endosperm of sweet corn, waxy and amylose extender maize genotypes, were studied during early germination. The α 1,4 —α 1,6 glucopolysaccharides were fractionated according to their branching degree.The results obtained showed that: the degradation pattern of the α 1,4 —α 1,6 glucopolysaccharides was similar for the different corn genotypes studied. In addition, soluble dextrins or partial degradation products were not detected, but reducing sugars were accumulated. Furthermore, the structure of the remaining polysaccharides was similar to those present in the non germinating seed.These results led us to propose that once a polysaccharide molecule was used as the substrate by degradative enzymes during germination, that molecule was total

ISSN:0038-9056    

DOI:10.1002/star.19930450602

出版商:WILEY‐VCH Verlag GmbH    

年代:1993

数据来源: WILEY

摘要:

AbstractCorn grains with different filling times were fractionated in order to obtain their α 1,4 — α 1,6 glucopolysaccharide composition and structure. Sugary, waxy, flint and several hybrids were the varieties analyzed.There is an increase in the total content of polysaccharides, as the grain is completed. But, no differences in composition and structure were detected between the first sample analyzed (15th day after pollination) and the last one, which corresponds to the complete grain filling period.The methodology developed by us, allowed us to observe that the introduction of su character on the hybrids (F x S and S x F) has influence on the final polysaccharide structure. Also, in the F x W hybridα 1,4 — α 1,6 glucans, their structural characteristics were different from those of F or

ISSN:0038-9056    

DOI:10.1002/star.19930450603

出版商:WILEY‐VCH Verlag GmbH    

年代:1993

数据来源: WILEY

摘要:

AbstractDNA sequence fromAspergillus oryzaegenome which, confers on pOK‐1 the ability to replicate autonomously inSaccharomyces cerevisiaeis described. A hybrid plasmid pOK‐1 was constructed from pBR325 and YEp13 fragment containing Leu2+gene.Asp. oryzaeDNA and pOK‐1 were cleaved withBamHI, ligated and introduced intoEscherichia coli.About 600 recombinant plasmids were obtained. One of them transformsS. cerevisiaeSHY3 to Leu2+with middle efficiency. The plasmid designated as pSB1–2 contained twoBamHI fragments (4.3 kb and 4.1 kb) ofAsp. or

ISSN:0038-9056    

DOI:10.1002/star.19930450604

出版商:WILEY‐VCH Verlag GmbH    

年代:1993

数据来源: WILEY

摘要:

AbstractStarch was isolated from the seeds ofAmaranthus hypochondriacusandAmaranthus cruentusby two established methods and a new simpler method involving steeping in dilute alkali, neutralization, and ambient air drying without using expensive or highly hazardous chemicals. The latter is recommended for isolating amaranth starch for human food uses on a laboratory scale.

ISSN:0038-9056    

DOI:10.1002/star.19930450605

出版商:WILEY‐VCH Verlag GmbH    

年代:1993

数据来源: WILEY

摘要:

AbstractStarch isolated fromA. hypochondriacusandA. cruentuswas chemically modified by cross‐linking with phosphate. Native and modified starches from both species did not differ in crude protein or fat content and overall purity and contained about 90% amylopectin and 10% amylose. Phosphorus and ash contents were highly correlated (r = 0.98). Modification eliminated swelling power at 85°C and increased gelatinization temperature range, gel consistency, and peak and overall consistencies while decreasing resistence to mechanical breakdown, blue value and initial pasting temperature. Modification effects were greater forA. hypochondriacusthan forA. cruentusstarch. Acidification to pH 4.5 decreased overall viscosity more in modified than in native for

ISSN:0038-9056    

DOI:10.1002/star.19930450606

出版商:WILEY‐VCH Verlag GmbH    

年代:1993

数据来源: WILEY

摘要:

AbstractComplexes of amylose with various organic guest molecules have been studied by means of c. d. spectroscopy and microcalorimetry in aqueous solution. From the results the structure of the complexes and the mechanism of their formation are deduced. It is concluded that amylose can adjust its helix conformation to the shape and structure of the guest molecule included. Investigations about intramolecular and intermolecular crosslinking of amylose indicate that the complexing behaviour of amylose can be manipulated specifically.

ISSN:0038-9056    

DOI:10.1002/star.19930450607

出版商:WILEY‐VCH Verlag GmbH    

年代:1993

数据来源: WILEY

摘要:

AbstractThree types of cationic starches were preparedviareacting starch with 3‐chloro‐2‐hydroxypropyl amine, 1,1,1,n‐Tris(3‐chloro‐2‐hydroxypropyl) amine and glycidyl trimethyl ammonium acetate in presence of sodium hydroxide. The different factors affecting these reactions were investigated. These factors include sodium hydroxide/amine, amine/starch molar ratios, liquor ratio, reaction duration and temperature. The amination extent and amination reaction efficiency percent were traced by estimating the nitrogen content of the aminated starch. Characterization of the prepared cationic starches such as solubility, moisture content, anion‐exchange capacity and metal ions sorpti

ISSN:0038-9056    

DOI:10.1002/star.19930450608

出版商:WILEY‐VCH Verlag GmbH    

年代:1993

数据来源: WILEY

摘要:

AbstractOptimum ratio of glucoamylase to α‐amylase for synergistic hydrolysis of starch in corn flour was 1.8 AGU/1.0 KNU. The rate of hydrolysis of starch in dry milled corn was faster than that of waxy maize starch and wet processed corn. Hydrolysis of the starch in dry milled corn was the most efficient compared with that of wet milled, corn steeped in water or Na

ISSN:0038-9056    

DOI:10.1002/star.19930450609

出版商:WILEY‐VCH Verlag GmbH    

年代:1993

数据来源: WILEY

摘要:

AbstractDie Zusammensetzung der alkoholunlöslichen Substanzen (AUS) von Kartoffelpülpe wurde untersucht nach Einwirkung von verschiedenen pektolytischen und cellulolytischen Enzymen gefolgt von stärkeabbauenden Enzymen. Die Vorbehandlung mit Pektinase/Cellulase‐Kombinationen übt einen signifikanten Einfluß auf die Menge und die Eigenschaften des nach dem Stärkeabbau verbleibenden Rückstandes aus. Weiterhin ergeben sich hier die bedeutendsten Veränderungen in der Zusammensetzung der Rückstände nach Einwirkung der amylolytischen Enzyme. Es wird ein Zusammenhang zwischen dem Gehalt an Reststärke in den Rückständen und der Wirkung der zellwandabbauenden Enzyme gefunden. Der Gehalt an Reststärke korreliert negativ mti dem Zellwandabbau. Das bedeutet, daß die enzymatische Abbaubarkeit der Stärke wesentlich von der Beschädigung der Kartoffelpülpe‐Zellwand und in diesem Zusammenhang hauptsächlich vom Abbaugrad der Cellulose abhängt. Die Wasserbindungskapazität (WBK) nimmt nach Einwirkung von Pektinase/Cellulase‐Kombinationen intensiv ab. Die anschließende Behandlung mit amylolytischen Enzymen bewirkt nur gerin

ISSN:0038-9056    

DOI:10.1002/star.19930450610

出版商:WILEY‐VCH Verlag GmbH    

年代:1993

数据来源: WILEY

ISSN:0038-9056    

DOI:10.1002/star.19930450611

出版商:WILEY‐VCH Verlag GmbH    

年代:1993

数据来源: WILEY