摘要:

Abstractβ‐Limit dextrins were isolated from smooth pea starch. It was shown by gel chromatography that the sample contained smaller limit dextrins with a degree of polymerization (D.P.) of 40–4000 in addition to high‐molecular‐weight material. The smooth pea starch and the β‐limit dextrins were hydrolysed by the α‐amylase of B. amyloliquefaciens and the molecular weight distribution of the reaction mixtures was analysed on Sepharose CL 6B. Initially the reaction was fast, but at later stages branched dextrins with 10–60 were only very slowly hydrolysed further. In addition, linear dextrins with d.p. 2–10 were formed continously. Based on the branched dextrins produced from the β‐limit dextrins a model of the structure of the amylopectin component in smooth pea starch is suggested, in which clusters of defined sizes are reg

ISSN:0038-9056    

DOI:10.1002/star.19930451102

出版商:WILEY‐VCH Verlag GmbH    

年代:1993

数据来源: WILEY

摘要:

AbstractStarch granules were isolated from rice endosperms of twenty mutants, included two kinds of shrunken (shr) mutant, and two cultivars of their normal counterparts. Theshrmutants, EM‐20 and Kenkei 2088, showed opposite effects on the amylose content, that is, EM‐20 had 5% higher than its normal counterpart and Kenkei 2088 had 3% lower than its one. The amylopectin of EM‐20 was composed of slightly shorter chains on the average than its normal one. The gelatinization temperature and heat of gelatinization were affected by the mutation ofshr, EM‐20. The amylose extender (ae) mutant, Kenkei 2064, had a comparable amylose content with its normal counterpart but its amylopectin had higher content of long chain than the normal one. Twelve kinds of dull (du) mutant reduced the amylose content which varied from 2%

ISSN:0038-9056    

DOI:10.1002/star.19930451103

出版商:WILEY‐VCH Verlag GmbH    

年代:1993

数据来源: WILEY

摘要:

AbstractCooking of starch is traditionally achieved by supplying sufficient thermal energy to it as in baking and broiling processes. Whereas in extrusion cooking, both thermal and shear energy are usually present in doing the job. The relative importance of each of the two energy sources are difficult to assess in the process. The interactions between water and the anhydroglucose unit of the starch are discussed. The kinetics of starch conversion to cooked starch at excess or limited water contents are reviewed. Calorie per calorie, shear energy is more efficient in cooking starch than thermal energy. And shear energy alone, without thermal energy input, can cause cooking of starch if the energy level is high enough. In order to capitalize on the effect of shear energy on starch cooking, running the extruder at low temperatures, say lower than 50°C is recommended

ISSN:0038-9056    

DOI:10.1002/star.19930451104

出版商:WILEY‐VCH Verlag GmbH    

年代:1993

数据来源: WILEY

摘要:

AbstractMolecular status of starch in ready‐to‐eat breakfast cereal foods and its relationship with cereal produkt functional properties such as water solubility index and water absorption index were studied. Gel chromatographic separation of cereal product polymers dispersed in DMSO gave three major fractions. Factions I and II reflected starch content, whereas Fraction III reflected the sugar content in the product formulation. Contents of Fraction I, II and III varied from 0.31 to 3.53 mg, 0.06 to 2.82 mg, and O to 4.63 mg, respectively. Water absorption index increased while water solubility index decreased with increasing Fraction I or Fraction II contents. Conversely, water absorption index decreased whereas water solubility index increased with increasing Fraction III content. Iodine blue values showed that Fraction I and Fraction II mainly composed of amylopectin and amylose, respectively. λmaxvalues of Fraction I and II varied from 511 to 584 nm, 490 to 661 nm, respectively. Iodine binding capacity which was indicative of the amount of amylose present, varied from 0.37% (Kellogg's Corn Flakes) to 2.84% (Kellogg's Honey Sma

ISSN:0038-9056    

DOI:10.1002/star.19930451105

出版商:WILEY‐VCH Verlag GmbH    

年代:1993

数据来源: WILEY

摘要:

AbstractWhen cationised starch containing inorganic water‐soluble salts is used in manufacture papermaking, salts that are not retained in the fibre web will accumulate in the white water of the paper machine. When the white water is recirculated, the inorganic salts are carried into the paper machine's process water. The presence of these salts in the process water constitutes a potential detrimental factor in paper‐making.Point analysis of cross‐sections of granules of dry and wet‐cationised starch with a scanning electron microscope (SEM) and an energy‐dispersive X‐ray microanalyser (EDXA) revealed that the Cl content in dry‐cationised granules was lowest in the central part of the granule (0.8%), higher at the layer under the surface (1.3%) and highest in the surface of the granule (2.5%). The starch sample contained on average (chemical analysis) 1.21% Cl, 0.43% Si and 0.58% Ca. The Cl content in cross sections of starch granules cationised in a water slurry proved to be the same in both the centre and the surface of the granule (0.4%). Chemical analysis of the starch sample revealed no Si and C

ISSN:0038-9056    

DOI:10.1002/star.19930451106

出版商:WILEY‐VCH Verlag GmbH    

年代:1993

数据来源: WILEY

摘要:

AbstractIn response to an increasing demand from consumers for healthier and calorie controlled foods, Cerestar has developed a new food ingredient, erythritol. Erythritol can be produced from starch by a full biotechnological process, combining enzymatic and fermentative conversions. The use of an osmophilic yeast allows the fermentation step to be performed at high dry substance, giving an economic advantage. An extremely pure end product is then easily obtained by final crystallisation.Erythritol is structurally a polyol and shares the health properties of other polyols such as being toothfriendly and safe for diabetics. However, it offers in addition two very important nutritional advantages: a lower calorific value (0.3 Kcal/g) and a good tolerance. This is due to its low molecular weight, which allows erythritol to be rapidly absorbed from the small intestine, with subsequent excretion in the urine. Fermentation in the colon is therefore excluded and any resulting gastro‐intestinal discomfort avoided. The combination of these properties makes erythritol a unique low calorie bulk sweetener.From a functionality point of view, erythritol is a moderately sweet bulking agent with a cooling taste: workability is similar to other polyols. It has a taste profile close to that of sucrose and may therefore improve the taste quality of a blend with intense sweeteners. Its low solubility and ease of crystallisation, make erythritol very suitable for applications which require a crystalline sweetener, such as chocolate. Other potential application areas are bakery, table‐top and confectionery.Presently erythritol is under evaluation to establish beyond any doubt its safety and to obtain food approval as a new, low calorie, bulk sweetener.Potential non‐food applications of erythritol are in polymers, fine chemicals and pharmaceutical intermed

ISSN:0038-9056    

DOI:10.1002/star.19930451107

出版商:WILEY‐VCH Verlag GmbH    

年代:1993

数据来源: WILEY

摘要:

AbstractNuclear Magnetic Resonance (NMR) spectroscopy was used to probe the primary structure of the glucan pullulan. Carbon‐13, proton and phosphorus‐31 NMR spectra in aqueous solution of the intact poly‐saccharide obtained from three different sources indicate that significant structural differences can occur among these samples. In particular, two samples consist solely of α(1 → 6) linked maltotriose units, in accord with the generally accepted structure. However a third sample has fewer α(1 → 6) linkages and appears to consist of higher α(1 → 6) linked maltooligosaccharides in addition to maltotriose. Unlike the other samples, this sample was also phosphorylated. Enzymatic digestion of pullulan followed by NMR spectroscopy using pullulanase confirmed these results, as did HPLC analysis of the resulting digest, which showed the presence of maltooligosaccharides consisting of ten and more glucose units. However, HPLC analysis of acid hydrolysed pullulan indicated that no sugars other than glucose were present in any of the sa

ISSN:0038-9056    

DOI:10.1002/star.19930451108

出版商:WILEY‐VCH Verlag GmbH    

年代:1993

数据来源: WILEY

ISSN:0038-9056    

DOI:10.1002/star.19930451109

出版商:WILEY‐VCH Verlag GmbH    

年代:1993

数据来源: WILEY

ISSN:0038-9056    

DOI:10.1002/star.19930451110

出版商:WILEY‐VCH Verlag GmbH    

年代:1993

数据来源: WILEY

ISSN:0038-9056    

DOI:10.1002/star.19930451111

出版商:WILEY‐VCH Verlag GmbH    

年代:1993

数据来源: WILEY