ISSN:0038-9056    

DOI:10.1002/star.19920440102

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractThe present paper outlines the approach and principal results of a full‐fledged performance evaluation and functional analysis program conducted at the Egyptian Starch and Glucose Company that has been wholly documented elsewhere [12]. The ultimate goal of the program is to come up with well‐defined and appropriate courses of action to improve products quality, plant productivity and overall economy. The paper also reports the results of additional computer work that has been undertaken to enhance the applicability of the results. The adopted methodology for applying the developed computer material balance (MASSBAL) in the evaluation program and in analysing the impacts of stepwise improvements in the individual plant sectors of concern is also presen

ISSN:0038-9056    

DOI:10.1002/star.19920440103

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractRye starch shows the typical inhibited swelling behaviour of triticeae starches with an onset of swelling at rather low temperature (50–55°C). Swollen rye starch granules exist as individuals even after swelling at 100°C. The total dispersion of rye starch needs temperatures above 120°C with pressure cooking. On heating of the rye starch suspension preferentially amylose is leached. Defatting of rye starch exhibits no influence on swelling power but results in higher solubility and in increased amylose leaching. The drying procedures applied here resulted in stronger assoziation of the polymer molecules in the starch granule leading to higher swelling temperatures and a reduced solubility. Shiftings of the crystalline/ amorphous‐ratio of the starch granules as caused by different drying procedures, had no influence on the results of swelling power investigation but the highest swelling enthalpy as well as Brabender viscosity were exhibited by a sample dried at room temperature. It is proved to be possible to change the swelling behaviour of rye starch to “potato starch type” by slight chemical modification like s

ISSN:0038-9056    

DOI:10.1002/star.19920440104

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractIt was investigated whether the degradability of starch could be predicted by differential scanning calorimetry (DSC). Degradation of potato starch with a varying degree of gelatinization. of isolated starch of different origins, and of raw materials differing in origin and technological treatment was determined with α‐amylase and bovine ruminal fluid. Gelatinization enthalpy and the gelatinization temperature of starch were determined by DSC.There was a good correlation between gelatinization enthalpy measured by DSC and degradation with α‐amylase and ruminal fluid for potato starches with varying degrees of gelatinization and for isolated starch granules of different origins. For raw materials of different origins there was a good correlation between gelatinization enthalpy and degradation with α‐amylase, whereas the correlation between gelatinization enthalpy and degradation with ruminal fluid was poor. There was a good correlation between gelatinization enthalpy and degradation with both α‐amylase and ruminal fluid for (technologically treated) raw materials of one and the same origin. There was no relation between starch degradation and gelatinization

ISSN:0038-9056    

DOI:10.1002/star.19920440105

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractA spectrophotometric method for the determination of iodine binding capacity (IBC) for amylose, amylopectin and starch on a microscale is developed. It is based on the observation that free iodine (I3) can be determined fairly accurately by recording the absorbance at 286 nm. By using a constant volume titration method, bound iodine is calculated by subtracting the free iodine from the total iodine. A plot of free iodine vs bound iodine shows an inflection, which on extrapolation gives the bound iodine. The IBC values obtained by this method are in good agreement with those obtained by conventional potentiometric and amperometric methods.

ISSN:0038-9056    

DOI:10.1002/star.19920440106

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractWith the purpose of obtaining animalarial prodrugs, oxidized starch derivatives with antimalarials were prepared. Imines with one drug, sulfonamide or pyrimidine, were synthesized and submitted to usual spectrometric analysis, IR. UV and1H NMR. With these analysis it was concluded that the following compounds were obtained: derivatives of sulfamethoxazole(ML7), sulfisoxazole(ML8) sulfameter(ML11) and trimethoprim(ML13). Only sulfameter derivative was curative in 100% of mice infected with Plasmodium berghei at 50 mg/weight kg dosis.

ISSN:0038-9056    

DOI:10.1002/star.19920440107

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractWe have prepared raw starch digesting amylase fromPenicillium brunneum, which is similar to other raw starch digesting enzymes, and is effective in hydrolyzing raw cereal starches, but not effective for raw sago starch and raw root starches. Treatment of sago starch granules before incubation with the enzyme by heating to below gelatinization temperature at low pH condition was effective in improving the hydrolysis. Observation by scanning electron microscope showed that structure of treated sago starch granules at 60°C pH 2.0 for 2h was not changed. Observation under polarized light showed the birefringence clearly was preserved. However, viscosity of treated sago starch granules decreased. After incubation with the enzyme, untreated starch granules corroded and several holes were seen on the surface of granule. Enzyme action on the treated starch granules resulted in much higher intensity of degradation and the holes deepened into the interior of granules. Analysis of the product of this process showed that mainly glucose was produced from the hydrolysis of treated or untreated sago starch granules by crude enzyme. But on gelatinized sago starch other types of sugars were formed during enzyme reaction

ISSN:0038-9056    

DOI:10.1002/star.19920440108

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractTo estimate the degrees of starch retrogradation in the complex foods, an enzymatic method using α‐amylase fromBacillus subtiliswas proposed in the previous report (Tsuge, H.et al.: Starch/Stärke42(1990), 213–216). However, actual digestibility of the enzyme for the native starch granules was not checked at that time. A comparative study to see the digestibility of native starch granules was carried out using four different α‐amylase preparations and digestion of retrograded wheat starch was tested by two α‐amylase preparations. Pancreas α‐amylase preparation digested some native starch granules to a great extent, whileAspergillus oryzaeenzyme did not digest native starch granules virtually. In conclusion, α‐amylase preparation fromA. oryzaewas an ideal enzyme as the tool to distinguish between raw and gelatinized starches. It was justified for the use ofA. oryzaeenzyme as well asB. subtilisα‐amylase to evaluate the retrograded starch contents

ISSN:0038-9056    

DOI:10.1002/star.19920440109

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractThree crude glucoamylase preparations fromRhizopussp.,Chalara paradoxaandAspergillussp. K‐27 were used to determine the digestibility of raw starches from eight sweet potato varieties. Granule sizes and amylose contents were also measured. The average granule sizes ranged between 10.5 and 14.2 μm. The amylose contents varied between 18.2 and 21.8%. The hydrolysis rates for the raw starches by any of the three glucoamylases were similar. However, starch of the variety Hi‐starch had a slightly lower hydrolysis rate than other starches whenRhizopussp, enzyme was

ISSN:0038-9056    

DOI:10.1002/star.19920440110

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY

ISSN:0038-9056    

DOI:10.1002/star.19920440111

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY