摘要:

AbstractPure, white starches were isolated in ∼30% yields from defatted sal and dhupa meals. Both starches consisted of granules of varying size and shape characteristics, and contained considerable amounts of protein and lipid constituents. C 18:1, C 16:0 and C 18:0 were the major fatty acids present in both free and bound lipid fractions; whereas the latter in addition contained C 18:2 (∼20%). Both starches exhibited two‐stage swelling in water; for sal starch the solubility was markedly lower but its swelling power was considerably higher. In DMSO the sal starch was readily soluble but not dhupa starch (only ∼20% solubility). The hot paste viscosity as well as set back viscosity of dhupa starch was much higher in comparison to those by sal starch. Very highly purified sal starch virtually exhibited no hot paste viscosity, and behaved like amylopectin‐rich material. The latter had only 1.5% amylose as against of ∼24% in original sal starch. X‐Ray powder patterns revealed sal starch to be of A‐type and dhupa starch to be of B‐type. Both the starch granules were susceptible forin vitroattack by human s

ISSN:0038-9056    

DOI:10.1002/star.19900420702

出版商:WILEY‐VCH Verlag GmbH    

年代:1990

数据来源: WILEY

摘要:

AbstractSouth American cultivated species of Chenopodium and Amaranthus have been studied. Qualitative optical methods, scanning electron microscopy and quantitative analytical microscopy have been used. Statistical tests have been applied to the results. The comparative study of pseudocereals perisperm starch grain morphology provides important characters for their identification. As a result, starch would be an element of high value in the determination of material recovered from archaeological sites in different preservation conditions or used in food elaboration.

ISSN:0038-9056    

DOI:10.1002/star.19900420703

出版商:WILEY‐VCH Verlag GmbH    

年代:1990

数据来源: WILEY

摘要:

AbstractSome grain properties of 20 starch mutants that were transferred from mutants of Japanese rices to IR36 (by two backcrosses to IR36) were studied. All had higher apparent amylose content (AC) and gelatinization temperature (GT) than the parent mutants, except the dull mutants, and the 82GFsugarymutant which had no amylose. All had lighter and lower density brown rices than IR36.Sugary82GF und EM5 had high free sugars, andsugaryand EM20shrunken‐1had high fat content. Phytoglycogen content of brown rice was 34% for 82GF and 7% for EM5sugarymutants.Amylose extendermutants had higher lysine in brown rice protein than IR36 parent. Alkali spreading value did not accurately estimate GT of these starch mutants. Milled rice of the two highamylose extendermutants 2064 and EM16 had lower Amylograph peak viscosity but higher cooked rice Instron hardness than IR36 milled ric

ISSN:0038-9056    

DOI:10.1002/star.19900420704

出版商:WILEY‐VCH Verlag GmbH    

年代:1990

数据来源: WILEY

摘要:

AbstractThe use of one‐dimensional Nuclear Magnetic Resonance (NMR) spectroscopy as applied to structural studies of starch, starch products and glycogen is reviewed. Proton, carbon‐13 and phosphorus‐31 NMR spectra of a range of starches and starch products are described. These spectra, particularly carbon‐13 NMR spectra, permit one to obtain structural information regarding these molecules. From the proton NMR spectra, which can be obtained with greater sensitivity, it is possible to determine the DP (degree of polymerization, the average number of glucose units per molecule) and the degree of branching (the proportion of glucose units which are (1→6) linked) without recourse to chemical or enzymatic methods. Moreover, the anomer distribution of the reducing sugars can be determined by1H or13C NMR. Finally, some examples of the application of NMR to follow the time course of enzymatic digestion and sugar anomerization are discussed, as is the solid‐state NMR of starch and glycogen. The phosphorus‐31 NMR spectra provide information about the nature of the phosphate groups in

ISSN:0038-9056    

DOI:10.1002/star.19900420705

出版商:WILEY‐VCH Verlag GmbH    

年代:1990

数据来源: WILEY

摘要:

AbstractBy addition of saturated fatty acids (C14‐C18) in concentrations of 0.34 and 0.57% gelatinization temperature (GT) of wheat starch is reduced from 82.5°C to 81°C. Oleic acid (C18:1) increases GT. Palmitic and stearic acid (0.57%) cause a little increase of viscosity only, but during heating a slope of viscosity is observed. In contrast to saturated fatty acids monoglyderides increase GT with exception of glycerinmonooleate, which reduces GT. Glycerinmonomyristate and glycerinmonolinoleate increase the initial viscosity. Monoglyceride ethers, first time used for those studies, influence viscosity differently. Rac‐1‐O‐octadecylglycerol reduces GT from 82.5 to 81°C and the final viscosity is lowered remarkable but rac‐1‐O‐[(Z)‐9‐octadecenyl]glycerol causes an increase of GT from 82.5 to 85.5°C. Initial and end visc

ISSN:0038-9056    

DOI:10.1002/star.19900420706

出版商:WILEY‐VCH Verlag GmbH    

年代:1990

数据来源: WILEY

摘要:

AbstractSyntheses of alkanosulfonylated starches are presented with alkane moiety being 1‐propyl‐, 1‐butyl‐, 1‐octyl, 1‐decyl‐ and 1‐octadecyl. Some properties of these compounds are described and results of their biological screening againstEscherichia coli, Bacillus subtilis, Aspergillus nigerandAspergillus

ISSN:0038-9056    

DOI:10.1002/star.19900420707

出版商:WILEY‐VCH Verlag GmbH    

年代:1990

数据来源: WILEY

摘要:

AbstractUsing the pH‐jump (neutral to above 11) for Tyr‐OH ionization as a probe, two glucoamylases fromRhizopus niveusandRhizopus delemarwere found to be caused the change in conformation, which is in a kinetically single step. The pH titration at pHs below 12 was carried out on a multidimensional correlation spectrophotometer. Correlations among the spectrophotometric properties: fluorescence, absorption and circular dichroism are almost identical for the two enzymes. These results suggest that conformational characteristics of theniveusenzyme is almost the same as that of thedelemar

ISSN:0038-9056    

DOI:10.1002/star.19900420708

出版商:WILEY‐VCH Verlag GmbH    

年代:1990

数据来源: WILEY

摘要:

AbstractA moderate thermophile, which produces a large amount of extracellular and thermostable cyclomaltodextrin glucanotransferase, was isolated from soil samples at hot spring areas in Japan. The isolate (A‐147), that grew at 30–60°C with an optimum at 45–50°C, was identified as a strain ofBacillus coagulans. The enzyme, which was most active at pH 6.5 and 60°C, was stabilized by 2–3 mM Ca2+, and degraded about 40% (as dry basis) of 13% (w/w) potato starch solution into cyclodextrins composed of α‐ and β‐cyclodextrins dominantly at 74°C and pH 6.5 in the presence of 3 mM Ca2+. The ratio of α‐, β‐ and γ‐cyclodextrins was almost constant (2:2.6:1) during all stages of the reaction. By simultaneous actions of two enzymes from the bacterium and other 2 kinds ofBacillus, starch hydrolysates containing various amounts and rations of cyclodextrins were produced from starch.Ein mäßiges Thermophiles, das eine große Menge an extracellulärer und thermostabiler Glucanotransferase produziert, wurde aus Bodenproben in Heißquellengebieten von Japan isoliert. Das Isolat (A‐147), das bei 30–60°C mit einem Optimum von 45–50°C wuchs, wurde als ein Stamm vonBacillus coagulansidentifiziert. Das bei pH 6,5 und 60°C aktivste Enzym wurde durch 2–3 mM Ca2+stabilisiert und baute etwa 40% (TS) einer 30%igen (w/w) Kartoffelstärkelösung zu Cyclodextrin ab, bestehend aus α‐ und β‐Cyclodextrin, vorwiegend bei 74°C und pH 6,5 in Gegenwart von 3 mM Ca2+. Das Verhältnis von α‐, β‐ und γ‐Cyclodextrinen war nahezu konstant (2:2,6:1) während sämtlicher Reaktionsschritte. Durch gleichzeitige Einwirkung von zwei Enzymen aus dem Bakterium und zwei anderen Arten vonBacteriawurden Stärkehydrolysate hergestellt, die v

ISSN:0038-9056    

DOI:10.1002/star.19900420709

出版商:WILEY‐VCH Verlag GmbH    

年代:1990

数据来源: WILEY

ISSN:0038-9056    

DOI:10.1002/star.19900420710

出版商:WILEY‐VCH Verlag GmbH    

年代:1990

数据来源: WILEY

ISSN:0038-9056    

DOI:10.1002/star.19900420711

出版商:WILEY‐VCH Verlag GmbH    

年代:1990

数据来源: WILEY