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1.
Water dispersion kinetics during starch gelatinization 总被引:1,自引:0,他引:1
The kinetics of water dispersion during the gelatinization of dilute suspensions of maize starch was studied by analyzing changes in electrical conductance data recorded continuously with time. Several analytical methods were compared for the preliminary study of the activation energy of gelatinization. The probable mechanism of the process was investigated by a number of homogeneous and heterogeneous reaction kinetic models. A modified composite methodology coupled with a reduced-plot method was employed to fit the kinetic data. Two simultaneous elementary reactions, expressed by an autocatalytic kinetic model and a 3D moving phase-boundary rate model, predicted the overall kinetic behavior with appreciable success. 相似文献
2.
Gisela Richardson Yemin Sun Maud Langton Anne-Marie Hermansson 《Carbohydrate polymers》2004,57(4):369-377
The interaction of lignosulfonates with starches was examined by microscopy and viscosity measurements. 8% starch dispersions with Ca- or Na-lignosulfonate, or with only Ca2+ or Na+, were heated to 97 °C and cooled to 50 °C in a Brabender Viscograph, the gelatinization was followed by light microscopy and image analysis, and the gel network formed after cooling to 4 °C was studied under the transmission electron microscope.
The lignosulfonates (2%) delayed the initial granule swelling in all starches (native maize, waxy maize and waxy barley). The presence of ions enhanced amylose leakage resulting in lower peak viscosity. The viscosity during cooling increased more with Ca-LS than with Na-LS. With a low lignosulfonate concentration the network formed after cooling was homogeneous with fine strands. With Na-lignosulfonate, as well as with Na+, the network connectivity deteriorated and spherical aggregates formed. Ca-lignosulfonate induced a network with thick strands, but with Ca2+ the strands became thinner. 相似文献
3.
The effects of β-glucan (BG) prepared from spent brewer’s yeast on gelatinization and retrogradation of rice starch (RS) were investigated as functions of mixing ratio and of storage time. Results of rapid visco-analysis (RVA) indicated that addition of BG increased the peak, breakdown, setback, and final viscosities, but decreased the pasting temperatures of the rice starch/β-glucan (RS/BG) mixtures. Differential scanning calorimetry (DSC) data demonstrated an increase in onset (To), peak (Tp), and conclusion (Tc) temperatures and a decrease in gelatinization enthalpy (ΔH1) with increasing BG concentration. Storage of the mixed gels at 4 °C resulted in a decrease in To, Tp, Tc, and melting enthalpy (ΔH2). The retrogradation ratio (ΔH2/ΔH1) and the phase transition temperature range (Tc − To) of the mixed gels increased with storage time, but this effect was reduced by the addition of BG. BG addition also slowed the syneresis of the mixed gels. Results of dynamic viscoelasticity measurement indicated that the addition of BG promoted RS retrogradation at the beginning and then retarded it during longer storage times. The added BG also retarded the development of gel hardness during refrigerated storage of the RS/BG mixed gels. 相似文献
4.
Effect of salts on pasting, thermal, and rheological properties of rice starch in the presence of non-ionic and ionic hydrocolloids 总被引:5,自引:0,他引:5
Effects of salts on pasting, thermal, and rheological properties of rice starch (RS) in the presence of non-ionic (guar gum; GG) or ionic (xanthan; XT) hydrocolloid were studied. Rapid visco-analysis (RVA) showed that addition of salts significantly increased peak, breakdown, and final viscosities, and pasting temperatures of RS/XT blends, whereas those of RS/GG blends were varied depending on the type of salts added. Differential scanning calorimetry (DSC) demonstrated that salt addition significantly increased gelatinization temperatures of either RS/GG or RS/XT blend, whereas gelatinization enthalpy was less affected. Dynamic viscoelastic tests revealed that addition of salts had a more pronounced effect on enhancing structure formation of RS/XT gels than that of RS/GG gels. The steady shear viscosity was generally in line with the values of final viscosity obtained during pasting. These results would be used as a guideline for developing starch-based food products containing salts. 相似文献
5.
Henky Muljana Francesco Picchioni Hero J. Heeres Leon P.B.M. Janssen 《Carbohydrate polymers》2009,78(3):511-519
The degree of gelatinization (DG) of potato starch after treatment with scCO2 was investigated. A broad range of experimental conditions were applied, including variations in temperature (50–90 °C), pressure (0.1–25 MPa), and the starch water content (16.2–40% wt/wt). Changes in the DG were observed by in situ FT-IR measurements, DSC and confirmed by the XRD analysis. The DG increases at higher temperatures and pressures. A maximum DG of about 14% was achieved at the highest pressure (25 MPa) and temperature in the range (90 °C). A series of experiments under N2 pressure confirms that scCO2 plays a special role in the gelatinization process. 相似文献
6.
Summary In order to improve nitrogen recovery by rice, the effect of a urease inhibitor phenylphosphorodiamidate (PPD) on the efficiency
of fertilizer urea was studied in laboratory and greenhouse. Addition of PPD to urea (5% w/w) delayed urea hydrolysis by 3
to 4 days and reduced ammonia volatilization from 45% (without PPD) to 8.5% (with PPD). Ammonia volatilization obeyed first
order kinetics. Urea hydrolysis was sufficiently strongly inhibited to match the nitrification potential of the soil. N application
to rice by three different modes showed that a delayed mode (4 splits) was superior to two conventional modes (3 splits) in
nitrogen recovery and fertilizer efficiency since it met nitrogen requirement of plants at reproductive stage. In 2 out of
3 modes of application, there was a 14% increase (relative) in grain yields and dry matter, and 6.8% increase in N uptake
efficiency on application of PPD along with urea. The results indicate that urease inhibitors like PPD can be effectively
used to block urea hydrolysis, reduce ammonia volatilization losses and improve N use efficiency by rice. 相似文献
7.
Yuuki Nakayoshi Sumiko Nakamura Yoji Kameo Daisuke Shiiba Yoshihisa Katsuragi Ken’ichi Ohtsubo 《Bioscience, biotechnology, and biochemistry》2013,77(11):1860-1866
Digestion-resistant starch (RS) has many physiologic functions. The RS content is measured by enzymatically degrading flour samples according to the method of the Association of Official Analytical Chemists. Experiments have been performed with wheat, corn, and other grains, but there are no data for cooked rice grains in the form ingested by humans. Thus, we investigated a method to measure RS that is suitable for cooked rice grains using rice cultivars that are reported to differentially increase postprandial blood glucose in humans. Using a method for cooking individual rice grains and optimized enzyme reaction conditions, we established an RS measurement method. We also found that the amylopectin crystal condition affects the RS content measured using our method. 相似文献
8.
A new insight into the gelatinization process of native starches 总被引:1,自引:0,他引:1
The gelatinization characteristics of seven different food starches (regular corn, high-amylose corn, waxy corn, wheat, rice, potato, and tapioca) were investigated. Each starch sample type was heated to 35, 40, 45, etc. up to 85 °C at 5 °C intervals, and freeze-dried. The treated samples were analyzed using light microscopy, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and high-performance size exclusion chromatography (HPSEC). When heated, granules underwent structural changes prior to the visible morphological changes that took place during gelatinization. The nature of these structural changes depended on starch type. These results indicate that the starch gelatinization process is more complex than a simple granular order-to-disorder transition. 相似文献
9.
Larkin Patrick D. Park William D. 《Molecular breeding : new strategies in plant improvement》2003,12(4):335-339
The waxy gene, which encodes the granule bound starch synthase enzyme, is one of the key genes influencing starch synthesis in the rice endosperm. To investigate functional differences between GBSS alleles, we cloned and sequenced GBSS cDNA from a series of cultivars that differed substantially in apparent amylose content and starch viscosity characteristics. We found two single nucleotide polymorphisms in exons 6 and 10 that resulted in amino acid substitutions. These substitutions are associated with differences in apparent amylose content and viscosity characteristics. Subsequent sequencing of these regions from additional cultivars confirmed their association with particular rice quality characteristics. These point mutations could prove useful as molecular markers in the production of cultivars with superior eating, cooking and processing quality, and contribute to our understanding of the various structural and functional differences among granule bound starch synthase alleles. 相似文献
10.
The effect of sodium chloride on the gelatinization and rheological properties of wheat and potato starches has been studied using differential scanning calorimetry, dynamic mechanical thermal analysis, and electron spin resonance techniques. All samples contained 60% water (w/w wet starch basis) and the salt content ranged from 0 to 16% (g/100 g starch-water). The presence of salt affected the onset (T(o)), peak (T(p)), and end (T(e)) temperatures of gelatinization, gelatinization enthalpy (DeltaH), storage modulus (G'), and rotational mobility coefficient (D(rot)), and the effect differed by salt concentration. 1H-NMR was used in parallel in order to elucidate how salts affect the properties of water in starch suspensions and in aqueous salt solutions according to their position on the Hofmeister series classification. The obtained results suggest that the mechanism of starch gelatinization in salt solutions can be attributed to the effect of solute on water properties and direct polymer-solute interactions. These two effects conflict with one another and result in complex effect patterns depending on the concentration of the salts. 相似文献
11.
The structure of starch can be manipulated by changing the expression levels of starch branching enzyme IIb in rice endosperm 总被引:1,自引:0,他引:1
Tanaka N Fujita N Nishi A Satoh H Hosaka Y Ugaki M Kawasaki S Nakamura Y 《Plant biotechnology journal》2004,2(6):507-516
When the starch branching enzyme IIb (BEIIb) gene was introduced into a BEIIb-defective mutant, the resulting transgenic rice plants showed a wide range of BEIIb activity and the fine structure of their amylopectins showed considerable variation despite having the two other BE isoforms, BEI and BEIIa, in their endosperm at the same levels as in the wild-type. The properties of the starch granules, such as their gelatinization behaviour, morphology and X-ray diffraction pattern, also changed dramatically depending on the level of BEIIb activity, even when this was either slightly lower or higher than that of the wild-type. The over-expression of BEIIb resulted in the accumulation of excessive branched, water-soluble polysaccharides instead of amylopectin. These results imply that the manipulation of BEIIb activity is an effective strategy for the generation of novel starches for use in foodstuffs and industrial applications. 相似文献
12.
Map-based cloning of the ALK gene, which controls the gelatinization temperature of rice 总被引:11,自引:0,他引:11
As a primary crop in China, rice provides the staple food for more than 50% population in the world. With the increasing grain yield and improvement of living conditions, grain quality has drawn more and more attention. Gelatinization temperature (GT), an important parameter for rice cooking quality, is the critical temperature at which the starch granules start to lose crystallinity and birefringence by irreversible expanding and to change the starch surface from polarized to soluble state c… 相似文献
13.
Physico-chemical characterisation of sago starch 总被引:3,自引:0,他引:3
Fasihuddin B. Ahmad Peter A. Williams Jean-Louis Doublier Sylvie Durand Alain Buleon 《Carbohydrate polymers》1999,38(4):361-370
The physico-chemical characteristics of various sago starch samples from South East Asia were determined and compared to starches from other sources. X-ray diffraction studies showed that all the sago starches exhibited a C-type diffraction pattern. Scanning electron microscopy showed that they consist of oval granules with an average diameter around 30 μm. Proximate composition studies showed that the moisture content in the sago samples varied between 10.6% and 20.0%, ash between 0.06% and 0.43%, crude fat between 0.10% and 0.13%, fiber between 0.26% and 0.32% and crude protein between 0.19% and 0.25%. The amylose content varied between 24% and 31%. The percentage of amylose obtained by colourimetric determination agreed well with the values obtained by fractionation procedures and potentiometric titration. Intrinsic viscosities and weight average molecular weight were determined in 1M KOH. Intrinsic viscosity for amylose from sago starches varied between 310 and 460 ml/g while for amylopectin the values varied between 210 and 250 ml/g. The molecular weight for amylose was found to be in the range of 1.41×106 to 2.23×106 while for amylopectin it was in the range of 6.70×106 to 9.23×106. The gelatinisation temperature for the sago starches studied varied between 69.4°C and 70.1°C. The exponent ‘a’ in the Mark–Houwink equation and the exponent ‘’ in the equation Rg=kM was found to be 0.80 and 0.58, respectively for amylose separated from sago starch and these are indicative of a random coil conformation. Two types of pasting properties were observed. The first was characterised by a maximum consistency immediately followed by sharp decrease in consistency while the second type was characterised by a plateau when the maximum consistency was reached. 相似文献
14.
Temperature induced changes in the starch components and biosynthetic enzymes of two rice varieties 总被引:3,自引:0,他引:3
The effects of temperature on starch and amylose accumulation, fine structure of amylopectin and activities of some enzymes related to starch synthesis in developing rice endosperms was examined. Two early indica rice varieties were used, differing in amylose concentration (AC, %), namely Jia 935 (low AC) and Jia 353 (high AC). The results showed that the effects of high temperature on AC and amylopectin fine structure were variety-dependent. High temperature caused a reduction in amylose concentration and an increase in the short chain (CL<22) proportion of amylopectin for Jia 935; while opposite was true for Jia 353. High temperature also reduced and increased the activity of granule-bound starch synthase (GBSS) in Jia 935 and in Jia 353, respectively. This suggests that a change in the ratio of amylose/starch due to temperature was attributable to a change in GBSS activity. Moreover, obvious differences between the two rice varieties were detected in the activities of sucrose synthase (SuSy), ADP-glucose pyrophosphorylase (ADPG-Ppase), soluble starch synthase (SSS), starch branching enzyme (SBE), starch de-branching enzyme (SDBE) and starch phosphorylase (SPase) to high temperature. Accumulation rate of amylose was significantly and positively correlated with GBSS for Jia 935, but not for Jia 353. Amylose accumulation was also significantly and positively correlated with the activities of SDBE, SBE, ADPG-Ppase and SuSy for both varieties. The results suggest that the ratio of amylose to starch in rice endosperm is not only related to GBSS, but also affected by the activities of SDBE, SBE, ADPG-Ppase and SuSy. 相似文献
15.
Molecular analysis of the gene encoding a rice starch branching enzyme 总被引:16,自引:0,他引:16
Tsutomu Kawasaki Kouichi Mizuno Tadashi Baba Hiroaki Shimada 《Molecular & general genetics : MGG》1993,237(1-2):10-16
Summary The sequence of a rice gene encoding a starch branching enzyme (sbe1) shows extreme divergence from that of the rice gene, that is homologous to bacterial glycogen branching enzyme (sbe2). sbe1 is expressed abundantly and specifically in developing seeds and maximally in the middle stages of seed development. This expression pattern completely coincides with that of the waxy gene, which encodes a granule-bound starch synthase. Three G-box motifs and consensus promoter sequences are present in the 5 flanking region of sbe1. It encodes a putative transit peptide, which is required for transport into the amyloplast. A 2.2 kb intron (intron 2) precedes the border between the regions encoding the transit peptide and the mature protein, and contains a high G/C content with several repeated sequences in its 5 half. Although only a single copy of sbe1 is present in the rice genome, Southern analysis using intron 2 as a probe indicates the presence of several homologous sequences in the rice genome, suggesting that this large intron and also the transit peptide coding region may be acquired from another portion of the genome by duplication and insertion of the sequence into the gene. 相似文献
16.
Gene expression of the biosynthetic enzymes and biosynthesis of starch during Rice Grain development 总被引:1,自引:0,他引:1
Amylose and amylopectin are determinants of the physicochemical properties for starch and grain quality in rice. Their biosynthesis
is catalyzed by the interplay of ADP-glucose pyrophosphorylase (AGPase), granule-bound starch synthase (GBSS), soluble starch
synthase (SSS), a starch branching enzyme (SBE), and a starch debranching enzyme (SDE). In this study, the genes for these
enzymes were highly expressed 7 to 28 days after flowering during grain development, and their expression closely matched
increases in both starch content and grain weight Among all the tested cultivars, amylose contents in the rice grains remained
essentially constant throughout their development The AGPase gene was highly expressed in the high-yield cultivars of both
glutinous and non-glutinous rice. The SSS gene was actively expressed when mature GBSS mRNA decreased. Genes responsible for
amylopectin biosynthesis were simultaneously expressed in the late stage of grain development. We have now demonstrated that
the expression patterns of starch biosynthetic genes differ between glutinous and non-glutinous rice, and between Tongil (a
Japonica/ Indica hybrid) and Japonica types. 相似文献
17.
In this study, the structures of the hot-water (80°C) soluble starch fractions (HWS) of six new Japanese rice cultivars (Saikai 194, Saikai 198, Hokuriku 149, Suigen 258, Hoshiyutaka, and Saikai 184) were investigated following a previous study [Mizukami, H., Hizukuri, S. and Takeda, Y. Structures and pasting properties of starches from new characteristic rice cultivars, Oyo Toshitu Kagaku (J. Appl. Glycosci.) 43 (1996) 15–23]. The HWS were subfractionated into 1-butanol-precipitate (SAM) and supernatant (SAP) fractions. The yields of the SAM and SAP fractions were 0.3%–2.4% and 3.1%–4.1% by starch weight, respectively. The Hoshiyutaka and the Saikai 184 yielded both relatively large (2.4%) and small amounts (0.3%) of SAM. The SAM were small amylose molecules with a
n between 320 and 420 and a
w between 950 and 1850. The SAM from the Hoshiyutaka and the Saikai 184 were the larger molecules with
n 390 and 420, respectively, and having slightly more branches (6.0 and 8.1) than those from the others (1.5–4.5). The SAP were smaller molecules having a
n between 60 and 190 as compared to the SAM. The SAP was composed of small amylopectin molecules (
n 280–790, CL 17–32, β-amylolysis limit (β-AL), 54%–68%) including very small amylose molecules (
n 24–34) having an average number of branch linkage (
) of between 0.4 and 0.5. Both the amount and the structures of hot-water-extractable rice starch fractions vary with cultivar, and may influence their cooking properties. 相似文献
18.
Study on the granular characteristics of starches separated from Chinese rice cultivars 总被引:1,自引:0,他引:1
Granule size distribution, the relative crystallinity, morphology and thermal degradation of starches from 10 different non-waxy rice cultivars were measured in present study. The relationships between granular structure and thermogravimetric parameters of tested starches were evaluated using Pearson correlation analysis. The range of median size for rice starches was 6.23-7.81 μm. The relative crystallinity of 10 non-waxy rice starches ranged from 20.4% to 33.4%. The range of activation energy from different rice starches was between 155.6 and 201.5 kJ/mol. The Pearson correlation results showed that the relative crystallinity was positively correlated (r = 0.6750, p < 0.05) with the percentage of branch chains with DP12-23. Furthermore, the activation energy of the rice starches showed a positive correlation (r = 0.7903, p < 0.01) with relative crystallinity. 相似文献
19.
H. Shimada Y. Tada T. Kawasaki T. Fujimura 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1993,86(6):665-672
The waxy gene encodes a granule-bound starch synthase. A 1.0-kb portion of the sequence of the rice waxy gene, which includes the region between exon 4 and exon 9, was inserted in an antisense orientation between the 35 S promoter and the GUS gene of pBI221. The resultant plasmid, pWXA23, was introduced into rice protoplasts by electroporation. GUS activity was clearly detected in derived callus lines, suggesting that the antisense component of the fusion gene was also expressed. Transgenic rice plants were regenerated from these callus lines and their GUS activity was confirmed. Some of the rice seeds from these transformants showed a significant reduction in the amylose content of grain starch, even though they had become polyploid. These results suggest that even when intron sequences are included, antisense constructs can bring about a reduced level of expression of a target gene. The utility of GUS, included as a reporter gene, for the simple detection of expression of an antisense gene, was apparent from these results. 相似文献
20.
Soma Fukuzawa Takenobu Ogawa Kyuya Nakagawa 《Bioscience, biotechnology, and biochemistry》2016,80(8):1609-1614
Wheat starch dispersions of 10–40% (w/w) were gelatinized and the change in turbidity of each solution during storage was measured in the 400–1100 nm wavelength range. The relative transmittance, defined as the ratio of transmittance at any storage time to that at the initial time, decreased when the solutions were stored at 5 and 30 °C; the decrease, reflecting the progress of retrogradation, was larger at 5 °C than at 30 °C. Most of the changes in relative transmission taking place over 14 days were achieved during the first 90 min. The change in the relative transmittance is inversely proportional to the energy required for deformation. The kinetics on change in relative transmittance can be expressed by Weibull equation. The larger rate constant at higher starch concentration could be ascribed to the state of the starch granules, which depended on starch concentration. 相似文献