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1.
Proteins originating from dry legumes are not that much used in food formulations, yet, they are interesting components from a sustainability point of view, and could have interesting functional properties, e.g. for emulsion preparation. Therefore, this work focuses on the potential of the water soluble part of pea, chickpea and lentil protein isolates under acidic emulsions (pH 3.0) using a novel mild technique: premix membrane emulsification. Pea proteins (PP) and chickpea proteins (CP) lower the interfacial tension in the same way as whey protein isolate (WPI), which suggests that they could facilitate emulsion droplet formation similarly as WPI, while lentil proteins (LP) are slightly less effective. It is possible to make oil-in-water (O/W) emulsions with an average droplet diameter (d 4,3 ) of ~5 μm after 5 cycles in the premix system. The droplet size distribution of the emulsions remained constant during one day of storage, indicating that legume proteins are able to form and kinetically stabilize O/W emulsions. CP and PP exhibited emulsifying properties comparable to those of WPI, whereas LP is slightly less efficient, therewith indicating the great potential and that pea and chickpea protein isolates hold as emulsifiers in acidic food formulations.  相似文献   

2.
The influence of chaotropic and kosmotropic salts on Mucuna pruriens protein isolates was investigated. Protein solubility profile indicated that solubility was minimal at the isoelectric point of the protein isolate (4.0) while the solubility was maximal at pH 10.0 in all salt solutions. Chaotropes (I(-), ClO(4)(-) and SCN(-)) exhibit better protein solubility than the kosmotropes (SO(4)(2-), Cl(-) and Br(-)). Increase in protein solubility follows the Hofmeister series: NaSO(4)相似文献   

3.
Peever TL  Barve MP  Stone LJ 《Mycologia》2007,99(1):59-77
Evolutionary relationships were inferred among a worldwide sample of Ascochyta fungi from wild and cultivated legume hosts based on phylogenetic analyses of DNA sequences from the ribosomal internal transcribed spacer regions (ITS), as well as portions of three protein-coding genes: glyceraldehyde-3-phosphate-dehydrogenase (G3PD), translation elongation factor 1-alpha (EF) and chitin synthase 1 (CHS). All legume-associated Ascochyta species had nearly identical ITS sequences and clustered with other Ascochyta, Phoma and Didymella species from legume and nonlegume hosts. Ascochyta pinodes (teleomorph: Mycosphaerella pinodes [Berk. & Blox.] Vestergen) clustered with Didymella species and not with well characterized Mycosphaerella species from other hosts and we propose that the name Didymella pinodes (Berk. & Blox.) Petrak (anamorph: Ascochyta pinodes L.K. Jones) be used to describe this fungus. Analysis of G3PD revealed two major clades among legume-associated Ascochyta fungi with members of both clades infecting pea ("Ascochyta complex"). Analysis of the combined CHS, EF and G3PD datasets revealed that isolates from cultivated pea (P. sativum), lentil (Lens culinaris), faba bean (Vicia faba) and chickpea (Cicer arietinum) from diverse geographic locations each had identical or similar sequences at all loci. Isolates from these hosts clustered in well supported clades specific for each host, suggesting a co-evolutionary history between pathogen and cultivated host. A. pisi, A. lentis, A. fabae and A. rabiei represent phylogenetic species infecting pea, lentil, faba bean and chickpea, respectively. Ascochyta spp. from wild relatives of pea and chickpea clustered with isolates from related cultivated hosts. Isolates sampled from big-flower vetch (Vicia grandiflora) were polyphyletic suggesting that either this host is colonized by phylogenetically distinct lineages of Ascochyta or that the hosts are polyphyletic and infected by distinct evolutionary lineages of the pathogen. Phylogenetic species identified among legume-associated Ascochyta spp. were fully concordant with previously described morphological and biological species.  相似文献   

4.
The thermal properties of cowpea protein isolates (CPI) were studied by differential scanning calorimetry under the influence of various conditions. An increase in the pH of protein extraction, from 8.0 to 10.0, during CPI preparation promoted a partial denaturation of cowpea proteins. Increases in enthalpy change of denaturation (ΔH) and temperature of denaturation (Td) were detected with increasing protein concentration from 7.5 to 10.5% (w/w). This behavior suggests that denaturation involves a first step of dissociation of protein aggregates. Calcium induced thermal stabilization in cowpea proteins, the increase in Td was ca. 0.3 °C/mM for protein dispersions of 7.5% (w/w) for 0 to 40 mM CaCl2. High hydrostatic pressure (HHP) induced denaturation in CPI in a pressure level dependent manner. The presence of calcium protected cowpea proteins towards HHP-induced denaturation when pressure level was 400 MPa, but not when it was 600 MPa. Thermal properties of cowpea protein isolates were very sensitive to processing conditions, these behaviors would have implications in processing of CPI-containing foodstuff.  相似文献   

5.
The following properties of food proteins polymerized by guinea pig liver transglutaminase were investigated: (1) solubility, (2) emulsifying activity and emulsion stability, and (3) unfrozen water content by pulsed NMR. Several food proteins (αsl- and k-caseins, and soybean 7S and 11S globulins) were polymerized by this enzyme. Solubility and emulsifying activity of polymerized αsl-casein were higher than those of the native protein in the range of pH 4~6. Unfrozen water contents of polymerized soybean globulins were much higher than those of the native proteins. These results suggest that transglutaminase treatment may be used for the production of new food protein material with higher hydration ability.  相似文献   

6.
The transferability of genome-specific sequence tagged microsatellite site (STMS) primers from field pea (P. sativum) and chickpea (C. arietinum) to other major pulses was examined. Overall, field pea STMS primers amplified products in most of the accessions in comparison to that of the chickpea STMS primers, which amplified products in relatively few accessions. The highest level of successful amplifications with a single primer was 89% for field pea and 33% for chickpea primers respectively. The potential transferability of the STMS primers among species, expressed as the total mean percentage of positive amplifications, was 53% for the field pea STMS primers and 9% for the chickpea STMS primers. The individual mean percentage of successful transferability of field pea STMS primers across lentil, vetch and chickpea/Cicer sp. accessions was 60%, 39% and 62%, respectively. Whereas, for the chickpea STMS primers successful transferability was 5%, 3% and 18% for lentil, vetch and field pea, respectively. The trnasferability of these STMS primers indicates a high level of sequence conservation in these regions across species. Together with their locus-specificity, co-dominant nature and potential to amplify multiple alleles, their transferability makes STMS markers a powerful tool for genetic mapping, diversity analysis and genotyping.  相似文献   

7.
The suitability of five grain legume species (narrow-leafed lupin, chickpea, faba bean, field pea, lentil) as hosts for three aphid species (green peach aphid, cowpea aphid, bluegreen aphid) was evaluated by measuring the mean relative growth rate (MRGR) and survivorship of nymphs over a 5 day period. For each aphid species, intraspecific (interclonal) variation was also determined by independently measuring the performance of 30 clones collected from a variety of hosts and from different parts of the Western Australia (WA) wheatbelt. The suitability of the grain legumes varied among aphid species. Chickpea was not a suitable host for any of the aphids tested. Averaged over all clones, lentil and faba bean were the most suitable hosts for cowpea aphid, and narrow-leafed lupin was the most suitable host for green peach aphid. Field pea was a suitable host for all three species, but only at a suboptimal level. Cowpea aphid showed the greatest amount of intraspecific variation, with significant variation in MRGR among clones on all hosts except chickpea and significant variation in survivorship on chickpea and lupin. For green peach aphid, there was significant variation in MRGR among clones on field pea and lupin, but in survivorship on lupin only. Bluegreen aphid clones showed significant variation only for MRGR on faba bean and lupin. There were positive correlations in performance of green peach aphid clones on faba bean and lentil, and of cowpea aphid clones on faba bean and lentil. Bluegreen aphid clones showed a negative correlation in performance on field pea and faba bean. These results show the importance of screening cultivars against a wide variety of aphid clones when assessing aphid susceptibility in breeding programmes. The implications of these results on the adaptability of parthenogenetic aphids are discussed.  相似文献   

8.
Chan P  Lovrić J  Warwicker J 《Proteomics》2006,6(12):3494-3501
A characteristic of two-dimensional proteomics gels is a general bimodal distribution of isoelectric (pI) values. Discussion of this feature has focussed on the balance of acidic and basic ionisable residues, and potential relationships between pI distributions and organism classification or protein subcellular location. Electrostatics calculations on a set of protein structures with known subcellular location show that predicted folded state pI are similar to those calculated from sequence alone, but adjusted according to a general stabilising effect from interactions between ionisable groups. Bimodal distributions dominate both pI and the predicted pH of maximal stability. However, there are significant differences between these features. The average pH of maximal stability generally follows organelle pH. Average pI values are well removed from organelle pH in most subcellular environments, consistent with the view that proteins have evolved to carry (on average) net charge in a given subcellular location, and relevant to discussion of solubility in crowded environments. Correlation of the predicted pH of maximum stability with subcellular pH suggests an evolutionary pressure to adjust folded state interactions according to environment. Finally, our analysis of ionisable group contributions to stability suggests that Golgi proteins have the largest such term, although this dataset is small.  相似文献   

9.
The isoelectric point of the two pea isophytohemagglutinins varies from pH 5.7 to pH 8.4 depending on the composition of the buffer used. Isoelectric focusing reveals three main molecular species with pI at pH 5.90, 6.35 and 7.00. Molecular species with pI at pH 5.9 and 7.0 correspond to the two pea isophytohemagglutinins which can be obtained by DEAE-cellulose chromatography (Entlicher, G., Kostír, J.V. and Kocurek, J. (1970) Biochim. Biophys. Acta 221, 272-281). A molecular species with pI at pH 6.35 is formed from the two pea isophytohemagglutinins by hybridization. According to the hybridization pattern and subunit composition of the pea isophytohemagglutinins the subunit composition AABB, AACC and AABC can be proposed for the three molecular species with respect to ionic properties of the subunits.  相似文献   

10.
Benzyl alcohol and starch-free commercial wheat bran were effective inducers of the laccase activity in cultures of Fusarium proliferatum (MUCL 31970). Initial pH value in the cultures was also an overriding factor for increasing its production. By gel permeation high-performance liquid chromatography, the enzyme eluted as an apparently homogeneous peak with a molecular mass of 54 kDa, but by isoelectrofocusing, two proteins with pI values of 5.17 and 5.07 were revealed. Two different phenoloxidase activities were also detected after nondenaturing polyacrylamide gel electrophoresis. By matrix-assisted laser desorption/ionization–time of flight–mass spectrometry (MALDI-TOF-MS), both proteins showed unique fingerprints, so they were classifiable as isozymes, and were named laccase 1 (Lac1, pI 5.17) and laccase 2 (Lac2, pI 5.07). No clear matches were found when compared with other proteins. The tandem mass spectrometry of some peptides from both isozymes reanalyzed by nanoelectron ionization–ion trap–mass spectrometry (nESI-IT-MS) confirmed their unique character. The following interesting properties, particularly its stability at alkaline pH, make this laccase a promising industrial enzyme for biotechnological applications: maximum activity at 60°C, thermal stability for 2 h at 40°C, optimum pH 3.5 (km=62 μM) measured on 2,2′-azino-bis(3-ethylbenz-thiazoline-6-sulfonate), and pH stability 4–8 (75% stability at pH levels 2.2 and 9) for 2 h at 25°C.  相似文献   

11.
The polyphagous larvae of click beetles (Coleoptera: Elateridae) are major pests of spring wheat in Montana, USA. Presently available insecticides are unable to provide control over wireworm populations, and the use of natural enemies has not been successful under field conditions. In this study, we examined the effect of seven trap crops: pea, lentil, canola, corn, durum, barley, and wheat, for their attractiveness to wireworms compared to spring wheat. Experimental plots were located in two commercial grain fields in Valier and Ledger, Montana, USA and the trials took place from May to August in 2015 and 2016. Wheat plants damaged by wireworms were recorded and their relative locations in wheat rows and adjacent trap crop rows within a plot were determined using destructive soil samples. In 2016, variable row spacing (0.25, 0.5, 0.75, and 1 m) between the trap crops (pea and lentil) and wheat was assessed. Shade house bioassays were conducted using potted pea, lentil, and wheat plants to support field trial results. Limonius californicus larvae, released at the center of each pot were sampled 4 and 10 days after sowing. Wheat intercropped with pea and lentil had significantly fewer damaged wheat plants. Wireworm numbers were lower in wheat intercropped with pea compared to the control for both locations and years. Shade house results corresponded with field results, with more wireworms collected from pea and lentil than wheat. In the spacing trials, wheat plant counts were also significantly higher when paired with pea and lentil, particularly at 0.5 m spacing. Regardless of inter-row spacing, significantly fewer wireworms were associated with wheat when intercropped with pea and lentil trap crops.  相似文献   

12.
The use of beneficial soil microorganisms as agricultural inputs for improved crop production requires selection of rhizosphere-competent microorganisms with plant growth-promoting attributes. A collection of 563 bacteria originating from the roots of pea, lentil, and chickpea grown in Saskatchewan was screened for several plant growth-promoting traits, for suppression of legume fungal pathogens, and for plant growth promotion. Siderophore production was detected in 427 isolates (76%), amino-cyclopropane-1-carboxylic acid (ACC) deaminase activity in 29 isolates (5%), and indole production in 38 isolates (7%). Twenty-six isolates (5%) suppressed the growth of Pythium sp. strain p88-p3, 40 isolates (7%) suppressed the growth of Fusarium avenaceum, and 53 isolates (9%) suppressed the growth of Rhizoctonia solani CKP7. Seventeen isolates (3%) promoted canola root elongation in a growth pouch assay, and of these, 4 isolates promoted the growth of lentil and one isolate promoted the growth of pea. Fatty acid profile analysis and 16S rRNA sequencing of smaller subsets of the isolates that were positive for the plant growth-promotion traits tested showed that 39%-42% were members of the Pseudomonadaceae and 36%-42% of the Enterobacteriaceae families. Several of these isolates may have potential for development as biofertilizers or biopesticides for western Canadian legume crops.  相似文献   

13.
Summary The value of iron pyrites as a source of S for legumes (chickpea, pea and lentil) was studied on the Typic Ustochrepts of Pura in 1982–1983. It provided sufficient sulphur to increase their S uptake and concentration and increased their yield of seed and straw. Dry matter production per unit of S absorbed increased in the order: lentil<chickpea <pea.  相似文献   

14.
The purpose of the present study was to investigate the effects of cryoprotectants (4 % sucrose?+?4 % sorbitol) on functional and rheological changes, including thermal stability, dynamic rheological and emulsifying properties, gel texture profile, gel whiteness, gel water-binding capacity, and gel microstructure, in the myofibrillar proteins (MP) of common carp (Cyprinus carpio) surimi subjected to multiple freeze-thaw cycles (FT, 0, 1, 3 and 5 times). Increased numbers of FT cycles were accompanied by reduced thermal transition temperature (T max), reduced enthalpy of denaturation (ΔH) (P?<?0.05), and enhanced susceptibility to thermal aggregation. The observation of the gel microstructure indicated that the FT processes produced empty spaces and changed the aggregate gel structure into a coarser-stranded network. The addition of cryoprotectants significantly prevented the reduction of MP thermal stability (P?<?0.05). The protective effect on protein functionality was demonstrated by the cryoprotectant’s efficacy in maintaining the three-dimensional gel network by small-strain oscillatory rheological testing and increasing the emulsifying capacity and emulsion stability of the MP. The FT process caused a decrease (P?<?0.05) in whiteness, water-binding capacity, and texture (hardness, springiness, and gumminess) of the MP gels, which were reduced by the addition of cryoprotectants. Overall, the FT-induced loss of the abovementioned functional and rheological properties was significantly reduced by the presence of cryoprotectants.  相似文献   

15.
Ribonuclease Sa and two charge-reversal variants can be converted into amyloid in vitro by the addition of 2,2,2-triflouroethanol (TFE). We report here amyloid fibril formation for these proteins as a function of pH. The pH at maximal fibril formation correlates with the pH dependence of protein solubility, but not with stability, for these variants. Additionally, we show that the pH at maximal fibril formation for a number of well-characterized proteins is near the pI, where the protein is expected to be the least soluble. This suggests that protein solubility is an important determinant of fibril formation.  相似文献   

16.
The net charge and isoelectric pH (pI) of a protein depend on the content of ionizable groups and their pK values. Ribonuclease Sa (RNase Sa) is an acidic protein with a pI = 3.5 that contains no Lys residues. By replacing Asp and Glu residues on the surface of RNase Sa with Lys residues, we have created a 3K variant (D1K, D17K, E41K) with a pI = 6.4 and a 5K variant (3K + D25K, E74K) with a pI = 10.2. We show that pI values estimated using pK values based on model compound data can be in error by >1 pH unit, and suggest how the estimation can be improved. For RNase Sa and the 3K and 5K variants, the solubility, activity, and stability have been measured as a function of pH. We find that the pH of minimum solubility varies with the pI of the protein, but that the pH of maximum activity and the pH of maximum stability do not.  相似文献   

17.
To understand how pulse and oilseed crops might use nitrogen (N) more efficiently under varying levels of water and N availability in soil, we conducted a 2-year field study to monitor N accumulation in aboveground (AG-N) and root material at five growth stages, for canola (Brassica napus L.), mustard (Brassica juncea L.), chickpea (Cicer arietinum L.), dry pea (Pisum sativum L.) and lentil (Lens culinaris Medicum) alongside spring wheat (Triticum aestivum L.). Crops were grown in lysimeters (15 cm diameter × 100 cm deep) installed in the field in southern Saskatchewan, Canada. AG-N in all crops was greater under high-water than under low-water conditions. In oilseeds and wheat, AG-N increased until flowering then tended to level off, while in pulses it increased gradually to maturity. At maturity, dry pea and wheat had the greatest AG-N and mustard the least. Enhanced water availability increased seed N but did not affect straw N; consequently, N harvest index was greater under high-water than under low-water conditions. Root N increased until late-flowering or late-pod (dough stage in wheat) then decreased to maturity. Mustard had the lowest root N, chickpea the second lowest, and canola, wheat, dry pea, and lentil the highest. Improved water availability increased root N for oilseeds and wheat but did not affect root N in pulses. At maturity, average root N of oilseeds, pulses, and wheat was 14, 17, and 20 kg ha-1, respectively. At the seedling stage pulse crops had about 27% of total plant N in their roots, a much greater proportion than for the non-legumes. However, by maturity all crops had about 14% of plant N in their roots. Soil NO3-N increased gradually between seedling and maturity in non-legumes but in pulses there was a sharp spike at early flowering. Estimated apparent net N mineralized was similar for wheat and pulse crops which were greater than for canola and mustard. Soil N amounts and temporal change patterns varied substantially among crops evaluated, and these differences need to be considered in the development of diverse cropping systems where cereals, legumes, and oilseeds are included in rotation systems.  相似文献   

18.
Legumes are recalcitrant to androgenesis and induction protocols were only recently developed for pea (Pisum sativum L.) and chickpea (Cicer arietinum L.), albeit with low regeneration frequencies. Androgenesis is thought to be mediated through abscisic acid (ABA) but other phytohormones, such as auxins, cytokinins, and gibberellins, have also been implicated. In view of improving induction protocols, the hormone content of pea, chickpea, and lentil anthers was measured after exposure to cold, centrifugation, electroporation, sonication, osmotic shock, or various combinations thereof using an analytical mass spectrometer. Indole-3-acetic acid (IAA) had a key function during the induction process. In pea, high concentrations of IAA-asparagine (IAA-Asp), a putative IAA metabolite, accumulated during the application of the different stresses. In chickpea, the IAA-Asp concentration increased 30-fold compared to pea but only during the osmotic shock treatment and likely as a result of the presence of exogenous IAA in the medium. In contrast, no treatment in lentil (Lens culinaris) invoked such an increase in IAA-Asp content. Of the various cytokinins monitored, only cis zeatin riboside increased after centrifugation and electroporation in pea and possibly chickpea. No bioactive gibberellins were detected in any species investigated, indicating that this hormone group is likely not linked to androgenesis in legumes. In contrast to the other stresses, osmotic shock treatment caused a reduction in the levels of all hormones analyzed, with the exception of IAA-Asp in chickpea. A short period of low hormone content might be a necessary transition phase for androgenesis induction of legumes. KEY MESSAGE: Five androgenesis-inducing stress treatments changed content of ABA, auxin and cytokinin in anthers of three legumes. Osmotic shock treatment differed because it reduced hormone content to very low levels.  相似文献   

19.
A total of 15 endophytic Bacillus thuringiensis isolates were obtained from root nodules of six legumes (soybean, ricebean, gahat, frenchbean, lentil and pea). All of these isolates were characterized by the presence of one of two different types of crystalline inclusions (spherical and bipyramidal) and tolerance to a wide pH range (4–10; optimum 7.0) and NaCl concentrations up to 8%. Genetic diversity among the B. thuringiensis isolates was determined by repetitive extragenic palindromic PCR assays (rep-PCR) using the Bacillus cereus-repetitive extragenic palindromic, BOX, enterobacterial repetitive intergenic consensus sequence and (GTG)5 primers. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis proteogram of the B. thuringiensis isolates revealed the presence of two major polypeptides (24.4 and 131.0 kDa). Maximum crystal protein profile was observed in the B. thuringiensis isolates producing the spherical crystal, while those isolates producing the bipyramidal crystal protein showed four four major polypeptides (24.4, 33.8, 81.2 and 131.0 kDa). The purified crystal protein profile of the B. thuringiensis isolates revealed the presence of only one major protein of 130 kDa mass. Isolates VRB1 and VLG15 possessing the cry1 and cry2 family genes demonstrated 100% mortality against first-instar larvae of the Bihar hairy caterpillar (lepidopteran pest). Our study of the ecological and molecular diversity among newly identified B. thuringiensis isolates suggests that these could be useful in planning new strategies for integrated pest management in sustainable agricultural systems.  相似文献   

20.
Functional properties and antioxidant activities of protein hydrolysates from tuna (Thunnus thynnus) heads (THPHs), with different degrees of hydrolysis, obtained by treatment with Bacillus mojavensis A21 alkaline proteases and Alcalase, were investigated. Protein content of all freeze-dried THPHs ranged from 73.74 ± 0.5 to 78.56 ± 1.2%. The THPHs had excellent solubility, compared to untreated tuna head proteins and possessed interfacial properties, which were governed by their concentrations. Similarly, at a degree of hydrolysis (DH) of 12 and 15%, > 90% nitrogen solubility was observed at all experimental pH values tested. The emulsifying activity index (EAI) and emulsion stability index (ESI) of both hydrolysates at different DHs decreased (p < 0.05) with increasing DH. At low DH (5%), hydrolysates exhibited strong emulsifying properties. All THPHs produced by the A21 proteases generally showed higher antioxidative activity than that of the Alcalase protein hydrolysates. The highest DPPH radical-scavenging activity (78 ± 2.1% at 3 mg/mL) was obtained with a DH of 15%. The IC50 value for the β-carotene bleaching assay was 0.5 ± 0.03 mg/mL. Alcalase (DH = 12%) and A21 (DH = 15%) protein hydrolysates contained glutamic acid/glutamine and arginine as the major amino acids, followed by lysine, aspartic acid/ asparagine, histidine, valine, phenylalanine, and leucine. In addition, the THPHs had a high percentage of essential amino acids, which made up 50.52 and 50.47%, of the protein hydrolysates obtained by the Alcalase and A21 proteases, respectively. Therefore, THPHs can be used as a promising source of functional peptides with antioxidant properties.  相似文献   

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