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1.
Ultrason Sonochem ; 81: 105866, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34896805

RESUMO

A new ultrasound-assisted enzymatic extraction (UAEE) method of starch from kiwifruit was established and optimized using response surface methodology (RSM). Under optimal conditions (the pectinase-to-cellulase-to-papain ratio = 1:2:1 g/kg, solid/liquid ratio = 1:6.68, extraction pH = 5.23, ultrasound power = 300 W, and extraction temperature = 52 °C), the kiwi starch (KS) yield was about 4.25%, and the starch content of KS was 873.23 mg/g. Compared to other extraction methods, UAEE can obtain KS with high yield and purity with a shorter extraction time and less solvent and enzyme. The extracted KS has a low gelatinization enthalpy (8.02 J/g) and a high peak viscosity (7933 cP), with obvious particle properties and low adhesion. In addition, KS is rich in polyphenols, has strong antioxidant activity, and has higher contents of amylose starch (30.74%) and resistant starch (60.18%). This study established a novel and highly efficient method for KS extraction and suggest several possible applications for KS in the food industry.


Assuntos
Frutas , Amido , Ultrassom , Frutas/química , Amido/química , Amido/isolamento & purificação , Amido/fisiologia
2.
Int J Biol Macromol ; 183: 614-626, 2021 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-33933543

RESUMO

The potential use of nopal cladode flour (NC) as reinforcing/bioactive agent in cassava starch-based films was evaluated and compared with the use of propolis extract or lignin, which are commonly used for these purposes. Cassava starch-based films containing untreated NC (S-NC), NC treated at pH 12 (S-NC12), aqueous propolis extract at two different concentrations (SP1 or SP2), or lignin (S-L) were produced by the casting technique; glycerol was used as plasticizer. NC12 and NC affected the mechanical properties of the cassava starch-based film similarly as compared to propolis extract and lignin. Moreover, NC and NC12 had different performance as reinforcing and antioxidant agent in cassava starch-based film. Thus, S-NC12 film was more elongable (28.5 ± 6.5%), more hydrophobic (contact angle: 70.8° ± 0.1), less permeable to water vapor (0.8 ± 0.0 × 10-10 g·m-1·s-1·Pa-1) and had better antioxidant activity by ABTS•+ (44.70 ± 0.3 µM Trolox·g-1 of film) than the S-NC film. SEM and TGA analysis of films showed that NC12 was better incorporated into the cassava starch matrix than NC, lignin and propolis extract. Overall, nopal cladode flour has potential use in the production of active biodegradable packaging for the food preservation with high oxidation rate.


Assuntos
Antioxidantes/farmacologia , Filmes Comestíveis , Aditivos Alimentares/farmacologia , Embalagem de Alimentos , Conservação de Alimentos , Lignina/farmacologia , Manihot , Opuntia , Própole/farmacologia , Amido/farmacologia , Antioxidantes/isolamento & purificação , Aditivos Alimentares/isolamento & purificação , Interações Hidrofóbicas e Hidrofílicas , Manihot/química , Opuntia/química , Amido/isolamento & purificação
3.
Int J Biol Macromol ; 183: 55-67, 2021 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-33857520

RESUMO

In recent years, suitable bioactive materials coated nanoparticles have attracted substantial attention in the field of biomedical applications. The present study emphasizes experimental details for the synthesis of boiling rice starch extract (BRE) coated iron oxide nanoparticles (IONPs) to treat cancer by photoacoustic imaging (PAI)-guided chemo-photothermal therapy. The solvothermal method was used to synthesize IONPs. The physical immobilization method helps to coat BRE-loaded doxorubicin (DOX) molecules on the iron oxide surface. In vitro drug release was estimated in basic (pH 9.0), neutral (pH 7.2), and acidic (pH 4.5) media for varying time periods using ultraviolet-visible spectroscopy. The chemical and physical properties of the synthesized spherical BRE-IONPs were characterized using sophisticated analytical instrumentation. A magnetic saturation experiment was performed with BRE-IONPs for evaluating possible hyperthermia in targeted drug delivery. The biological activity of the synthesized BRE-IONPs was investigated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay and acridine orange/propidium iodide fluorescence cell viability study. BRE-IONPs showed excellent photothermal stability, with a high photothermal conversion efficiency (η = 29.73%), biocompatible property, and high near-infrared region absorption for PAI-guided PTT treatment. This study will provide a better understanding of rice starch as a suitable bioactive coating material for possible theranostic applications.


Assuntos
Antibióticos Antineoplásicos/farmacologia , Neoplasias Ósseas/terapia , Doxorrubicina/farmacologia , Nanopartículas Magnéticas de Óxido de Ferro/química , Oryza , Osteossarcoma/terapia , Técnicas Fotoacústicas , Terapia Fototérmica , Amido/farmacologia , Nanomedicina Teranóstica , Antibióticos Antineoplásicos/química , Neoplasias Ósseas/diagnóstico por imagem , Neoplasias Ósseas/metabolismo , Linhagem Celular Tumoral , Preparações de Ação Retardada , Doxorrubicina/química , Portadores de Fármacos , Liberação Controlada de Fármacos , Humanos , Concentração de Íons de Hidrogênio , Cinética , Oryza/química , Osteossarcoma/diagnóstico por imagem , Osteossarcoma/metabolismo , Amido/isolamento & purificação
4.
Int J Biol Macromol ; 173: 13-25, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33482201

RESUMO

In this study, cassava starch aldehyde was functionalized with catechin through acid catalyzed condensation reaction. The structural characterization, stability and antioxidant activity of starch aldehyde-catechin conjugates were investigated. Thin layer chromatography revealed the conjugates did not contain free catechin. UV-vis spectra of the conjugates exhibited an absorption band at 280 nm, attributing to the B-ring of catechin moiety. Fourier-transform infrared and proton nuclear magnetic resonance spectroscopy demonstrated the conjugation occurred between the H-6/H-8 of catechin A-ring and the aldehyde groups of starch aldehyde. X-ray diffraction pattern indicated that the conjugates had an amorphous structure. Scanning electron microscopy showed the conjugates were fragmentary slices with rough surfaces. Notably, the conjugates were more stable than catechin in phosphate buffered saline (pH 7.4). In addition, the conjugates could not be digested in simulated saliva, gastric and small intestinal juices. The reducing power and free radical scavenging activity of starch aldehyde were remarkably elevated by conjugating with catechin. Meanwhile, the conjugates were non-cytotoxic to RAW264.7 mouse macrophage cells and possessed higher resistant starch contents than starch. Our results suggest starch aldehyde-catechin conjugates can be used as antioxidants in food industry.


Assuntos
Aldeídos/química , Antioxidantes/síntese química , Catequina/química , Glicoconjugados/síntese química , Manihot/química , Amido/análogos & derivados , Animais , Antioxidantes/farmacologia , Materiais Biomiméticos/química , Sobrevivência Celular/efeitos dos fármacos , Estabilidade de Medicamentos , Tecnologia de Alimentos , Suco Gástrico/química , Glicoconjugados/farmacologia , Humanos , Camundongos , Células RAW 264.7 , Saliva/química , Amido/isolamento & purificação
5.
Int J Biol Macromol ; 172: 439-451, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33453260

RESUMO

The aim of this research work was to investigate novel tools given by nanotechnology and green chemistry for improving the disadvantages typically associated to the starch-based films: water susceptibility and brittle mechanical behavior. With this in mind, four food packaging film systems were developed from corn starch or corn starch nanocrystals (SNCs), and modified by phosphating under reactive extrusion (REx) conditions using sodium tripolyphosphate (Na5P3O10 - TPP) as a crosslinker. The structural, physicochemical, thermal, rheological and mechanical properties, as well as studies associated with the management of carbohydrate polymer-based plastic wastes (biodegradability and compostability) were carried out in this study. The hierarchical structure and the modification of the starch were dependent on the amylose content and degree of substitution (DS), which in turn depended on the hydrogen (H)-bonding interactions. In both cases, a higher molecular ordering of the starch chains in parallel was decisive to obtain the self-assembled thermoplastic starches. Beyond the valuable results obtained and scientifically analyzed, unfortunately none of the manufactured materials achieved to improve their performance compared to the control film (thermoplastic starch - TPS). It was even thought that the phosphated starch-based films could fertilize lettuce (Lactuca sativa) seedlings during their biodegradation, and this was not achieved either. This possibly due to the low content of phosphorus or its poor bioavailability.


Assuntos
Embalagem de Alimentos/métodos , Nanopartículas/química , Polifosfatos/química , Amido/química , Amilose/análise , Humanos , Ligação de Hidrogênio , Membranas Artificiais , Nanopartículas/ultraestrutura , Fosforilação , Amido/isolamento & purificação , Zea mays/química
6.
Mol Biol Rep ; 47(12): 9499-9509, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33237398

RESUMO

All flowering plants have evolved through multiple rounds of polyploidy throughout the evolutionary process. Intergenomic interactions between subgenomes in polyploid plants are predicted to induce chromatin modifications such as histone modifications to regulate expression of gene homoeologs. Nicotiana benthamiana is an ancient allotetraploid plant with ecotypes collected from climatically diverse regions of Australia. Studying the chromatin landscape of this unique collection will likely shed light on the importance of chromatin modifications in gene regulation in polyploids as well its implications in adaptation of plants in environmentally diverse conditions. Generally, chromatin immunoprecipitation and high throughput DNA sequencing (ChIP-seq) is used to study chromatin modifications. However, due to the starchy nature of mature N. benthamiana leaves, previously published protocols were unsuitable. The higher amounts of starch in leaves that co-precipitated with nuclei hindered downstream processing of DNA. Here we present an optimised ChIP protocol for N. benthamiana leaves to facilitate comparison of chromatin modifications in two closely related ecotypes. Several steps of ChIP were optimised including tissue harvesting, nuclei isolation, nuclei storage, DNA shearing and DNA recovery. Commonly available antibodies targeting histone 3 lysine 4 trimethylation (H3K4me3) and histone 3 lysine 9 dimethylation (H3K9me2) histone modifications were used and success of ChIP was confirmed by PCR and next generation sequencing. Collectively, our optimised method is the first comprehensive ChIP method for mature starchy leaves of N. benthamiana to enable studies of chromatin landscape at the genome-wide scale.


Assuntos
Imunoprecipitação da Cromatina/métodos , Código das Histonas , Histonas/metabolismo , Nicotiana/metabolismo , Proteínas de Plantas/metabolismo , Processamento de Proteína Pós-Traducional , Acetilação , Cromatina/química , Cromatina/metabolismo , Histonas/genética , Metilação , Fosforilação , Células Vegetais/química , Células Vegetais/metabolismo , Folhas de Planta/química , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Amido/isolamento & purificação , Amido/metabolismo , Sumoilação , Tetraploidia , Nicotiana/química , Nicotiana/genética , Ubiquitinação
7.
PLoS One ; 15(9): e0229841, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32946470

RESUMO

Starch based gluten-free bread (formulations containing mixture of corn and potato starch with hydrocolloids) are deficient in nutrients and do not contain health promoting compounds. Therefore they could be supplemented with raw materials rich in such components, especially antioxidants. Among them pseudo-cereals, seeds, fruits and vegetables are often applied to this purpose. Potato pulp produced by processing red fleshed (Magenta Love) and purple fleshed (Violetta) varieties could become a new innovative substrate for gluten-free bread enrichment, because of high levels of endogenous polyphenols, namely flavonoids, flavonols, phenolic acids and especially anthocyanins with high antioxidant potential, as well as dietary fiber. Study material consisted of gluten-free bread enriched in the pulp. Dietary fiber, acrylamide content and antioxidant and antiradical potential of the bread were determined. Sensory evaluation included crumb elasticity, porosity and other characteristics, taste and smell. Among all analyzed gluten-free breads, the sample containing 7.5% share of freeze-dried red potato pulp Magenta Love was characterized by high content of phenolic compounds and dietary fiber, pronounced antioxidant activity, low levels of potentially dangerous acrylamide and good physical and sensory characteristics. Therefore such an addition (7.5% Magenta Love) could be recommended for industrial production of gluten-free bread.


Assuntos
Pão , Farinha/análise , Ingredientes de Alimentos/análise , Solanum tuberosum/química , Verduras/química , Acrilamida/análise , Antioxidantes/análise , Doença Celíaca/dietoterapia , Doença Celíaca/imunologia , Fibras na Dieta/análise , Liofilização/métodos , Glutens/imunologia , Humanos , Valor Nutritivo , Polifenóis/análise , Porosidade , Olfato , Amido/isolamento & purificação , Paladar
8.
Int J Biol Macromol ; 156: 144-152, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32251750

RESUMO

Gelatinization and retrogradation characteristics of starches from tigernut (Cyperus esculentus) tuber before and after various oil extraction processes were studied in this investigation. The results indicated that starches isolated from tigernut tuber after the various oil extraction processes varied significantly in gelatinization and retrogradation properties. The starches isolated from the cakes of tigernut tuber after hot press extraction exhibited higher retrogradation tendency and relatively less shear-thinning than other starch samples. The results of FT-IR, XRD, and NMR analysis indicated that oil extraction had an unfavorable influence on starch retrogradation, which may be due to structural changes caused by oil extraction processes. In particular, oil extraction led to more efficient packing of double helices in the crystalline lamella of the starches during storage. Retrogradation of the starch gels also reduced the water holding capacities of the starches. The starch sample isolated from the cake after cold press extraction exhibited the highest water absorption capacity among the five samples for all storage times. This investigation provides valuable novel information for the industrial utilization of tigernut tuber starches isolated from meals and cakes after oil extraction.


Assuntos
Cyperus/química , Gelatina/química , Óleos de Plantas/isolamento & purificação , Tubérculos/química , Amido/química , Fracionamento Químico/métodos , Cristalização , Tecnologia de Alimentos , Géis/química , Espectroscopia de Ressonância Magnética , Microscopia Eletrônica de Varredura , Pomadas/química , Óleos de Plantas/química , Reologia , Resistência ao Cisalhamento , Espectroscopia de Infravermelho com Transformada de Fourier , Amido/isolamento & purificação , Amido/ultraestrutura , Termogravimetria , Viscosidade , Água/química , Difração de Raios X
9.
PLoS One ; 14(8): e0221351, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31437204

RESUMO

In recent years, the sweet potato cultivar Jishu 25 has exhibited good characteristics for starch processing in northern China. The storage root dry matter yields of this cultivar can exceed one ton per mu (1/15 of a hectare) at nitrogen (N) rates of 60-90 kg ha-1 based on soil nutrient content. However, the effect of N fertilizer on the physicochemical properties of starches isolated from this cultivar has not been reported. In order to evaluate these effects, three different N rates, 0 (control, N0), 75 (N1), and 150 kg ha-1 (N2), were selected for a field experiment in 2017. The results showed that N1 exhibited the highest storage root yield and starch yield. Compared to the control group, N fertilizer significantly increased the total starch content while no significant difference was found in these between the N1 and N2 groups. The amylose (AM) content was highest in the N2 group and lowest in the N0 group. In addition, N fertilizer exhibited no significant effects on the values of [D(v, 0.9)], D [4, 3] and D [3, 2]. Compared to the control group, N1 demonstrated significantly higher setback viscosity (SV), while N2 showed significantly higher peak viscosity (PV), cold paste viscosity (CPV) and SV. However, there were no significant differences in the hot paste viscosity (HPV), peak time and pasting temperature between the N1 and N2 groups. For the thermal properties of starch, there were no significant differences in peak temperature (Tp), conclusion temperature (Tc) or gelatinization enthalpy (ΔH) between the N1 and N2 groups. Overall, for the starch samples of cultivar Jishu 25, N fertilizer exerts significant effects on the starch content, AM content and viscosity properties but little effect on the particle size distribution and ΔH. 75 kg N ha-1 can easily lead to substantial planting benefits from the high storage root yield, dry matter yield and total starch content of this cultivar.


Assuntos
Fertilizantes , Ipomoea batatas/efeitos dos fármacos , Nitrogênio/farmacologia , Raízes de Plantas/efeitos dos fármacos , Amido/química , China , Análise de Alimentos/métodos , Humanos , Ipomoea batatas/crescimento & desenvolvimento , Ipomoea batatas/metabolismo , Nitrogênio/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Amido/biossíntese , Amido/isolamento & purificação , Temperatura , Viscosidade
10.
Pak J Pharm Sci ; 31(6): 2435-2442, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30473515

RESUMO

The binding properties of banana (Musa paradisiaca) starchwas investigated using maize starch BP and polyvinylpyrrolidone (PVP) as standards in the formulation of metformin tablets. Starch from unripe banana fruits was extracted with distilled water. Mucilages of the banana and maize starches and solutions of PVP at 5 and 10 %w/v were used to produce metformin granules by wet granulation and compressed into tablets. Granules and tablets properties were evaluated. Compatibility studies using differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) were also carried out. Granules flow properties was of the order: PVP>banana starch > maize starch. DSC and FTIR analysis reveals no interaction between excipients and metformin. Increase in concentration of banana starch mucilage from 5-10% w/v led to an increase in hardness, disintegration time and decrease in friability of the tablets. Tablets of banana starch mucilages were comparable in tablet properties with those of maize starch mucilages and PVP solutions with no significant differences (p<0.05). The tablets exhibited crushing strength, friability and disintegration time values ranging from 6.75-12.00 kp, 0.82-1.50 % and 11.04-14.51 min, respectively. The tablet parameters met compendial requirements at binder concentrations studied except friability values for tablets of PVP. Results revealed that banana starch could be used as a binding agent in metformin tablet formulation due to its comparable binding property with maize starch BP and PVP.


Assuntos
Excipientes/química , Hipoglicemiantes/química , Metformina/química , Musa/química , Amido/química , Varredura Diferencial de Calorimetria , Força Compressiva , Composição de Medicamentos , Liberação Controlada de Fármacos , Frutas , Dureza , Povidona/química , Pós , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Amido/isolamento & purificação , Comprimidos , Tecnologia Farmacêutica/métodos , Zea mays/química
11.
J Food Sci ; 82(12): 2794-2804, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29194598

RESUMO

Chemical composition, granular morphology and pasting properties of native starch extracted from tubers of Plectranthus edulis were analyzed. Starch was extracted from tubers of 6 accessions collected from 4 different areas in Ethiopia. Particle size analysis (PSA) and cryo-scanning electron microscope (cryo-SEM) imaging were used to examine the granular morphology and visualize the starch paste, respectively. Pasting properties, water absorption, and gelation capacity were compared. A wide range was found for the amylose (14.2% to 23.9%), calcium (216 to 599), potassium (131 to 878), and phosphorus (1337 to 2090) contents (parts per million per dry matter). PSA showed a bimodal distribution containing small spherical (14.6 µm) and large ellipse-shaped (190.4 µm) granules. Major differences were found for the pasting with peak viscosities differing from 3184 to 7312 mPa⋅s. Starch from accessions Chencha and Inuka showed a difference in packing density as clearly seen through cryo-SEM image at 75% of the peak viscosity (PV), and the granular integrity was mainly responsible for the significant difference in their PV and breakdown. Principal component analysis revealed 2 distinct groups: native starch extracted from accessions at the Wolayta zone (Inuka, Lofua, and Chenqoua) and other accessions (Jarmet, Arjo white, and Chencha). The study revealed the potential of P. edulis starch for its application in food industries. However, the inherent variation due to environmental conditions on physicochemical properties of the starch needs further investigation. PRACTICAL APPLICATION: Plectranthus edulis is cultivated in considerable amounts throughout Ethiopia, which makes it a valuable starch source. Due to its low tendency to retrograde, it could be applied in food industry as an equivalent for the current starch sources. Moreover, the low amylose content makes it preferable for an application in refrigerated foods as this unique quality trait prevents syneresis in end products during storage. Based on the significantly higher pasting temperature of the studied P. edulis starch extracts, it can form an alternative for potato starch, which is less suitable for its use in pasteurized foods.


Assuntos
Extratos Vegetais/química , Plectranthus/química , Amilose/química , Amilose/isolamento & purificação , Extratos Vegetais/isolamento & purificação , Tubérculos/química , Amido/química , Amido/isolamento & purificação , Temperatura , Viscosidade , Água/análise
12.
Acta Pol Pharm ; 73(2): 469-78, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27180440

RESUMO

In the past few years, there are number of researchers carrying out their research on the excipients derived from polysaccharides and some of these researches show that natural excipients are comparable and can serve as an alternative to the synthetic excipients. Hence, the objectives of this research are to characterize the naturally sourced chickpea starch powder and to study the pharmaceutical excipient behavior of chickpea starch in gliclazide immediate release (IR) tablets. In this research, the binding properties of chickpea starch were compared to that of povidone, whereas the disintegrant properties of chickpea starch were compared to those of crospovidone, croscarmellose sodium and sodium starch glycolate. Flow property of chickpea starch was assessed with the measurement of bulk density, tapped density, compressibility index and angle of repose. Calibration curve for gliclazide in phosphate buffer pH 7.4 was developed. Gliclazide IR tablets were then produced with direct compression method. Physicochemical characteristics of the tablets, including thickness, tablet weight uniformity, hardness, disintegration time and friability were evaluated. Then, in vitro dissolution studies were performed by following United States Pharmacopeia (USP) dissolution method. The dissolution results were analyzed and compared with t30, t50, dissolution efficiency (DE). Lastly, drug-excipient compatibility studies, including Fourier transform infrared (FTIR) spectroscopic analysis and differential scanning calorimetric (DSC) analysis were carried out. Fair flow property was observed in the chickpea starch powder. Furthermore, the tablets produced passed all the tests in physicochemical characteristics evaluation except hardness and disintegration test. Additionally, in vitro dissolution studies show that chickpea starch acted as a disintegrant instead of a binder in gliclazide IR tablets and its disintegrant properties were comparable to those of crospovidone, croscarmellose sodium and sodium starch glycolate. Besides that, gliclazide was also compatible with the excipients used. Chickpea starch acted as a disintegrant in gliclazide IR tablets, instead of a binder. Therefore, chickpea starch can be a promising disintegrant in gliclazide IR tablets.


Assuntos
Cicer/química , Excipientes/química , Gliclazida/química , Hipoglicemiantes/química , Amido/química , Varredura Diferencial de Calorimetria , Carboximetilcelulose Sódica/química , Química Farmacêutica , Excipientes/isolamento & purificação , Concentração de Íons de Hidrogênio , Cinética , Povidona/química , Pós , Reologia , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Amido/análogos & derivados , Amido/isolamento & purificação , Comprimidos , Tecnologia Farmacêutica/métodos
13.
J Food Sci ; 81(6): T1576-84, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27159878

RESUMO

In this study detoxification of 3 Chinese Cd-contaminated cultivars (Jinyou463, Yuchi, and Xiangzaoxian 32) of rice was explored. By separation with an alkaline method, Cd concentrations of the starch isolates were decreased from 0.2769, 0.4037, and 0.5156 mg/kg in starting milled rice to 0.1056, 0.1585, and 0.1923 mg/kg, respectively. However, the Cd concentrations reached up to 2.5905, 3.1628, and 4.8593 mg/kg in the protein isolates, respectively. Therefore, 10 common acids in food industry were investigated to remove Cd from protein isolate by washing process. The optimal washing conditions were 0.5 M citric acid, acid to rice protein isolate ratio of 6:1 v/w, shaking time of 1 h at room temperature. The rice protein isolate showed a significant decrease in Cd concentration and the removal efficiency was more than 95% after 2 washings at optimized conditions. Rice proteins were not degraded at all and had very little loss during citric acid washing process. The study presents a promising way of depurating Cd-contaminated rice, and meanwhile it reduces the risk of heavy metal causing food safety issues effectively.


Assuntos
Cádmio/isolamento & purificação , Oryza/química , Proteínas de Plantas/química , Ácido Cítrico/química , Contaminação de Alimentos/análise , Manipulação de Alimentos , Concentração de Íons de Hidrogênio , Metais Pesados/isolamento & purificação , Peso Molecular , Proteínas de Plantas/isolamento & purificação , Amido/química , Amido/isolamento & purificação
14.
Carbohydr Polym ; 124: 245-53, 2015 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-25839818

RESUMO

Microgels synthesized with different crosslinking densities were characterized by Fourier transform infrared (FT-IR) spectroscopy, thermogravimetry analysis (TGA), swelling, and rheological analyses. The lysozyme uptake capacity of these microgels was evaluated through the effects of lysozyme concentration, pH, and ionic strength. The microgel particle size mostly ranged within 25µm to 45µm. FT-IR analysis results suggested that sodium trimetaphosphate reacted with the hydroxyl groups of carboxymethyl starch (CMS), thereby forming ester linkages. TGA data indicated that crosslinking increased the thermal stability of CMS. Swelling degree increased with increasing pH before pH 5, and then remained almost constant. However, swelling degree decreased with increasing ionic strength and crosslinking density. The microgels behaved as viscoelastic solids because the storage modulus was higher than the loss modulus over the entire frequency range of dispersions with polymer concentrations of 3% (W/W) at 25°C. The data for the uptake of lysozyme by microgels demonstrated that the protein uptake increased with increasing pH and lysozyme concentration, as well as with decreasing ionic strength and crosslinking density. The lysozyme-microgels complex was identified by CLSM, and the distribution of lysozyme in microgels with low crosslinking density was rather homogeneous.


Assuntos
Géis/química , Amido/análogos & derivados , Módulo de Elasticidade , Concentração de Íons de Hidrogênio , Microscopia Confocal , Muramidase/metabolismo , Concentração Osmolar , Tamanho da Partícula , Polifosfatos/química , Reologia , Espectroscopia de Infravermelho com Transformada de Fourier , Amido/química , Amido/isolamento & purificação , Amido/metabolismo , Termogravimetria
15.
Food Chem ; 172: 433-40, 2015 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-25442575

RESUMO

The physicochemical properties of starches isolated from 14 rice cultivars produced in China were investigated. These rice starches showed a non-random combination of AAC and GT. Rice starches showed a typical A-type diffraction pattern with the degree of crystallinity ranging from 32.3% (a high AAC rice) to 45.5% (a waxy rice). AAC was significantly correlated with the pasting, thermal and textural properties. The positive correlations were found with PV, HPV, CPV, SB and HD (p<0.05), while the negative corrections were found with SP, ADH, COH, T(o), T(p), T(c) and ΔH (p<0.05). However, AAC had no correlations with BD, PTime and percentage of retrogradation (R%). The degree of crystallinity and GT had a positive correlation with the retrogradation properties. It could be concluded that although AAC was the major factor affecting the physicochemical properties of rice starch, the retrogradation property of rice starch was mainly determined by the degree of crystallinity and GT.


Assuntos
Amilose/análise , Géis/química , Oryza/metabolismo , Amido/química , Adesividade , Dureza , Microscopia Eletrônica de Varredura , Oryza/química , Solubilidade , Amido/isolamento & purificação , Temperatura de Transição , Difração de Raios X
16.
Food Chem ; 172: 528-36, 2015 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-25442588

RESUMO

The grain and flour characteristics of different field pea (FP) accessions were evaluated. Accessions with higher grain weight had less compact structure with a greater proportion of large-sized starch granules. Accessions with higher protein content had lower starch content, blue value and λ(max) whereas accessions with higher amylose showed higher resistant starch (RS) and final viscosity and lower rapidly digestible starch (RDS). Ca, Zn, K and Fe content vary significantly amongst different accessions and creamish green and white seeds accessions showed higher Fe and Zn content. Yellow coloured accessions (1.36-3.71%) showed lower antioxidant activity as compared to brownish and green coloured accessions (4.06-9.30%). Out of 21 major polypeptides observed (9-100 kDa), 11 showed differential trypsin inhibitory activity (TIA) under non-reducing conditions. Polypeptides of 68, 46, 33 and 22 kDa showed prominent TIA.


Assuntos
Pisum sativum/metabolismo , Proteínas de Plantas/metabolismo , Amilose/análise , Antioxidantes/química , Eletroforese em Gel de Poliacrilamida , Farinha/análise , Metais/análise , Pisum sativum/química , Fenóis/química , Sementes/química , Sementes/metabolismo , Amido/química , Amido/isolamento & purificação , Inibidores da Tripsina/análise , Viscosidade
17.
Appl Microbiol Biotechnol ; 99(4): 1745-53, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25190667

RESUMO

Polyphenol oxidase (PPO) has multiple functions, and the lack of commercially available enzyme sources limits its widespread application in various industries. An accurate PPO assay was developed by HPLC determination of the substrate oxidation. Resources screening indicated that sweet potato (Ipomoea batatas L.) wastewater in starch production has high PPO activity. A procedure was developed for separately recovering PPO, ß-amylase, sporamins, and small molecular nutrients (SMNs) from sweet potato wastewater. The wastewater was adjusted to pH 3.5 to precipitate PPO, and then adjusted to 50 % acetone to precipitate ß-amylase and further to 80 % acetone to precipitate sporamins. The SMNs were obtained after acetone recovery. Purified powders of 4.3 × 10(5) units of PPO, 4.0 × 10(6) units of ß-amylase, 8.70 g sporamins, and 20.2 g SMNs were obtained from the wastewater of 1 kg sweet potato. More than 50 million tons of sweet potato is used for starch production annually around the world. Through this simple procedure, huge amount of biochemical resources can be recovered from the wastewater, which greatly increases the economic value of the crop and saves the environment.


Assuntos
Catecol Oxidase/isolamento & purificação , Ipomoea batatas/química , Amido/isolamento & purificação , Águas Residuárias/análise , Fracionamento Químico , Precipitação Química , Proteínas de Plantas/isolamento & purificação , beta-Amilase/isolamento & purificação
18.
Br J Nutr ; 107(8): 1147-59, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21875448

RESUMO

The potential benefits on human health have prompted an interest in developing nutritional strategies for reducing saturated and increasing specific unsaturated fatty acids (FA) in ruminant milk. The impact of the level and type of starchy concentrate added to diets supplemented with sunflower-seed oil on caprine milk FA composition and on mammary, omental and perirenal adipose, and liver lipid metabolism was examined in fourteen Alpine goats in a replicated 3 × 3 Latin square with 21 d experimental periods. Treatments were a grass hay-based diet with a high level of forage (F) or a high level of concentrate with either maize grain (CM) or flattened wheat (CW) as source of starch and supplemented with 130 g/d sunflower-seed oil. Milk yield was enhanced (P<0·01) and milk fat content was decreased on the CM and CW diets compared with the F diet, resulting in similar milk fat secretion. Both high-concentrate diets increased (P<0·05) milk yield of 10 : 0-16 : 0 and decreased trans-9,11-18 : 1 and cis-9, trans-11-18 : 2. The CW diet decreased (P<0·05) the output of ΣC18 and Σcis-18 : 1 and increased (P<0·05) the output of trans-10-18 : 1 in milk. The expression and/or activity of fourteen proteins involved in the major lipogenic pathways in mammary tissues and of lipogenic genes in adipose and liver tissues were similar among treatments. In conclusion, high starch concentrates alter milk FA yield via mechanisms independent of changes in mammary, liver or adipose tissue lipogenic gene expression. Furthermore, data provided indications that mammary lipogenic responses to starch-rich diets differ between caprine and bovine ruminants.


Assuntos
Ácidos Graxos/análise , Metabolismo dos Lipídeos , Lipogênese/genética , Leite/química , Óleos de Plantas/administração & dosagem , Amido/administração & dosagem , Tecido Adiposo/metabolismo , Fenômenos Fisiológicos da Nutrição Animal , Animais , Sequência de Bases , Bovinos , Ácidos Graxos/metabolismo , Feminino , Expressão Gênica , Cabras , Humanos , Lactação , Fígado/metabolismo , Glândulas Mamárias Animais/metabolismo , Leite/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Especificidade da Espécie , Amido/isolamento & purificação , Óleo de Girassol , Triticum , Zea mays
19.
Pak J Pharm Sci ; 24(4): 415-20, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21959799

RESUMO

The main purposes of this study are to prepare cross-linked carboxymethyl jackfruit starch (CL-CMJF) and to evaluate its pharmaceutical property as a tablet disintegrant. CL-CMJF was prepared by a dual carboxymethyl-crosslinking reaction in a flask containing jackfruit seed starch (JFS), chloroacetic acid (CAA), sodium hydroxide (NaOH) and sodium trimetaphosphate (STMP). The reaction was carried out using methanol as a solvent for 60 min at 70°C and at JFS:CAA:NaOH:STMP ratio of 1.0:0.29:0.28:0.07. The obtained CL-CMJF, with degree of substitution and degree of crosslinking calculated to be 0.34 and 0.06, respectively, was insoluble but swellable in water. Rheological study revealed a decreased in solution viscosity compared to the non-crosslinked CMJF. The water uptake of CL-CMJF was 23 times higher than that of native starch and was comparable to that of a commercial superdisintegrant, sodium starch glycolate (SSG). The swelling ability of CL-CMRS was similar to that of crosscarmellose sodium (CCS), another commercial superdisintegrant. Disintegration test of aspirin tablets containing 2%w/w of JFS, CL-CMJF, SSG and CCS showed disintegration times in the order of SSG < CCS ~ CL-CMJF <<< JFS. The results suggested that CL-CMJF could be developed as a tablet disintegrant.


Assuntos
Artocarpus/química , Excipientes/química , Amido/análogos & derivados , Comprimidos/química , Acetatos/química , Aspirina/administração & dosagem , Carboximetilcelulose Sódica/química , Reagentes de Ligações Cruzadas/química , Excipientes/síntese química , Microscopia Eletrônica de Varredura , Polifosfatos/química , Sementes/química , Solubilidade , Amido/síntese química , Amido/química , Amido/isolamento & purificação , Viscosidade , Água/química , Difração de Raios X
20.
J Appl Genet ; 51(4): 431-47, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21063061

RESUMO

The starch and protein in wheat (Triticum aestivum L.) endosperm provide 20 percent of the calories eaten by humans and were heavily selected for during domestication. We examined the main storage products and gene expression patterns that may embody compositional differences between two wild species Aegilops crassa and Aegilops tauschii and cultivated bread wheat. The storage product profiles differed significantly with T. aestivum accumulating twice as much carbon as the wild species, while the latter had 1.5 to 2-fold more total nitrogen per seed. Transcriptional analyses of endosperms of similar fresh weight were compared using a cDNA macroarray. Aegilops tauschii, and especially Ae. crassa had stronger hybridizations with storage protein sequences, but while there were differences in transcripts for starch biosynthetic genes, they were less dramatic. Of these, we cloned the Starch Branching Enzymes (SBE) IIa promoter region and the genomic clone of the Brittle-1 (Bt1) ADPglucose transporter. While Ae. crassa SBEIIa sequence was more divergent than that of Ae. tauschii's compared to bread wheat, there were no sequence polymorphisms that would explain the observed expression differences in Bt1 between these species. Furthermore, while there were nucleotide differences between Bt1 in Ae. crassa and bread wheat, they were synonymous at the amino acid level. Some of transcriptional differences identified here, however, deserve further examination as part of a strategy to manipulate wheat starch and protein composition.


Assuntos
Agricultura , Endosperma/genética , Proteínas de Plantas/genética , Transcrição Gênica , Triticum/genética , Enzima Ramificadora de 1,4-alfa-Glucana/genética , Adenosina Difosfato Glucose/genética , Sequência de Aminoácidos , Sequência de Bases , DNA Complementar/genética , Endosperma/enzimologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Dados de Sequência Molecular , Análise Multivariada , Análise de Sequência com Séries de Oligonucleotídeos , Proteínas de Plantas/química , Proteínas de Plantas/isolamento & purificação , Proteínas de Plantas/metabolismo , Análise de Componente Principal , Regiões Promotoras Genéticas/genética , Análise de Sequência de DNA , Especificidade da Espécie , Amido/biossíntese , Amido/isolamento & purificação , Triticum/enzimologia
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