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1.
Microsc Res Tech ; 83(5): 490-498, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32319189

RESUMO

Starch granules from rice and corn were isolated, and their molecular mechanism on interaction with α-amylase was characterized through biochemical test, microscopic imaging, and spectroscopic measurements. The micro-scale structure of starch granules were observed under an optical microscope and their average size was in the range 1-100 µm. The surface topological structures of starch with micro-holes due to the effect of α- amylase were also visualized under scanning electron microscope. The crystallinity was confirmed by X-ray diffraction patterns as well as second-harmonic generation microscopy. The change in chemical bonds before and after hydrolysis of the starch granules by α- amylase was determined by Fourier transform infrared spectroscopy. Combination of microscopy and spectroscopy techniques relates structural and chemical features that explain starch enzymatic hydrolysis which will provide a valid basis for future studies in food science and insights into the energy transformation dynamics.


Assuntos
Oryza/ultraestrutura , Amido/metabolismo , Amido/ultraestrutura , Zea mays/ultraestrutura , alfa-Amilases/metabolismo , Hidrólise , Microscopia Eletrônica de Varredura , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
2.
Sci Rep ; 10(1): 4097, 2020 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-32139712

RESUMO

In this study resistant starch (RS) was extracted from five Himalayan rice cultivars and Indian Horse chestnut (HCN) using porcine pancreatin enzyme following which it was subsequently characterized for its physicochemical, structural and functional properties. In vitro digestibility test showed that RS content of the rice cultivars and HCN was in the range of 85.5 to 99.5%. The RS extracted from the rice cultivars and HCN showed significant difference in the apparent amylose content (AAC), ranging between 31.83 to 40.68% for rice and 45.79% for HCN. Water absorption capacity (WAC), swelling and solubility index of RS ranged from 112-133.9%, 5.28-7.25 g/g and 0.033-0.044 g/g, respectively. The rice RS granules were polyhedral and irregular shaped with granular length in the range of 4.8-5.9 µm. The HCN RS granule morphology showed smooth surfaced, round, elliptical, irregular and oval shapes with average granular length of 21 µm. Pasting behavior also varied significantly between rice RS and HCN RS with later showing the lower values of pasting properties. Thermal properties (T0, Tp, Tc) and ΔH gel also varied considerably between the rice RS and HCN RS, wherein the highest values for peak gelatinization temperature and gelatinization enthalpy were seen for CH-1039. X-ray diffraction pattern of rice RS and HCN RS showed the characteristic A type of pattern in consonance with cereal starches.


Assuntos
Aesculus/química , Oryza/química , Amido/química , Amido/isolamento & purificação , Amilose/isolamento & purificação , Digestão , Especificidade da Espécie , Espectroscopia de Infravermelho com Transformada de Fourier , Amido/metabolismo , Amido/ultraestrutura , Água , Difração de Raios X
3.
Food Chem ; 318: 126489, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32135425

RESUMO

In the present study, starches isolated from heat-moisture treated (HMT) adlay seeds were characterized with hierarchical structures and digestibility to understand the relationships in structural and digestible behaviors of starches in a HMT starch-based food system. The results indicated that HMT not only caused the disorganizations of hierarchical structures, but also promoted the molecular rearrangements and reassembly of starch chains to form a new ordered molecular aggregation architecture (i.e., highly ordered molecular structure, amylose-lipids complexes and thicker crystalline lamella). And the reinforced molecular interactions between starch molecules during HMT occurred to form more densely ordered structure, thus reducing the digestibility and digestion rate coefficients (k) of adlay starch. Particularly, HMT applied directly in adlay seeds with 30% moisture content displayed the highest resistant starch level (20.6%) and lowest k (2.74 × 10-3 min-1). Thus, the results are useful to realize the desired regulation of starch digestibility in adlay products following HMT.


Assuntos
Amilose/química , Coix/química , Lipídeos/química , Estrutura Molecular , Amido/química , Digestão , Temperatura Alta , Microscopia Eletrônica de Varredura , Sementes/química , Amido/ultraestrutura , Água/química
4.
Plant Mol Biol ; 103(3): 355-371, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32193789

RESUMO

KEYMESSAGE: Biphasic starch granules in maize ae mutant underwent the weak to strong SBEIIb-defective effect during endosperm development, leading to no birefringence in their exterior due to extended long branch-chains of amylopectin. Biphasic starch granules are usually detected regionally in cereal endosperm lacking starch branching enzyme (SBE). However, their molecular structure, formation mechanism, and regional distribution are unclear. In this research, biphasic starch granules were observed in the inner region of crown endosperm of maize ae mutant, and had poorly oriented structure with comb-like profiles in their exterior. The inner endosperm (IE) rich in biphasic starch granules and outer endosperm (OE) without biphasic starch granules were investigated. The starch had lower amylose content and higher proportion of long branch-chains of amylopectin in IE than in OE, and the exterior of biphasic starch granules had less amylose and more long branch-chains of amylopectin than the interior. Compared with OE, the expression pattern of starch synthesis related enzymes changed significantly in IE. The granule-bound starch synthase I activity within biphasic starch granules decreased slightly. The IE experienced more severe hypoxic stress than OE, and the up-regulated anaerobic respiration pathway indicated an increase in carbon consumption. The starch in IE underwent the SBEIIb-defective effect from weak to strong due to the lack of sufficient carbon inflow, leading to the formation of biphasic starch granules and their regional distribution in endosperm. The results provided information for understanding the biphasic starch granules.


Assuntos
Enzima Ramificadora de 1,4-alfa-Glucana/metabolismo , Regulação Enzimológica da Expressão Gênica/fisiologia , Regulação da Expressão Gênica de Plantas/fisiologia , Amido/metabolismo , Zea mays/enzimologia , Enzima Ramificadora de 1,4-alfa-Glucana/classificação , Enzima Ramificadora de 1,4-alfa-Glucana/genética , Endosperma/enzimologia , Endosperma/ultraestrutura , Amido/ultraestrutura
5.
Int J Biol Macromol ; 147: 268-275, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31926233

RESUMO

In this study, characterization was conducted on resistant starch, isolated from different cultivars of V. unguiculata (Bechuana White, Fahari, PAN 311, TVU 11424 and DT 129-4). The fraction of resistant starch obtained was found in the range of 9.42-13.74%, with DT 129-4 yielding the highest fraction. Amylose content of the starches varied between 18.72 and 19.67%. Swelling power, solubility index and syneresis was directly proportional to the different temperatures. A correlation between amylose content and swelling power was observed as swelling power was indirectly proportional to amylose content. Water and oil absorption capacity was 31.93-88.06% and 10.29-27.71% respectively. Foaming, emulsion capacity, and stability were done, however, due to the lack of protein in the resistant starch samples, results obtained were relatively low, ranging between 0.00 and 22.41%. The degree of whiteness during colour analysis ranged between 80.81 and 84.61%. The FTIR-spectra displayed no distinctive difference amongst the vibration bands on the hydroxyl, methine and carbonyl frequency stretches and confirmed the polysaccharide nature of the resistant starch. The XRD spectra displayed a Ca-type crystalline structure for all 5 cultivars. Overall, this study shows that resistant starch has the potential to be used in many food applications and as a microencapsulation membrane.


Assuntos
Fenômenos Químicos , Amido/química , Amido/isolamento & purificação , Vigna/química , Cor , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Amido/ultraestrutura , Difração de Raios X
6.
Food Chem ; 314: 125082, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31982853

RESUMO

The structures and physicochemical properties of ginkgo starches from seven cultivars were investigated and their relationships analyzed. The ginkgo starches had oval or irregular shapes, size distributions with a unimodal peak, and an A-type crystal pattern. The fine structures, crystalline structures, and physicochemical properties varied significantly among these ginkgo starches. Pearson correlation analysis and a PCA loading plot indicated that amylopectin A-chains and amylose had negative effects on the IR ratio, Imax, and D, while amylopectin B-chains had a clear positive effect on the relative crystallinity. Furthermore, the amylopectin short B1-chains and long B-chains contributed amorphous and single-helix structures, respectively. The thermal properties of the ginkgo starches were mainly influenced by the amylopectin B-chains and Imax, while the pasting properties were mainly influenced by amylopectin B-chains and helical structures. These results indicated that the starch fine structures and crystalline structures had significant effects on the physicochemical properties.


Assuntos
Ginkgo biloba/química , Amido/química , Amilopectina/química , Amilose/química , Cristalografia por Raios X , Especificidade da Espécie , Amido/ultraestrutura
7.
Int J Biol Macromol ; 144: 67-75, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31816380

RESUMO

The objectives of this study were to investigate and compare the structural and physicochemical properties of native ginger starch (NGS) and ginger resistant starch (GRS). NGS had oblate and compact granules, whereas GRS exhibited fissures. Compared to GRS, NGS had a narrower molar mass distribution and a higher molecular weight (Mw). According to X-ray diffraction measurements, Fourier transform infrared spectroscopy, and 13C CP/MAS NMR spectroscopy, NGS sample had an A-type crystalline pattern with high relative crystallinity and short-range order structure, and GRS had a B-type crystalline pattern. Furthermore, NGS exhibited significantly higher gelatinization enthalpy than GRS. NGS displayed lower peak viscosity and final viscosity, whereas GRS had higher through viscosity and final viscosity, presumably due to the content and type of resistant starch. The pasting and gelatinization properties of NGS and GRS might be related to relative crystallinity and short-range order structure. The information obtained from this study can be used by manufacturers and researchers in the production of ginger-containing products.


Assuntos
Fenômenos Químicos , Gengibre/química , Amido/química , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Cristalização , Emulsões/química , Peso Molecular , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Amido/ultraestrutura , Temperatura
8.
Int J Biol Macromol ; 143: 704-713, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31783070

RESUMO

The present study aimed at developing edible composite films from pearl millet starch (PMS) and carrageenan gum (CG) blends. Central composite rotatable design of response surface methodology was used to optimize concentrations of PMS (2-5%), carrageenan (1-3.5%) and glycerol (15-35%) for the development of composite film. The optimization was done on the basis of responses viz. thickness, water vapor permeability (WVP), solubility and tensile strength (TS). Both starch and carrageenan concentrations positively affected the TS of films, whereas the reverse trend was observed with increased concentration of glycerol. The optimum level of different parameters resulting in a composite film with maximum TS and lower WVP and solubility values were obtained under conditions of 4.9% starch, 5% carrageenan and 15.73% plasticizer concentrations. The melting temperature of optimized PMS/CG film was higher than PMS film. Morphological studies exhibited homogeneous structure of PMS film while PMS/CG composite film had rough, coarser and slightly irregular surface. The stretched regions in Fourier-transform infrared spectroscopy and Differential Scanning Calorimeter analysis confirmed the miscibility and thermal stability of different components of PMS/CG composite films. The results indicated that the developed optimized PMS/CG film possessed lower WVP, solubility but higher transparency and TS in comparison to PMS film.


Assuntos
Carragenina/química , Pennisetum/química , Amido/química , Temperatura , Varredura Diferencial de Calorimetria , Carragenina/ultraestrutura , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Amido/ultraestrutura , Vapor , Resistência à Tração
9.
Int J Biol Macromol ; 144: 242-251, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31846657

RESUMO

The excessive use of disposable plastic material in our society demands packaging material which can undergo quick degradation without harming the environment. Agricultural products can serve as one of the essential sources for the production of biodegradable packaging material. In the present study, starch was isolated from mung bean and used for the synthesis of nano starch, and it's physicochemical, morphological, and film-forming properties were studied. The average particle size distribution of nano starch was 141.772 nm. Mung bean native starch granules were of oval shape having a smooth surface, free from cracks while mung bean nano starch appeared in an agglomerated form with irregular and rough surface. Nano starch-based composite films with varying concentrations (0.5, 1, 2, 5, and 10%) of nano starch were prepared by the solution casting method. The native starch film properties such as thickness (0.040 ± 0.010 mm), moisture content (8.03 ± 0.26%), water vapor transmission rate (5.982 × 10-3 ± 0.30 g-2 s-1), water solubility (38.49 ± 0.51%) and burst strength (868.49 ± 26.5 g) were observed. With the incorporation of nano starch at concentration of 0.5 to 10.0%, film properties such as thickness (0.043 ± 0.006 to 0.063 ± 0.006 mm), burst strength (943.56 ± 18.1 to 1265 ± 18.9 g), moisture content (6.09 ± 0.28 to 4.80 ± 0.48%), water vapor transmission rate (5.558 × 10-3 ± 0.25 to 3.364 × 10-3 ± 0.35 g-2 s-1) and solubility (37.99 ± 0.47 to 34.11 ± 0.40%) were improved.


Assuntos
Amido/química , Vigna/química , Amilose/análise , Biodegradação Ambiental , Varredura Diferencial de Calorimetria , Fenômenos Químicos , Difusão Dinâmica da Luz , Microscopia Eletrônica de Varredura , Solubilidade , Amido/isolamento & purificação , Amido/ultraestrutura , Vapor
10.
Int J Biol Macromol ; 144: 252-258, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31846664

RESUMO

This work concerns different cultivars of waxy maize starch (WMS), from which a significant correlation between the multi-scale structure and the digestibility has been identified. WMSs show a typical A-type crystalline polymorph. The surface porosity of WMS granules facilitates their digestibility. In contrast, the in vitro digestion results indicate that the resistant starch (RS) content increased with higher contents of amylose, single helices, and surface short-range ordered structures. Resistant starch (RS) was found to be made up of single helices and perfect crystallites formed by the fraction of chains with a degree of polymerization (DP) between 13 and 24. Slowly digestible starch (SDS) consists of single helices. Rapidly digestible starch (RDS) is mainly composed of disordered molecular chains in the amorphous regions of starch. This work reveals the relationship between the multiscale structure and digestibility of different WMSs and can provide guidance for the application of WMSs in food or non-food fields.


Assuntos
Amilose/química , Amido/química , Zea mays/química , Amilose/ultraestrutura , Microscopia Eletrônica de Varredura , Polimerização , Amido/ultraestrutura , Zea mays/metabolismo
11.
Int J Biol Macromol ; 144: 143-150, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31843606

RESUMO

Herein we describe the interaction of starch, urea, and melamine (C3N6H6) in composite materials for use as controlled-release plant fertilizer. Slow-release fertilizers are important in minimizing nutrient losses due to run-off, leaching, and other factors. Urea is an effective plasticizer for starch and is an important nitrogen fertilizer throughout the world. Melamine also has high nitrogen content and could be combined with urea-starch composites to provide enhanced controlled-release fertilizer. This study reports the structural interaction and the performance gain of melamine addition to starch-urea composites. Composites were characterized by spectroscopic techniques (FT-Raman and 13C NMR) detailing the interaction between melamine, urea, and starch. These interactions helped facilitate extrusion processing by lowering viscosity and processing temperatures suggesting an enhanced starch plasticizing effect of starch-urea-melamine composites. Further research into the co-plasticization of starch by urea and melamine could be exploited for improved controlled-release fertilizer products. Further research into the co-plasticization of starch by urea and melamine could be exploited for improved controlled-release fertilizer products.


Assuntos
Fertilizantes/análise , Plastificantes/química , Amido/química , Triazinas/química , Ureia/química , Varredura Diferencial de Calorimetria , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Análise Espectral Raman , Amido/ultraestrutura , Difração de Raios X
12.
Int J Biol Macromol ; 142: 237-243, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31593722

RESUMO

The effects of native starch (NS), acetylated starch (AS), and acetylated distarch phosphate (ADSP) on the gel properties of soybean protein thermal gel were investigated using texture analysis, low-field nuclear magnetic resonance (LF-NMR) spectroscopy, dynamic rheometry and scanning electron microscopy. The results of the textural profile analysis showed that 10% ADSP increased the hardness and chewiness of the mixed gel, while NS and AS led to decreases in the textural properties. The results of the LF-NMR analysis indicated that the AS improved the water-holding capacity of the mixed gel due to the transformation of weakly bound water to strongly bound water. During heating and cooling, the rheological profiles of the elastic (G') and viscous modulus (G″) of all the samples exhibited a two-stage pattern of decrease and then increase, and the final values of G' and G″ reached maxima when the ADSP content was 10%. The scanning electron microscopy images showed that the ADSP granules dispersed in the gel network. The integrity of the starch granules was crucial for regulating the properties of the soybean protein gel. These results provided information about the further design and preparation of soybean protein foods containing modified starch.


Assuntos
Géis/química , Reologia , Proteínas de Soja/química , Amido/química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Proteínas de Soja/isolamento & purificação , Proteínas de Soja/ultraestrutura , Amido/ultraestrutura , Viscosidade
13.
Int J Biol Macromol ; 143: 984-990, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31747566

RESUMO

Pongamia pinnata seed (PPS) starch was studied for its physicochemical, thermal, rheological and morphological properties. As PPS starch is a novel starch, it was compared with corn, mung bean, potato, pearl millet and mango kernel starches. Peak, trough and final viscosity of PPS starch was found the lowest as compared to other starches. Plots of shear stress versus shear rate for starch pastes were plotted and fitted to Herschel-Bulkley model. Yield stress and consistency index value of starch pastes varied between 6.5 and 58.9 Pa and 1.4-10.6 Pa s, respectively. During frequency sweep testing, G' and G'' values of starch pastes varied between 33 and 484 Pa and 18-71 Pa, PPS starch paste had the lowest values. Transition temperatures (Tο, Tp, Tc) for PPS starch was 61.5, 72.1 and 82.9 °C, respectively. Scanning electron microscopy of PPS starch showed small to large and round to oval shape starch granules with small pitches on their surface.


Assuntos
Fenômenos Químicos , Millettia/química , Reologia , Sementes/química , Amido/química , Amilose/química , Solubilidade , Análise Espectral , Amido/ultraestrutura
14.
Molecules ; 24(24)2019 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-31817118

RESUMO

The modification of achira starch a thermoplastic biopolymer is shown. Glycerol and sorbitol, common plasticizers, were used in the molten state with organic acids such as oleic acid and lactic acid obtaining thermodynamically more stable products. The proportion of starch:plasticizer was 70:30, and the acid agent was added in portions from 3%, 6%, and 9% by weight. These mixtures were obtained in a torque rheometer for 10 min at 130 °C. The lactic acid managed to efficiently promote the gelatinization process by increasing the available polar sites towards the surface of the material; as a result, there were lower values in the contact angle, these results were corroborated with the analysis performed by differential scanning calorimetry and X-ray diffraction. The results derived from oscillatory rheological analysis had a viscous behavior in the thermoplastic starch samples and with the presence of acids; this behavior favors the transitions from viscous to elastic. The mixture of sorbitol or glycerol with lactic acid promoted lower values of the loss module, the storage module, and the complex viscosity, which means lower residual energy in the transition of the viscous state to the elastic state; this allows the compounds to be scaled to conventional polymer transformation processes.


Assuntos
Ácido Láctico/química , Ácido Oleico/química , Plásticos/química , Reologia , Amido/química , Temperatura , Varredura Diferencial de Calorimetria , Módulo de Elasticidade , Espectrofotometria Ultravioleta , Amido/ultraestrutura , Termogravimetria , Torque , Viscosidade , Difração de Raios X
15.
Int J Biol Macromol ; 139: 387-396, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31381921

RESUMO

The influence of guar gum and its hydrolysate at different concentrations (1 and 2% w/w) on physicochemical, pasting, thermal, rheological and textural properties of pearl millet starch was assessed. The addition of guar gum and its hydrolysate significantly improved the hydration properties of pearl millet starch. NGG significantly (p < 0.05) increased the peak, breakdown, and final viscosities while GGH did not modify the peak and final viscosities but decreased breakdown viscosity. The molecular weight of guar gum had a predominating role in modifying the functional properties of pearl millet starch. Steady shear measurements showed that both NGG and GGH decreased the flow behavior index (n) increased and consistency index (K). Higher G' and G″ values were obtained after the addition of NGG and GGH, suggesting the formation of more solid like pastes.


Assuntos
Fenômenos Químicos , Galactanos/química , Mananas/química , Pennisetum/química , Gomas Vegetais/química , Amido/química , Concentração de Íons de Hidrogênio , Hidrólise , Peso Molecular , Reologia , Análise Espectral , Amido/ultraestrutura , Temperatura , Termodinâmica
16.
Int J Biol Macromol ; 140: 1026-1036, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31470048

RESUMO

Enhancing the performance of starch-based wood adhesive is vitally important for its practical applications. Accordingly, we designed the use of micronized starch (MS) to prepare micronized starch-based wood adhesive (MSWA) by incorporating 0, 2, 4 and 6% (w/w, dry basis starch) sodium dodecyl sulfate (SDS). The results showed that 2% SDS exhibited remarkable improvement in shear strength and viscosity of MSWA. The grafted reaction was demonstrated by 1H NMR and the steady shear results indicated that the adhesive possessed a pseudoplastic behavior under yield stress conditions. Besides, dynamic rheological measurements were applied to evaluate the structure of MSWA under varying frequencies, temperatures and constant stain. The transmission electron microscopy (TEM), Zeta potential and surface tension indicated that SDS could improve the surficial properties. Meanwhile, the microstructure of adhesive films and fracture surfaces of glued wood veneers by scanning electron microscopy (SEM) demonstrated that the migration of SDS led to the formation of surfactant layer. Furthermore, element analysis revealed the distribution of S/N in latex slices. The results of this study provide the detailed information about the influence of SDS on the rheological properties and microstructures of MSWA, which may facilitate the preparation of high performance bio-based adhesive for wood applications.


Assuntos
Adesivos/química , Reologia , Dodecilsulfato de Sódio/química , Amido/química , Madeira/química , Módulo de Elasticidade , Elementos , Látex/química , Tamanho da Partícula , Espectroscopia de Prótons por Ressonância Magnética , Resistência ao Cisalhamento , Amido/ultraestrutura , Propriedades de Superfície , Madeira/ultraestrutura , Difração de Raios X
17.
Molecules ; 24(16)2019 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-31426303

RESUMO

The aim of this work was to compare the composition and physicochemical properties (SEM, XRD, solubility, swelling power, paste clarity, retrogradation, freeze-thaw stability, thermal property, and pasting property) of three Chinese yam (Dioscorea opposita Thunb.) starches (CYYS-1, CYYS-2, and CYYS-3) in Yunlong town, Haikou, Hainan Province, China. Our results show that all the CYYS gave a typical C-type X-ray diffraction pattern. The swelling power of CYYS varied from 10.79% to 30.34%, whereas solubility index was in the range of 7.84-4.55%. The freeze-thaw stability of each CYYS showed a contrary tendency with its amylose content. In addition, CYYS-3 showed the highest To (81.1 °C), Tp (84.8 °C), Tc (91.2 °C), and ΔH (14.1 J/g). The pasting temperature of CYYS-1 increased significantly with sucrose addition. NaCl could inhibit the swelling power of CYYS. There were significant decreases in pasting temperature and pasting time of CYYS when pH decreased.


Assuntos
Dioscorea/química , Cloreto de Sódio/química , Amido/química , Sacarose/química , Tecnologia de Alimentos/métodos , Liofilização , Temperatura Alta , Humanos , Microscopia Eletrônica de Varredura , Solubilidade , Amido/isolamento & purificação , Amido/ultraestrutura , Molhabilidade
18.
Int J Biol Macromol ; 140: 1091-1097, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31415857

RESUMO

Excipient plays an essential role in drug delivery system, which promotes the drug to reach a particular site of action. Excipients directly or indirectly affect the duration and rate of drug release and absorption. In the current study, physicochemical properties, flow properties and release characteristics of native and modified pink potato starches were investigated to determine their excipient characteristics. Amylose content, water holding capacity, swelling and solubility properties were found to increase after pregelatinization and retrogradation. The SEM micrographs reveals the loss of granular structure of native after thermal modification. The FT-IR study confirms the gelatinization characteristics of the pregelatinized starch. X-ray diffraction pattern confirms the reduction of crystallinity after thermal modification. Tablets containing Paracetamol as a model drug showed that native, pregelatinized and modified pink potato starch could be useful for the manufacturing of immediate release formulation.


Assuntos
Liberação Controlada de Fármacos , Solanum tuberosum/química , Amido/química , Temperatura , Acetaminofen/farmacologia , Amilose/química , Umidade , Concentração de Íons de Hidrogênio , Índia , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Amido/ultraestrutura , Comprimidos , Viscosidade , Água/química , Difração de Raios X
19.
Plant Cell Environ ; 42(12): 3355-3371, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31429107

RESUMO

Starch is the major form of carbohydrate storage in plants and exists as discrete starch granules (SGs). Isolation of high-quality SGs in different plant tissues is a prerequisite for studying the roles of SGs during plant growth, development, and responses to abiotic stress. However, it is difficult to isolate transitory SGs from leaves and storage SGs from pollen grains due to their small sizes and low quantities. Herein, we develop a novel method for isolating SGs by using the aqueous two-phase system (ATS) of ethanol/NaH2 PO4 . The ATS method efficiently separated SGs from contaminants based on their differences in density, solubility, and polarity. Using this method, we first isolated and purified three kinds of SGs from maize seeds, pollen, and leaves. The biochemical, microscopic, and proteomic analyses demonstrated the high purity of the isolated SGs. Proteomic analysis revealed distinct differences in SG-bound proteins between seed SGs and pollen SGs. As a simple, rapid, and low-cost method, the ATS-based method exhibits highly universal and reproducible results for starch-containing tissues in various plant species.


Assuntos
Especificidade de Órgãos , Plantas/metabolismo , Amido/metabolismo , Endosperma/metabolismo , Folhas de Planta/metabolismo , Pólen/metabolismo , Pólen/ultraestrutura , Amido/ultraestrutura , Zea mays/metabolismo
20.
Food Chem ; 298: 124982, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31261014

RESUMO

This work studies the physicochemical properties of quinoa flour and isolated starch. Starch in the seed forms clusters rich in amylopectin that are immersed in a matrix with spherical and polygonal shapes in the submicron scale. The isolated quinoa starch is rich in Sulphur and Magnesium. The quinoa flour has a higher content of protein, carbohydrates and lipids than isolated starch. Water absorption and water solubilized indexes of starch exhibited high values that could had originated by the extraction method. The broad peaks found for the X-ray patterns of isolated quinoa starch indicate that amylose and amylopectin are composed by nanocrystals, according to the PDF-4+2019 software. The viscosity of isolated starch had a higher value than flour; therefore, the quinoa starch could be used as a thickener in different formulations with the advantage of keeping a significant presence of minerals which are important to the human health.


Assuntos
Chenopodium quinoa/química , Farinha/análise , Análise de Alimentos/métodos , Amido/química , Amilopectina/química , Amilose/análise , Microscopia Eletrônica de Varredura , Minerais/análise , Sementes/química , Sementes/ultraestrutura , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Amido/análise , Amido/ultraestrutura , Temperatura , Viscosidade , Água/química , Difração de Raios X
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