Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 67.605
Filtrar
1.
Food Chem ; 351: 129315, 2021 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-33647686

RESUMEN

Mangiferin-loaded nanobilosomes (MGF-NBSs) were developed using microfluidic-based techniques to improve aqueous solubility, digestive stability, and cellular antioxidant activity (CAA) of mangiferin. Preliminary experiments showed that optimal formation conditions were 5:1 aqueous (water) to solvent (ethanol) phase ratio and 85 mL/min total flow rate. Further optimization using response surface methodology provided the optimal formulation (200 mg encapsulant consisting of 90.91% phosphatidylcholine and 9.09% sodium glycocholate, and 25.89 mg mangiferin), achieving 9.25% mangiferin loading and 80.65% encapsulation efficiency. Mono-dispersed MGF-NBSs with an average size of around 48.14 nm and zeta potential of -30.1 mV were obtained. FTIR and DSC results confirmed the successful encapsulation of mangiferin into the nanobilosomes and revealed interactions among the components. MGF-NBSs showed a 7-fold increase in the aqueous solubility compared with non-encapsulated mangiferin. CAA of MGF-NBSs in Caco-2 cells was 2 times higher than that of mangiferin and the in vitro digestive stability was improved.


Asunto(s)
Antioxidantes/química , Antioxidantes/farmacología , Nanoestructuras/química , Agua/química , Xantonas/química , Xantonas/farmacología , Antioxidantes/metabolismo , Células CACO-2 , Digestión , Composición de Medicamentos , Humanos , Dispositivos Laboratorio en un Chip , Tamaño de la Partícula , Solubilidad , Xantonas/metabolismo
2.
Food Chem ; 351: 129344, 2021 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-33647688

RESUMEN

Protein oxidation is considered as an important factor affecting the texture quality of surimi. In this work, the myofibrillar protein (MP) from shrimp (Penaeus vannamei) was subjected to a hydroxyl radical generating system at various concentrations of H2O2, to simulate the oxidative environment during surimi processing. After the hydroxyl radical oxidation, it was found that the carbonyl content, surface hydrophobicity, and MP aggregation increased. Meanwhile, the a-helix decreased, but ß-sheet increased after oxidation. The moderate oxidation led to a dense network microstructure, increased water holding capacity (WHC) and decreased water mobility, which ultimately enhanced textural (hardness and springiness increased by 0.51- and 0.06-fold, respectively) and rheological properties of MP gel (MPG). However, excessive oxidation could reduce the mechanical properties of MPG. The microstructure, WHC and water distribution played a key role in the mechanical properties of MPG. This study can provide a theoretical basis for processing of shrimp surimi products.


Asunto(s)
Anostraca , Fenómenos Químicos , Radical Hidroxilo/química , Proteínas Musculares/química , Animales , Geles , Interacciones Hidrofóbicas e Hidrofílicas , Oxidación-Reducción , Reología , Alimentos Marinos , Agua/química
3.
Food Chem ; 351: 129227, 2021 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-33647695

RESUMEN

Cold chain transportation is an important link in postharvest logistics of agricultural products. In current study, we developed a novel water-based phase change coolant (PCC), which showed longer effectiveness in maintaining low temperature condition compared with ice, and applied in preserving the postharvest mushrooms. The results showed that the novel PCC effectively inhibited water loss, as well as maintained quality attributes including firmness, color, phenolics, flavonoids, and thus prolonged the shelf-life of mushrooms. Low temperature condition created by the novel PCC treatment maintained high level of energy charge by activating the activities of SDH, CCO, H+-ATPase and Ca2+-ATPase, resulting in the delay of postharvest senescence. In addition, sufficient energy supply decreased the consumption of glutamate as carbon skeleton by inhibiting GDH activity, improved glutamate accumulation, and therefore maintained sensory properties as a result. Thus, the novel PCC might be an excellent substitute for ice in cold chain transportation of mushrooms.


Asunto(s)
Frío , Metabolismo Energético/efectos de los fármacos , Calidad de los Alimentos , Ácido Glutámico/metabolismo , Transición de Fase , Hongos Shiitake/química , Hongos Shiitake/metabolismo , Color , Hongos Shiitake/efectos de los fármacos , Agua/química , Agua/farmacología
4.
Int J Nanomedicine ; 16: 2045-2058, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33731993

RESUMEN

Background: Carbon dots (CDs) emitting near-infrared fluorescence were recently synthesized from green leaves. However, the Hg2+ detection of CDs was limited because of the insufficient water solubility, low fluorescence and poor stability. Methods: Dual fluorescence emission water-soluble CD (Dual-CD) was prepared through a solvothermal method from holly leaves and low toxic PEI1.8k. PEG was further grafted onto the surface to improve the water solubility and stability. Results: The Dual-CD solution can emit 487 nm and 676 nm fluorescence under single excitation and exhibit high quantum yield of 16.8%. The fluorescence at 678 nm decreased remarkably while the emission at 470 nm was slightly affected by the addition of Hg2+. The ratiometric Hg2+ detection had a wide linear range of 0-100 µM and low detection limit of 14.0 nM. In A549 cells, there was a good linear relation between F487/F676 and the concentration of Hg2+ in the range of 0-60 µM; the detection limit was 477 nM. Furthermore, Dual-CD showed visual fluorescence change under Hg2+. Conclusion: Dual-CD has ratiometric responsiveness to Hg2+ and can be applied for quantitative Hg2+ detection in living cells.


Asunto(s)
Carbono/química , Ilex/química , Mercurio/análisis , Hojas de la Planta/química , Puntos Cuánticos/química , Agua/química , Células A549 , Supervivencia Celular , Humanos , Iones , Fenómenos Ópticos , Espectroscopía de Fotoelectrones , Puntos Cuánticos/ultraestructura , Espectrometría de Fluorescencia , Espectrofotometría Ultravioleta
5.
Int J Nanomedicine ; 16: 2203-2217, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33762821

RESUMEN

Background: It is well known that smoking is harmful to health; however, it can also ameliorate anxiety. To date, it is unclear whether any nanoparticles found in cigarette mainstream smoke (CS) contribute to this effect. Aim: The aim of this study was to assess the particle composition of CS to identify novel anti-anxiety components. Methods: Carbon dots (CDs) from CS (CS-CDs) were characterised using high-resolution transmission electron microscopy, Fourier-transform infrared, ultraviolet, fluorescence, X-ray photoelectron spectroscopy, X-ray diffraction and high-performance liquid chromatography. The anti-anxiety effects of CS-CDs in mouse models were evaluated and confirmed with the elevated plus maze and open-field tests. Results: The quantum yield of CS-CDs was 13.74%, with a composition of C, O, and N. In addition, the surface groups contained O-H, C-H, C=O, C-N, N-H, C-O-C, and COO- bonds. Acute toxicity testing revealed that CS-CDs had low in vitro and in vivo toxicity within a certain concentration range. The results of the elevated plus maze and open-field tests showed that CS-CDs had a significant anti-anxiety effect and a certain sedative effect in mice. The mechanism of these effects may be related to the decrease in glutamate levels and promotion of norepinephrine production in the mouse brain, and the decrease in dopamine in mouse serum due to CS-CDs. Conclusion: CS-CDs may have anti-anxiety and certain sedative effects. This study provides a new perspective for a more comprehensive understanding of the components, properties, and functions of CS. Furthermore, it offers a novel target for the development of smoking cessation treatments, such as nicotine replacement therapy.


Asunto(s)
Conducta Animal , Carbono/química , Fumar Cigarrillos/efectos adversos , Sistema Endocrino/metabolismo , Neurotransmisores/metabolismo , Puntos Cuánticos/química , Agua/química , Hormona Adrenocorticotrópica/sangre , Animales , Ansiedad/sangre , Ansiedad/patología , Encéfalo/metabolismo , Encéfalo/patología , Cromatografía Líquida de Alta Presión , Corticosterona/sangre , Hormona Liberadora de Corticotropina/sangre , Dopamina/sangre , Masculino , Ratones , Ratones Endogámicos ICR , Espectroscopía de Fotoelectrones , Puntos Cuánticos/ultraestructura , Células RAW 264.7 , Espectrometría de Fluorescencia , Espectroscopía Infrarroja por Transformada de Fourier , Espectrometría Raman , Pruebas de Toxicidad Aguda , Difracción de Rayos X
6.
Phys Rev Lett ; 126(8): 088102, 2021 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-33709739

RESUMEN

The interaction between proteins and hydration water stabilizes protein structure and promotes functional dynamics, with water translational motions enabling protein flexibility. Engineered solvent-free protein-polymer hybrids have been shown to preserve protein structure, function, and dynamics. Here, we used neutron scattering, protein and polymer perdeuteration, and molecular dynamics simulations to explore how a polymer dynamically replaces water. Even though relaxation rates and vibrational properties are strongly modified in polymer coated compared to hydrated proteins, liquidlike polymer dynamics appear to plasticize the conjugated protein in a qualitatively similar way as do hydration-water translational motions.


Asunto(s)
Polímeros/química , Proteínas/química , Diaminas/química , Glicolatos/química , Enlace de Hidrógeno , Simulación de Dinámica Molecular , Mioglobina/química , Difracción de Neutrones , Polietilenglicoles/química , Conformación Proteica , Termodinámica , Agua/química
7.
Food Chem ; 351: 129264, 2021 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-33662908

RESUMEN

The valorization of the brewer's spent grain (BSG) generated in a craft beer industry was studied by subcritical water hydrolysis in a semi-continuous fixed-bed reactor. Temperature was varied from 125 to 185 °C at a constant flow rate of 4 mL/min. Biomass hydrolysis yielded a maximum of 78% of solubilized protein at 185 °C. Free amino acids presented a maximum level at 160 °C with a value of 55 mg free amino acids/gprotein-BSG. Polar amino acid presented a maximum at lower temperatures than non-polar amino acids. The maximum in total phenolic compounds was reached at 185 °C. This maximum is the same for aldehyde phenolic compounds such as vanillin, syringic and protocatechuic aldehyde; however, for hydroxycinnamic acids, such as ferulic acid and p-coumaric, the maximum was obtained at 160 °C. This allows a fractionation of the bioactive compounds. Subcritical water addresses opportunities for small breweries to be incorporated within the biorefinery concept.


Asunto(s)
Fraccionamiento Químico/métodos , Grano Comestible/química , Proteínas de Plantas/aislamiento & purificación , Residuos , Agua/química , Bebidas Alcohólicas/análisis , Biomasa , Ácidos Cumáricos/análisis , Hidrólisis , Fenoles/análisis , Proteínas de Plantas/química , Factores de Tiempo
8.
Nat Commun ; 12(1): 1183, 2021 02 19.
Artículo en Inglés | MEDLINE | ID: mdl-33608518

RESUMEN

Ice-nucleation active (INA) bacteria can promote the growth of ice more effectively than any other known material. Using specialized ice-nucleating proteins (INPs), they obtain nutrients from plants by inducing frost damage and, when airborne in the atmosphere, they drive ice nucleation within clouds, which may affect global precipitation patterns. Despite their evident environmental importance, the molecular mechanisms behind INP-induced freezing have remained largely elusive. We investigate the structural basis for the interactions between water and the ice-nucleating protein InaZ from the INA bacterium Pseudomonas syringae. Using vibrational sum-frequency generation (SFG) and two-dimensional infrared spectroscopy, we demonstrate that the ice-active repeats of InaZ adopt a ß-helical structure in solution and at water surfaces. In this configuration, interaction between INPs and water molecules imposes structural ordering on the adjacent water network. The observed order of water increases as the interface is cooled to temperatures close to the melting point of water. Experimental SFG data combined with molecular-dynamics simulations and spectral calculations show that InaZ reorients at lower temperatures. This reorientation can enhance water interactions, and thereby the effectiveness of ice nucleation.


Asunto(s)
Proteínas de la Membrana Bacteriana Externa/química , Proteínas de la Membrana Bacteriana Externa/metabolismo , Frío , Agua/química , Atmósfera , Proteínas de la Membrana Bacteriana Externa/genética , Óxido de Deuterio , Congelación , Hielo , Simulación de Dinámica Molecular , Plantas/microbiología , Pseudomonas syringae/metabolismo
9.
J Vis Exp ; (167)2021 01 27.
Artículo en Inglés | MEDLINE | ID: mdl-33586706

RESUMEN

A versatile twin-screw extrusion process to provide an efficient thermo-mechano-chemical pre-treatment on lignocellulosic biomass before using it as source of mechanical reinforcement in fully bio-based fiberboards was developed. Various lignocellulosic crop by-products have already been successfully pre-treated through this process, e.g., cereal straws (especially rice), coriander straw, shives from oleaginous flax straw, and bark of both amaranth and sunflower stems. The extrusion process results in a marked increase in the average fiber aspect ratio, leading to improved mechanical properties of fiberboards. The twin-screw extruder can also be fitted with a filtration module at the end of the barrel. The continuous extraction of various chemicals (e.g., free sugars, hemicelluloses, volatiles from essential oil fractions, etc.) from the lignocellulosic substrate, and the fiber refining can, therefore, be performed simultaneously. The extruder can also be used for its mixing ability: a natural binder (e.g., Organosolv lignins, protein-based oilcakes, starch, etc.) can be added to the refined fibers at the end of the screw profile. The obtained premix is ready to be molded through hot pressing, with the natural binder contributing to fiberboard cohesion. Such a combined process in a single extruder pass improves the production time, production cost, and may lead to reduction in plant production size. Because all the operations are performed in a single step, fiber morphology is better preserved, thanks to a reduced residence time of the material inside the extruder, resulting in enhanced material performances. Such one-step extrusion operation may be at the origin of a valuable industrial process intensification. Compared to commercial wood-based materials, these fully bio-based fiberboards do not emit any formaldehyde, and they could find various applications, e.g., intermediate containers, furniture, domestic flooring, shelving, general construction, etc.


Asunto(s)
Biotecnología/instrumentación , Biotecnología/métodos , Lignina/química , Absorción Fisicoquímica , Biomasa , Desecación , Calor , Agua/química , Madera/química
10.
Food Chem ; 351: 129284, 2021 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-33640773

RESUMEN

Coating damage destroys the integrity features critical for maintaining the modified atmosphere inside the fruit. In this study, we developed a self-healing edible coating that maintains its barrier properties for extending the shelf life of strawberries. The coating was fabricated via the layer-by-layer assembly of chitosan (CS) and sodium alginate (SA). (SA/CS)3 formed by three assembly cycles could completely heal the visibly damaged area by treating water. The mechanical properties and the water and oxygen rates of the healed coating were 97%, 63%, and 95%, respectively, of the intact coating. (SA/CS)3 coating effectively delayed strawberry deterioration. Moreover, the coating reduced the impact of coating damage on strawberries by restoring the coating barrier properties. The present findings have important implications for solving the reduction in freshness caused by coating damage.


Asunto(s)
Películas Comestibles , Conservación de Alimentos/métodos , Alginatos/química , Quitosano/química , Calidad de los Alimentos , Fragaria/química , Fragaria/metabolismo , Frutas/química , Frutas/metabolismo , Interacciones Hidrofóbicas e Hidrofílicas , Oxígeno/química , Tereftalatos Polietilenos/química , Resistencia a la Tracción , Agua/química
11.
Food Chem ; 351: 129285, 2021 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-33640775

RESUMEN

Macro- and microelement determination in chocolate bars by microwave-induced plasma optical emission spectrometry (MIP OES) was evaluated after microwave-assisted sample digestion. Optimization of the sample digestion was carried out, and the recommended conditions were obtained at a temperature of 190 °C, with a digestion time of 40 min and in a mixture constituted by 2.3 mL of nitric acid, 1.0 mL of hydrogen peroxide and 4.7 mL of water. The method was applied in the analysis of chocolate bars, and the concentration ranges of the elements determined were (in mg kg-1): Ca (653-3096); Cr (<0.6-2.8); Cu (<0.16-19.5); Fe (<1.6-227); Mg (147-2775); K (3554-8573); Mn (<0.03-25.2); Na (45.6-1095); Ni (3.2-10.2); P (1111-22594) and Zn (4.8-33.3). The association of the proposed microwave-assisted acid digestion with the MIP OES technique was adequate for multi-element determination in chocolate bars for routine analysis.


Asunto(s)
Chocolate/análisis , Microondas , Gases em Plasma/química , Espectrofotometría/métodos , Digestión , Calor , Peróxido de Hidrógeno/química , Límite de Detección , Metales/análisis , Ácido Nítrico/química , Agua/química
12.
Food Chem ; 348: 129035, 2021 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-33524690

RESUMEN

In order to improve its aqueous solubility and emulsifying function, zein was partially hydrolyzed by trypsin and conjugated to chitosan oligosaccharide lactate by transglutaminase. Hydrolysis and covalent linkage to chitosan oligosaccharide was confirmed by free amine content, gel electrophoresis, and infrared spectroscopy. Enzymatic glycosylation was optimized at pH 6, 44 °C, and 4 h to bind approximately 95% of the free amines in the hydrolysates to chitosan oligosaccharide. Hydrolysis and conjugation increased solubility of zein by 47.60% and 72.93%. Hydrolysis and conjugation also decreased surface hydrophobicity by more than 20% and more than doubled emulsifying activity index, emulsion stability index, and foaming capacity. This enzymatic modification has potential to be applied to improve functional properties of other prolamins.


Asunto(s)
Quitosano/química , Oligosacáridos/química , Zeína/química , Glicosilación , Hidrólisis , Interacciones Hidrofóbicas e Hidrofílicas , Oligosacáridos/metabolismo , Solubilidad , Transglutaminasas/metabolismo , Agua/química
13.
Food Chem ; 348: 129021, 2021 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-33545643

RESUMEN

Lemon essential oils (LEO), as natural bacteriostatic agents, show significant loss in the preparation processes of food packaging materials, therefore, an effective encapsulation of LEO is urgent for realizing the protection. In this study, LEO was absorbed by thermally stable and porous vermiculite (VML) to form LEO/VML complex, which is further coupled with konjac glucomannan-grafted-poly (acrylic acid)/polyvinyl alcohol (KGM-g-PAA/PVA) composite. KGM-g-PAA/PVA bacteriostatic water-absorbing pad was prepared via electrospinning technique, which can minimize the loss of LEO. The VML (1 g) can significantly reduce LEO loss and achieve sustained control LEO release from the pad, which follows the predominant mechanism of Fick diffusion law. The sustained control LEO release from the pad can effectively inhibit the growth of E. coli during storage, thus prolonging shelf life of chilled pork for 3 day. This study suggests that KGM-g-PAA/PVA pad may have a great potential in the field of intelligent packaging.


Asunto(s)
Silicatos de Aluminio/química , Antibacterianos/química , Antibacterianos/farmacología , Conservación de Alimentos/métodos , Mananos/química , Aceites Vegetales/química , Alcohol Polivinílico/química , Animales , Preparaciones de Acción Retardada , Escherichia coli/efectos de los fármacos , Embalaje de Alimentos , Almacenamiento de Alimentos , Agua/química
14.
Food Chem ; 349: 129206, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-33578245

RESUMEN

Sunflower oil-in-water emulsions were enriched with two Satureja thymbra extracts - obtained by ethyl acetate (EAcs) or ethanol (Es), rosmarinic acid (RA), or quercetin (Que), and the effect of storage temperature (5-40 °C) on the emulsions' phenolic content and oxidative stability was studied. HPLC analysis of the extracts indicated RA as the main component. The phenolic content of the emulsions decreased during storage, following first-order kinetics, with a temperature-dependent rate. RA was the main compound that decreased, Que followed a slower decrease and the rest flavonoids remained almost constant. The additives protected the emulsion against oxidation according to the order Es > Que > EAcs > RA. The protection factor ranged from 73 to 81% at 5 °C, but decreased to around 53% for Que and Es, 33% for EAcs, and 22% for RA at 40 °C. Emulsions enriched with extracts from S. thymbra retain their phenolic content and oxidative stability at refrigeration temperatures.


Asunto(s)
Fenoles/análisis , Satureja/química , Temperatura , Antioxidantes/análisis , Emulsiones , Oxidación-Reducción , Fenoles/aislamiento & purificación , Agua/química
15.
Food Chem ; 349: 129203, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-33581433

RESUMEN

Fabrication of food-grade water-in-oil (W/O) emulsions without surfactant, as the primary substitutes of trans-fat and saturated fat, was still a significant challenge in food science. A facial method has been adopted to fabricate W/O emulsions at 20 °C. The obtained emulsion had long-time stability, and there was no apparent phase separation or oiling-out after 60 days of storage. In this system, beeswax served as a stabilizer for both oleogels and oleogel-based emulsions. The sol-gel melting temperature of the oleogel was 37 ± 0.5 °C by regulating beeswax content to 4% w/w, and then the oleogel was used to fabricate W/O emulsion with the droplet diameter of around 9 µm. Thermo-reversible and thixotropic properties of oleogels were both retained for emulsions. Furthermore, both oleogels and oleogel-based emulsions had compact gel-like structures. The self-emulsifying W/O emulsions without surfactant would have great potential applications in food industry, pharmaceutical industry and feed industry.


Asunto(s)
Emulsionantes/química , Aceites/química , Temperatura , Agua/química , Ceras/química , Emulsiones , Compuestos Orgánicos/química , Tensoactivos/química
16.
Food Chem ; 349: 129210, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-33582541

RESUMEN

This study investigated the effects of an improved extraction method that utilized freeze-thaw, termed improved conventional extraction (ICE), on the yield and properties of the water-soluble non-starch polysaccharide of taro (Tc-WS-NSP) and compared this method to the conventional extraction (CE) method. The freeze-thaw condition was optimized using response surface methodology (RSM) based on yield. The use of the ICE method resulted in a 227.8% increase in yield of Tc-WS-NSP compared to the CE method. The Tc-WS-NSP-ICE had higher purity, lighter color, larger particle size, and higherζ-potential than Tc-WS-NSP-CE. Both of the samples contain the sugar arabinose, galactose, glucose, and mannose and exhibited comparative FTIR, 1H, and 13C NMR spectra. The Tc-WS-NSP-ICE had a semi-crystalline structure resulting in higher thermal stability and had a higher consistency index than Tc-WS-NSP-CE. Overall, the use of the ICE method provided a simple, efficient, and green alternative to CE for the extraction of Tc-WS-NSP.


Asunto(s)
Fraccionamiento Químico/métodos , Fenómenos Químicos , Colocasia/química , Congelación , Polisacáridos/química , Polisacáridos/aislamiento & purificación , Agua/química , Tamaño de la Partícula , Polisacáridos/análisis , Solubilidad
17.
Food Chem ; 349: 129125, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-33535111

RESUMEN

This study investigated the effect of germination time on compositional changes and functionality of whole wheat malt flour (WMF) as well as its influence on cookie quality. The results illustrated that malting resulted in decreases of starch, protein, fat and ash, while it increased dietary fiber, carbohydrate and energy. Gel hydration, emulsifying and foaming ability, pasting viscosity decreased significantly, particularly during the first 2 days of germination. Both bound and immobilized water in WMF decreased with increasing germination time while the concentration and antioxidant capacity of extractable and hydrolyzable phenolic compounds (EPP and HPP) increased significantly in WMF and malt-based cookies. Flours changed from an integrated granular to an irregular tousy structure during germination. The incorporation of WMF induced a distorted "honey-like" comb structure to the cookies. Conclusively, controlled germination not only improves the physicochemical, functional properties of WMF but also increases nutrition value and technological performance of malt-based cookies.


Asunto(s)
Antioxidantes/análisis , Germinación , Triticum/química , Triticum/crecimiento & desarrollo , Fibras de la Dieta/análisis , Harina/análisis , Valor Nutritivo , Fenoles/análisis , Almidón/análisis , Agua/química
18.
Food Chem ; 349: 129117, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-33556722

RESUMEN

Changes in the cell wall of Japanese radish due to heating at 100 °C or 117 °C for 3 h were examined. Signals in 13C cross polarization magic angle spinning solid-state NMR (which detects rigid components) showed no differences between heating temperatures. 13C pulse saturation transfer magic angle spinning NMR (which detects flexible components) showed clear temperature-dependent changes in the rhamnose side chains of rhamnogalacturonan. Alcohol-insoluble solids isolated from raw samples were heated in water at 100 °C or 117 °C for 3 h. The concentrations of dissolved sugars and metal ions measured after heating in water at 117 °C were greater than in samples heated at 100 °C, indicating that loosening of cell wall structures increased with temperature, likely via degradation and elution of rhamnogalacturonan followed by ß-elimination of homogalacturonan, and fewer interactions between cell wall components, including divalent metal ions. Vegetable shape was retained despite fewer interactions.


Asunto(s)
Pared Celular/química , Culinaria , Calor , Espectroscopía de Resonancia Magnética , Presión , Raphanus/química , /química , Pectinas/análisis , Agua/química
19.
Food Chem ; 349: 129037, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-33556726

RESUMEN

Antioxidant activities of 1-o-galloylglycerol (GG), propyl gallate, rosmarinic acid (RA), tocopherols (TOC), and 1:1 combinations of GG/RA and GG/TOC were evaluated using in vitro assays including 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS+), and ferric reducing antioxidant power (FRAP). Soybean oil stripped of TOC was utilized as bulk oil and as the oil phase in O/W emulsions for accelerated oxidation test with the selected phenolic compounds. Efficacies of antioxidants were evaluated by monitoring total oxidation (TOTOX) values and fatty acid profiles of oil and O/W samples during the accelerated oxidation. In bulk oil, GG outperformed other singular antioxidants, preventing 39.04% of oxidation for ω-3 fatty acids with a TOTOX value of 166.68. In emulsions, TOC outperformed other singular antioxidants, preventing 38.04% of oxidation with a TOTOX value of 196.72. Considering the polarities of the antioxidants and our testing systems, these results provide supporting evidence for the polar paradox theory.


Asunto(s)
Antioxidantes/análisis , Fenoles/análisis , Aceite de Soja/química , Agua/química , Emulsiones , Oxidación-Reducción
20.
Food Chem ; 349: 129066, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-33556728

RESUMEN

The objective of this study was to explore the oxidative modification induced by AAPH (2,2'-azobis (2-amidinopropane) dihydrochloride) on the microbial transglutaminase (MTGase) cross-linking reaction and gelling properties of silver carp myofibril protein (SCMP). Compared to AAPH treatment, MTGase addition resulted further changes of protein properties as evidenced by the decreasing free amino and thiol group content, the decreased secondary and tertiary structure, and the increasing storage modulus (G') and gel strength (P < 0.05). The proper oxidation induced by AAPH (5 mM) promoted the glutamine-lysine and disulfide cross-linking due to MTGase (10 U/g). Therefore, the quality of the SCMP gel was improved with a good water-holding capacity (WHC), gel strength and G'. This results could lay a theoretical foundation for the development of silver carp surimi products with good quality. Chemical compounds: (2,2'-azobis(2-amidinopropane)dihydrochloride (PubChem CID:76344); O-Phthalaldehyde (PubChem CID:4807); 5,5'-Dithiobis(2-Nitrobenzoic Acid) (PubChem CID:6254); 8-Anilino-1-naphthalenesulfonic acid (PubChem CID:1369); Acrylamide (PubChem CID: 6579); ß-Mercaptoethanol (PubChem CID: 1567); Sodium dodecyl sulfate (PubChem CID:3423265).


Asunto(s)
Carpas , Proteínas Musculares/química , Peróxidos/farmacología , Proteínas/metabolismo , Animales , Geles , Oxidación-Reducción/efectos de los fármacos , Alimentos Marinos , Compuestos de Sulfhidrilo/química , Transglutaminasas/metabolismo , Agua/química
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...