Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
Plant Foods Hum Nutr ; 79(1): 242-249, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38329612

RESUMEN

This work employed supramolecular solvents (SUPRAS) made up of octanoic acid, ethanol, and acidified water (pH ~ 3) to extract and concentrate bioactive compounds from Eugenia pyriformis Cambess (uvaia) pulp. At first, the SUPRAS phase characterization demonstrated the spherical aggregates' formation with an internal hydrophobic structure and an external hydrophilic media. Subsequently, the simultaneous production and extraction (SUPRAS-SPE) method was employed in the solid-liquid extraction (SLE) of uvaia pulp. The extracts were evaluated through Folin-Ciocalteu reducing capacity, antioxidant activity (DPPH assay), total carotenoid content (TCC), and total flavonoid content (TFC). The results showed that reducing the ethanol concentration in the SUPRAS composition boosted the TCC extraction while increasing the ethanol presence, promoting a high TFC yield. Moreover, the SUPRAS-SPE method was compared with the ex situ method (SUPRAS-ES), where the solvent was previously produced and then applied to the SLE. Both methods were evaluated concerning their EE% and thermal degradation. The SUPRAS-SPE method increased the EE% of uvaia pulp bioactive compounds compared to the SUPRAS-SE method, providing a suitable microenvironment to extract, concentrate, and stabilize carotenoids from uvaia pulp, offering a sustainable alternative to obtain valuable compounds.


Asunto(s)
Eugenia , Solventes/química , Eugenia/química , Antioxidantes/química , Carotenoides , Etanol
2.
Food Chem ; 440: 138195, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38103506

RESUMEN

This work aimed to evaluate the influence of the mechanical defibrillation technique on the pinhão nanosuspensions production obtained from the whole pinhão, its coat, and almond. The nanosuspensions were characterized concerning their composition, morphology, thermal stability, rheological behavior, compound profiling, and cytotoxicity. The results revealed a significant fiber content in pinhão coat nanosuspension (63.12 ± 0.52 %) and non-fiber carbohydrates in whole pinhão (59.00 ± 0.13 %) and almond (74.39 ± 0.23 %) nanosuspensions. The defibrillation process led to micro/nano-sized fibers in pinhão coat nanosuspensions and small-size starch granules in almond nanosuspensions. The nanosuspensions containing pinhão coat exhibited a gel-like behavior, while almond nanosuspensions displayed liquid-like characteristics. Pinhão coat nanosuspensions presented a significant content of flavonoids and phytosterols, whereas almond-based nanosuspensions contained substantial sugar amounts. No cytotoxicity was observed at the concentrations evaluated. These findings demonstrated that the defibrillation technique impacted the properties of pinhão constituents, allowing their application in new product development.


Asunto(s)
Araucaria , Nanopartículas , Flavonoides , Semillas , Almidón , Suspensiones , Tamaño de la Partícula
3.
Food Chem ; 394: 133518, 2022 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-35749878

RESUMEN

Antinutrients (ANs) interact with proteins changing its behavior and may affect Maillard reaction (MR). This work aimed to study the effect of phytic acid, tannic acid, and saponin on asparagine-glucose MR. The effect of AN concentration (0-1 mM) and reaction time (3-30 min at 150 °C) on the formation of melanoidins and acrylamide was determined. Other MR compounds were analyzed by gas chromatography and nuclear magnetic resonance. The ANs effect on asparagine-glucose thermal behavior was studied by differential scanning calorimetry. Results showed that ANs increase the melanoidins formation. Acrylamide content increased in saponin and phytic acid presence. The volatile profile was similar among the samples and formed mainly by pyrazines (>50%). ANs affect glucose's melting point, however, only phytic acid and saponin affect asparagine and glucose thermal behavior. The results presented in this work are important for food science and the industry to control MR in processed foods.


Asunto(s)
Reacción de Maillard , Saponinas , Acrilamida/análisis , Asparagina/química , Glucosa/química , Calor , Ácido Fítico , Taninos
4.
J Food Sci Technol ; 57(11): 4201-4210, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-33071341

RESUMEN

Plant-derived protein can present antinutrients (ANs) in its composition. The ANs can interact with the protein, affecting its solubility and functional properties, such as gelation. This work evaluated the effect of three ANs, namely phytic acid (PA), tannic acid (TA), and Quillaja bark saponin (QBS), on the gelation and solubility of soy (SPI), pea (PPI), and rice protein isolate (RPI). The ANs altered the protein isolates gelation and solubility. PA decreased the solubility and gelation of the three protein isolates at pH 3.0. The TA was the AN that most decreased the solubility and gelation characteristics of SPI and PPI at both pHs analyzed. QBS increased the gelation of SPI at pH 3.0 but decreased the final gel strength of RPI at the same pH. These results show that the knowledge of the presence of ANs in the protein isolates is of fundamental relevance for the processing of vegetable proteins.

5.
Food Chem ; 303: 125388, 2020 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-31454757

RESUMEN

Saponins are known for their bioactive and surfactant properties, showing applicability to the food, cosmetic and pharmaceutical industries. This work evaluated the saponins effects on Kluyveromyces lactis ß-galactosidase activity and correlated these changes to the protein structure. Enzyme kinetic was evaluated by catalytic assay, protein structure was studied by circular dichroism and fluorescence, and isothermal titration calorimetry was used to evaluate the interactions forces. In vitro enzymatic activity assays indicated an increase in the protein activity due to the saponin-protein interaction. Circular dichroism shows that saponin changes the ß-galactosidase secondary structure, favoring its protein-substrate interaction. Besides, changes in protein microenvironment due to the presence of saponin was observed by fluorescence spectroscopy. Isothermal titration calorimetry analyses suggested that saponins increased the affinity of ß-galactosidase with the artificial substrate o-nitrophenyl-ß-galactoside. The increase in the enzyme activity by saponins, demonstrated here, is important to new products development in food, cosmetic, and pharmaceutical industries.


Asunto(s)
Kluyveromyces/enzimología , Saponinas/farmacología , beta-Galactosidasa/efectos de los fármacos , Calorimetría , Dicroismo Circular , Cinética , Nitrofenilgalactósidos/metabolismo , Corteza de la Planta/química , Estructura Secundaria de Proteína , Quillaja/química , Espectrometría de Fluorescencia , beta-Galactosidasa/metabolismo
6.
J Agric Food Chem ; 67(32): 9002-9008, 2019 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-31322885

RESUMEN

The diphenylurea 4,4'-dinitrocarbanilide (DNC) is the residue of concern left in edible tissues of broilers fed diets containing the anticoccidial nicarbazin. When chicken meat is submitted to thermal processing, p-nitroaniline (p-NA) is expected from DNC degradation. This work aimed at evaluating whether thermal processing of DNC-containing chicken meat induces p-NA appearance. First, a hydrolysis assay was performed in aqueous solutions at 100 °C in different pH, confirming that DNC cleavage yields p-NA. Then a novel LC-MS/MS method was used to detect traces of this aromatic amine in DNC-containing chicken breast fillets subjected to cooking methods. Our evidence showed p-NA occurrence in such chicken meat samples, which corroborated results from hydrolysis assay. The p-NA appearance in fillets was rather discrete during boiling treatment, but its concentration became pronounced over time for grilling, frying, and roasting, achieving respectively 326.3, 640.0, and 456.9 µg/kg. As far as we are concerned, no other research identified degradation products from DNC residue in heat-processed chicken fillets. Therefore, this study leads to additional approaches to assess impacts on food safety.


Asunto(s)
Compuestos de Anilina/química , Carbanilidas/química , Coccidiostáticos/química , Residuos de Medicamentos/química , Carne/análisis , Nicarbazina/química , Compuestos de Anilina/metabolismo , Animales , Carbanilidas/metabolismo , Pollos/metabolismo , Coccidiostáticos/metabolismo , Culinaria , Residuos de Medicamentos/metabolismo , Calor , Nicarbazina/metabolismo , Espectrometría de Masas en Tándem
7.
Int J Biol Macromol ; 136: 486-492, 2019 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-31207325

RESUMEN

Tannins, proteins, and divalent cations interactions are important for many processes in the food industry and human and animal nutrition and health. The effect of magnesium, calcium, and manganese on the interaction, turbidity, and in vitro protein digestibility of bovine serum albumin and tannic acid complexes was studied. The divalent cations increase the affinity and influence the enthalpy and entropy changes of the protein and tannin binding. Magnesium maintained the nature of interactions, and calcium and manganese changed the binding mechanism. The factor that most influenced turbidity was the tannic acid and divalent cations binary interaction. Samples containing tannic acid and magnesium and calcium decreased the protein digestibility. Manganese increased the in vitro protein digestibility when compared with samples without salt addition; nevertheless, the complexes formed was higher. These finds can help in the understanding of interactions involved food system and in physiological conditions.


Asunto(s)
Cationes Bivalentes/farmacología , Albúmina Sérica Bovina/metabolismo , Taninos/metabolismo , Animales , Bovinos , Digestión/efectos de los fármacos , Concentración de Iones de Hidrógeno , Concentración Osmolar , Unión Proteica/efectos de los fármacos , Estabilidad Proteica , Termodinámica
8.
Food Chem ; 275: 346-353, 2019 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-30724206

RESUMEN

Tannins are compounds with antinutrient properties that hinder food digestibility, prejudicing human and animal nutrition. This work aimed to evaluate the negative effects of tannic acid on Kluyveromyces lactis ß-galactosidase catalytic activity and correlate these changes with the protein structure. ß-Galactosidase activity decreased in the presence of tannins, which caused changes to the structure of the enzyme, as demonstrated by circular dichroism. It was verified that tannin binds to the protein by a static mechanism. Additionally, isothermal titration calorimetry suggested that tannic acid modified the molecular interaction between ß-galactosidase and o-nitrophenyl-ß-d-galactoside, reducing their affinity and prejudicing the protein activity. This study helps to understand the effects of tannins on the ß-galactosidase structure and how they are related to the enzyme catalytic activity. The alterations in the conformation and activity of the enzyme should be taken into consideration when dairy products are consumed with tannin-rich food.


Asunto(s)
Kluyveromyces/enzimología , Taninos/metabolismo , beta-Galactosidasa/química , beta-Galactosidasa/metabolismo , Animales , Calorimetría/métodos , Dicroismo Circular , Proteínas Fúngicas/química , Proteínas Fúngicas/metabolismo , Humanos , Cinética , Nitrofenilgalactósidos/química , Nitrofenilgalactósidos/metabolismo , Conformación Proteica , Espectrometría de Fluorescencia , Taninos/química , Termodinámica
9.
J Agric Food Chem ; 66(40): 10543-10551, 2018 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-30227705

RESUMEN

Phytate decreases mineral and protein availability and influences protein properties, such as solubility and stability. The binding constants and turbidity data can help with the understanding of the influence of phytate and divalent salts on protein behavior. Ternary complexes formed between bovine serum albumin, sodium phytate, and divalent salts were investigated by isothermal titration calorimetry, turbidity, and in vitro protein digestibility. Results showed a positive entropy change and a negative and small enthalpy change as a result of electrostatic binding forces and ternary and binary complex precipitation. The interaction was favored for the systems containing calcium and manganese, whereas those containing magnesium showed a low heat of interaction. Despite the high protein digestibility, the stability of divalent phytates in a wide pH range may decrease mineral bioavailability. These results can provide important insights for the study of mineral bioavailability and diverse processes that involve protein and minerals in several areas of knowledge.


Asunto(s)
Calcio/química , Magnesio/química , Ácido Fítico/química , Albúmina Sérica Bovina/química , Animales , Calcio/metabolismo , Bovinos , Digestión , Magnesio/metabolismo , Modelos Biológicos , Ácido Fítico/metabolismo , Unión Proteica , Albúmina Sérica Bovina/metabolismo , Solubilidad , Termodinámica
10.
J Agric Food Chem ; 66(31): 8391-8397, 2018 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-29992813

RESUMEN

Nicarbazin is one of the major anticoccidials used in broiler feeds. The compound 4,4'-dinitrocarbanilide (DNC) is the marker residue of concern left from nicarbazin in chicken meat. The effect of thermal processing on DNC content accumulated in chicken breast was assessed, and samples were analyzed by liquid chromatography-tandem mass spectrometry. Five conventional cooking methods were evaluated: boiling, grilling, microwaving, frying, and roasting. To ensure DNC in meat, broilers were fed nicarbazin without withdrawal period. All heating methods surpassed the 70 °C end point core temperature in chicken breast. Maximum DNC degradation was reached at 10 min for boiling, at 30 min for grilling, and at 2 min for microwaving, and no further reduction was observed for longer thermal processing time. Boiling was more efficient in reducing DNC (69%). Grilling, microwaving, and frying achieved on average 55% of degradation. The outcomes reported herein may be considered in decision-making regarding further review of maximum residue limits.


Asunto(s)
Carbanilidas/análisis , Carbanilidas/química , Pollos , Culinaria/métodos , Contaminación de Alimentos/análisis , Carne/análisis , Animales , Coccidiostáticos/administración & dosificación , Residuos de Medicamentos/análisis , Contaminación de Alimentos/prevención & control , Manipulación de Alimentos/métodos , Calor , Nicarbazina/administración & dosificación
11.
J Environ Manage ; 222: 284-292, 2018 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-29860122

RESUMEN

Cassava is the most important tuberous root in tropical and subtropical regions of the world, being the third largest source of carbohydrates. The root processing is related to the production of starch, an important industrial input, which releases a highly toxic liquid wastewater due to its complex composition, which inhibits high performances of conventional effluent treatments. This study aims to evaluate Fenton-like and photo-Fenton-like reactions for treatment of cassava wastewater, reusing ferrous ions from the preliminary coagulation stage. Pre-treated cassava wastewater was submitted to oxidation in three variations of hydrogen peroxide concentrations, with more relevant analytical responses verified in color, turbidity, COD (Chemical Oxygen Demand), and acute toxicity in Artemia salina, besides the action of radicals during Fenton-like reactions. At higher peroxide concentrations, a decrease of 68% in turbidity and 70% in COD on the photo-Fenton-like system was observed, even at slow reaction rates (fastest rate constant k = 2 × 10-4 min-1). Inclusion of UV increases the viability of the Fenton-like reactions by supplementing the reaction medium with hydroxyl radicals, verified by the tert-butanol tests. The oxidation process leads to high EC50 values in 24 h of incubation in Fenton-like reactions and 48 h in photo-Fenton-like reactions. Final COD and turbidity suggests that the reuse of iron, which remains in the preliminary treatment step shows a great potential as a catalyst for Fenton-like advanced oxidation processes. Tertiary treatment can be less expensive and harmful to the environment, reducing production of residual sludge and metal content in the final effluent, which reduces polluting potential of the effluent regarding solid waste.


Asunto(s)
Análisis de la Demanda Biológica de Oxígeno , Eliminación de Residuos Líquidos , Aguas Residuales , Peróxido de Hidrógeno , Residuos Industriales , Hierro , Oxidación-Reducción , Aguas del Alcantarillado , Contaminantes Químicos del Agua
12.
Environ Technol ; 39(10): 1238-1249, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-28464729

RESUMEN

Due to the widespread use of methylparaben (MEP) and its high chemical stability, it can be found in wastewater treatment plants and can act as an endocrine disrupting compound. In this study, the photocatalytic degradation and mineralization of MEP solutions were evaluated under UV-A, UV-C and Vis radiations in the presence of the photocatalyst TiO2. In this sense, the effects of the catalyst load, pH and MEP initial concentration were studied. Remarkably higher reaction rates and total photodegradation were achieved in systems assisted by UV-C radiation. The complete degradation was achieved after 60 min of reaction using the MEP concentration of 30 mg L-1 at pH 9 and 500 mg L-1 TiO2. The experimental data apparently followed a Langmuir-Hinshelwood kinetic model, which could predict 88-98% of the reaction behavior. For the best photodegradation condition, the model predicted an apparent reaction rate constant (kapp) equal to 0.0505 min-1 and an initial reaction rate of 1.5641 mg (L min)-1. Mineralization analyses showed high removal for MEP and derived compounds from the initial solution when using UV-C after 90 min of reaction. The lower toxicity was also confirmed by in vivo tests using MEP solutions previously treated by photocatalysis.


Asunto(s)
Parabenos/química , Contaminantes Químicos del Agua/química , Purificación del Agua , Catálisis , Cinética , Fotólisis , Titanio , Rayos Ultravioleta
13.
Food Chem ; 232: 263-271, 2017 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-28490074

RESUMEN

This work aimed to study the influence of pH (3.5 and 7.0) and CaCl2 and MgCl2 addition on heat-set gelation of a quinoa protein isolate at 10% and 15% (w/w). The protein isolate obtained was composed mainly of 11S globulin as was observed by electrophoresis and mass spectrometry analysis. Heat-set gelation occurred at both pH values studied. Nevertheless, the gels formed at pH 3.5 were more viscoelastic and denser than those formed at pH 7.0, that was coarser and presented syneresis. The CaCl2 and MgCl2 addition increased the gel strength during rheological analysis at pH 3.5, possibly due to the formation of fiber-like connections in the gel network. At pH 7.0, the divalent salts resulted in weaker gels formed by agglomerates, suggesting a neutralization of the protein surface charges. The differences in quinoa protein gelation were attributed to solubility, and the flexibility of proteins secondary structure at the pH studied.


Asunto(s)
Chenopodium quinoa/química , Proteínas de Plantas/aislamiento & purificación , Geles , Calor , Concentración de Iones de Hidrógeno , Reología
14.
J Food Sci Technol ; 54(1): 236-243, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28242921

RESUMEN

Freezing is a widely applied method in food preservation. The technique has negative effects on sensory and textural properties of some foods. In this study the effects of the freeze-thaw process and lactobionic acid (LBA) as a cryoprotectant on GlnK protein solution were evaluated by circular dichroism (CD) analysis and isothermal titration calorimetry (ITC). The freeze-thaw cycles caused changes in GlnK conformation and interactions with small ligands (adenosine triphosphate, ATP). CD assay demonstrated changes in the molar ellipticity values of the samples subjected to freezing, indicating conformational changes to the GlnK protein. Additionally, ITC analysis indicated that the freeze-thaw process caused changes in the interaction properties of GlnK with its ligand ATP. LBA cryoprotectant activity was also evaluated and with both of the techniques it was demonstrated that the compound prevented the damage caused by the freeze-thaw process, thereby maintaining the characteristics of the samples.

15.
Environ Technol ; 35(9-12): 1532-40, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24701953

RESUMEN

This paper reports a study on the adsorption of the dye sunset yellow, present in an aqueous synthetic solution and a real effluent from a soft drink plant, onto granular-activated carbon derived from coconut husks, using a batch system. The kinetic equilibrium was investigated using two different dye concentrations (10(2) and 10(3) mg L(-1)) at 25 degrees C and 150 rpm. The adsorption isotherms and thermodynamics parameters were evaluated at 25 degrees C, 35 degrees C, 45 degrees C and 55 degrees C, using the synthetic and real effluents (5-10(3) mg L(-1)). Experimental data showed that the adsorbent was effective in the removal of sunset yellow dye and the contact time required to attain the adsorption equilibrium did not exceed 10 h. The adsorption capacity was not influenced within a wide range of pH values (1-12), although at high dye concentrations it increased with increasing temperature for both the synthetic and real effluents. The Redlich-Peterson isotherm best represented the equilibrium data of the system. The negative values obtained for DeltaG0 and DeltaH0 suggest that this adsorption process is spontaneous, favourable, and exothermic. The positive values for DeltaS0 indicate an increase in the entropy at the solid/liquid interface. Based on the results of this study, adsorption appears to be a promising method for the removal of sunset yellow azo dye from effluent generated at soft drink plants.


Asunto(s)
Compuestos Azo/aislamiento & purificación , Modelos Químicos , Eliminación de Residuos Líquidos , Adsorción , Residuos Industriales , Cinética , Termodinámica , Aguas Residuales/análisis
16.
Environ Technol ; 34(13-16): 2361-9, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24350492

RESUMEN

The most common methods currently used for the removal of waste glycerol, monoglycerides and diglycerides remaining after phase separation during biodiesel production involve wet processes. These procedures are not environmentally viable because they require large volumes of water and thus generate significant quantities of effluent. In this study, adsorption was employed to replace this purification step. Some commercial activated carbons were tested along with adsorbents chemically modified with HNO3. A kinetics study was conducted at 30 degrees C and adsorption isotherms were obtained at 20 degrees C, 30 degrees C and 40 degrees C. The results indicated that the adsorption of glycerol increased with the use of chemically-modified activated carbon, showing that pH has a strong influence on glycerol adsorption. The pseudo-first-order kinetic model provided the best fit with the experimental data for the monoglycerides while the pseudo-second-order model showed a better fit for the glycerol and diglycerides. The Freundlich model had the best fit with experimental data on the adsorption equilibrium for all temperatures. The thermodynamic study indicated that the adsorption process is endothermic and thus adsorption is favoured by increasing the temperature. The adsorption process using chemically-modified activated carbon was therefore very effective for the removal of waste glycerol resulting from biodiesel production, which is of considerable significance given the legal limits imposed.


Asunto(s)
Biocombustibles , Glicéridos/aislamiento & purificación , Glicerol/aislamiento & purificación , Aceite de Soja/metabolismo , Eliminación de Residuos Líquidos/métodos , Adsorción , Glicéridos/química , Glicéridos/metabolismo , Glicerol/química , Glicerol/metabolismo , Cinética , Termodinámica
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...