RESUMEN
HYPOTHESIS: Effective removal of oil pollutants from the surface of water is important in oil-polluted environments. Since living microorganisms can be used as particle-stabilizers for oil emulsification, magnet-responsive oil-degrading bacteria (M-Bacteria) are expected to integrate three intriguing properties, such as Pickering emulsification, magnet-responsiveness and bioactivity. Hence, by acting as an efficient Pickering emulsifier to encapsulate oil pollutants, it should be possible to eliminate oil from water under the application of an external magnetic field. EXPERIMENTS: Oil-degrading bacteria, Brevibacillus parabrev, were successfully coated with a shell of magnetic Fe3O4 nanoparticles using polycations. The morphology and physicochemical characteristics of M-Bacteria were characterized by various techniques. A systematic study on Pickering emulsification of M-Bacteria and the removal of five types of oils were performed. Specific adsorption of M-Bacteria at the oil droplet surface was observed through optical, fluorescence, and scanning electronic microscopy images. The biodegradation process of oil was monitored using gas chromatography. FINDINGS: Eco-friendly M-Bacteria not only acts as an effective particle emulsifier to realize encapsulation and magnetic separation of oil contaminants but also shows a strong ability for further conversion of oil. This is the first report of oil removal via Pickering emulsification of living bacterial cells, which shows the potential of bacterial cells as functional colloidal materials in treating oily wastewater.
Asunto(s)
Biodegradación Ambiental , Brevibacillus/crecimiento & desarrollo , Emulsionantes/química , Nanopartículas/química , Aceites/aislamiento & purificación , Aceites/metabolismo , Agua/química , Emulsionantes/economía , Fenómenos Magnéticos , Contaminación por Petróleo/prevención & control , Aguas Residuales/química , Purificación del Agua/métodosRESUMEN
Soaking of legumes results in the loss of macronutrients, micronutrients and phytochemicals. Fibre, protein and phytochemicals found in legumes exert emulsifying activity that may improve the structure and texture of gluten-free bread. The legume soaking water of haricot beans, garbanzo chickpeas, whole green lentils, split yellow peas and yellow soybeans were tested in this study for functional properties and use as food ingredients. Composition, physicochemical properties and effect on the quality of gluten-free bread were determined for each legume soaking water. Haricot beans and split yellow peas released the highest amount of solids in the legume soaking water: 1.89 and 2.38 g/100 g, respectively. Insoluble fibre was the main constituent of haricot beans legume soaking water, while water-soluble carbohydrates and protein were the major fraction of split yellow peas. High quantities of phenolics (â¼400 µg/g) and saponins (â¼3 mg/g) were found in the legume soaking water of haricot beans, whole green lentils and split yellow peas. High emulsifying activity (46 and 50%) was found for the legume soaking water of garbanzo chickpeas and split yellow peas, probably due to their protein content and high ratio of water-soluble carbohydrates to dry matter. Such activity resulted in softer texture of the gluten-free bread. A homogeneous structure of crumb pores was found for split yellow peas, opposing that of whole green lentils. A balance between the contents of yeast nutrients and antinutrients was the likely basis of the different appearances.
Asunto(s)
Pan/análisis , Culinaria , Dieta Sin Gluten , Emulsionantes/química , Fabaceae/química , Semillas/química , Agua/química , Pan/economía , Pan/microbiología , Culinaria/economía , Dieta Sin Gluten/economía , Carbohidratos de la Dieta/análisis , Carbohidratos de la Dieta/economía , Fibras de la Dieta/análisis , Fibras de la Dieta/economía , Proteínas en la Dieta/análisis , Proteínas en la Dieta/química , Proteínas en la Dieta/economía , Emulsionantes/análisis , Emulsionantes/economía , Fabaceae/metabolismo , Fermentación , Calidad de los Alimentos , Industria de Procesamiento de Alimentos/economía , Humanos , Residuos Industriales/análisis , Residuos Industriales/economía , Nueva Zelanda , Valor Nutritivo , Fenoles/análisis , Fenoles/química , Fenoles/economía , Pigmentos Biológicos/análisis , Pigmentos Biológicos/biosíntesis , Saccharomyces cerevisiae/crecimiento & desarrollo , Saccharomyces cerevisiae/metabolismo , Saponinas/análisis , Saponinas/química , Saponinas/economía , Semillas/metabolismo , Especificidad de la EspecieRESUMEN
BACKGROUND: Walnut (Juglans regia L.) is a good source of protein that has potential application in new product formation and fortification. The main objectives of this study were to investigate the effects of high hydrostatic pressure (HHP) treatment (300-600 MPa 20 min) on physicochemical and functional properties of walnut protein isolate (WPI) using various analytical techniques at room temperature. RESULTS: The results showed significant modification of solubility, free sulfhydryl content and surface hydrophobicity with increased levels of HHP treatment, indicating partial denaturation and aggregation of proteins. Differential scanning calorimetry and fluorescence spectrum analyses demonstrated that HHP treatment resulted in gradual unfolding of protein structure. Emulsifying activity index was significantly (P < 0.05) increased after HHP treatment at 400 MPa, but significantly decreased (P < 0.05) relative to the untreated WPI with further increase in pressure. HHP treatment at 300-600 MPa significantly decreased emulsion stability index. Additionally, HHP-treated walnut proteins showed better foaming properties and in vitro digestibility. CONCLUSION: These results suggest that HHP treatment could be applied to modify the properties of walnut proteins by appropriate of pressure levels, which will help in using walnut protein as a potential food ingredient.
Asunto(s)
Proteínas en la Dieta/análisis , Juglans/química , Nueces/química , Proteínas de Plantas/química , Fenómenos Químicos , China , Proteínas en la Dieta/economía , Proteínas en la Dieta/metabolismo , Digestión , Emulsionantes/química , Emulsionantes/economía , Emulsionantes/metabolismo , Alimentos Fortificados/economía , Industria de Procesamiento de Alimentos/economía , Interacciones Hidrofóbicas e Hidrofílicas , Presión Hidrostática , Residuos Industriales/análisis , Residuos Industriales/economía , Peso Molecular , Proteínas de Plantas/economía , Proteínas de Plantas/metabolismo , Estabilidad Proteica , Estructura Terciaria de Proteína , Desplegamiento Proteico , Solubilidad , Compuestos de Sulfhidrilo/análisis , Propiedades de SuperficieRESUMEN
The oral route is the most frequently used method of drug intake in humans. Oral administration of drugs to laboratory animals such as mice typically is achieved through gavage, in which a feeding needle is introduced into the esophagus and the drug is delivered directly into the stomach. This method requires technical skill, is stressful for animals, and introduces risk of injury, pain and morbidity. Here we investigated another method of drug administration. The benzimidazole derivative albendazole was emulsified in commercially available honey and administered to mice by voluntary feeding or gavage. Mice that received albendazole by either gavage or honey ingestion had virtually identical levels of serum albendazole sulfoxide, indicating that uptake and metabolism of albendazole was similar for both administration techniques. In addition, dosing mice with the albendazole-honey mixture for 8 wk had antiparasitic activity comparable to earlier studies using gavage for drug administration. Compared with gavage, voluntary ingestion of a drug in honey is more rapid, less stressful to the animal, and less technically demanding for the administrator. Because of its low cost and ready availability, honey presents a viable vehicle for drug delivery.
Asunto(s)
Albendazol/administración & dosificación , Anticestodos/administración & dosificación , Portadores de Fármacos , Emulsionantes/administración & dosificación , Miel , Administración Oral , Albendazol/sangre , Animales , Anticestodos/sangre , Carboximetilcelulosa de Sodio/administración & dosificación , Cromatografía Líquida de Alta Presión/veterinaria , Portadores de Fármacos/economía , Equinococosis/tratamiento farmacológico , Equinococosis/veterinaria , Emulsionantes/economía , Femenino , Miel/economía , Ratones , Ratones Endogámicos BALB C , Enfermedades de los Roedores/tratamiento farmacológicoRESUMEN
Effect of acylation with saturated fatty acids on surface functional properties of tofu whey-derived peptides was investigated. Tofu whey (TW) and soy proteins (7S, 11S, and acid-precipitated soy protein [APP]) were hydrolyzed by Protease M 'Amano' G, and resulting peptide mixtures were acylated with esterified fatty acids of different chain length (6C to 18C) to form a covalent linkage between the carboxyl group of fatty acid and the free amino groups of peptide. Acylation significantly (P < 0.05) increased emulsifying properties of 7S, 11S, and APP peptides independent of fatty acid chain length. Acylation decreased water binding capacity although oil binding capacity of acylated tofu whey ultra filtered fraction (UFTW < 3 kDa), 7S- and 11S-peptides were improved compared to native peptides. 7S peptides acylated with long chain fatty acids had shown significant higher surface hydrophobicity as in contrast with acylated UFTW < 3 kDa and APP peptides. Fluorescence spectra studies revealed structural conformation of acylated soy peptides as compared to native peptides. This study shows that chemical modification with fatty acids can further affect functional properties of soy proteins.
Asunto(s)
Emulsionantes/química , Ácidos Grasos/química , Aditivos Alimentarios/química , Lipopéptidos/química , Fragmentos de Péptidos/química , Proteínas de Vegetales Comestibles/química , Proteínas de Soja/química , Acilación , Antígenos de Plantas/química , Antígenos de Plantas/metabolismo , Fenómenos Químicos , Emulsionantes/economía , Emulsionantes/aislamiento & purificación , Emulsionantes/metabolismo , Endopeptidasas/metabolismo , Aditivos Alimentarios/economía , Aditivos Alimentarios/aislamiento & purificación , Aditivos Alimentarios/metabolismo , Industria de Procesamiento de Alimentos/economía , Globulinas/química , Globulinas/metabolismo , Interacciones Hidrofóbicas e Hidrofílicas , Residuos Industriales/análisis , Residuos Industriales/economía , Lipopéptidos/aislamiento & purificación , Lipopéptidos/metabolismo , Peso Molecular , Fragmentos de Péptidos/aislamiento & purificación , Fragmentos de Péptidos/metabolismo , Proteínas de Vegetales Comestibles/aislamiento & purificación , Proteínas de Vegetales Comestibles/metabolismo , Conformación Proteica , Proteínas de Almacenamiento de Semillas/química , Proteínas de Almacenamiento de Semillas/metabolismo , Proteínas de Soja/aislamiento & purificación , Proteínas de Soja/metabolismo , Propiedades de Superficie , Ultrafiltración , Agua/análisisRESUMEN
Microfiltration (MF) membranes with pore sizes of 200 and 450 nm and ultrafiltration (UF) membranes with molecular weight cut off of 50, 100, and 500 kDa were assessed for their ability to eliminate nonprotein substances from okara protein extract in a laboratory cross-flow membrane system. Both MF and UF improved the protein content of okara extract to a similar extent from approximately 68% to approximately 81% owing to the presence of protein in the feed leading to the formation of dynamic layer controlling the performance rather than the actual pore size of membranes. Although normalized flux in MF-450 (117 LMH/MPa) was close to UF-500 (118 LMH/MPa), the latter was selected based on higher average flux (47 LMH) offering the advantage of reduced processing time. Membrane processing of soy extract improved the protein content from 62% to 85% much closer to the target value. However, the final protein content in okara (approximately 80%) did not reach the target value (90%) owing to the greater presence of soluble fibers that were retained by the membrane. Solubility curve of membrane okara protein concentrate (MOPC) showed lower solubility than soy protein concentrate and a commercial isolate in the entire pH range. However, water absorption and fat-binding capacities of MOPC were either superior or comparable while emulsifying properties were in accordance with its solubility. The results of this study showed that okara protein concentrate (80%) could be produced using membrane technology without loss of any true proteins, thus offering value addition to okara, hitherto underutilized. Practical Application: Okara, a byproduct obtained during processing soybean for soymilk, is either underutilized or unutilized in spite of the fact that its protein quality is as good as that of soy milk and tofu. Membrane-processed protein products have been shown to possess superior functional properties compared to conventionally produced protein products. However, the potential of membrane technology has not been exploited for the recovery of okara protein. Our study showed that protein content of okara extract could be improved from approximately 68% to approximately 81% without losing any true proteins in the process.
Asunto(s)
Tecnología de Alimentos , Proteínas de Vegetales Comestibles/química , Proteínas de Vegetales Comestibles/aislamiento & purificación , Proteínas de Soja/química , Proteínas de Soja/aislamiento & purificación , Algoritmos , Emulsionantes/análisis , Emulsionantes/química , Emulsionantes/economía , Emulsionantes/aislamiento & purificación , Emulsiones , Filtración , Industria de Procesamiento de Alimentos/economía , Concentración de Iones de Hidrógeno , Residuos Industriales/análisis , Residuos Industriales/economía , Peso Molecular , Aceites de Plantas/análisis , Proteínas de Vegetales Comestibles/economía , Proteínas de Vegetales Comestibles/metabolismo , Semillas/química , Solubilidad , Proteínas de Soja/economía , Proteínas de Soja/metabolismo , Glycine max/química , Factores de Tiempo , Inhibidores de Tripsina/metabolismo , Ultrafiltración , Agua/análisisRESUMEN
UNLABELLED: Canola meal protein isolates were prepared from defatted canola meal flour using alkaline solubilization and acid precipitation. A central composite design was used to model 2nd-order response surfaces for the protein yield and the functional properties of protein isolates. The solubilization pH and precipitation pH were used as design factors. The models showed that the protein yield and functional properties of isolates, such as water absorption and fat absorption, were sensitive to both solubilization pH and precipitation pH, whereas the emulsification was sensitive to only solubilization pH. Gel electrophoresis analysis of protein fractions gave evidence to the compositional changes between proteins isolated under different conditions. Differences in glass transition temperatures suggest that proteins tend to be more denatured when solubilized at highly alkaline conditions. These conformational and compositional changes due to different protein separation conditions have contributed to the changes in functional properties of protein isolates. PRACTICAL APPLICATION: Protein isolation conditions may be determined primarily through optimization of total protein yield. Improvements in protein functional properties may be achieved with a relatively small sacrifice in yield by altering isolation conditions.