Lipid nanocarriers for the loading of polyphenols - A comprehensive review.

Polyphenols are secondary metabolites found in all vascular plants and constitute a large group of at least 10,000 unique compounds. Particular attention is currently being paid to polyphenols attributed to their beneficial effects in the protection and prevention of several diseases. While their use in food, pharmaceutical and cosmetic industries is largely documented, several environmental conditions (e.g. light, temperature or oxygen) may affect the physicochemical stability of polyphenols, compromising their bioactivity in vivo. To overcome these limitations, the loading of polyphenols into nanoparticles has been proposed aiming at both increasing their bioavailability and reducing eventual side effects. Lipid nanoparticles offer several advantages, namely their biodegradability and low toxicity, with the additional capacity to modify the release profile of loaded drugs. This paper is a review of the recent advances of lipid nanocarriers commonly used for the encapsulation of polyphenols, highlighting their added value to increase bioavailability and bioactivity of this group of compounds as well as their application in several diseases.

Novel micro/ultra/nanocentrifugation membrane process assessment for revalorization and reclamation of agricultural wastewater.

The concentration and recovery of the high-added value phenolic fraction from two-phase olive mill wastewater and the simultaneous effluent treatment by a novel micro/ultra/nanocentrifugation membrane process assessment is addressed, permitting to gather information for a correct and effective screening procedure for the adequate membrane election (MF-UF-loose NF) for the target. Phenolic compounds are the major factor of phytotoxicity of these effluents, but on the other hand they present high antioxidant properties that makes them very relevant for food, cosmetic, pharmaceutical and biotechnological industries. The selection of a membrane MWCO between 100 kDa and 0.45 µm permitted the complete transfer of the phenolic fraction to the permeate, whereas below 3 kDa they would be transferred to the concentrate stream instead, with ∼60% COD reduction and EC lowered to 551-662 µS cm-1 in the final treated stream ensured, sensibly improving the effluent quality. This would provide a purified effluent with good salinity standards according to the indications given by the FAO for irrigation reuse. This procedure could be quick and reliable for the assessment of the adequate membrane needed for a particular purification process, in contrast with long-term, time consuming common bench-scale procedures.

Experimental design optimization of reverse osmosis purification of pretreatedolive mill wastewater.

The management of the effluents generated by olive oil industries, commonly known as olive mills, represents an ever increasing problem still unresolved. The core of the present work was the modelling and optimization of a reverse osmosis (RO) membrane operation for the purification of a tertiary-treated olive mill wastewater stream (OMW2TT). Statistical multifactorial analysis showed all the studied variables including the operating pressure (PTM), crossflow velocity (vt) and operating temperature (T) remarkably influence the permeate flux yielded by the selected membrane (p-value practically equal to zero), confirming a statistically significant relationship among the variables considered at 95% confidence level. However, PTM and T exhibit a deeper influence than vt, according to the p-values withdrawn from the analysis, being the squared effects significant too, but more in case of the former ones. The obtained contour plots and response surface support the former results. In particular, the optimized parameters were ambient temperature range (24-29.6°C), moderate operating pressure (31.5-35bar) and turbulent crossflow (4.1-5.1ms-1). In the end, the quality standards to reuse the purified effluent for irrigation purposes and discharge to sewers were stably ensured.

Reuse of olive mill effluents from two-phase extraction process by integrated advanced oxidation and reverse osmosis treatment.

In this work, complete reclamation of the olive mill effluents coming from a two-phase olive oil extraction process (OME-2) was studied on a pilot scale. The developed depuration procedure integrates an advanced oxidation process based on Fenton's reagent (secondary treatment) coupled with a final reverse osmosis (RO) stage (purification step). The former aims for the removal of the major concentration of refractory organic pollutants present in OME-2, whereas the latter provides efficient purification of the high salinity. Complete physicochemical composition of OME-2 after the secondary treatment was examined, including the particle size distribution, organic matter gradation and bacterial growth, in order to assess the selection of the membrane and its fouling propensity. Hydrodynamics and selectivity of the membrane were accurately modelized. Upon optimization of the hydrodynamic conditions, the RO membrane showed stable performance and fouling problems were satisfactorily overcome. Steady-state permeate flux equal to 21.1 L h(-1)m(-2) and rejection values up to 99.1% and 98.1% of the organic pollutants and electroconductivity were respectively attained. This ensured parametric values below standard limits for reuse of the regenerated effluent, e.g. in the olives washing machines, offering the possibility of closing the loop and thus rending the production process environmentally friendly.

Effective treatment of olive mill effluents from two-phase and three-phase extraction processes by batch membranes in series operation upon threshold conditions.

Production of olive oil results in the generation of high amounts of heavy polluted effluents characterized by extremely variable contaminants degree, leading to sensible complexity in treatment. In this work, batch membrane processes in series comprising ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO) are used to purify the effluents exiting both the two-phase and tree-phase extraction processes to a grade compatible to the discharge in municipal sewer systems in Spain and Italy. However, one main problem in applying this technology to wastewater management issues is given by membrane fouling. In the last years, the threshold flux theory was introduced as a key tool to understand fouling problems, and threshold flux measurement can give valuable information regarding optimal membrane process design and operation. In the present manuscript, mathematical approach of threshold flux conditions for membranes operation is addressed, also implementing proper pretreatment processes such as pH-T flocculation and UV/TiO2 photocatalysis with ferromagnetic-core nanoparticles in order to reduce membranes fouling. Both influence the organic matter content as well as the particle size distribution of the solutes surviving in the wastewater stream, leading, when properly applied, to reduced fouling, higher rejection and recovery values, thus enhancing the economic feasibility of the process.

A focus on pressure-driven membrane technology in olive mill wastewater reclamation: state of the art.

Direct disposal of the heavily polluted effluent from olive oil industry (olive mill wastewater, OMW) to the environment or to domestic wastewater treatment plants is actually prohibited in most countries, and conventional treatments are ineffective. Membranes are currently one of the most versatile technologies for environmental quality control. Notwithstanding, studies on OMW reclamation by membranes are still scarce, and fouling inhibition and prediction to improve large-scale membrane performance still remain unresolved. Consequently, adequately targeted pretreatment for the specific binomium membrane-feed, as well as optimized operating conditions for the proper membranes, is today's challenge to ensure threshold flux values. Several membrane materials, configurations and pore sizes have been elucidated, and also different pretreatments including sedimentation, centrifugation, biosorption, sieving, filtration and microfiltration, various types of flocculation as well as advance oxidation processes have been applied so far. Recovery of potential-value compounds, such as a variety of polyphenols highlighting oleuropein and hydroxytyrosol, has been attempted too. All this research should constitute the starting point to proceed with OMW purification beyond recycling for irrigation or depuration for sewer discharge, with the aim of complying with standards to reuse the effluent in the olive oil production process, together with cost-effective recovery of added-value compounds.

Impacts of operating conditions on reverse osmosis performance of pretreated olive mill wastewater.

Management of the effluent from the olive oil industry is of capital importance nowadays, especially in the Mediterranean countries. Most of the scarce existing studies concerning olive mill wastewater (OMW) treatment by means of membrane processes not only do fix their aims simply on achieving irrigation standards, but lack suitable pretreatments against deleterious fouling issues. With the target of achieving the parametric requirements for public waterways discharge or even for reuse in the production process, a bench-scale study was undertaken to evaluate the feasibility of a thin-film composite reverse osmosis (RO) membrane (polyamide/polysulfone) for the purification of OMW. Previously, OMW was pretreated by means of chemical oxidation based on Fenton's reagent, flocculation-sedimentation and biosorption through olive stones. Impacts of the main operating parameters on permeate flux and pollutants rejection of the RO process, as well as fouling on the membrane surface, were examined for removing the significant ionic concentration and remaining organic matter load of the pretreated OMW. Combining operating parameters adequately in a semibatch operating regime ensured high and sustainable permeate flux, yielding over 99.4% and 98.5% removal efficiencies for the chemical oxygen demand and ionic content respectively, as well as complete rejection of phenols, iron and suspended solids.

n-3 Fatty acids plus oleic acid and vitamin supplemented milk consumption reduces total and LDL cholesterol, homocysteine and levels of endothelial adhesion molecules in healthy humans.

BACKGROUND AND AIMS: Numerous studies suggest n -3 polyunsaturated fatty acids (n -3 PUFA) and oleic acid intake have beneficial effects on health including risk reduction of coronary heart disease. The purpose of this study was to evaluate the effect of a commercially available skimmed milk supplemented with n -3 PUFA, oleic acid, and vitamins E, B(6), and folic acid (Puleva Omega3) on risk factors for cardiovascular disease. (CVD). METHODS: Thirty volunteers were given 500 ml/day of semi-skimmed milk for 4 weeks and then 500 ml/day of the n -3 enriched milk for 8 further weeks. Plasma and LDL lipoproteins were obtained from volunteers at the beginning of the study (T(pre)), and at 4, 8 and 12 weeks. RESULTS: The consumption of n -3 enriched milk produced a significant decrease in plasma concentration of total and LDL cholesterol accompanied by a reduction in plasma levels of homocysteine. Plasma and LDL oxidability and vitamin E concentration remained unchanged throughout the study. A significant reduction in plasma levels of vascular cell adhesion molecule 1, and an increase in plasma concentration of folic acid were also observed. CONCLUSION: Daily intake of n -3 PUFA and oleic acid supplemented skimmed milk plus folic acid and B-type vitamins has favourable effects on risk factors for CVD.

Péptidos y proteínas de la lechecon propiedades funcionales / Bioactive milk peptidos and proteins

La fracción proteica de la leche contiene un gran número de compuestos biológicamente activos. Además de las proteínas de la leche, caseínas y proteínas del suero lácteo, existen también pequeñas cantidades de otras proteínas y péptidos. Estos péptidos, que son inactivos dentro de la secuencia de la proteína nativa, pueden ser liberados por hidrólisis enzimática, por ejemplo, durante la digestión gastrointestinal o durante el procesado del alimento. Estos péptidos bioactivos procedentes de proteínas lácteas presentan una actividad moduladora de numerosos procesos metabólicos del organismo. Asimismo, las proteínas del suero lácteo representan una mezcla variada de proteínas secretadas, tales como á-lactoalbúmina, â-lactoglobulina, lactoferrina, lactoperoxidasa, inmunoglobulinas, glicomacropéptido y una gran cantidad de factores de crecimiento. Estas proteínas tienen una serie de efectos biológicos, que van desde un efecto anticancerígenos hasta efectos en la función digestiva (AU)

Componentes biológicamente activosde la leche materna / Bioactive compounds derived from human milk

La leche materna es un complejo fluido biológico que aporta la energía y los nutrientes esenciales para el desarrollo y crecimiento del recién nacido. Pero además, la leche materna contiene toda una serie de compuestos bioactivos como enzimas, hormonas, factores de crecimiento, proteínas específicas, poliaminas, nucleótidos, oligosacáridos, etc., que ejercen efectos biológicos y que en conjunto reciben el nombre de "factores tróficos de la leche". Estos compuestos biactivos son considerados nutrientes potencialmente esenciales en periodos de desarrollo y en determinadas enfermedades, cuando la capacidad de síntesis no supera las necesidades de los mismos. Aunque las fórmulas infantiles aportan todos los nutrientes para un adecuado desarrollo del recién nacido, carecen de muchos de estos compuestos. Este artículo pretende realizar una revisión acerca de los conocimientos actuales sobre los efectos biológicos de la lactoferrina, nucleótidos, poliaminas y oligosacáridos (AU)