Post-extraction Treatment Research Articles

The two-faced functionality of birch glucuronoxylan in an emulsion-based carrier of vitamin D3

Emulsions are commonly used to fortify beverages with oil-soluble nutrients. Such emulsions must be physically stable, prevent the cargo nutrient from chemical degradation, and release the nutrient at the right time during digestion. Wood hemicelluloses, with their proven capability in producing nanoemulsions and preventing oil oxidation, have the potential to facilitate such a fortification method. These hemicelluloses are unique, as the presence of residual lignin was proven essential in their functionality. However, the structural interplay between the residual lignin and the polysaccharide fraction at the oil-water interface is unknown, including their effects on the storage stability and digestibility of a loaded bioactive compound. We studied the performance of emulsions stabilized by two grades of birch glucuronoxylans (GX) as vessels for vitamin D3. Both GXs showed similar protective performance to methylcellulose regardless of the lignin content during storage and the gastric phase of digestion. The unrefined GX, which contained larger lignin moieties, delayed the release of vitamin D3 during intestinal digestion. We concluded that the interface is primarily built of a polysaccharide layer with the lignin moieties facing towards the oil phase. We have thus highlighted the potential of GX-stabilized emulsions as carriers of vitamin D3. Additionally, these results advance the understanding of lignin-polysaccharide interplay towards a rationalized strategy in biorefining of wood hemicelluloses, for which the ratio of lignin-to-polysaccharide can be adjusted during extraction and post-extraction treatments to obtain a tailor-made emulsifier for various emulsion-based products.

Optimization of a Simple Analytical Workflow to Characterize the Phenolic Fraction from Grape Pomace

The recovery of polyphenols from grape pomace (GP) supports the promotion of sustainable bioeconomy. Accordingly, the development of pre-treatment and extraction techniques using low-solvent amounts and energy-efficient processes is highly desirable. In this work, a comprehensive strategy to maximize phenol extraction from two Umbrian red wine cultivars, Cabernet Sauvignon and Merlot, was proposed. Focus was paid to sample pre- (fresh, air-, oven- and freeze-dried pomace) and post-extraction (chemical- and enzymatic-hydrolysis) treatments. An experimental design was applied to optimize phenol recovery by ultrasound-assisted extraction: the variables water content in ethanol (20–80% v/v) and time (10–30 min) highlighted a critical influence on the total phenol content (TPC) selected as the response. β-glucuronidase hydrolysis provided the highest TPC and in vitro total antioxidant capacity also improving phenol identification and quantification via HPLC–DAD (particularly evident for freeze-dried Merlot and Cabernet GP, which gave a total phenolic content measured by HPLC equal to 1904.08 mg/g and 2064.64 mg/g, respectively). LC-HRMS/MS analysis allowed identity confirmation of the major phenols, and cytotoxicity assay highlighted the safety of the selected β-glucuronidase extracts towards Caco2 cell line. Ultimately, in the present work, we have addressed the importance of the recovery of bioactive compounds from grape pomace by proposing a comprehensive analytical strategy in which different methodological alternatives have been evaluated to preserve these compounds, in a frame of sustainability on a larger industrial scale.

Structure modification, functionality and interfacial properties of kidney bean (Phaseolus vulgaris L.) protein concentrate as affected by post-extraction treatments

In this study, in-house extracted kidney bean protein concentrate (KPC) was treated with pH-shift (pH-S), pH-shift combined with ultrasound (pH-SU) or heat (pH-SH), and the structural, functional, and interfacial properties of the modified KPC were comprehensively evaluated. Upon treatments, the increase of KPC surface hydrophobicity (H 0 ) was observed, and the intensity was in the order of pH-SH > pH-SU > pH-S > control. The intrinsic tryptophan fluorescence of KPC solution had a negatively proportional relationship with their H 0 . All post-extraction treatments also significantly decreased the contents of total and free sulfhydryl groups. But disulfide bonds (SS) showed a different trend that the KPC from pH-S had the highest SS of 18.60 μmol/g followed by the control (17.32 μmol/g), pH-SU (17.15 μmol/g), and pH-SH (11.90 μmol/g). In functional properties, KPC from pH-SH showed significantly improved percentage solubility at pH 6.0 when compared to the others. All treated KPC exhibited a higher emulsifying activity index (EAI) than the control (8.2 m 2 /g), and pH-S, pH-SU, and pH-SH showed EAI values of 20.9, 19.0, 23.9 m 2 /g, respectively. But only KPC from pH-SH showed an improved emulsifying stability index (ESI) of 60.7% when compared to the control (27.2%). Meanwhile, the improved foaming capacity was only found in KPC from pH-SH, but a decrease in foaming stability was observed. The interfacial properties indicated that the improvement in EAI is associated with the fast diffusion rate while a higher ESI found in KPC from pH-SH has been closely related to the formation of a stronger viscoelastic film. Overall this study has established the relationships among structural characteristics of KPC upon various post-extraction treatments, their functional properties and interfacial properties. • Kidney bean protein concentrate (KPC) was modified via post-extraction treatment. • Three treatments include pH-shift (pH-S), pH-shift + ultrasound/heat (pH-SU/pH-SH). • Different structural characteristics were observed in pH-SU and pH-SH modified KPC. • Structural change notably affected interfacial and functional properties of KPC. • KPC with pH-SH treatment showed better emulsifying properties.

Xylan extraction strategies and the performance of the resulting high purity cellulose fiber to swelling and dissolution

In this study, we investigated the influence of hemicelluloses removal treatment on the reactivity of the resulting pulp. The idea was to develop treatment strategies consisting of mechanical refining (different refining technologies), chemical treatment (CCE), and xylanase treatment that enabled both quantitative xylan removal as well as good reactivity to dissolution without the need for additional post-extraction treatments (cellulose activation) to improve reactivity. Cellulose post-extraction treatments result in additional production costs. The reactivity of the extracted pulps was evaluated based on the degree of swelling in NaOH and dilute cupriethylene diamine solution (CUEN), the solubility in 8% NaOH at -10 °C, and the Fock reactivity. The result obtained showed that hemicelluloses removal strategies that included mechanical refining treatment led to better pulp reactivity than unrefined pulp. The best result was obtained with refined pulp extracted with 6% soda (cellulose II not detected). In addition, we obtained a Fock reactivity ranging from 60 to 70%. The good correlations found between fiber swelling, solubility in caustic soda, and Fock reactivity suggest that the tedious Fock test could be substituted by the much simpler swelling and solubility measurements. The negative impact of cellulose II on pulp reactivity is due to the higher number of hydrogen bonds formed under dewatering and drying. This problem would most likely be averted in the ideal case where pulp dissolution is integrated into the pulp mill.

Fundamentals and applications of stir bar sorptive dispersive microextraction: A tutorial review

Current trends in sample preparation focus on the miniaturization of the process resulting in what is known as microextraction techniques. Among them stir bar sorptive dispersive microextraction (SBSDME) is one of the most recent techniques. It was presented a few years ago as a hybrid microextraction technique that combines the principles of stir bar sorptive extraction (SBSE) and dispersive solid phase extraction (DSPE). This novel technique introduces, into the sample solution, a bar-shaped magnet coated with a magnetic (nano)material, which is maintained on the surface by magnetism. Once stirring starts, the competitive action between magnetism and rotational force is exploited. At low rotational speed the (nano)material is retained on the magnet reminding SBSE, whereas at high sufficiently rotational speed the rotational force surpasses magnetism so that the magnetic (nano)material is dispersed into the sample solution as in DSPE. Upon halting rotation, the magnetic field prevails again and attracts the magnetic (nano)material containing the analytes back on the surface of the stirring bar. Finally, the extracted analytes are chemically or thermally desorbed before their measurement with the appropriate analytical instrument. When compared separately to SBSE and DSPE procedures, SBSDME affords, in a single approach, advantages such as lower extraction times than SBSE and easier extraction and post-extraction treatment than DSPE. The main purpose of this tutorial review is to describe the fundamentals and the experimental variables involved in this technique, as well as to compile and critically discuss the published papers concerning analytical methods based on the use of the SBSDME approach, analyzing its evolution and future prospects.

Extraction Socket Preservation Using Growth Factors and Stem Cells: a Systematic Review

ABSTRACTObjectivesTo evaluate the reported literature on the use of stem cells or growth factors for post extraction treatment of the alveolar bone.Material and MethodsA NCBI PubMed and PubMed Central databases search was conducted between September 2010 and August 2018, to identify animal or clinical studies reporting the clinical, radiographical and/or histological outcomes of socket preservation techniques after applying mesenchymal stem cells or growth factors. Only studies published in English language in the last 10 years were included in the study.ResultsEleven studies were identified fulfilling the inclusion criteria. They evaluate a total of 386 post extraction sockets. The main tested materials identified in the current review were bone morphogenetic protein-2 - 3 studies and mesenchymal stem cells - 3 studies. Other comparators were bone morphogenetic protein-9, platelet-derived growth factor-BB homodimers and bone marrow. Overall evaluation indicate positive results for all test groups showing differences in final socket width between 0.64 and 1.28 mm favouring the test groups. Histologically, no particular differences are detected between test and control groups. Most of the studies present low risk of bias.ConclusionsIn general, the use of mesenchymal stem cells or bioactive osteogenic molecules favours bone regeneration after tooth extraction, as evaluated clinically, radiographically and histologically. However, specific differences that support particular recommendations are still unclear in light of the current published evidence. Future studies should include the standardization of the mesenchymal stem cells selection and purification as well as dosage and delivery methods of bioactive molecules.

Stir bar sorptive-dispersive microextraction mediated by magnetic nanoparticles–nylon 6 composite for the extraction of hydrophilic organic compounds in aqueous media

A new and sensitive analytical method based on the recently developed approach termed stir bar-sorptive dispersive microextraction (SBSDME) using a magnetic CoFe2O4@SiO2–nylon 6 composite as sorbent material is presented for the extraction of hydrophilic organic compounds. The simultaneous determination of four hydrophilic UV filters in environmental water samples has been chosen as a model analytical application due to the increasing awareness regarding the occurrence of sunscreen residuals in natural waters. The developed SBSDME approach combines the principles and benefits of stir bar sorptive extraction (SBSE) and dispersive solid phase extraction (DSPE) but allows for lower extraction time and easier post-extraction treatment. Moreover, most importantly, it enables the use of new magnetic materials that affords higher versatility and can be tailored to the needs of the analysis. The main experimental parameters involved in the SBSDME process (i.e. composite amount, extraction time, pH, ionic strength, desorption solvent and desorption time) were evaluated to provide the best enrichment factors. Under the optimized conditions, the method was successfully validated showing good linearity, enrichment factors between 105 and 145 depending on the analyte, limits of detection and quantification in the low ng mL−1 range (1.6–2.9 ng mL−1 and 5.4–9.6 ng mL−1, respectively) and good intra- and inter-day repeatability (RSD < 13%). The developed method was applied to the analysis of water samples of different origin (sea, river and swimming pool). Relative recovery values ranged between 90 and 115%, thus showing that the matrices under consideration do not affect the extraction process.

Determination of ultraviolet filters in bathing waters by stir bar sorptive–dispersive microextraction coupled to thermal desorption–gas chromatography–mass spectrometry

In this work, a new approach that combines the advantages of stir bar sorptive extraction (SBSE) and dispersive solid phase extraction (DSPE), i.e. stir bar sorptive–dispersive microextraction (SBSDµE), is employed as enrichment and clean-up technique for the sensitive determination of eight lipophilic UV filters in water samples. The extraction is accomplished using a neodymium stir bar magnetically coated with oleic acid-coated cobalt ferrite magnetic nanoparticles (MNPs) as sorbent material, which are detached and dispersed into the solution at high stirring rate. When stirring is stopped, MNPs are magnetically retrieved onto the stir bar, which is subjected to thermal desorption (TD) to release the analytes into the gas chromatography–mass spectrometry (GC–MS) system. The SBSDµE approach allows for lower extraction time than SBSE and easier post-extraction treatment than DSPE, while TD allows for an effective and solvent-free injection of the entire quantity of desorbed analytes into GC–MS, and thus achieving a high sensitivity. The main parameters involved in TD, as well as the extraction time, were evaluated. Under the optimized conditions, the method was successfully validated showing good linearity, limits of detection and quantification in the low ngL−1 range and good intra- and inter-day repeatability (RSD<12%). This accurate and sensitive analytical method was applied to the determination of trace amounts of UV filters in three bathing water samples (river, sea and swimming pool) with satisfactory relative recovery values (80–116%).

Development of stir bar sorptive-dispersive microextraction mediated by magnetic nanoparticles and its analytical application to the determination of hydrophobic organic compounds in aqueous media

A novel microextraction technique combining the principles of stir bar sorptive extraction (SBSE) and dispersive micro-solid phase extraction (DμSPE) is presented. The main feature of the method is the use of a neodymium-core stirring bar physically coated with a hydrophobic magnetic nanosorbent. Depending on stirring speed, the magnetic sorbent either acts as a coating material to the stir bar, thus affording extraction alike SBSE, or as a dispersed nanosorbent medium for the collection and extraction of the target analytes, in close analogy to DμSPE. Once the stirring process is finished, the strong magnetic field of the stir bar prevails again and rapidly retrieves the dispersed MNPs. Alike SBSE, the stir bar is collected and the analytes are back-extracted by liquid desorption into an appropriate organic solvent, which is used for analysis. This enrichment technique is easy to prepare since it does not require special surface modification procedures, uses low volumes of non-toxic organic solvents and most importantly imbues SBSE with additional functionalities against a wide range of analytes (since nanosorbents with various coatings can be employed) while it affords additional merits to DμSPE in terms of extraction and post-extraction treatment. As proof-of-concept this new approach was applied to the determination of organic UV filters in seawater samples using oleic acid-coated cobalt ferrite (CoFe2O4@oleic acid) magnetic nanoparticles as sorbent material. The method showed good analytical features in terms of linearity, enrichment factors (11–148), limits of detection (low ngmL−1), intra- and inter-day repeatability (RSD<11%) and relative recoveries (87–120%).

Solution Phosphorus-31 Nuclear Magnetic Resonance Spectroscopy of Soils from 2005 to 2013: A Review of Sample Preparation and Experimental Parameters

Phosphorus nuclear magnetic resonance (³¹P NMR) spectroscopy is an important tool for the study of soil P and has significantly advanced our knowledge of soil P forms, particularly organic P; however, it must be used correctly to provide meaningful results. This review covers the ³¹P NMR studies of soil published from 2005 to 2013. The first part discusses preparing samples for ³¹P NMR, including extractants, pre- and post-extraction treatments, the physical state of the soil sample at the time of extraction, extraction length, the soil/extractant ratio, P recovery, P in residues, methods to concentrate extracts, redissolving samples for ³¹P NMR experiments, the use of the internal standard methylene diphosphonic acid, and the potential for degradation with any of these steps. The second part of this review focuses on NMR experiment parameters, including delay times, proton decoupling, and experiment length. Potential concerns in these areas are noted, and suggestions are given for procedures to optimize the information obtained from a ³¹P NMR experiment.

Automated On-Line Renewable Solid-Phase Extraction-Liquid Chromatography Exploiting Multisyringe Flow Injection-Bead Injection Lab-on-Valve Analysis

In this paper, the third generation of flow injection analysis, also named the lab-on-valve (LOV) approach, is proposed for the first time as a front end to high-performance liquid chromatography (HPLC) for on-line solid-phase extraction (SPE) sample processing by exploiting the bead injection (BI) concept. The proposed microanalytical system based on discontinuous programmable flow features automated packing (and withdrawal after single use) of a small amount of sorbent (<5 mg) into the microconduits of the flow network and quantitative elution of sorbed species into a narrow band (150 microL of 95% MeOH). The hyphenation of multisyringe flow injection analysis (MSFIA) with BI-LOV prior to HPLC analysis is utilized for on-line postextraction treatment to ensure chemical compatibility between the eluate medium and the initial HPLC gradient conditions. This circumvents the band-broadening effect commonly observed in conventional on-line SPE-based sample processors due to the low eluting strength of the mobile phase. The potential of the novel MSFI-BI-LOV hyphenation for on-line handling of complex environmental and biological samples prior to reversed-phase chromatographic separations was assessed for the expeditious determination of five acidic pharmaceutical residues (viz., ketoprofen, naproxen, bezafibrate, diclofenac, and ibuprofen) and one metabolite (viz., salicylic acid) in surface water, urban wastewater, and urine. To this end, the copolymeric divinylbenzene-co-n-vinylpyrrolidone beads (Oasis HLB) were utilized as renewable sorptive entities in the micromachined unit. The automated analytical method features relative recovery percentages of >88%, limits of detection within the range 0.02-0.67 ng mL(-1), and coefficients of variation <11% for the column renewable mode and gives rise to a drastic reduction in operation costs ( approximately 25-fold) as compared to on-line column switching systems.

Analysis of polycyclic aromatic hydrocarbons in soil: minimizing sample pretreatment using automated Soxhlet with ethyl acetate as extraction solvent.

A simplified sample pretreatment method for industrially PAH-contaminated soils applying automated Soxhlet (Soxtherm) with ethyl acetate as extraction solvent is presented. Laborious pretreatment steps such as drying of samples, cleanup of crude extracts, and solvent exchange were allowed to be bypassed without notable performance impact. Moisture of the soil samples did not significantly influence recoveries of PAHs at a wide range of water content for the newly developed method. However, the opposite was true for the standard procedure using the more apolar 1:1 (v/v) n-hexane/acetone solvent mixture including postextraction treatments recommended by the U.S. EPA. Moreover, ethyl acetate crude extracts did not appreciably effect the chromatographic performance (HPLC-(3D)FLD), which was confirmed by a comparison of the purity of PAH spectra from both pretreatment methods. Up to 20% (v/v) in acetonitrile, ethyl acetate proved to be fully compatible with the mobile phase of the HPLC whereas the same concentration of n-hexane/acetone in acetonitrile resulted in significant retention time shifts. The newly developed pretreatment method was applied to three historically contaminated soils from different sources with extraction efficiencies not being significantly different compared to the standard procedure. Finally, the certified reference soil CRM 524 was subjected to the simplified procedure resulting in quantitative recoveries (>92%) for all PAHs analyzed.

Characterization of the effects of postextraction treatments on human dentin-resin interface by micro-Raman spectroscopy

Raman microprobe spectroscopy was used to investigate the effects of post-extraction treatments of human dentin on the penetration of the 4-methacryloxyethyl trimellitic acid (4-MET)/methyl methacrylate (MMA)/ tri-n-butyl borane (TBB) dentin adhesive. Human molar teeth, extracted and stored in distilled water or 70% ethanol solution for 7 or 28 days, were treated with the resin. Spatially resolved Raman microspectroscopy was used to measure penetration. The band intensity ratio 1612 cm -1 (resin): 962 cm -1 (dentin) was used as a diagnostic. Diffusion of the resin into dentin increased with the length of storage period. The results indicate that the effects of postextraction treatments on teeth must be considered when laboratory measurements of bonding strengths are employed to predict the clinical performance of dental cements. In addition, it is demonstrated that Raman microprobe spectroscopy is a feasible analytical tool to evaluate the effects of postextraction treatments on teeth.