Extraction of sugarcane bagasse arabinoxylan, integrated with enzymatic production of xylo-oligosaccharides and separation of cellulose.

Sugarcane processing roughly generates 54 million tonnes sugarcane bagasse (SCB)/year, making SCB an important material for upgrading to value-added molecules. In this study, an integrated scheme was developed for separating xylan, lignin and cellulose, followed by production of xylo-oligosaccharides (XOS) from SCB. Xylan extraction conditions were screened in: (1) single extractions in NaOH (0.25, 0.5, or 1 M), 121 °C (1 bar), 30 and 60 min; (2) 3 × repeated extraction cycles in NaOH (1 or 2 M), 121 °C (1 bar), 30 and 60 min or (3) pressurized liquid extractions (PLE), 100 bar, at low alkalinity (0-0.1 M NaOH) in the time and temperature range 10-30 min and 50-150 °C. Higher concentration of alkali (2 M NaOH) increased the xylan yield and resulted in higher apparent molecular weight of the xylan polymer (212 kDa using 1 and 2 M NaOH, vs 47 kDa using 0.5 M NaOH), but decreased the substituent sugar content. Repeated extraction at 2 M NaOH, 121 °C, 60 min solubilized both xylan (85.6% of the SCB xylan), and lignin (84.1% of the lignin), and left cellulose of high purity (95.8%) in the residuals. Solubilized xylan was separated from lignin by precipitation, and a polymer with ß-1,4-linked xylose backbone substituted by arabinose and glucuronic acids was confirmed by FT-IR and monosaccharide analysis. XOS yield in subsequent hydrolysis by endo-xylanases (from glycoside hydrolase family 10 or 11) was dependent on extraction conditions, and was highest using xylan extracted by 0.5 M NaOH, (42.3%, using Xyn10A from Bacillus halodurans), with xylobiose and xylotriose as main products. The present study shows successful separation of SCB xylan, lignin, and cellulose. High concentration of alkali, resulted in xylan with lower degree of substitution (especially reduced arabinosylation), while high pressure (using PLE), released more lignin than xylan. Enzymatic hydrolysis was more efficient using xylan extracted at lower alkaline strength and less efficient using xylan obtained by PLE and 2 M NaOH, which may be a consequence of polymer aggregation, via remaining lignin interactions.

Multivariate optimization of a combined static and dynamic supercritical fluid extraction method for trace analysis of pesticides pollutants in organic honey.

The intensive application of pesticides to increase crop production has resulted in contamination of the agricultural products. Due to their occurrence at trace levels and the complexity of food samples, analysis of pesticide residues requires selective and efficient sample preparation methods. For this purpose, an extraction method based on supercritical carbon dioxide and acetonitrile as entrainer solvent was developed for trace analysis of atrazine, diazinon, chlorothalonil, and deltamethrin pesticides in honey samples. A Box-Behnken experimental design was applied to optimize extraction variables including static extraction time (5-15 min), pressure (200-700 bar), and temperature (45-70°C). The optimum extraction conditions were found to be 11.5 min static extraction time, 252 bar, and 70°C. The proposed analytical method showed a good linearity (≥0.998), low limit of detection (0.005-0.009 mg/kg), and good extraction recovery (74-111%). The precision study of the proposed method at two concentration levels of each pesticides, 0.25 and 1.0 mg/kg was found to be in the ranges of 2.3-4.21% for intraday (n = 3) and 3.93-8.02% for interday precisions (n = 3). The developed method is promising for use in trace analysis of pesticides in complex food samples including honey.

Solubility and Thermal Degradation of Quercetin in CO2-Expanded Liquids.

The solubility of quercetin and its thermal degradation was studied in CO2-expanded ethanol and ethyl lactate. An equipment setup was constructed that enabled the separation of the products of degradation while quantifying the solubility of quercetin. Three different conditions of temperature were analyzed (308, 323, and 343 K) at 10 MPa. Higher solubility and thermal degradation of quercetin were observed for CO2-expanded ethyl lactate in comparison with CO2-expanded ethanol. At the same time, as the amount of CO2 was increased in the CO2-expanded liquids mixtures, the thermal degradation of quercetin decreased for almost all the conditions of temperature considered in this work. The importance of considering thermal degradation while performing solubility measurements of compounds that are thermally unstable such as quercetin was highlighted.

High Density Supercritical Carbon Dioxide for the Extraction of Pesticide Residues in Onion with Multivariate Response Surface Methodology.

The excessive use of pesticides is a serious health problem due to their toxicity and bioaccumulation through the food chain. Due to the complexity of foods, the analysis of pesticides is challenging often giving large matrix effects and co-extracted compounds. To overcome this problem, a selective and "green" supercritical fluid extraction method was developed, using neat carbon dioxide as a solvent at pressures of up to 800 bars. A Box-Behnken response surface experimental design was used, with the independent variables of density (0.70-1.0 g mL-1), temperature (40-70 C), and volume (10-40 mL) of solvent, and the dependent variable of extracted amount of pesticides. The optimum extraction condition was found at the use of 29 mL of supercritical CO2 at 0.90 g mL-1 and 53C (corresponding to 372 bars of pressure). It was observed that increasing the density of CO2 significantly increased the extraction recovery of endrin and 2,4'-dichlorodiphenyldichloroethane. Matrix-matched calibration curves showed satisfactory linearity (R2 ≥ 0.994), and LODs ranged from 0.2 to 2.0 ng g-1. Precision was lower than 11% and recoveries between 80%-103%. Thus, the developed method could efficiently be used for trace analysis of pesticides in complex food matrices without the use of organic solvents.

Selective pressurized hot water extraction of nutritious macro-nutrients vs. micro-nutrients in Moringa oleifera leaves-a chemometric approach.

Moringa oleifera leaves are widely used in traditional medicine as a food supplement because they are high in essential and nutritious content. Pressurized hot water extraction (PHWE), which is a green approach, was used for the recovery of the macro-nutrient and micro-nutrient elements from dried leaf powder of Moringa oleifera. In this study, response surface methodology was applied to assess the influence of temperature (50-200 °C) and time (5-60 min) on the extractability pattern of macro-nutrient and micro-nutrient elements from the leaves of Moringa oleifera when processed by PHWE. The quantification of macro-nutrient elements such as Ca, K and Mg and micro-nutrient elements like Al, Co, Cr, Cu, Fe, Ni and Zn from the leaves was determined using inductively coupled plasma optical emission spectroscopy (ICP-OES). Obtained results revealed that the extraction of macro-nutrient elements from the Moringa oleifera leaves was enhanced by increasing the extraction time more than the extraction temperature. On the contrary, the amounts of extractable micro-nutrient elements were increased by increasing the extraction temperature. Hence, the recovery for macro-nutrient elements ranged from 88 to 98% while for micro-nutrients it ranged from 21 to 46%. This implies that macro-nutrient elements are extracted with relatively high selectivity in relation to micro-nutrient elements in Moringa dried leaf powder using the PHWE technique.

Dynamic extraction coupled on-line to liquid chromatography with a parallel sampling interface-a proof of concept for monitoring extraction kinetics.

On-line hyphenation of extraction with chromatography has been explored in several different types of combinations. However, monitoring the complete process of a dynamic, continuous-flow extraction is not possible with any hyphenated system reported so far. The current work demonstrates that this challenging task can be effectively fulfilled by using a parallel sampling interface, which mimics the concept of comprehensive two-dimensional chromatography. In this study, pressurised hot water extraction was coupled on-line with ultra-high-performance liquid chromatography. The set-up was utilised in a kinetic study of dynamic pressurised hot water extraction of curcuminoids from turmeric powder. Compound-specific extraction curves were obtained, which clearly indicated the rate-limiting factors of the extraction processes under different conditions. Additionally, thermal degradation of curcumin during the extraction could also be demonstrated in some of the extractions.

Ultrahigh-pressure supercritical fluid extraction and chromatography of Moringa oleifera and Moringa peregrina seed lipids.

An ultrahigh-pressure supercritical fluid extraction method was optimized and applied to extract seed oil lipids from two moringa species, namely Moringa oleifera (MO) and Moringa peregrina (MP). A full-factorial design was used to investigate the direct and interaction influence of pressure and temperature in the range of 40 to 80 MPa and 40 to 70 °C, respectively, on the extracted amount of oil from crushed seeds. The results revealed that pressure has a significant positive influence on the extracted amount of oil. The best extraction condition using neat CO2 was found at 80 MPa and 57 °C, yielding 396 ± 23 and 529 ± 26 mg oil per gram of seeds for MO and MP, respectively. An extraction kinetics study revealed a mainly solubility-controlled extraction of oil, and 28 g of CO2 was required to extract 400 mg of oil per gram of seeds of MO using the developed method. Addition of ethanol to the sample prior to the extraction increased the proportion of extractable polar lipids as well as the total amount of extracted oil. The developed method increased the extracted amount of oil twofold compared to a reference method based on solvent sonication. The obtained oil consisted mainly of glycerolipids, sterol esters, and phospholipids. Phospholipids, campesterol, and stigmasterol ester concentrations were found to be higher in MO while cholesterol ester was more abundant in MP.

Efficient methodology for the extraction and analysis of lipids from porcine pulmonary artery by supercritical fluid chromatography coupled to mass spectrometry.

Pulmonary artery grafts are needed as cardiovascular bioprosthetics. For successful tissue recellularization after transplantation, lipids have to be removed from the donor artery. Developing a selective process to remove lipids without damaging the extracellular matrix greatly depends on knowing the amount and type of lipid compounds in the specific tissue. Here we present an efficient methodology for the study of lipids present in porcine pulmonary arteries. The performance of six extraction methods to recover lipids from artery was evaluated. For this purpose, a supercritical fluid chromatography method coupled to quadrupole time-of-flight mass spectrometry detection (UHPSFC/QTOF-MS) was adapted. The method enabled separation of lipids of a wide range of polarity according to lipid class in less than 7 min. One dichloromethane-based extraction method was shown to be the most efficient one for the recovery of lipids from pulmonary artery. However, one MTBE-based extraction method was able to show the highest fatty acid extraction yields (to the expense of longer extraction times). Lipids were relative quantified according to class, and the major species within each class were identified. Triacylglycerols and glycerophospholipids were the most abundant classes, followed by sphingomyelins, monoacylglycerols and fatty acyls. The matrix effect exerted no interference on the analytical method, except for some few combinations of extraction method and lipid class. These results are of relevance for lipidomic studies from solid tissue, in particular for studies on pulmonary and cardiovascular diseases. Finally, our work sets the basis for the further development of a selective processes to remove lipids from pulmonary artery without damaging the tissue prior to transplantation.

Composition and physicochemical properties of dried berry pomace.

BACKGROUND: Berry pomace is a valuable but little used by-product of juice manufacturing. When processed to a stable fruit powder, the composition differs from that of the whole fruit. To facilitate application in foods, a detailed knowledge of its composition and physicochemical properties is essential. RESULTS: Blackcurrant, redcurrant, chokeberry, rowanberry and gooseberry were selected for analysis. All pomace powders had a high fibre content (> 550 g kg-1 ) and a fat content of up to 200 g kg-1 . Despite identical milling conditions, the particle sizes of the pomace powders varied. This can be traced back to seed content and brittleness, which also becomes apparent with respect to surface characteristics. Blackcurrant pomace powder differed from other varieties in terms of its low water-binding capacity (3.2 g g-1 ) and a moderate moisture uptake, whereas chokeberry pomace powder showed the highest polyphenol content and rowanberry pomace powder was rich in flavonols. CONCLUSION: The results obtained in the present study provide a comprehensive overview of the properties of berry pomace powder and allow conclusions to be made regarding their applicability for use in complex food systems. © 2018 Society of Chemical Industry.

Screening of stationary phase selectivities for global lipid profiling by ultrahigh performance supercritical fluid chromatography.

The performance of seven sub-2-µm particle packed columns (2-picolylamine, 2-PIC; charged surface hybrid fluoro-phenyl, CSH-FP; high strength silica C18 SB, HSS-C18; diethylamine, DEA; 1-aminoanthracene, 1-AA; high density diol and ethylene bridged hybrid; BEH) was examined for lipid separation in ultra-high performance supercritical fluid chromatography (UHPSFC) coupled to quadrupole time-of-flight mass spectrometry. Based on the results of the column screening a method for profiling of multiple lipid species from the major lipid classes was developed. Stationary phases containing ß-hydroxy amines, i.e. 1-AA, DEA and 2-PIC, yielded strong retention and poor peak shapes of zwitterionic lipids with primary amine groups, such as phosphatidylserines, phosphatidylethanolamines and its lyso forms. The BEH and HSS-C18 columns showed strong retention of polar and nonpolar lipids, respectively. The Diol column retained the majority of major lipid classes and also produced symmetric peaks. In addition, this column also produced the highest resolution within and between major lipid classes. An injection solvent composed of methanol:chloroform (1:2, v:v) and the addition of 20 mM ammonium formate in the mobile phase improved chromatographic separation and mass spectrometry detection in comparison to ammonium acetate or absence of additive. Finally, chromatographic and mass spectrometric parameters were optimized for the Diol column using a design of experiments approach. The separation mechanism on the Diol column depended on the lipid functionality and the length and degree of unsaturation of the acyl groups. The developed method could resolve 18 lipid classes and multiple lipids within each class, from blood serum and brain tissue in 11 min.

Alterations in the plasma metabolite profile associated with improved hepatic function and glycemia in mice fed lingonberry supplemented high-fat diets.

SCOPE: Lingonberries have been shown to reduce the detrimental effects of high-fat diet (HFD) on weight gain, plasma glucose, and inflammation. However, the extent of effects was recently shown to vary between different batches of berries. Here, we examine the metabolic response to two independent batches of lingonberries. METHODS AND RESULTS: Alterations in the phenotype and circulating metabolome elicited by three matched HFDs, two of which containing lingonberries (L1D and L2D) from different sources, were investigated. Glycemia was improved only in mice fed L1D, whereas liver function was improved and inflammation reduced in mice fed both L1D and L2D, compared to mice fed HFD. The unique improvement in glycemia elicited by L1D was associated with a 21% increase in circulating levels of fatty acids. Increased levels of phosphatidylcholines (62%) and lysophosphatidylcholines (28%) and decreased levels of serine (-13%) and sphingomyelins (-26%) were observed in mice fed L1D and L2D, as compared to HFD. CONCLUSION: The unique improvement in glycemia in mice fed L1D was associated with a normal metabolic control with an altered set point. Moreover, the batch-independent reduction in liver steatosis and inflammation, was associated with an altered sphingomyelin metabolism.

Carbon Dioxide Expanded Ethanol Extraction: Solubility and Extraction Kinetics of α-Pinene and cis-Verbenol.

In general, diffusion rates in extractions are enhanced by increasing the temperature. In this study, we instead add compressed liquid carbon dioxide to the extraction phase to accomplish faster mass transfer. The feasibility of using carbon dioxide expanded ethanol (CXE) as the extraction phase was explored, targeting two medium-polar analytes, α-pinene and cis-verbenol in Boswellia sacra tree resin. Hansen solubility parameters (HSP) were first calculated for the analytes and the extraction phases investigated, ethanol, CXE, and supercritical carbon dioxide (scCO2) containing ethanol as a cosolvent. Second, an extraction method with CXE as the extraction phase was optimized using a Box Behnken design, giving optimal conditions of 40 °C, 9.3 MPa, and 0.31 molar fraction of CO2 in ethanol. Third, the developed method was compared with a supercritical fluid extraction (SFE) method and a conventional solid liquid extraction (SLE) method, showing that CXE enables faster and more efficient extraction than both SFE and SLE. In fact, calculations based on Peleg's equation showed that the initial extraction rate of the new method is up to 10 times faster than SFE when using the highest flow rate tested, 3 mL/min. It was also discovered that it is crucial to cool the makeup solvent in the collection system for efficient analyte collection, at least in modern SFE equipment where pressure is regulated by a backpressure regulator. The use of CXE and pertinently also other CO2-expanded liquids in sample preparation shows a great potential in terms of increasing the extraction rate without elevating the temperature.

Behaviour of nonsteroidal anti-inflammatory drugs and eight of their metabolites during wastewater treatment studied by hollow fibre liquid phase microextraction and liquid chromatography mass spectrometry.

In this work hollow fibre liquid phase microextraction combined with liquid chromatography mass spectrometry was applied for the determination of the nonsteroidal anti-inflammatory drugs (NSAIDs) ketoprofen, naproxen, diclofenac and ibuprofen as well as eight of their known human metabolites in wastewater samples. Extraction time and addition of tri-n-octylphosphine oxide (TOPO) to the liquid membrane were evaluated resulting in a method with an optimal extraction time of 5h and 5% (w/V) TOPO addition to the membrane liquid (di-n-hexyl ether). With the optimized method, enrichment factors ranged between 778 and 4830. The method was applied for analysis of samples collected from Källby wastewater treatment plant in the city of Lund, Sweden. Samples were collected from the influent, water entering as well as exiting the conventional activated sludge treatment and the effluent to study the behaviour of these compounds during the treatment process. All twelve substances were found in the influent and for all four drugs, higher concentrations were detected of the metabolites than the parent compounds. Highest concentrations were detected of o-desmethylnaproxen, 2-hydroxyibuprofen and carboxyibuprofen (average influent concentrations of 45, 35 and 63 µg/L respectively). The study showed only partial removal during the primary treatment whereas both parent compounds and metabolites were efficiently removed during the activated sludge process. In the effluent all analytes were detected in concentrations below 1 µg/L thus showing that either the investigated metabolites do not belong to the NSAID transformation products formed during the activated sludge treatment or they are also quickly further transformed within the treatment.