Min In Presence Research Articles

Thermal degradation of rice husk: Effect of pre-treatment on kinetic and thermodynamic parameters

Pyrolysis of untreated, acid treated and alkali treated rice husk (URH, ARH and ALRH, respectively) was investigated. Pre-treatment resulted in change in values of proximate and ultimate analyses parameters, gross calorific values and cellulose, hemi-cellulose and lignin contents. Thermal degradation experiments were carried out from ambient to 800 °C at heating rates of 5, 10 and 15 °C/min in presence of nitrogen (flow rate 50 mL/min). Analysis of the pyrolysis data was carried out using, Flynn – Wall – Ozawa (FWO), Kissinger – Akahira – Sunose (KAS) and Starink iso-conversional models. The activation energy was estimated to be 219.67, 220.09 and 218.83 kJ/mol using FWO model; 222.18, 222.69 and 227.98 kJ/mol using KAS model and 222.19, 223.57 and 228.38 kJ/mol using Starink model for URH, ARH and ALRH, respectively. Thermodynamic parameters (ΔH, ΔG, ΔS) were also evaluated in each case. Effect of pre-treatment on the pyrolysis reaction mechanism was predicted using Criado method. The results indicated that pre-treatment of RH improved its thermal degradation process.

Thin film Sn2S3 via chemical deposition and controlled heating – Its prospects as a solar cell absorber

As a semiconductor of “earth-abundant” elements, Sn2S3 with a bandgap (Eg) close to 1 eV merits attention, but a method to prepare phase-pure thin film remains elusive. We report the formation of Sn2S3 thin film of 360 nm in thickness by heating chemically deposited tin sulfide thin films at 450 °C during 30–45 min in presence of sulfur at a pressure, 75 Torr of nitrogen. Energy dispersive x-ray emission spectra and grazing incidence x-ray diffraction established a reaction route for this conversion of SnS completely to Sn2S3 via an intermediate phase, SnS2. The optical bandgap of the material is 1.25 eV (indirect) and 1.75 eV (direct, forbidden). The optical absorption suggests a light-generated current density of 30 mA/cm2 for the Sn2S3 film (360 nm) as a solar cell absorber. Thin film Sn2S3 formed in 30 min heating has a p-type electrical conductivity in the dark of 1 × 10−4 Ω−1 cm−1, which increases to 3 × 10−4 Ω−1 cm−1 in 0.2 s under 800 W/m2 tungsten-halogen illumination. An estimate made for its mobility-lifetime product is, 6 × 10−6 cm2 V−1. We discuss the prospects of this material for solar cells.

Precolumn fluorescence labelling of sodium valproate using 9-chloromethyl anthracene: Application to dosage form and spiked human plasma

A new simple, sensitive and selective reversed phase precolumn fluorescence labelling method was developed for determination of sodium valproate (Na-VLP) in bulk, tablet dosage form and human plasma. The method is based on the reaction of carboxylic group containing drug Na-VLP using a new reagent 9-chloromethyl anthracene (9- CMA) producing a fluorescent product emitting at λem 413 nm after excitation at 365 nm. The derivatization reaction was carried out at 78 °C for 40 min in presence of tetrabutylammonium bromide (TBABr) as catalyst. The fluorescent products were separated on Inertsil® ODS.3 (250 mm × 4.6 mm, particle size: 5 μm) reversed phase column using ethanol and water (85:15, v/v) as mobile phase, at a flow rate of 1.0 mL.min−1. Benzoic acid was used as internal standard. The method was validated according to ICH guidelines and show good linearity over the concentration range of (0.25–20) μg.mL−1. The proposed method was successfully applied for determination of Na-VLP in tablet dosage form with no interference from excipients, the mean % recovery was found to be 100.898% ± 0.561. Furthermore, the method was also successfully applied for determination of Na-VLP in spiked human plasma without any interference from plasma matrix with mean % recovery of 100.402% ± 0.847.

An intelligent dual mode filtration device for separation of immiscible oil/water mixtures and emulsions

Herein, we report an intelligent mesh for dual mode reversible separation of immiscible heavy/light oil water mixture and both oil-in-water as well as water-in-oil emulsions. ZnO nanowires coated stainless steel mesh with pore size 50 μm and 10 μm were fabricated successfully. The wettability of mesh can be reversibly switched between “oil-blocking” and “water-blocking” modes by alternatively annealing the smart mesh at about 210 °C for about 20 min in presence of poly (dimethyl siloxane) vapors and at 300 °C for 25 min in air, respectively. The “oil-blocking” mode was suited for the efficient separation of light oil/water mixture and oil-in-water emulsion, while “water-blocking” mode was found to be suitable for the separation of heavy oil/water mixture and water-in-oil emulsion. This work provides a simple, cost effective, eco-friendly and time saving approach applicable for separation of both form of oil/water mixture, free as well as surfactant stabilized emulsions, irrespective of the types of oil involved. The separation efficiency of the mesh was found to be more than 99% for free as well as emulsified mixtures. Even after cyclic usage in both modes alternatively, the separation efficiency of the mesh remained relatively unchanged, showing antifouling property and excellent recyclability of the mesh.

Alloying and phase transformation in CdS/CdSe bilayers annealed with or without CdCl2

The present paper studies the structural, compositional, morphological and optical properties of thin CdS/CdSe stacks annealed in an inert atmosphere or subjected to a CdCl2 treatment. The bilayer stacks were fabricated by chemical bath deposition (CBD) of a 50 nm thick CdS layer followed by evaporation of a CdSe film with equal thickness. It was found that when this stack was annealed at 400 °C for up to 10 min, no appreciable intermixing/alloying between the two layers was detected. Upon heating for 5–10 min in presence of a CdCl2 layer disposed over the CdSe film, however, led to appreciable alloying and formation of CdSSe, which was confirmed through XRD, optical transmission and room temperature photoluminescence measurements. XRD data further showed that the CdS layer in the CdS/CdSe stack had nano-amorphous structure that did not change upon annealing in inert atmosphere. The CdSe layer of the stack, which had a cubic structure, also preserved its phase upon annealing in inert atmosphere. When the CdS/CdSe stack was CdCl2 treated, the phase of the CdSSe alloy formed was transformed to hexagonal. These observations may have consequences in applications where CdS/CdSe bilayers are formed within device structures and subjected to various types of heat treatments.

In vitro detection of allergen sensitized basophils by HSA-DNP antigen-anchored liquid crystal microdroplets

A simple and easy to handle biosensing technique for in vitro detection of HSA-DNP antigen induced allergen reactions in patients has been developed through the detection of sensitized basophils expressed with anti-IgE receptor (FcεRI) by using human serum albumin-dinitrophenol (HSA-DNP) antigen-anchored liquid crystal (LC) microdroplets emulsion. The radial to bipolar transition in nematic 4-cyano-4′-pentyl biphenyl liquid crystal molecules (5CB) confined in HSA-DNP antigen anchored LC microdroplets (8.5 pg HSA-DNP/LC microdroplet) is found to be sensitive in PBS solution in detection of allergen sensitized basophils expressed with a minimum amount of anti HSA-DNP (anti-IgE) receptor (≥4.5 pg/basophil). The detection of allergen sensitized basophils was possible within a contact time of 30 min in presence of control cells and with 10% solution of human blood plasma. The HSA-DNP antigen anchored LC microdroplets in presence of macrophages or non-sensitized basophils did not show radial to bipolar transition in 5CB molecules in PBS or solution with 10 wt% human blood plasma. Thus HSA-DNP antigen anchored LC microdroplets biosensor may be used for in vivo detection of stage I allergen reaction basophils in blood samples.

Rapid degradative effect of microbially synthesized silver nanoparticles on textile dye in presence of sunlight

Abstract In the study, the dye collected from industry was identified as methyl violet by LC-MS/MS analysis. The biosynthesized silver nanoparticles (AgNPs) used were characterized by UV–visible spectrophotometry, HR-TEM and FT-IR analysis. Further, the AgNPs were used to evaluate the photocatalytic degradation of methyl violet. The results showed rapid degradation (85.56%) of methyl violet within a period of 20 min in presence of AgNPs and sunlight. The superior photocatalytic activity of AgNPs observed in the study indicates its application for dye degradation.

Study of 'co-solvent effect' on production of biodiesel from Schleichera Oleosa oil using a mixed metal oxide as a potential catalyst

Abstract In this study, biodiesel was prepared from a non edible feedstock using two step process followed by heterogeneous base catalyzed transesterification reaction. A novel solid heterogeneous base catalyst (strontium lanthanum mixed metal oxide) was synthesized via co- precipitation route and was characterized by XRD, FT-IR, SEM, and EDX. The free fatty acid content of the feedstock was assuaged by esterification process followed by transesterification for the synthesis of biodiesel. Effect of co-solvent on biodiesel yield was investigated in each subsequent experiment. Effect of various factors including calcination time, temperature, reaction time, molar ratio (methanol: oil), and catalyst concentration were also taken into account using OVAT (one variable at a time). High quality and pure biodiesel was synthesized at optimized conditions viz. Alcohol to oil molar ratio (14:1), catalyst dose (1.5%), temperature (60 °C), stirring speed (600 rpm) for 40 min in presence of DPE (co-solvent to alcohol molar ratio, 1:1) and was characterized by H1 NMR and FT-IR analysis. Properties of synthesized biodiesel were determined according to ASTM standards. Reusability of catalyst was checked and the catalyst was found stable up to six runs without any significant loss of catalytic activity.

39 Embryo Development of Kazakh Argali (Ovis ammon collium) by Handmade Cloning

Wildlife conservation requires innovative preservation methods in order to preserve gene and species biodiversity. Nuclear transfer has the potential to preserve genes from critically endangered wildlife species where few or no oocytes are available from the endangered species, and where cryopreserved cell lines have been conserved in cryobanks. The purpose of this study was to investigate the developmental ability of embryos reconstructed with transfer of cryopreserved somatic cells from the Kazakh argali (Ovis ammon collium) to enucleated domestic sheep (Ovies aries) oocytes. Frozen-thawed fibroblasts were diluted with DMEM (1:5) and centrifuged at 300g for 7 to 10 min. Supernatants were removed, and cells were diluted with DMEM at a concentration of 2 × 106 cells mL−1. Fibroblasts were placed into culture Petri dishes containing DMEM supplemented with 20% (v/v) fetal bovine serum (FBS), and incubated at 5% CO2, 95% relative humidity, and 37°C. After 21 to 22 days of incubation, a fibroblast monolayer was observed, culture medium was removed, and cells were incubated for 7 to 10 min in presence of Dulbecco’s PBS + 0.25% trypsin. Dissociated fibroblasts were washed with DMEM by centrifugation at 300 × g for 10 min. Cumulus-oocyte complexes were aspirated from slaughterhouse ovaries. Subsequently, the cumulus cells were removed by pipetting in 1 mg mL−1 hyaluronidase in HEPES-buffered TCM-199; zonae pellucidae were removed by incubation in 2 mg mL−1 pronase in HEPES-buffered TCM-199 supplemented with 2% cattle serum (T2) for 1 min. Bisection was performed by hand under a stereomicroscope using a microblade in 5 μg mL−1 cytochalasin B in TCM-199 supplemented with 20% cattle serum (T20). Fusions were performed 24 to 28 h after the start of maturation. One cytoplast was attached to one fibroblast in 500 μg mL−1 phytohemagglutinin dissolved in T2. In the fusion chamber, covered with fusion medium (0.3 M mannitol, 0.1 mM MgSO4, 0.05 mM CaCl2, and 0.01% polyvinyl alcohol), one cytoplast-fibroblast pair was fused with one cytoplast in a single step. The fusions were performed with a single DC pulse of 100V, each pulse for 9 μs. Successfully fused embryos were activated 1 h after the end of fusion by incubation in 2 μM calcium ionophore (Sigma, St. Louis, MO, USA) in T20 for 5 min followed by 3-h incubation in microdrops of culture medium containing 2 mM 6-DMAP. After successful reconstruction, 79 nuclear transferred and activated embryos were cultured in well-of-the-wells in trigas (5% O2, 5% CO2, 90% N2) in Submarine incubation system for 7 days. All except 15 embryos cleaved; 35 (44.3%) developed to compacted morula, and 15 (18.9%) to the blastocyst stage. In conclusion, argali embryos developed from reconstruction using their frozen–thawed fibroblasts combined with domestic sheep cytoplasts; however, in vitro developmental ability to the blastocyst stage was limited. Additional research that establishes the early embryo development with optimising nuclear transfer techniques may have a potential role in the conservation of critically endangered wildlife species.

Charge-conversional polyprodrug amphiphiles for intracellular dual-responsive drug delivery

A simple and easy to handle biosensing technique for in vitro detection of HSA-DNP antigen induced allergen reactions in patients has been developed through the detection of sensitized basophils expressed with anti-IgE receptor (FcεRI) by using human serum albumin-dinitrophenol (HSA-DNP) antigen-anchored liquid crystal (LC) microdroplets emulsion. The radial to bipolar transition in nematic 4-cyano-4′-pentyl biphenyl liquid crystal molecules (5CB) confined in HSA-DNP antigen anchored LC microdroplets (8.5 pg HSA-DNP/LC microdroplet) is found to be sensitive in PBS solution in detection of allergen sensitized basophils expressed with a minimum amount of anti HSA-DNP (anti-IgE) receptor (≥4.5 pg/basophil). The detection of allergen sensitized basophils was possible within a contact time of 30 min in presence of control cells and with 10% solution of human blood plasma. The HSA-DNP antigen anchored LC microdroplets in presence of macrophages or non-sensitized basophils did not show radial to bipolar transition in 5CB molecules in PBS or solution with 10 wt% human blood plasma. Thus HSA-DNP antigen anchored LC microdroplets biosensor may be used for in vivo detection of stage I allergen reaction basophils in blood samples.

Synthesis of TbMnO<sub>3</sub> by Microwave Assisted Method and its Photocatalytic Activity

Using terbium oxide (Tb4O7), manganese acetate (MnC4H6O4·4H2O), citric acid (C6H8O7) and urea (CO(NH2)2) as the main materials, the TbMnO3 was prepared by a facile microwave assisted process. The TbMnO3 samples were characterized by thermogravimetric and differential thermal analysis (TG-DTA), powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform Infrared (FT-IR) spectroscopy. XRD and SEM demonstrated the successful synthesis of single phase TbMnO3 and an average grain size of 100 nm in diameter. Under UV-light, the photocatalytic activity of TbMnO3 calcination at 800 °C was investigated by decomposition simulation wastewater containing 20 mg/L methyl orange (MO). The degradation rate of methyl orange can arrive to 95% when light irradiation was 180 min in presence of TbMnO3. The results show that TbMnO3 has highly photocatalytic activity for the degradation of methyl orange.

Nano FexZn1−xO as a tuneable and efficient photocatalyst for solar powered degradation of bisphenol A from aqueous environment

Currently, the photocatalytic nanomaterials performing under solar radiation have gained worldwide attentions due to increasing environmental deterioration. For utilizing the sunlight for degradation of emerging pollutants it is important to develop visible active photocatalysts. This laboratory scale work reports magnetic and optically active nano-photocatalyst FexZn1−xO(x = 0.01, 0.03, 0.05) synthesized by solution combustion method. High resolution transmission microscopy suggests a slight degradation in the crystallite structure with Fe doping. X-ray photoelectron spectroscopy analysis shows the presence of intrinsic defects in the crystal structure. Zn resides in +2 and and Fe in +3 oxidation state. Optical band gap studies were made with band structure for each doped sample. The photoctalytic activity of the samples was tested by solar degradation of noxious pollutant Bisphenol A. 99.1% of bisphenol was degraded in 90min in presence of Fe0.03Zn0.97O under synergistic adsorption and photocatalysis. The results were analyzed in terms of total organic carbon, chemical oxygen demand, effect of scavengers, gas chromatography-mass spectrometry and reusability. In presence of Fe0.03Zn0.97O, 45.3% of total organic carbon was removed and chemical oxygen demand was reduced to 11.2%. A possible mechanism with structures of the intermediates has been given. Effect of scavengers reveal that hydroxyl radicals are major reactive oxygen species involved which is also supported by the band edge positions. The research work promises to design highly photo-active tuneable magnetic photocatalysts for solar powered degradation of contaminants of emerging concern with a simple and cost-effective approach.

Synthesis of mesoporous ZSM-5 from rice husk ash with ultrasound assisted alkali-treatment method used in catalytic cracking of light naphtha

A series of mesoporous ZSM-5 zeolite was synthesized with ultrasonic assisted alkali-treatment technique and their catalytic activity was investigated in catalytic cracking of light naphtha. ZSM-5 zeolite was synthesized from rice husk ash without using any organic template. Effect of alkali-treatment conditions on physicochemical properties of synthesized zeolite was investigated with XRD, FESEM, TEM, N2 adsorption-desorption isotherm, NH3-TPD and TGA technique. It was found that ultrasound energy facilitates the creation of hierarchical structure of ZSM-5 during alkali-treatment. According to XRD analysis, zeolite structure was preserved after 20min ultrasonic assisted alkaline treatment. However, prolonged dessilication time led to the destruction of MFI zeolite structure. The synthesized ZSM-5 represented highly ordered hexagonal-shape morphology. With increasing alkali-treatment time, the plough land roughness appeared on the surface of zeolite. Comparison of the textural properties samples revealed that the mesopore surface area of alkali-treated samples increased considerably with the increase of ultrasonic assisted alkali-treatment time. Results from catalytic activity tests showed that ultrasound energy has great influence on the activity of ZSM-5. The sample had the highest activity after alkali-treated for 20min in presence of ultrasound energy which was due to their appropriate hierarchical structure.

Beneficial effects of calcium chloride on glucose dehydration to 5-hydroxymethylfurfural in the presence of alumina as catalyst

Aluminas with different acid-base properties (acid, neutral and basic) have been characterized by using XRD, N2 sorption at −196°C, XPS and NH3-TPD, and tested for the dehydration of glucose to 5-hydroxymethylfurfural (HMF). Under the operating conditions used, the acid alumina showed the highest total acidity and the best catalytic performance, but the HMF yield hardly exceeded 20% since γ-Al2O3 apparently favored the secondary reactions. The presence of CaCl2 in the reaction medium notably improved the catalytic performance, even at very short reaction times, due to the interaction between Ca2+ ions and glucose molecules, which favors the α-d-glucopyranose formation, thus enhancing glucose conversion and HMF yield up to 96% and 52%, respectively, at 175°C after 15min in presence of 0.65 gCaCl2·gaq.sol.−1 and acid γ-Al2O3 as catalyst. The isomerization of glucose to fructose and subsequent dehydration to HMF does not seem to take place when CaCl2 is present in the reaction medium, as inferred from 1H NMR spectroscopy. Moreover, the catalyst was reused at least for three runs maintaining the catalytic activity, without an intermediate regeneration step.

Non-Hydrothermal Synthesis of Cu(I)-Microleaves from Cu(II)-Nanorods

Simultaneous transformation of structural morphology, material dimension and oxidation state of Cu (II)-nanorod was achieved with 3-(Triethoxysilyl)propylamine, (APTS) and 4-nitrobenzaldehyde (4-NB) under non-hydrothermal condition. Morphology of the modified Cu(I) material was found to resemble with the leaf of colocasea. Conversion of a Cu(II) based nono-material to a Cu(I)-based micro-material was confirmed from EPR, MAS- NMR and cyclic voltametric (CV) study. BET-surface area, Raman signal intensity and thermal stability of the Cu(I)-microleaf was greatly enhanced due to presence of Cu-O−Si linkage. Both the Cu(II) and Cu(I) material were found to be effective catalyst systems for nitro-aldol reaction as well as catalytic oxidation of methylene blue (MB) dye in presence of H2O2. High %yield (>90 %) of nitro-aldol product was obtained with both the catalyst. Catalytic reaction under microwave irradiation was found to bring substantial decrease in reaction time. Cu (II)-material was however not recyclable because of its soft nature. While the Cu(I)-microleaf was recycled upto four consecutive cycles. These materials were found to degrade methylene blue dye within 20 min in presence of H2O2 but in absence of light. Dark phase catalytic oxidation of MB was monitored both via UV-vis and cyclic voltametric study.

Effect of Fe(II)/Fe(III) species, pH, irradiance and bacterial presence on viral inactivation in wastewater by the photo-Fenton process: Kinetic modeling and mechanistic interpretation

Advanced Oxidation Processes and in particular photo-Fenton, represent promising strategies of pathogen inactivation in wastewater effluents. Nevertheless, its full potential is not yet unlocked, as the efficacy of photo-Fenton against viruses has not been deeply explored. In this work, we characterize the effect of major parameters (Fe species and concentration, solar irradiance, pH and microbial competition) on the inactivation of MS2 Coliphage by the photo-Fenton process. The use of Fe(II) salts, under any combination of H2O2 concentration, sunlight irradiance or starting pH (6–8), induced a faster inactivation compared to their Fe(III) counterparts. Moreover, ICP-MS analyses revealed that starting with Fe(II) resulted to higher amount of iron in solution longer than Fe(III), which led to higher inactivation kinetics. Even so, a 4-log MS2 inactivation was achieved upon exposure to 600W/m2 for 30min in presence of Fe(III) and H2O2 (1:1 ratio). Furthermore, the inactivation of MS2 was only slightly decreased in presence of the bacterial host, suggesting a low competition for the oxidants in the bulk. The enhancement of iron solubilization through its complexation by organic matter present in wastewater was also investigated, observing an efficient viral inactivation despite the presence of reactive oxygen species (ROS) scavengers. The present data have been used to propose a simple model describing MS2 photo-Fenton inactivation in wastewater. Finally, the pathway describing the photo-Fenton-induced MS2 inactivation in wastewater was proposed, in presence or absence of bacteria.

ChemInform Abstract: Synthesis of 2,4,5‐Trisubstituted Imidazoles, Quinoxalines and 1,5‐Benzodiazepines over an Eco‐Friendly and Highly Efficient ZrO2—Al2O3 Catalyst.

ZrO2–Al2O3 containing 80 mol% of ZrO2 was prepared by solution combustion, impregnation and precipitation methods. All the prepared catalytic materials were characterized by PXRD, NH3-TPD, N2 adsorption isotherms, FTIR, TEM, SEM, EDAX and ICP-OES techniques. These catalytic materials were used in a rapid, simple, versatile and efficient synthesis of 2,4,5-trisubstituted imidazoles under solvent-free conditions at moderate temperature in shorter reaction time (20 min). This is achieved by three-component cyclo-condensation of benzil, aldehydes and ammonium acetate in excellent yields. The derivatives of quinoxalines and 1,5-benzodiazepines were synthesized effectively by cyclo-condensation of 1,2-diamine with α-diketones and carbonyl compound with O-phenylenediamines respectively over ZrO2–Al2O3 at moderate temperature (80 °C) for the reaction time of 20–40 min in presence of ethanol as a solvent. The present method is experimentally simple, non-toxic and involves inexpensive reagents, clean reaction pathways and an eco-friendly catalyst. The catalytic materials used can be easily separated from the reaction mixture and reused for several reaction cycles without much loss of catalytic activity.

Real-Time Monitoring of Bacterial Metabolites By Scanning Electrochemical Microscopy (SECM)

Scanning Electrochemical Microscopy (SECM) is used to study the local chemical environment above live bacterial biofilms such as S. gordonii (Sg), S. mutans (Sm) etc. In this study, we report the development of a Pt decorated carbon nanotubes (CNTs) based dual SECM probe to detect low micro-molar range hydrogen peroxide (H2O2) produced by the live bacterial biofilm. This sensor showed sensitivity 2.2 ± 5 mA cm-2 mM-1 with low detection limit of 0.5 µM. Our results indicate that the Sg produced 65-70 μM H2O2 within 30 min in presence of 1 mM glucose in artificial saliva solution (pH 7.2) at 37°C. In addition, we have also developed a unique solid state carbon based potentiometric pH sensor and used as a SECM probe to map the pH change at high spatial resolution above the Sg biofilm. The sensor showed Nernstian response with slope of 58±4 and very fast response time of 5s. The pH mapping above the biofilm showed that pH above the biofilm dropped by one pH unit within 30 min only in 6 pH artificial saliva with 30 mM sucrose at 37°C. Recent developments about the real-time metabolic exchange between two bacterial species (Sg and Sm) in terms of peroxide and pH will be presented in the conference. Figure 1

Real-time monitoring of glucose and phenols intestinal absorption through an integrated Caco-2TC7cells/biosensors telemetric device: Hypoglycemic effect of fruit phytochemicals

An integrated device for real-time monitoring of glucose and phenols absorption, that consists of a sensors/biosensors system (SB) and a Caco-2TC7 human intestinal cell culture, is described in this study. The SB is composed of a glucose oxidase-based biosensor, a sentinel platinum sensor, a laccase/tyrosinase-based biosensor and a sentinel carbon sensor, all located in the basolateral compartment (BC) of a cell culture plate. Caco-2TC7 cells, differentiated on culture inserts, separated the apical compartment that simulates the intestinal lumen, from the BC which represented the bloodstream. The system recorded currents relative to glucose (1mM) absorption, obtaining bioavailability values (5.1%) comparable to HPLC analysis (4.8%). Phloridzin and phloretin, specific phenolic inhibitors of SGLT1 and GLUT2 glucose transporters, reduced the glucose transport of almost 10 times. They were minimally absorbed in the BC with a bioavailability of 0.13% and 0.49% respectively. The hypoglycemic potential of blueberry and pomegranate juices was also studied. In particular, the amount of glucose absorbed through the Caco-2TC7 monolayer was 8‰ for pomegranate and 1.7‰ for blueberry, demonstrating the potential hypoglycemic effect of the juices. Polyphenols absorption was also monitored by the SB and an increase was recorded during the first 50min in presence of both blueberry and pomegranate juices, then a constant decrease occurred. The proposed device has been developed as innovative tool for the dynamic monitoring of natural compounds effects on glucose absorption, in order to manage postprandial hyperglycemia.

Fermentative lactic acid production from coffee pulp hydrolysate using Bacillus coagulans at laboratory and pilot scales

In this study, the lignocellulosic residue coffee pulp was used as carbon source in fermentative l(+)-lactic acid production using Bacillus coagulans. After thermo-chemical treatment at 121°C for 30min in presence of 0.18molL−1 H2SO4 and following an enzymatic digestion using Accellerase 1500 carbon-rich hydrolysates were obtained. Two different coffee pulp materials with comparable biomass composition were used, but sugar concentrations in hydrolysates showed variations. The primary sugars were (gL−1) glucose (20–30), xylose (15–25), sucrose (5–11) and arabinose (0.7–10). Fermentations were carried out at laboratory (2L) and pilot (50L) scales in presence of 10gL−1 yeast extract. At pilot scale carbon utilization and lactic acid yield per gram of sugar consumed were 94.65% and 0.78gg−1, respectively. The productivity was 4.02gL−1h−1. Downstream processing resulted in a pure formulation containing 937gL−1l(+)-lactic acid with an optical purity of 99.7%.