Aqueous extraction of bitter gourd (

Introduction. Bitter gourd (Momordica charantia), belonging to the Cucurbitaceae family, is a well-recognized therapeutic herbal plant with numerous nutritious benefits, improving the overall health of consumers. It possesses many phytonutrients with medicinal activities. Aqueous extraction of phytonutrients is the safest procedure, which can circumvent the challenges associated with other extraction techniques. Materials and methods. To optimize the process parameters for aqueous extraction of bitter gourd juice, three independent variables, i.e. the fruit:water ratio, extraction time and temperature, were selected within the ranges of 0.3–1.0 g mL-1, 20–160 min and 30–90 °C, respectively. A Box-Behnken design of a numerical optimization technique was used to optimize these variables. The corresponding responses were estimated in terms of concentrations of protein, polyphenols and total solids, and juice clarity. Results and discussion. The effects of linear, interaction and quadratic terms of independent variables on the responses were investigated. The present study generated a regression model that could explain 99% of the total variability, with a coefficient of determination (R2) of 0.99. Conclusion. The optimum conditions for aqueous extraction of bitter gourd fruit are: a fruit:water ratio of 0.48 g mL-1, an extraction time of 95 min and an extraction temperature of 68 °C. The corresponding responses at optimum points were estimated to be 131.7 mg L-1, 23.1 mg GAE 100 mL-1, 0.89 g 100 mL-1 and 60.6% for concentrations of protein, polyphenols, total solids and juice clarity, respectively

An integral formulation for mass transfer of a reactive species in a channel from a moving surface with blowing

71-77<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:arial;mso-ansi-language:en-us;mso-fareast-language:="" en-us;mso-bidi-language:ar-sa"="">An integral method for mass transfer analysis of a reactive species in laminar boundary layer in a channel from a moving surface with blowing is developed. The effects of relevant process parameters, e.g., Reynolds number, reaction rate, reaction order, Schmidt number and blowing, on mass transfer have been studied. When reaction rate is dominant compared to convection, several asymptotic solutions are formulated for high and low Schmidt number. The model presented in this paper provides a simplistic mathematical description of a complex situation encountered in several industrial applications like, post processing of extrusion in polymer processing rolling and moulding in metallurgical processes and in electrochemistry.</span

Combined ultrafiltration and ozone processing of sugarcane juice: Quantitative assessment of polyphenols, investigation of storage effects by multivariate techniques and shelf life prediction

Sugarcane juice (SJ) is prone to rapid spoilage post-extraction that limits its storage and marketing. To address this problem, two non-thermal techniques, viz., ultrafiltration (UF) and ozone treatment (OZ) combinedly are attempted. Cumulative enzyme and microbial inactivation effects were obtained by combining the processes (UF-OZ) providing about 85% polyphenoloxidase, 91% peroxidase, 7 log bacteria and 5.2 log yeast and mold inactivation. The effects of processing on major phenolic acids, flavonoids and sensory properties were evaluated. From HPLC characterization, it was found that, caffeic acid (13.22 ppm) which was the most abundant accounting for 50.5% of the total evaluated phenolic acids reduced by 26.7% in processed SJ. Among flavonoids, vitexin and its derivatives (22.19 ppm) constituted the highest proportion (63.3%) of total evaluated flavones which did not decrease significantly (p>0.05) after processing. Principal component analysis (PCA) and hierarchical cluster analysis efficiently distinguished the stored samples and showed the dissimilarities in quality characteristics after 12 weeks of storage. PCA very well outlined the interrelationship status of quality parameters and spoilage indicators associated with browning and microbial degradation. The microbiological stability analysis using microbial growth (Gompertz) model confirmed that the ultrafiltered ozonised sugarcane juice could be safely stored up to 90 days under refrigeration

Membrane Separation for Water and Wastewater Treatment

© 2012 by World Scientific Publishing Co. Pte. Ltd. All rights reserved. Both solid and liquid wastes and air emission are generated by every population. These solid and liquid wastes are mixed with surface water, ground water, and rainfallwater and finally mixed with riverwater. Treatedwastewater from industrial effluent treatment plant is also mixed with riverwater and inhibits the normal growth of aquatic plants and animals. As a result, treatment of wastewater is essential for the protection of human health and this universe

Performance prediction of membrane modules incorporating the effects of suction in the mass transfer coefficient under laminar and turbulent flow conditions for non-Newtonian fluids

Design equations for spiral wound membrane modules in case of power law fluid are derived for the first time. The case is solved for both laminar and turbulent flow regimes considering orange juice as the model system. The governing equations are solved numerically and the profiles of transmembrane pressure drop, bulk velocity, concentration, permeate flux, membrane surface concentration and permeate concentration along the membrane module are obtained. A detailed parametric study is carried out to observe the effects of operating conditions on the permeate flux and permeate concentration. The present analysis is helpful to design and simulate the performance of the membrane modules adequately. For the model system, it is observed that the axial pressure drop is about 2 to 3% of the inlet transmembrane pressure drop for 1.0 m length of the module. The mass transfer coefficient increases by twofold when the flow regime becomes turbulent. In case of laminar flow, at 7,000‐kPa inlet transmembrane pressure drop, the average flux is about 22 L/m2·h and the flux value under turbulent flow condition becomes about 30 L/m2·h at the same pressure drop. For a slightly leaky membrane, at 7,000‐kPa pressure drop and 130 kg/m3 of feed soluble sugar concentration, the permeate stream contains about 10 kg/m3 of total sugar

Nanostructured polyaniline incorporated ultrafiltration membrane for desalination of brackish water

A novel salt rejecting ultrafiltration (UF) membrane was prepared by a facile, scalable route involving in situ incorporation of negatively charged polyaniline (PANI) nanoparticles within polysulfone (PSF). The incorporated PANI acts as a porogen and charge inducing agent, improving the porosity, permeability, hydrophilicity as well as the surface charge, leading to an enhancement of the permeate flux and improvement of the salt rejection capability. Specifically, 2 wt% PANI loading leads to a 25 times increase in the molecular weight cut-off (from 0.2 to 4.8 kDa). Also, there is improvement in porosity (from 20% to 64%), and a 2-fold increase in permeability (from 8 x 10(-12) to 16 x 10(-12) m(3) m(-2) Pa-1 s(-1)). Surface hydrophilicity (reduction of the contact angle from 82 degrees to 69 degrees) was enhanced as well. All of these effects ultimately lead to a 2.5 times enhancement in the permeate flux (from 21 l m(-2) h(-1) to 38 l m(-2) h(-1) at 690 kPa transmembrane pressure, TMP and 20 l h(-1) cross flow rate, CFR). This reflects the change in membrane behavior from nanofiltration (NF) to UF. An increase in zeta potential (from -4 mV to -28 mV at pH 7) results in salt rejection between 40-53%, equivalent to the NF performance. Developed UF membranes match the desalination performance of NF membranes showing a higher flux and lower energy requirement. Advantageously, these membranes are also found to be fouling resistant during salt solution filtration, requiring no extensive regeneration. Desalination performance of these membranes is also demonstrated using artificially synthesized seawater. These UF membranes may be exploited as a pretreatment for inlet load reduction to reverse osmosis or for the production of industrial process water. It is believed these charged membranes lay the foundation for the development of next generation desalination membranes possessing high flux and fouling resistant characteristics

Process Modeling for the Removal of Phenolic Compounds from Industrial Wastewater Using a Mixed-Matrix Membrane

Application of a mixed-matrix membrane in the treatment of industrial wastewater provides an added advantage of coupling adsorption with membrane filtration. This is particularly useful in achieving high selectivity with enhanced throughput. Continuous cross-flow experiments were conducted with effluent from a secondary treatment plant of the steel industry containing a high concentration of phenol. The transport phenomenon involves the concentration polarization over the gel layer, growth of the gel-layer dynamics, and adsorption in the membrane matrix. Because the real-life effluent is a complex mixture containing several components, knowledge of the physical properties is challenging. Process modeling of the performance of the mixed-matrix ultrafiltration membrane of industrial effluent in a cross-flow configuration is attempted in this study. The mathematical analysis is based on the transport mechanism of the low-molecular-weight solute through a gel of large-molecular-weight solutes and consequent adsorption in the membrane matrix. The model results are compared with the actual experimental data. The effects of the adsorption isotherm and sensitivity of the model parameters on the system performance are also evaluated