AVERAGE SPECIFIC CAKE RESISTANCE DETERMINED IN the PRESENCE of SEDIMENTATION to FILTRATION of STARCH SLURRY UNDER CONSTANT PRESSURE

An equation for predicting filtration flow rates in the presence of sedimentation at constant pressure drop was developed. It was applied to determine the average specific cake resistance infiltration of starch slurries at 18.8 to 115 kPa pressure drop range. At these conditions, corn, potato and sweet potato starch filter cakes were incompressible but wheat starch cake was compressible.     

Extraction of saponin from Camellia oleifera cake and evaluation of its antioxidant activity

Response surface methodology was employed to optimise extraction conditions of saponins from Camellia oleifera cake. Optimal conditions were extraction at 82.2 °C for 3.3 h with an 8.6:1 ratio (mL g^?1) of solvent to solid. The saponin extract was further extracted with n‐butanol, and nine saponins were found as the main components. The identification of these saponins was carried out by HPLC–ESI–MS, and their possible structures were given. Antioxidant activities of the saponins were evaluated in vitro by 1,1‐diphenyl‐2‐picryl‐hydrazyl (DPPH), 1, 2, 3‐phentriol self‐oxidation and metal chelating activity assays. IC₅₀ value of each assay was 3866 ± 3, 4744 ± 2 and 2389 ± 2 μg mL^?1, respectively. The effects of environmental factors on antioxidant activity of saponins from C. oleifera cake were studied for the first time. The antioxidant activity is pH dependent with 9.0 as the optimal pH and is also temperature independent.     

QUANTIFICATION OF FLUX DECLINE OF DEPECTINIZED MOSAMBI (CITRUS SINENSIS[L.] OSBECK) JUICE USING UNSTIRRED BATCH ULTRAFILTRATION

Ultrafiltration of enzymatically treated mosambi (Citrus sinensis [L.] Osbeck) juice was performed in a batch, unstirred membrane cell. Thin film composite polyamide membrane of molecular weight cut‐off 50,000 was used. The flux‐decline mechanism was identified by the growth of a gel‐type layer over the membrane surface. The flux decline, the gel resistance, the gel‐layer thickness and various domains of resistances were calculated at a constant pressure difference in the range of 276–552 kPa. The conventional gel‐filtration theory was employed to analyze the flux‐decline behavior. The calculated permeate flux and gel‐layer resistances were consistent with the experimental results. The calculated gel‐layer thickness varied from 4.12 to 74.1 µm for different operating condition (pressure) and time. The time at which the gel resistance becomes equal to the membrane‐hydraulic resistance ranged from 13 to 31 s for the pressure range studied herein. Thus, the deposited layer resistance to permeate flow was substantial, throughout the whole operation, except in the first few seconds.     

Biodegradation of Jatropha curcas phorbol esters in soil

BACKGROUND: Jatropha curcas seed cake is generated as a by‐product during biodiesel production. Seed cake containing toxic phorbol esters (PEs) is currently used as a fertiliser and thus it is of eco‐toxicological concern. In the present study the fate of PEs in soil was studied. RESULTS: Two approaches for the incorporation of PEs in soil were used. In the first, silica was bound to PEs, and in the second, seedcake was used. At day 0, the concentration of PEs in soil was 2.6 and 0.37 mg g^?1 for approach 1 and 2 respectively. PEs from silica bound PEs were completely degraded after 19, 12, 12 days (at 130 g kg^?1 moisture) and after 17, 9, 9 days (at 230 g kg^?1 moisture) at room temperature, 32 °C and 42 °C respectively. Similarly at these temperatures PEs from seed cake were degraded after 21, 17 and 17 days (at 130 g kg^?1 moisture) and after 23, 17, and 15 days (at 230 g kg^?1 moisture). Increase in temperature and moisture increased rate of PEs degradation. Using the snail (Physa fontinalis) bioassay, mortality by PE‐amended soil extracts decreased with the decrease in PE concentration in soil. CONCLUSION: Jatropha PEs are biodegradable. The degraded products are innocuous. Copyright © 2010 Society of Chemical Industry     

Optimisation of hydrolysis of purple sea urchin (Strongylocentrotus nudus) gonad by response surface methodology and evaluation of in vitro antioxidant activity of the hydrolysate

BACKGROUND: Hydrolysates prepared from sea urchin (Strongylocentrotus nudus) gonad by enzymatic treatment showed strong 1,1‐diphenyl‐2‐picrylhydrazyl radical scavenging activity and reducing power. RESULTS: Hydrolysis of S. nudus gonad by the commercial protease papain was optimised for maximum degree of hydrolysis (DH) and trichloroacetic acid‐soluble peptide index (TCA‐SPI) using response surface methodology. Results showed that the optimal conditions were the following: temperature of 48.83 °C, pH of 6.92, enzyme‐to‐substrate ratio of 3143 U g^?1, and substrate concentration of 83.5 g L^?1. Under these conditions, a DH of 27.96 ± 0.54% and a TCA‐SPI of 57.32 ± 0.63% were obtained. The hydrolysate prepared in the optimal conditions was fractionated by an ultra‐filtration system and the resultant fraction below 10 kDa was found to effectively scavenge hydroxyl radical (EC₅₀ = 13.29 ± 0.33 mg mL^?1) and hydrogen peroxide (EC₅₀ = 16.40 ± 0.37 mg mL^?1), inhibit lipid peroxidation (EC₅₀ = 11.05 ± 0.62 mg mL^?1), chelate Fe²⁺ (EC₅₀ = 7.26 ± 0.44 mg mL^?1), and protect mice macrophages against death induced by tert‐butyl hydroperoxide. CONCLUSION: Hydrolysates prepared from S. nudus gonad have the potential to be applied as natural antioxidant agents. Copyright © 2012 Society of Chemical Industry     

Structural development of sucrose‐sweetened and sucrose‐free sponge cakes during baking

The influence of sucrose, wheat starch and sorbitol upon the heat‐ and mass‐exchanging processes forming the structure of sponge cake was studied. Under the influence of wheat starch and sorbitol the structure of the sucrose‐free sponge cake was formed at more uniform total moisture release. This process was done at lower temperatures and smoother change of the sponge cake height with respect to the sucrose‐sweetened sponge cake. The porous and steady structure of both cakes was finally formed at identical time – between 18^th and 19^th minute, at the applied conditions for baking of each batter (metal pan with diameter 15.4 cm and depth 6.2 cm containing 300 g of batter and placed in an electric oven “Rahovetz – 02”, Bulgaria for 30 min at 180°C). The water‐losses at the end of baking (10.30% and 10.40% for the sucrose‐sweetened cake and sucrose‐free cake, respectively) and the final temperatures reached in the crumb central layers (96.6°C and 96.3°C for the sucrose‐sweetened cake and sucrose‐free cake, respectively) during baking of both samples were not statistically different. The addition of wheat starch and sorbitol in sucrose‐free sponge cake lead to the statistically different values for the porosity (76.15% and 72.98%) and the volume (1014.17 cm³ and 984.25 cm³) of the sucrose‐sweetened and sucrose‐free sponge cakes, respectively. As a result, the sucrose‐free sponge cake formed during baking had a more homogeneous and finer microstructure with respect to that of the sucrose‐sweetened one.     

Clarification of reconstituted frozen orange juice concentrate by continuous flow centrifugation for limonin glucoside solid phase extraction

BACKGROUND: The suitability of continuous flow centrifugation for the clarification of reconstituted frozen orange juice concentrate prior to its application to a solid phase extraction column for the isolation of limonin glucoside was evaluated. Clarification experiments spanning three flow rates (325, 588 and 875 mL min^?1) and three rotor speeds (equivalent to 2130, 8521 and 19 172 × g) were conducted in a simple factorial design. RESULTS: With increasing rotor speed or decreasing flow rate the average particle size, colour parameters (CIE L*, a*, b*) and residual solids in the resulting centrifugates were found to decrease, whereas juice characteristics including pH, conductivity, °Brix and limonin glucoside content were unchanged by the clarification process. Mean particle size in the resulting centrifugates ranged from 1.14 to 79.31 µm. The most effective clarification was obtained using a 325 mL min^?1 flow rate in conjunction with the maximum rotor speed. Suitability of the centrifugates for processing by solid phase extraction was tested through a two‐step process, in which the centrifugates were first screened using small columns, followed by application of the centrifugate to a larger self‐packed column (6.5 cm × 20 cm) containing SP‐70 Sepabeads. CONCLUSION: Centrifugates from two conditions (325 and 588 mL min^?1 at the maximum rotor speed) were suitable for direct application to both columns. It was found that up to 19 L of these centrifugates could be applied to the 6.5 cm × 20 cm column without clogging or experiencing a decrease in flow rate. Analysis of the column effluent revealed that 11 L of centrifugate was sufficient to saturate this column. Published in 2008 by John Wiley & Sons, Ltd.     

Study of continuous cake pre-baking in a rectangular channel using ohmic heating

An original device dedicated to additive manufacturing was developed to pre-bake cake batter. Its originality lies in the fact that pre-baking is ensured by ohmic heating implemented in a rectangular channel equipped with two parallel electrodes. Experiments and numerical studies were carried out and benchmarked. The rheological properties of the cake batter (non-Newtonian power-law fluid) and the influence of voltage and temperature on electrical conductivity were accommodated in the numerical model. Due to the low velocities of the very viscous products near the solid-liquid interface, it was found that the heterogeneity of the temperature at the nozzle outlet under continuous ohmic heating could lead to nozzle clogging when high temperatures are reached. Hot spots were identified in different areas of the channel, such as corners where the electric field is high and velocity is close to zero. A parametric study was performed on the impact of the thermophysical properties of the batter, showing that specific heat has a much greater impact than thermal conductivity on the accuracy of the temperatures computed. Analysis of the process parameters showed that a stronger electric field leads to a higher temperature gradient in the nozzle section. The temperature gradient decreases with electrode distance (d_elect) and nozzle width (l). This model could be used to optimize the ohmic heating nozzle configuration, with the objective of obtaining a continuous flow of pre-baked cake batter, while preventing clogging. Such a system could be used as 3D printing head.Industrial relevanceConventional 3D printing of bakery products is based on the deposition of a batter, followed by a baking. This study proposes an innovative approach based on a printing nozzle equipped with ohmic heating, with the objective of achieving a uniform temperature distribution and of obtaining high mass flow rate. Despite a significant temperature gradient in the baked batter at the exit of the nozzle, the obtained results showed that adjusting the nozzle geometry allows a reduction of the gradient. Further investigations are thus needed to reduce the temperature gradient and to accommodate expansion of the batter in the case of formulation using baking powder. The transfer of such concept for industry application may be doable in a close future.     

Optimising operating conditions in ultrafiltration fouling of pomegranate juice by response surface methodology

The resistance‐in‐series model was used to analyse flux behaviour, which involved the resistances of membrane itself, the fouling and solute concentration polarisation. Response surface methodology was used to establish the relationships between operating parameters and ultrafiltration (UF) efficiency and thus to determine optimal conditions. Experiments were performed according to Box–Behnken design by changing the levels of three parameters, namely transmembrane pressure, feed flow rate and temperature. The fitted mathematical models allowed us to plot isoresponse curves. It was shown that the resistance due to solute concentration polarisation (R_cp) dominated the flux decline (40–74%). The fouling resistance (R_f) varied from 12 to 46%. To optimise simultaneously the three responses studied (R_f, R_cp and permeate limit flux), we applied the desirability function approach which allowed us to determine the best acceptable compromise. The selected UF conditions of the compromise were as follows: three bars, 0.95 L min^?1 and 30 °C. Optimal values of R_f, R_cp and permeate limit flux were equal to 18%, 72% and 19 L h^?1 m^?2, respectively.     

Experimental assessment of toxic phytochemicals in Jatropha curcas: oil,cake, bio‐diesel and glycerol

BACKGROUND: Jatropha curcas seed is a rich source of oil; however, it can not be utilised for nutritional purposes due to presence of toxic and anti‐nutritive compounds. The main objective of the present study was to quantify the toxic phytochemicals present in Indian J. curcas (oil, cake, bio‐diesel and glycerol). RESULTS: The amount of phorbol esters is greater in solvent extracted oil (2.8 g kg^?1) than in expeller oil (2.1 g kg^?1). Liquid chromatography‐mass spectroscopy analysis of the purified compound from an active extract of oil confirmed the presence of phorbol esters. Similarly, the phorbol esters content is greater in solvent extracted cake (1.1 g kg^?1) than in cake after being expelled (0.8 g kg^?1). The phytate and trypsin inhibitory activity of the cake was found to be 98 g kg^?1 and 8347 TIU g^?1 of cake, respectively. Identification of curcin was achieved by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis and the concentration of curcin was 0.95 g L^?1 of crude concentrate obtained from cake. CONCLUSION: Higher amounts of phorbol esters are present in oil than cake but bio‐diesel and glycerol are free of phorbol esters. The other anti‐nutritional components such as trypsin inhibitors, phytates and curcin are present in cake, so the cake should be detoxified before being used for animal feed. Copyright © 2011 Society of Chemical Industry     

SOFTENING KINETICS OF COOKED DRY BEANS AT TEMPERATURES BELOW 100C

New value‐added dry bean products, such as sugar‐coated beans, require a shorter cooking time (15–30 min) and lower temperature (under 100C) than typical canned beans. Michigan bean classes navy, great white northern, small white, small red, dark red kidney, light red kidney, vine cranberry, bush cranberry, pinto and black beans were cooked at constant water temperatures of 90, 95 and 99C for 5–120 min. Isothermal rate constants for texture were estimated at each temperature for each bean class based on a modified first‐order model and an n ^th ‐order model. Heat transfer coefficients were estimated using aluminum beans and lumped capacity analysis. Isothermal parameters (rate constant and activation energy) and a nonisothermal parameter (activation energy) were used to predict texture from dynamic‐temperature experiments. The first‐order model (isothermal) was accurate up to 30 min, but was not appropriate for time greater than 30 min. The n ^th ‐order was considered superior to the modified first‐order model, because only three rather than four parameters needed to be estimated for similar accuracy. The nonisothermal method can save experimental time compared with the isothermal method, because additional experiments at different constant temperatures are unnecessary. A nomograph of equivalent heating time versus constant heating temperature was shown as a useful tool for process design.     

Hydrodynamic aspects of particle clogging in porous media

Data from 6 filtration studies, representing 43 experiments, are analyzed with a simplified version of the single-parameter O'Melia and Ali clogging model. The model parameter displays a systematic dependence on fluid velocity, which was an independent variable in each study. A cake filtration model also explains the data from one filtration study by varying a single, velocity-dependent parameter, highlighting that clogging models, because they are empirical, are not unique. Limited experimental data indicate exponential depth dependence of particle accumulation, whose impact on clogging is quantified with an extended O'Melia and Ali model. The resulting two-parameter model successfully describes the increased clogging that is always observed in the top segment of a filter. However, even after accounting for particle penetration, the two-parameter model suggests that a velocity-dependent parameter representing deposit morphology must also be included to explain the data. Most of the experimental data are described by the single-parameter O'Melia and Ali model, and the model parameter is correlated to the collector Peclet number.     

Contact toxicity of filter cake and Triplex powders from Ethiopia against Sitophilus oryzae

Contact toxicity of filter cake and Triplex powders from Ethiopia were evaluated against the rice weevil, Sitophilus oryzae (Linnaeus). The study was aimed at determining the lethal and effective concentrations and times for both powders against S. oryzae. The lethal concentrations for 50 and 99% mortality (LC₅₀ and LC₉₉) of filter cake and Triplex against S. oryzae were determined at 14 d after exposing 10 adults for 12 h to concrete arenas inside Petri dishes treated with filter cake concentrations of 0.5–8 g/m² and Triplex concentrations of 1–9 g/m². Lethal times for 50 and 99% mortality (LT₅₀ and LT₉₉) were determined at 14 d after exposing adults for 1–24 h to 3 g/m² of filter cake and 9 g/m² of Triplex. Effective concentrations (EC₅₀ and EC₉₉) and times (ET₅₀ and ET₉₉) for 50 and 99% reduction of adult progeny production were determined from reduction in adult progeny production relative to production in control treatments at 42 d after exposure to filter cake and Triplex. LC₅₀ and LC₉₉ values for S. oryzae adults were 0.70 and 8.49 g/m², respectively, when exposed to filter cake and 2.27 and 21.38 g/m², respectively, when exposed to Triplex. The corresponding LT₅₀ and LT₉₉ values were 3.13 and 27.21 h, respectively, for filter cake and 4.72 and 38.60 h, respectively, for Triplex. EC₅₀ and EC₉₉ values for progeny reduction were 0.57 and 7.95 g/m², respectively, for filter cake and 2.77 and 18.82 g/m², respectively, for Triplex. The corresponding ET₅₀ and ET₉₉ values were 2.57 and 17.73 h, respectively for filter cake and 3.39 and 24.74 h, respectively, for Triplex. S. oryzae exposed to filter cake produced significantly less number of insect damaged kernels and grain weight loss than those exposed to Triplex. Filter cake was more efficacious against S. oryzae than Triplex.     

Fundamental Understanding of Fouling Mechanisms During Microfiltration of Bitter Gourd (<Emphasis Type="Italic">Momordica charantia</Emphasis>) Extract and Their Dependence on Operating Conditions

Microfiltration of bitter gourd (Momordica charantia) extract using hollow fiber membrane module was carried out in the present study. To identify the dominant fouling mechanism, flux decline behavior was examined using Field model. At lower transmembrane pressure, pore blocking mechanism was found to be more important, while cake filtration was dominant at higher pressure. Higher cross flow rate reduced filtration constant indicating slower rate of membrane fouling. Additionally, surface and particle size analyses were undertaken to validate the findings of modeling. Scanning electron microscope analysis clearly showed prevalence of pore blocking mechanism at lower transmembrane pressure drop, whereas cake filtration was dominant fouling mechanism at higher pressure. Fourier transform infrared spectroscopy analysis supported the role of cake layer as a secondary membrane retaining some amount of polyphenols. Analysis of flux decline ratio also confirmed that for transmembrane pressure of 104 kPa and beyond, cake layer became compact, and hence, increase in cross flow rate was unable to influence the improvement of permeate flux. The current study provides an insight into the fouling mechanism involved in scaling up of clarification of bitter gourd extract for successful processing of this medicinal herb.     

Purification of diamine oxidase and its properties in germinated fava bean (Vicia faba L.)

Background: γ‐Aminobutyric acid (GABA) is a non‐protein amino acid with bioactive functions for human health. Diamine oxidase (DAO, EC 1.4.3.6) is one of the key enzymes for GABA formation. In the present study, this enzyme was purified from 5 day germinated fava bean and its properties were investigated in vitro. Results: The molecular mass of the enzyme estimated by Sephadex G‐100 gel filtration was 121 kDa. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‐PAGE) displayed a single band at a molecular mass of 52 kDa. The enzyme had optimal activity at 40 °C and retained its activity after being incubated at 30 °C for 30 min. It showed higher activity at pH 6.5 than at other pH values. The enzyme was significantly inhibited by Mg²⁺, Cu²⁺, Fe³⁺, aminoguanidine, ethylene glycol tetraacetic acid (EGTA), ethylene diamine tetraacetic acid disodium salt (EDTA‐Na₂), L ‐cysteine and β‐mercaptoethanol. The K_m value of DAO was 0.23 mmol L^?1 for putrescine and 0.96 mmol L^?1 for spermidine. However, the enzyme did not degrade spermine. Conclusion: DAO from germinated fava bean was purified. The optimal reaction temperature and pH of the enzyme were mild. The enzyme had higher affinity to putrescine than to spermidine and spermine. Copyright © 2011 Society of Chemical Industry     

PARTIAL PURIFICATION AND CHARACTERIZATION OF POLYPHENOL OXIDASE FROM FRESH-CUT CHINESE WATER CHESTNUT

The characteristics of polyphenol oxidase (PPO) from Chinese water chestnut (CWC) and its potential inhibitors for browning reactions were investigated. PPO was isolated from fresh‐cut CWC and was purified on a Sephadex G‐100 column, with a yield of total activity close to 10%. The molecular weight, Michaelis constant (K_m), substrate specificity, optimal pH and temperature of CWC PPO were examined. Kinetic studies indicated that the K_m and V_max values of CWC PPO for catechol were 10.32 mmol/L and 6.452 × 10⁴ U/min, respectively. The optimal pH and temperature for CWC PPO was 6.5 and 40C, respectively. Among the browning inhibitors tested, 4‐hexylresorcinol, at a concentration of 0.3 mmol/L, showed the strongest inhibition (70%) against the PPO activity of CWC, followed by 3.0 mmol/L N‐acetyl‐L‐cysteine with an inhibition of 53%.     

Different Oils and Health Benefit Statements Affect Physicochemical Properties,Consumer Liking,Emotion, and Purchase Intent: A Case of Sponge Cake

Effects of different oils on physicochemical properties, consumer liking, emotion, and purchase intent of sponge cakes were evaluated. Three healthy oils (extra virgin coconut oil, EVCO; extra virgin olive oil, EVOO; rice bran oil, RBO) compared with butter (the control), were used at 20% (w/w, wheat flour basis) in sponge cake formulations. Five positive (calm, good, happy, pleased, satisfied) and 3 negative (guilty, unsafe, worried) emotion terms, selected from the EsSense Profile^® with slight modification using an online (N = 234) check‐all‐that‐apply questionnaire, were used for consumer testing. Consumers (N = 148) evaluated acceptability of 9 sensory attributes on a 9‐point hedonic scale, 8 emotion responses on a 5‐point rating scale, and purchase intent on a binomial scale. Overall liking, emotion, and purchase intent were evaluated before compared with after health benefit statement of oils had been given to consumers. Overall liking and positive emotion (except calm) scores of sponge cake made with EVCO were higher than those made with EVOO and RBO. Specific volume, expansion ratio, and moisture content of control, EVCO, and EVOO were not significantly different, but higher than RBO sponge cake. JAR results showed that sponge cake made with RBO had the least softness that was reflected by the highest hardness (6.61 to 9.69 compared with. 12.76N). Oil (EVCO/EVOO/RBO) health benefit statement provided to consumer significantly increased overall liking, positive emotion, and purchase intent scores while decreased negative emotion scores. Overall liking and pleased emotion were critical attributes influencing purchase intent (odds ratio = 2.06 to 3.75), whereas calm and happy became not critical after health benefit statement had been given.     

啤酒过滤系统的选用

<正> 在啤酒生产厂计划实施过滤项目或扩大现有设备时,重要的决策之一是选取能满足生产所需的过滤系统。由于过滤是啤酒生产的最后步骤,也是关键的工序,能直接影响啤酒的风味稳定性和保质期,啤酒酿造厂在选用过滤系统时,除要满足消费者对产品质量的要求外,同时也要顾及采用有效而经济的生产设备。本文将剖析选取过滤系统的要点,其中包括不同过滤器的流动特性和滤饼形成的基本理论。     

Investigation of conventional membrane and tangential flow ultrafiltration artifacts and their application to the characterization of freshwater colloids

Artifacts associated with the fractionation of colloids in a freshwater sample were investigated for conventional membrane filtration (0.45 microm cutoff), and two tangential flow ultrafiltration cartridges (0.1 microm cutoff and 3000 MW cutoff). Membrane clogging during conventional filtration removed some colloids smaller than 0.1 microm in diameter, much smaller than the nominal size of the filter. For certain constituents (e.g., Fe), filter clogging had a significant effect on filtrate concentrations, while artifacts associated with tangential flow ultrafiltration using a 0.1 microm cutoff were minimal. Artifacts occurred during tangential flow ultrafiltration with a 3000 MW cutoff, but did not deviate from predicted changes in concentration based on a standard permeation model. Comparison of filtrate concentrations for membrane filtration (at 1.0 and 0.45 microm) and tangential flow ultrafiltration (at 0.1 microm) for a large number of samples from Connecticut rivers shows that significant and consistent differences exist between their separation characteristics. Results for organic carbon, Fe, Mn, Al, Cu, and Pb demonstrate the magnitude of the effects of the fractionation technique on filtrate element concentration, show variability by element and flow condition, and highlight the importance of larger colloids to freshwater metal speciation. One implication of the research is that tangential flow ultrafiltration with large size cutoff membranes (e.g., approximately 0.1 microm) may be superior to conventional filtration with filters in the same size discrimination range, and potentially more appropriate for the fractionation of natural water samples.     

Soymilk concentration by ultrafiltration: effects of pore size and transmembrane pressure on filtration performance

The effects of membrane pore size and operating pressure on filtration flux, membrane fouling and solute rejections of soymilk during ultrafiltration were studied. Soymilk was concentrated from an initial level of 6.5% solid content to 20% solid content using ultrafiltration membranes. Hollow fibre cross‐flow type cartridges having molecular weight cut‐off (MWCO) as 1, 10 and 30 kDa were used in the experiments. Filtration data were satisfactorily fitted to De La Garza and Boulton's exponential model to find the exponential fouling coefficient (k) and the membrane resistance (R_m). The permeate fluxes obtained in 10 and 30‐kDa MWCO membranes were found to be approximately four times higher than that of 1‐kDa MWCO membrane, at transmembrane pressure between 100 and 240 kPa. The average flux obtained was 0.7, 3.15 and 2.7 L m^?2‐h for 1, 10 and 30‐kDa MWCO membranes, respectively. The R_m value of membranes was found to decrease as the MWCO of membranes increased and transmembrane pressure decreased. The total solid content of permeates obtained by these membranes was between 0.45% and 1.4%. Membrane‐concentrated soymilk was found to have lighter colour and almost half the value of viscosity compared with evaporated milk.