By Box-Behnken Design Research Articles

Optimization of Ultrasonic-Microwave Synergistic Extraction of Ricinine from Castor Cake by Response Surface Methodology.

Castor cake is the residue in castor oil production in which many active components exist and the major one among them is ricinine. In this study, optimization of extraction of ricinine from castor cake using ultrasonic-microwave synergistic extraction (UMSE) was investigated to obtain high yield and purity by Box-Behnken design (BBD) response surface design. The optimal conditions of extraction were: ultrasound power 342 W, extracting time 5 min, microwave power 395 W, and non-significant factor of liquid/solid ratio 1:10. The crude extraction was recrystallized from ethanol. As a result, the maximum yield of ricinine was approximately 67.52%. The purity of ricinine was 99.39% which was determined by high performance liquid chromatography (HPLC). Additionally, the structure of purified ricinine was identified by fourier transforms infrared (FTIR) and liquid chromatography-mass spectrometry (LC-MS). Scanning electron microscope (SEM) was used to characterize the prismatic crystals morphology of ricinine. Results demonstrated that the present method combined the advantages of ultrasonic extraction and microwave extraction, which is time-saving with high extraction yield. Our results offer a suitable method for large-scale isolation of ricinine.

Optimization and antioxidant activity of polysaccharides from Plantago depressa

Polysaccharide from the herb of Plantago depressa (PDP) was obtained through ethanol precipitation preceded by a water extraction step. The optimum extraction yield of 5.68±0.46% was obtained with the treatment of raw material in water (w/v, 1:25.34) at 80.44°C during 1.97h, 3.28 times. Under these conditions, obtained yield value was in total agreement with value predicted by the model executed by Box-Behnken design (BBD). Following analysis by IR, HPLC-UV, MS and 1H NMR, the composition of PDP was found to be l-rhamnose, galactose, arabinose, glucose and d-galacturonic acid. The maximum tolerated dose of PDP was 10g/kg. The antioxidant activity of PDP was investigated using five tests and it was found that PDP was able to scavenge hydroxyl, DPPH and ABTS radicals, besides their β-carotene bleaching inhibitory activity. In particular, in the test of β-carotene bleaching inhibition, PDP displayed higher activity than Vitamin C.

Statistical modeling/optimization and process intensification of microwave-assisted acidified oil esterification

The esterification of acidified oil with ethanol under microwave radiation was modeled and optimized using response surface methodology (RSM) and artificial neural network (ANN). The impacts of mass ratio of ethanol to acidified oil, catalyst loading, microwave power and reaction time are evaluated by Box-Behnken design (BBD) of RSM and multi-layer perceptron (MLP) of ANN. RSM combined with BBD shows the optimal conditions as catalyst loading of 5.85g, mass ratio of ethanol to acidified oil of 0.35 (20.0g acidified oil), microwave power of 328W and reaction time of 98.0min with the free fatty acids (FFAs) conversion of 78.57%. Both of the models are fitted well with the experimental data, however, ANN exhibits better prediction accuracy than RSM based on the statistical analyses. Furthermore, membrane vapor permeation and in-situ molecular sieve dehydration were investigated to enhance the esterification under the optimized conditions.

Optimization of thermotolerant alkaline protease production from Brevibacillus brevis strain BT2 using surface response methodology

Abstract An efficient thermotolerant alkaline protease producer, strain Brevibacillus brevis BT2 was isolated from waste water effluents from textile dyeing industry. Effect of variables, i.e. soybean meal, soluble starch, inoculums, temperature and pH and their mutual interaction were analyzed by Box-Behnken design (BBD) for optimizing their levels in the medium and effect of their mutual interaction on thermotolerant alkaline protease production. All the above variables were found significantly influencing protease activity individually and also in interaction with other variables. The model predicted maximal protease production of 121.1 (U ml−1) at the soybean meal 7.46 (gL−1), soluble starch 10.00 (gL−1), inoculums 1.76%, temperature 49.3 °C, and pH 9.1. The maximum protease production obtained experimentally was found to be 128.5 U/ml. The result was coincident with the predicted value and the model was proven to be adequate.

Mercury Removal by Adsorption on Pectin Extracted from Sugar Beet Pulp: Optimization by Response Surface Methodology

AbstractConsidering the rich sugar beet resource in Xinjiang, China, the possibilities for Hg(II) removal by pectin extracted from sugar beet pulp and optimization of the extraction process using response surface methodology (RSM) were studied. The experiments were proposed by Box‐Behnken design (BBD) and a second‐order regression model was developed for regression analysis and analysis of variance. Optimized conditions in terms of temperature, concentration, and solid‐liquid ratio were determined. The effects of different parameters like pH, time, temperature, and initial Hg(II) concentration on adsorption capacity were investigated. The isotherm adsorption experiments were fitted with the Langmuir model which indicated monolayer adsorption.

Microwave-Assisted Method for Simultaneous Hydrolysis and Extraction for Preparation of Geniposidic Acid fromEucommia ulmoidesBark Using Basic Imidazolide Ionic Liquid

In order to hydrolyze geniposide and extract geniposidic acid, a novel microwave irradiation heating method for simultaneous hydrolysis and extraction for preparation of geniposidic acid fromEucommia ulmoidesbark using basic imidazolide ionic liquid was developed in this work. Basic ionic liquid paired by imidazolide anion and 1-hexyl-3-methylimidazolium cation ([C6mim]Im) was used as a dual hydrolysis catalyst and extraction solvent in the proposed approach. The optimal concentration of [C6mim]Im was 0.4 mol/L. And the independent parameters optimized by Box-Behnken design (BBD) based on single-factor tests were as follows: microwave irradiation time of 20 min at power of 415 W and liquid-solid ratio of 15 mL/g. Yield of geniposidic acid was increased to3.41±0.17 μmol/g. DM130 macroporous resin, after reaction, was selected to separate geniposidic acid from hydrolysate. The plant materials with different treatment were analyzed by scanning electron microscopy (SEM) and thermogravimetric analysis (TG). The analysis of SEM and TG further indicated that IMSHE is an efficient preparation method for geniposidic acid. It is reasonable to assume that the method and the dual hydrolysis catalyst and extraction solvent would offer an alternative for the preparation of some other kinds of bioactive substances from plant materials.

Establishment of hairy root cultures by Agrobacterium rhizogenes mediated transformation of Isatis tinctoria L. For the efficient production of flavonoids and evaluation of antioxidant activities.

In this work, Isatis tinctoria hairy root cultures (ITHRCs) were established as an alternative source for flavonoids (FL) production. I. tinctoria hairy root line V was found to be the most efficient line and was further confirmed by the PCR amplification of rolB, rolC and aux1 genes. Culture parameters of ITHRCs were optimized by Box-Behnken design (BBD), and eight bioactive FL constituents (rutin, neohesperidin, buddleoside, liquiritigenin, quercetin, isorhamnetin, kaempferol and isoliquiritigenin) were quali-quantitatively determined by LC-MS/MS. Under optimal conditions, the total FL accumulation of ITHRCs (24 day-old) achieved was 438.10 μg/g dry weight (DW), which exhibited significant superiority as against that of 2 year-old field grown roots (341.73 μg/g DW). Additionally, in vitro antioxidant assays demonstrated that ITHRCs extracts exhibited better antioxidant activities with lower IC50 values (0.41 and 0.39, mg/mL) as compared to those of field grown roots (0.56 and 0.48, mg/mL). To the best of our knowledge, this is the first report describing FL production and antioxidant activities from ITHRCs.

Continuous esterification of free fatty acids in crude biodiesel by an integrated process of supercritical methanol and sodium methoxide catalyst.

An integrated process of supercritical methanol (SCM) and sodium methoxide catalyst was developed to produce fatty acid methyl esters (FAMEs) via continuous esterification from crude biodiesel. The crude biodiesel with high free fatty acid (FFA) content must be refined to reduce the acid value (AV) for meeting the quality standards. The process parameters were studied by Box-Behnken design (BBD) of response surface methodology (RSM). The experimental results revealed that the AV of crude biodiesel decreased from 18.66 to 0.55mgKOHg(-1) at the reaction conditions of 350°C, 0.5% amount of sodium methoxide catalyst, and 10MPa. Temperature shows the most significant effect on the esterification, followed by pressure and amount of sodium methoxide catalyst. This integrated process proved to be a potential route to refine the crude biodiesel because of its continuity, high efficiency, and less energy consumption with relatively moderate reaction conditions compared with conventional methods.

Screening of Burkholderia sp. WGB31 producing anisic acid from anethole and optimization of fermentation conditions.

Anisic acid, the precursor of a variety of food flavors and industrial raw materials, can be bioconversed from anethole which extracted from star anise fruits. WGB31 strain with anisic acid molar production rate of 10.25% was isolated and identified as Burkholderia sp. Three significant influential factors, namely, glucose concentration, initial pH value, and medium volume were selected and their effects were evaluated by Box-Behnken Design (BBD). Regression analysis was performed to determine response surface methodology and the significance was tested to obtain the process model of optimal conditions for producing anisic acid. The fermentation conditions at the stable point of the model were obtained: glucose 6 g L(-1) , pH 6.2, culture medium volume 61 mL in a triangular flask with 250 ml volume. Verification test indicated that the production rate of anisic acid was 30.7%, which was three times of that before optimizing. The results provide a basis and reference for producing anisic acid by microbial transformation.

Multielemental composition of suet oil based on quantification by ultrawave/ICP-MS coupled with chemometric analysis.

Suet oil (SO) has been used commonly for food and medicine preparation. The determination of its elemental composition has became an important challenge for human safety and health owing to its possible contents of heavy metals or other elements. In this study, ultrawave single reaction chamber microwave digestion (Ultrawave) and inductively coupled plasma-mass spectrometry (ICP-MS) analysis was performed to determine 14 elements (Pb, As, Hg, Cd, Fe, Cu, Mn, Ti, Ni, V, Sr, Na, Ka and Ca) in SO samples. Furthermore, the multielemental content of 18 SO samples, which represented three different sources in China: Qinghai, Anhui and Jiangsu, were evaluated and compared. The optimal ultrawave digestion conditions, namely, the optimal time (35 min), temperature (210 °C) and pressure (90 bar), were screened by Box-Behnken design (BBD). Eighteen samples were successfully classified into three groups by principal component analysis (PCA) according to the contents of 14 elements. The results showed that all SO samples were rich in elements, but with significant differences corresponding to different origins. The outliers and majority of SO could be discriminated by PCA according to the multielemental content profile. The results highlighted that the element distribution was associated with the origins of SO samples. The proposed ultrawave digestion system was quite efficient and convenient, which could be mainly attributed to its high pressure and special high-throughput for the sample digestion procedure. Our established method could be useful for the quality control and standardization of elements in SO samples and products.

Optimal Decolorization Efficiency of Reactive Red 3 by Fe-RH-MCM-41 Catalytic Wet Oxidation Coupled with Box-Behnken Design

The reactive red 3 was degraded by catalytic wet oxidation process over Fe-RH-MCM-41 prepared by Direct Hydrothermal Technique (DHT) at Si/Fe molar ratio of 10 using silica from rice husk. The extended reaction conditions were studied as a function of reaction temperatures, initial H2O2 concentrations and initial pH of solutions designed by Box-Behnken design (BBD) based on Response Surface Methodology (RSM) to achieve the optimal condition and interaction of independent variables. The characterizations of catalyst were studied by XRD, BET surface area and TEM to explain the morphology of surface and to confirm the hexagonal structure. The results showed the 2theta peak can be indexed to hexagonal lattice that also confirmed by TEM result and surface area about 650 m2/g. All of independent variables showed significant on the degradation of reactive red 3 except for initial H2O2 concentration.

Optimization of the fermentation medium for Paecilomyces tenuipes N45 using statistical approach

In the present study, a sequential statistical approach was applied to optimize the medium in submerged cultivation of Paecilomyces tenuipes N45. Desirability value was used as response to simultaneously enhance the yields of mycelium, adenosine, polysaccharide and cordyceps acid. Based on single-factor optimization strategy, the suitable carbon sources, nitrogen sources and inorganic salts were obtained. Then key medium components were identified by Plackett-Burman design (PBD) and further optimized by Box-Behnken design (BBD). Finally, response surface methodology (RSM) and artificial neural network – genetic algorithm (ANN-GA) were used to model and optimize the experimental results obtained from BBD. The optimum components of nutrient medium comprised (g/L): glucose 40, beef extract 10, soy peptone 10, KH2PO4 0.688, MgSO4·7H2O 1, NaCl 0.500, VB1 0.201, VB12 0.130. In a word, a mean value of desirability valuesDv = 0.493 was obtained, which was 20.540% higher than the value achieved by the basal medium. The biomass, the production of adenosine, the polysaccharide and the cordyceps acid yields were enhanced by 8.200, 3.580, 23.170 and 31.510% respectively. Key words: Artificial neural network, optimization, Paecilomyces tenuipes, response surface methodology, genetic algorithm.

Optimization of photo-Fenton process of RO concentrated coking wastewater using response surface methodology

The objective of this study was aimed at investigating the removal of chemical oxygen demand (COD) from reverse osmosis (RO) concentrated coking wastewater by the photo-Fenton process. The optimum extraction conditions for the photo-Fenton process by Box-Behnken design (BBD) and response surface methodology (RSM) to establish a predictive polynomial quadratic model were discussed based on a single factor test. Optimized parameters validated by the analysis of variances (ANOVA) were found to be H(2)O(2) concentration of 345.2 mg/L, pH value of 4.1 and reaction time of 103.5 minutes under ultraviolet irradiation. The experimental results of the COD removal under the optimized conditions presented better agreement with the predicted values with deviation error of 3.2%. The results confirmed that RSM based on BBD was a suitable method to optimize the operating conditions of RO concentrated coking wastewater.

Optimization of the Wet Mechanochemical Process Conditions of SrSO4 to SrCO3 and (NH4)2SO4 by Using Response Surface Methodology

The wet mechanochemical process was optimized for insoluble SrCO3 and soluble (NH4)2SO4 formation from celestite (SrSO4)-(NH4)2CO3-H2O mixtures in a planetary ball mill by Box-Behnken design (BBD). The products formed during wet milling were analyzed with scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FT-IR) spectroscopy. For converting to SrCO3 of celestite (SrSO4) and to (NH4)2SO4 of (NH4)2CO3, a hydrometallurgical process optimization via the wet mechanochemical conversion using (NH4)2CO3 was developed the first time in this work using response surface methodology. The wet mechanochemical conversion was carried out by varying ball to grinding material mass ratio, (NH4)2CO3 to SrSO4 mole ratio and the rotational speed of mill in a planetary mill. Under the optimum experimental conditions (9.24 of ball to grinding material mass ratio, 1.86 of (NH4)2CO3 to SrSO4 mole ratio and 400 rpm of the rotational speed of mill), the conversion of SrCO3 was 99.08 pct. The (NH4)2SO4 obtained as byproduct was crystallized.

Alkali extraction and in vitro antioxidant activity of Monascus mycelium polysaccharides.

In the present work, alkali extraction technology was used to optimize the extraction of Monascus mycelium polysaccharides for the first time. The extracting parameters of alkali extracted Monascus mycelium polysaccharides were optimized by Box-Behnken design (BBD). The optimum conditions were extraction temperature 49°C, alkali concentration 7%, solvent/material ratio 23:1 (ml/g) and extraction time 2.3h with an enhanced yield of 10.1%, compared with the yield 4.76% of hot water extraction, indicating that alkali extraction is a more efficient way. In order to discuss the biological activity of alkali extracted polysaccharides, we compared the in vitro antioxidant activity of alkali extracted polysaccharides (AMP) with hot water extracted polysaccharides (HMP). The result showed that AMP have the similar capability of scavenging both superoxide radical and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical of HMP in vitro. Therefore, alkali extraction technology is not only a high-efficiency way to extract AMP, but also can retain the natural antioxidant activities of AMP, which can be used in pharmaceutical and food industries.

Statistical optimization of xylanase production by Aspergillus niger AN-13 under submerged fermentation using response surface methodology

Response surface methodology (RSM) was performed to evaluate the effects of cultivation time, pH and substrate concentration on production of xylanase by Aspergillus niger AN-13. Agricultural residue wheat bran was used as main substrate under submerged fermentation. Xylanase production was optimized by Box-Behnken design (BBD). Statistical analysis of results showed that, the linear and quadric terms of these three variables had significant effects, and evident interactions existing between pH and substrate concentration were found to contribute to the response at a significant level. Furthermore, Box-Behnken design (BBD) used for the analysis of treatment combinations gave a second-order polynomial regression model, which was in good agreement with experimental results, with R2=0.9959 (P namely cultivation time of 53.3 h, pH of 7.92 and wheat bran concentration of 54.2 g·L-1, the model predicted a xylanase activity of 125.14 U·mL-1. Verification of the optimization showed that xylanase production of 127.12 U·mL-1 was observed under the optimal condition, which had a marked increase compared with a xylanase activity of 4.80 U·mL-1 in experiments according to Box-Behnken design.