Simplex-centroid Experimental Design Research Articles

Statistical simplex centroid experimental design for evaluation of pectin, modified chitosan and modified starch as encapsulating agents on the development of vitamin E-loaded microparticles by spray-drying

Vitamin E encapsulation into biopolymer-based microparticles, obtained by spray-drying technology, was proposed to improve the encapsulation efficiency and the controlled release of fat-soluble vitamin. Binary and ternary blends of pectin, modified chitosan and modified starch, modified starch + modified chitosan, modified starch + pectin, modified chitosan + pectin and modified starch + modified chitosan + pectin ((0.33, 0.33, 0.33), (0.70, 0.15, 0.15), (0.15, 0.70, 0.15) and (0.15, 0.15, 0.70)) were proposed to produce and evaluate different carrier-based delivery systems. Vitamin E-loaded microparticles and empty microparticles were created with a product yield between 9 and 49 %. The mean diameter among all microparticles varied between 3.74 ± 0.02 and 421 ± 21 μm (differential volume distribution). Oval, spherical or irregular microparticles, with a variable morphology from a smooth to a high rough surface structure, with concavities, were produced. All vitamin E-loaded microparticles exhibited an encapsulation efficiency higher than 70 %. The slower vitamin E controlled release was observed from microparticles composed by modified chitosan (>36 h), while the faster release was achieved from microparticles individually composed by pectin (39 min). In general, the Fickian diffusion is the main release mechanism involved in the microparticles produced with modified chitosan, other formulations combine also other mechanisms such as swelling.

Multifunctional Biotechnological Lip Moisturizer for Lip Repair and Hydration: Development, In Vivo Efficacy Assessment and Sensory Analysis

The demand for sustainable cosmetics leads to the search for natural and biotechnological ingredients. The present study reports the development of a multifunctional lip moisturizer containing levan (LEV) from Bacillus subtilis natto, sophorolipids (SOPs) from Starmerella bombicola and Citrus paradisi (OCP) essential oil, using a simplex-centroid experimental design. The formulations were evaluated physicochemically, pharmacotechnically and by DPPH assay. The optimized formulation was selected through the Response Surface Method, and the evaluation of its efficiency in lip hydration was carried out using the bioimpedance method and sensory analysis. The formulations showed pH compatibility with lips and remained stable after a centrifuge test and thermal stress. Spreadability varied between 415.3 and 1217.1 mm2, moisture retention was above 95% and antioxidant capacity was around 50% for all formulations. The optimized formulation, containing 0.4% LEV and 0.8% SOF, maintained the lip hydration already shown by the participants; 85% of them reported improvement in this aspect. For the first time, LEV and SOP were incorporated in lip moisturizers, which is an environmentally friendly product with marketing potential. Furthermore, the use of the Skin Analyzer Digital equipment, a low-cost and non-invasive technique, to evaluate the effectiveness of lip products is innovative; this methodology may help in the development of future cosmetology studies.

Particleboard experimental production with bamboo, pine and mate for one product of new applications

Particleboard can be produced from a mixture of different lignocellulosic materials, which can be chosen depending on the density required for the panel and its applications. The aim of this study was to evaluate the mechanical properties of particleboard with bamboo, pine and mate for a new product of high density for the special applications currently served by HDF. Particles of bamboo (Phyllostachys aurea) finely chopped sticks of mate (Ilex paraguariensis) and commercial particles of southern pine (Pinus taeda) wood were used. These particles used 100 % by weight in the panel or in mixtures of 50 % each (three mixtures) or in a triple mixture of one third each, were glued in a drum-type rotary mixer with melamine-urea-formaldehyde (MUF) resin, and pressed in hydraulic press at 120 °C and 5,88 MPa for 10 minutes, up to 6 mm thickness. The panels were produced with 900 kg/m3 nominal density and, after pressing, were conditioned at 20 ºC and 65 % relative humidity. Statistical was performed by means the variance analysis and simplex centroid experimental design, with three replicates. It was found the use of pine particles contributed mainly to increase the panel's strength and stiffness, while the use of mate particles facilitated internal bond strength. The mixtures modeling showed that the water absorption, the strength and stiffness in bending and the internal bond strength are explained by the cubic model, while the thickness swelling and hardness are explained by the quadratic model. The best physical and mechanical properties results were found for the pine, bamboo and mate same ratio mixture.

The paper-forming properties of hemp fire peroxide cellulose in combination with wood sulphate cellulose

Hemp fire (Cannabis sativa) was delignified with the reaction mix “acetic acid - hydrogen peroxide - sulfuric acid catalyst - water” under sulfuric acid concentration of 0.45%, liquid module of 6, and temperature of 85 ° C. The cellulose was ground to 34 … 36°SHR and mixed in different ratios in compliance with the simplex-centroid experimental design with bleached sulfate softwood and hardwood pulp. The influence of the mixed composition formulations on the main strength properties of paper castings has been studied. It has been concluded that technical cellulose obtained from hemp fire applying this method, can be used for paper products manufacturing in combination with sulphate cellulose from coniferous and deciduous wood.

Preparation and performance of the ultra-high performance mortar based on simplex-centroid design method

The mix proportion, phase diagram components and mechanical properties of ultra-high performance mortar (UHPM) based on simplex-centroid design method were investigated. The effects of material components, sand/binder ratio (S/B) and water/binder ratio (W/B) on the strength and fluidity of UHPM were studied. Simultaneously, the relationship between water reducer dosage and slump flow of UHPM was investigated as well as the mix proportion design and performance prediction. The results showed that the simplex-centroid design method can be used to determine the relationship between influence factors and performance of UHPM. The differences of strength phase diagram for different mix proportion of UHPM were manifested in central position of minimum strength, strength contours and gradient, and position of maximum strength. There has a quadratic function relationship between water reducer dosage, slump flow and W/B. The slump flow of UHPM increases with the increase of water reducer dosage. The UHPM can be prepared based on simplex-centroid experimental design method.

Composição centesimal e intenção de compra de biscoitos obtidos pela mistura das farinhas de talos de beterraba, flocos de aveia e farinha de trigo

Biscoitos tipo cookies são amplamente consumidos por pessoas de todas as faixas etárias, no entanto geralmente são elaborados a partir de farinhas refinadas. Pensando em melhorar as características nutricionais do biscoito, o objetivo deste estudo foi desenvolver um cookie a base de farinha mista de talos de beterraba (FTB) e flocos de aveia (FA) em associação com a farinha de trigo (FT). Os cookies foram desenvolvidos empregando-se o delineamento experimental centróide simplex, com um ponto central e restrição do limite máximo de farinha de trigo em 50%. Nos biscoitos foi determinada a composição centesimal e intenção de compra. A influência da mistura sobre as variáveis umidade, fibra total, fibra insolúvel, fibra solúvel, cinzas, carboidratos e intenção de compra foi explicada pelo modelo linear, já o modelo quadrático mostrou-se mais adequado para justificar o efeito das farinhas sobre o teor de proteico dos biscoitos. Os modelos propostos não conseguiram explicar a influência sobre o teor de lipídeo dos biscoitos. A FTB esteve associada a biscoitos com maiores teores de umidade, fibras, cinzas e atividade de água, apresentando efeito antagônico sobre o teor de carboidratos e sobre a aceitação. Já os FA apresentaram efeito sinérgico sobre o teor de proteína dos biscoitos. Portanto a associação de FTB e FA mostrou-se promissora para melhorar a qualidade nutricional dos biscoitos. No entanto, ressalta-se que a FTB não deve exceder 17% da base farinácea para não interferir na aceitação do produto.

Lipid composition optimization in spray congealing technique and testing with curcumin-loaded microparticles

Spray-congealing, a technique based on the fast solidification of sprayed molten lipids, is considered a novel strategy to encapsulate natural products. Among others, it is a safe, low cost, fast and reproducible technique, with rising interest for several applications (e.g. food applications). One of the key parameters for the application of this technique is the lipid solidification temperature, which can be modulated by optimizing the lipid composition. In this work, three lipid components (beeswax, carnauba wax, and medium-chain triglycerides (Miglyol 812)) were selected, and the mixture composition modelled using a simplex-centroid experimental design. Three different lipid compositions were chosen to validate the proposed model, then tested in the preparation of curcumin-loaded microparticles (1.5%, w/w). The produced microparticles were analysed in terms of colour, morphology, particle size, encapsulation efficiency and load, physicochemical, crystalline, and thermal properties. Results evidenced that microparticle’s properties, including encapsulation efficiency, vary according to the used lipid mixture, supporting their tailoring role. This fact brings advantages in the design of microencapsulation systems based on spray congealing processes, broadening their applicability. Moreover, lipid composition optimisation was proved to be an important tool to precede the development of spray-congealing applications.

Processing and physicochemical characterization of a water-soluble extract based on Pará nut (Bertholletia excelsa) and baru nut (Dipteryx alata Vogel)

Despite the nutritional and functional qualities of Pará nut (Bertholletia excelsa) and of Baru nut (Dipteryx alata Vogel), the industrial exploitation of these two nuts is still scarce. With this, the elaboration of a water-soluble extract based on Pará and Baru nuts could be consider an alternative for the consumption of foods based on these vegetables, both little used industrially. Thus, by way of a simplex centroid experimental mixture design, this study aimed to elaborate water-soluble vegetable extracts based on Pará and Baru nuts. This study allowed evaluate the behavior of the physicochemical and physical characteristics of the processed vegetable extracts. The special cubic model obtained the best fit for the response variables, both for the physicochemical characterizations of moisture, lipid, protein, ash, carbohydrate, pH value and acidity, and for the physical characteristics of luminosity, chroma and hue angle. The results obtained showed that the model is highly predictive (all R2 > 97%). The water content directly influenced the nutritional aspects of the water-soluble extracts, where a decrease in the proportion of water in the mixture provided greater content of proximate composition. The behavior of the color parameter predicted by the model showed that variations in the proportions of the nuts concentrations changes the behavior of the luminosity indexes. The pH had higher values when there was an increase in the concentration of Pará nuts, while an increase in the proportion of baru nuts decreased the acidity of the water-soluble extract. The mathematical models used allow to evaluate the effects of the interactions between variables and responses, highlighting their applicability in the food industry.

Sward composition and soil moisture conditions affect nitrous oxide emissions and soil nitrogen dynamics following urea-nitrogen application

Increased emissions of N2O, a potent greenhouse gas (GHG), from agricultural soils is a major concern for the sustainability of grassland agriculture. Emissions of N2O are closely associated with the rates and forms of N fertilisers applied as well as prevailing weather and soil conditions. Evidence suggests that multispecies swards require less fertiliser N input, and may cycle N differently, thus reducing N loss to the environment. This study used a restricted simplex-centroid experimental design to investigate N2O emissions and soil N cycling following application of urea-N (40 kg N ha−1) to eight experimental swards (7.8 m2) with differing proportions of three plant functional groups (grass, legume, herb) represented by perennial ryegrass (PRG, Lolium perenne), white clover (WC, Trifolium repens) and ribwort plantain (PLAN, Plantago lanceolata), respectively. Swards were maintained under two contrasting soil moisture conditions to examine the balance between nitrification and denitrification. Two N2O peaks coincided with fertiliser application and heavy rainfall events; 13.4 and 17.7 g N2O-N ha−1 day−1 (ambient soil moisture) and 39.8 and 86.9 g N2O-N ha−1 day−1 (wet soil moisture). Overall, cumulative N2O emissions post-fertiliser application were higher under wet soil conditions. Increasing legume (WC) proportions from 0% to 60% in multispecies swards resulted in model predicted N2O emissions increasing from 22.3 to 96.2 g N2O-N ha−1 (ambient soil conditions) and from 59.0 to 219.3 g N2O-N ha−1 (wet soil conditions), after a uniform N application rate. Soil N dynamics support denitrification as the dominant source of N2O especially under wet soil conditions. Significant interactions of PRG or WC with PLAN on soil mineral N concentrations indicated that multispecies swards containing PLAN potentially inhibit nitrification and could be a useful mitigation strategy for N loss to the environment from grassland agriculture.

Evaluation and application of extracts of rosemary leaves, araçá pulp and peel of bacuri in the inhibition of the oxidation reaction of biodiesel

This research evaluated the efficiency of the extracts of aromatic plants and native fruits with antioxidant properties, such as bacuri (Platonia insignis), araçá (Psidium cattleianum) and rosemary (Rosmarinus officinalis), in biodiesel, through the study of the induction period and the oxidation reaction rate constant at the temperature of 110 °C using the simplex-centroid mixtures. The araçá pulp, rosemary leaves and bacuri peels extracts showed total phenol content of 3.67, 19.29 and 19.60 mgGAE/gdrymatter, respectively. The experimental design used was a simplex centroid with 7 assays and a duplicate of the central point. Biodiesel and extracts were mixed in the proportion established by the simplex-centroid experimental design, and ethyl alcohol was removed previously. All the samples with extracts showed an induction period higher than the control, indicating the antioxidant efficiency of all the extracts. All models obtained were significant at the 5% level. The most relevant results were obtained in the tests containing the highest proportions of the bacuri and rosemary leaves extracts. It was possible to obtain the optimization, in which an optimal mixture was achieved with 50% of bacuri and 50% of rosemary leaves extract, and with induction period of 8.14 h, a value above the minimum of 6 h provided in the legislation EN 14214 [1].

Radionuclide Immobilization by Sorption onto Waste Concrete and Bricks—Experimental Design Methodology

The utilization of construction and demolition waste materials for the radionuclide immobilization by sorption processes was investigated. Given that the liquid radioactive waste usually has a complex composition and that effects of competition may significantly influence the efficiency of the treatment, the Simplex Centroid experimental design was used to explore ions sorption from multi-component solutions. For the purpose of this study, the common components of construction and demolition waste, such as pathway concrete and different bricks samples, were used along with the multi-component Sr2+, Co2+, and Ni2+ ions solutions. The equations for the prediction of metal ions sorption capacities were derived. The coefficients that correspond to the linear and interaction terms were obtained using a special cubic model. Likewise, by analysis of variance, statistically significant terms of the obtained polynomial were defined. The investigation has shown that the most effective sorption was onto the pathway concrete for all three cations, while the highest sorption capacity was found for Co2+ ions. Also, it has been determined that concerning Sr2+ ion removal there was a competition with coexisting Co2+ and Ni2+ ions, reducing its sorption capacity, while sorption of Co2+ and Ni2+ occurred more independently on other cations in multi-component solutions. Based on the obtained results, the applied experimental design can be efficiently used for the description of competitive sorption process and could be a powerful tool for the prediction of cation immobilization in liquid radioactive waste treatment.

Influence of Brazilian pine seed flour addition on rheological, chemical and sensory properties of gluten-free rice flour cakes

ABSTRACT: Brazilian pine seeds (pinhão) are gluten-free seeds produced by the native pine species named Araucaria angustifolia. In this study, gluten-free cake mixes composed of Brazilian pine seed flour and rice flour were developed. The cake mixes were produced following a Simplex Centroid experimental design, with rice flour and Brazilian pine seed flour contents ranging from 50 to 100% and from 0 to 50%, respectively. Mixes were analyzed for chemical composition, apparent paste viscosity, and particle size distribution. The resulting cakes were analyzed for sensory acceptance, texture, specific volume and chemical composition. The Brazilian pine seed flour showed a peak viscosity on heating of 1.761Pa.s against 4.747Pa.s for the 100% rice flour sample. The variation of firmness of cakes decreased with increasing percentage of Brazilian pine seed flour. Cakes containing Brazilian pine seed flour at 25-37.5% of the formulation presented highest overall acceptance.

Exploring innovative solutions for aged concrete utilization: treatment of liquid radioactive waste

In this study, the applicability of waste concrete as a sorbent material for the liquid radioactive waste management was considered. The sample was properly characterized in terms of mineralogical and surface composition, particles morphology, radioactivity, and of the behavior in aqueous solutions at different solid/liquid ratios and pH values. Since radioactive isotopes of Sr, Co and Ni are significant components of the liquid radioactive waste, sequestering of their ions from aqueous media was studied in single and multi-component batch sorption systems. The capacity of waste concrete decreased in the order Ni2+ (0.54 mmol/g) > Co2+ (0.32 mmol/g) > Sr2+ (0.25 mmol/g). Concurrent sorption was analyzed using Simplex Centroid Experimental Design and the coefficients that correspond to the linear and interaction terms were obtained using a special cubic model. The presented results demonstrate the potential of waste concrete in the radioactive waste treatment and conditioning, due to its high sorption capacity and compatibility with the solidification matrices.

Component optimization of dairy manure vermicompost, straw, and peat in seedling compressed substrates using simplex-centroid design

ABSTRACTVermicomposting is a promising method to disposal dairy manures, and the dairy manure vermicompost (DMV) to replace expensive peat is of high value in the application of seedling compressed substrates. In this research, three main components: DMV, straw, and peat, are conducted in the compressed substrates, and the effect of individual components and the corresponding optimal ratio for the seedling production are significant. To address these issues, the simplex-centroid experimental mixture design is employed, and the cucumber seedling experiment is conducted to evaluate the compressed substrates. Results demonstrated that the mechanical strength and physicochemical properties of compressed substrates for cucumber seedling can be well satisfied with suitable mixture ratio of the components. Moreover, DMV, straw, and peat) could be determined at 0.5917:0.1608:0.2475 when the weight coefficients of the three parameters (shoot length, root dry weight, and aboveground dry weight) were 1:1:1. For different purpose, the optimum ratio can be little changed on the basis of different weight coefficients.Implications: Compressed substrate is lump and has certain mechanical strength, produced by application of mechanical pressure to the seedling substrates. It will not harm seedlings when bedding out the seedlings, since the compressed substrate and seedling are bedded out together. However, there is no one using the vermicompost and agricultural waste components of compressed substrate for vegetable seedling production before. Thus, it is important to understand the effect of individual components to seedling production, and to determine the optimal ratio of components.

Mixture design of starchy substrates hydrolysis by an immobilized glucoamylase from Aspergillus brasiliensis

Starch has great importance in human diet, since it is a heteropolymer of plants, mainly found in roots, as potato, cassava and arrowroots. This carbohydrate is composed by a highly-branched chain: amylopectin; and a linear chain: amylose. The proportion between the chains varies according to the botanical source. Starch hydrolysis is catalyzed by enzymes of the amilolytic system, named amylases. Among the various enzymes of this system, the glucoamylases (EC 3.2.1.3 glucan 1,4-alpha-glucosidases) are the majority because they hydrolyze the glycosidic linkages at the end of starch chains releasing glucose monomers. In this work, a glucoamylase secreted in the culture medium, by the ascomycete Aspergillus brasiliensis, was immobilized in Dietilaminoetil Sepharose-Polyethylene Glycol (DEAE-PEG), since immobilized biocatalysts are more stable in long periods of hydrolysis, and can be recovered from the final product and reused for several cycles. Glucoamylase immobilization has shown great thermal stability improvement over the soluble enzyme, reaching 66% more activity after 6 h at 60 °C, and 68% of the activity after 10 hydrolysis cycles. A simplex centroid experimental mixture design was applied as a tool to characterize the affinity of the immobilized enzyme for different starchy substrates. In assays containing several proportions of amylose, amylopectin and starch, the glucoamylase from A. brasiliensis mainly hydrolyzed the amylopectin chains, showing to have preference by branched substrates.

Determination of Chlorine in Crude Oil Emulsified via the MgCl Molecule by HR‑CS MAS

A method for chlorine determination in crude oil samples, through the formation of MgCl molecule, by high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS GF MAS) was developed and is described in this paper. The use of this molecule for chlorine determination in crude oil has not been reported up to now. Measures were carried out at the wavelength 377.010 nm and the samples were submitted to a simple treatment as emulsion, whose composition was optimized applying a simplex-centroid experimental design. Magnesium was used as molecule forming agent at the concentration of 10 g L-1, at least 500 times higher than the concentration of chlorine. This excess is required to ensure the molecule formation of all content of Cl present in the sample. Chemical modifier Pd was used and improved greatly the signal intensities. Optimized pyrolysis and vaporization temperatures, applied for determination, were 800 and 2300 °C, respectively. Accuracy was evaluated through analysis of certified reference materials, NIST 1848 and NIST 1634c, and addition and recovery tests with recoveries between 92 and 117%. Limits of detection and quantification were 3.0 and 9.0 µg g-1, respectively. The method was applied to eight crude oil samples.

Optimization of Aspergillus oryzae S2 α-amylase, ascorbic acid, and glucose oxidase combination for improved French and composite Ukrainian wheat dough properties and bread quality using a mixture design approach.

A simplex-centroid experimental design was used for the optimization of both reducing and oxidizing improvers, namely Aspergillus oryzae S2 α-amylase (Amy), ascorbic acid (Asc), and glucose oxidase (GOD). This optimization was performed to enhance the dough and breadmaking qualities of soft French wheat flour and a composite counterpart that contained 30% Ukrainian wheat flour. Statistically significant correlations were calculated between the W index and textural parameters (e.g., dough chewiness and bread cohesiveness). The findings revealed that while the best mixture for French flour comprised 21.8% of Amy, 41.2% of Asc, and 37% of GOD, for the composite counterpart, it comprised 2.3% of Amy, 66% of Asc, and 31.7% of GOD. These optimized mixtures rearranged soft French wheat flour and its composite counterpart to a good quality and an improved flour texture, respectively. Additionally, they increased the loaf specific volumes of the breads made from soft French wheat flour and its counterpart by 25.8 and 45.43%, respectively, significantly decreased the breads' susceptibility to microbial contamination, and reclassified the breads as "good" in terms of sensory attributes.

Effects of encapsulating agents on anthocyanin retention in pomegranate powder obtained by the spray drying process

The present work evaluates the effect of different encapsulating agents (gum Arabic, modified starch Capsul™ and maltodextrin DE 5) on anthocyanin retention in microcapsules produced by spray drying of raw pomegranate juice. A high concentration of anthocyanins is required in order to obtain a product that can be used as a functional ingredient. An accurate quantitative and qualitative analysis of the anthocyanins in the pomegranate juice and in the microcapsules was carried out by High Performance Liquid Chromatography (HPLC). Using the simplex-centroid experimental design employed here, the gum Arabic and Capsul™ (1:1) mixture, obtained a high retention (up to 70%) of total monomeric anthocyanins (delphinidin, cyanidin and pelargonidin 3-O-glucosides and 3,5-O-diglucosides). Pomegranate powder was stored at 25 °C for 3 months in laminated packaging and about 90% of the monomeric anthocyanins were preserved. In order to evaluate this product as a natural colorant for food, the anthocyanins in the microcapsules were also evaluated for color analysis. The results indicated a color hue with a predominance of red.

Oxidative stability of biodiesel from soybean oil: Comparison between synthetic and natural antioxidants

The oxidative stability of soybean oil biodiesel B100 in mixture with natural extracts of rosemary, oregano and basil and the synthetic antioxidant TBHQ, BHA and BHT was evaluated by the Rancimat test at temperatures of 110, 115, 120 and 125°C using the simplex-centroid experimental design. The values found for the induction period for all tests at 110°C were higher than the minimum allowed by Brazilian and European legislation. The joint optimization of predictive equations containing the discrete variable represented by natural and synthetic antioxidants, showed that the best formulation to prevent the oxidative process in biodiesel B100 was that containing 50.00% of rosemary, 12.50% of oregano and 37.50% of basil when using only natural antioxidants and 100% of TBHQ when using synthetic antioxidant.

Optimization of Different Medical and Edible Plant Formulation in Growth-Promoting Effects for <em>L. Bulgaricus</em> using Mixture Design

To improve the activity of probiotics and take advantage of abudant medical and edible plants in China, 18 kinds of medical and edible plants which were chosen to study growth-promoting effects for <em>L. Bulgaricus</em> by single factor, 8 kinds of plants that have significant growth-promoting effect through preliminary screening have obtained. On the basis of this, the different combinations which study growth-promoting effects to <em>L. Bulgaricus</em> using simplex-centroid experimental design and the viable number was chosen as detection index. The result shows that the medical and edible plants of obvious growth-promoting effects are Coix seed, Lotus seeds, Wheat germ, Chinese yam, Pueraria, Lilium, Mulberry, Jujube. The optimal combination according to simplex-centroid experimental design is Coix seed 5.507%, Lotus seeds 30.834%, Wheat germ 20.545%, Chinese yam 20.545%, Pueraria 4.739%, Lilium 15.259%, Mulberry 6.321%, Jujube 6.321%, the viable number is up to 3.89×10⁸ cfu/mL.