Revista Mexicana de Ingeniería Química 2019-08-27T19:58:45+00:00 Francisco J Valdes Parada Open Journal Systems <div class="_4wyf">The Mexican Journal of Chemical Engineering &nbsp;(ISSN 1665-2738) publishes original research papers with the aim of promoting a rapid share of relevant research in various disciplines of Chemical Engineering and its interfaces with other enigineering disciplines. A volume is published each year and it consists of three issues, which are published every four months.&nbsp;</div> COMPARISON OF FERMENTATION AND MEDICAL POTENTIALS OF Saccharomyces WITH Wickerhamomyces GENERA 2019-08-20T17:31:29+00:00 A. Nawaz A. Ashfaq S.M.A.M. Zaidi M. Munir I.U. Haq H. Mukhtar S.F. Tahir <p>Comparative assessment of two different yeast genera i.e. <em>Saccharomyces</em> and <em>Wickerhamomyces</em> is carried out regarding industrial and medical applications with special focus on their role in bioethanol production. Since second generation ethanol production from lignocellulosic material has become a hot topic of research due to its noncompetitive nature with food, economically feasible conversion of lignocellulosic biomass requires an organism capable of metabolizing both the hexoses and pentoses simultaneously. <em>Saccharomyces</em> which is in extensive use currently for bioethanol production can effectively convert hexoses into ethanol but unable to metabolize xylose. However, <em>Wickerhamomyces</em> have the potential to convert both the pentoses as well as the hexoses into bioethanol. Additionally, due to its glycosidase production ability, <em>Wickerhamomyces </em>is tolerant to high levels of glucose and ethanol. Furthermore, the capabilities of the two genera with respect to their role in probiotics, antimicrobial agents, food, beverages, biosorption, whole cell biocatalyst, and pectinolytic enzyme production have also been compared in this review.</p> 2019-06-10T05:59:02+00:00 ##submission.copyrightStatement## ESTABLISHMENT OF A CELL SUSPENSION CULTURE FROM Calophyllum brasiliense AND EVALUATION OF ITS ANTIOXIDANT AND ANTI-INFLAMMATORY ACTIVITY 2019-08-20T17:31:32+00:00 D. Cisneros-Tórres F. Cruz-Sosa M.P. Nicasio-Tórres M. González-Cortazar A. Romero-Estrada A. Bernabé-Antonio <p>In the present work reports the establishment of a cell suspension culture (CSC) from <em>C. brasiliense. </em>In addition, extracts were obtained from the CSC dry biomass and leaves of wild plant using organic solvents for the purpose of determining the total phenolic (FET) and total flavonoid (FLT) content. Furthermore, it was evaluated the antioxidant and anti-inflammatory activity of the obtained extracts. For the above, a CSC was established successfully, producing a maximum of 15.2 g L<sup>-1</sup> of dry biomass at 12 days of culture. The production of FET, FLT and antioxidant activity (DPPH or ABTS) were related with culture growth and its maximum values were produced between 12 and 16 days of culture. The results showed that CSC yielded more FET, FLT and showed higher antioxidative activity than the wild plant. The methanolic and acetone extracts from wild plant showed inhibition of the edema induced by TPA in ear mice at 2 mg/ear, with 44.49 ± 10.75 % and 27.83 ± 9.59 % of inhibition, respectively, while the dichloromethane extract of CSC showed 39.41 ± 7.74 % of inhibition at 2 mg/ear and the positive control (indomethacin) 42.30&nbsp; ± 4.46 % of inhibition at 0.5 mg/ear. It is the first time that a CSC establishment of <em>C. brasiliense</em> has been reported and its antioxidative and anti-inflammatory activity were demonstrated. The CSC reported here can be used as a bioresource to obtain extracts or bioactive compounds.</p> 2019-06-10T21:17:00+00:00 ##submission.copyrightStatement## LEAD REMOVAL FROM AQUEOUS SOLUTION BY SPHERICAL AGGLOMERATION USING AN EXTRACT OF Agave lechuguilla Torr. AS BIOSURFACTANT 2019-08-20T17:31:34+00:00 F.A. Alcázar-Medina C.M. Núñez-Núñez M.D.J. Rodríguez-Rosales S. Valle-Cervantes M.T. Alarcón-Herrera J.B. Proal-Nájera <p>This study focused on determining the optimal conditions for lead removal in aqueous solution models, by the spherical agglomeration technique (SAT), modifying the dose of <em>Agave lechuguilla</em> Torr. (lechuguilla) extract, used as biosurfactant. The SAT operating conditions at room temperature were:&nbsp; Initial pH 9, and constant agitation ω = 600 rpm. Experiments were performed under a 5x3 factorial design with five lechuguilla extract doses (0.3 - 2.0 g extract/g of pollutant), three different lead concentrations (1, 5 and 10 mg/L) and, for the SAT last stage, two different dosage ratio of CaCl<sub>2</sub> (10:1 and 20:1 parts of Ca<sup>2+</sup> by part of pollutant). Residual lead, sodium and calcium were determined by atomic absorption spectroscopy. According to statistical analysis, significant effects were observed for calcium dosages, initial lead concentration, extract dose and their interaction. The lead removal efficiency obtained by SAT reached 99.8%.</p> 2019-06-11T00:29:35+00:00 ##submission.copyrightStatement## A COMPARATIVE STUDY BETWEEN MULTIVARIATE CALIBRATION AND ARTIFICIAL NEURAL NETWORK IN QUANTIFICATION OF SOYBEAN BIODIESEL 2019-08-20T17:31:35+00:00 C.Z. Brusamarello M. Di Domenico C. Da Silva F. de Castilhos <p>Biodiesel is an alternative fuel and can be obtained by the transesterification of vegetable oils. Spectrophotometric methods can be used for the quantification of mixtures, associated with chemometric tools, enabling the analysis of overlapping signals. The aim of this work is to apply the multivariate calibration with PLS (partial least squares) and artificial neural network (ANN), to estimate the concentration of esters in the transesterification of soybean oil using molecular absorption spectrophotometry as analytical technique. Absorbance measurements were performed in a spectrophotometer UV/VIS. Synthetic solutions were prepared with standards of the five major compounds of soybean biodiesel and real samples were obtained by the reaction of transesterification of soybean oil with NaOH and enzymatic method was used Lipozyme® IM (Novozymes), as catalysts. Results shows that all components of this reaction medium absorb in the wavelength range of 190-280 nm. Reactions of basic catalysis reached conversions close to 100%, while enzymatic reactions reached lower conversions. For both methods, calibration and validation groups were composed, respectively, by synthetic and real samples. Results showed that the concentrations of esters estimated by ANN model in the real samples are more accurate (R<sup>2</sup>-0.93), showing the good ability to estimation of ANN.</p> 2019-06-11T15:09:34+00:00 ##submission.copyrightStatement## MODELING OF MICELIAL GROWTH OF PARENTAL, HYBRID AND RECONSTITUTED STRAINS OF Pleurotus AND Lentinula 2019-08-20T17:31:37+00:00 J.D. Valenzuela-Cobos R.O. Rodríguez-Grimón M.L. Jara-Bastidas A. Grijalva-Endara D.C. Zied M.E. Garín-Aguilar G. Valencia del Toro <p>The kinetics of mycelial growth of parental strains, hybrid and reconstituted of<em> Pleurotus</em> and <em>Lentinula </em>was calculated using the mycelial growth diameter for (malt extract agar) MEA and for wheat grain was determinate using the mycelial growth volume, the parameters were adjusted to 3 nonlinear models (Baranyi, Exponential, Logistic) and one Linear Model to determine the specific growth speed (μ<sub>max</sub>) and lag phase time (λ). The hybrid and reconstituted strains of <em>Pleurotus</em> spp. and <em>Lentinula</em> showed similar mycelial morphology with exception of the hybrid PD<sub>4</sub>xLC<sub>3</sub>. The mycelial kinetics of the dikaryotic strains on MEA using 4 mathematical models showed a μ<sub>max </sub>between 6.30 and 23.49 mm day<sup>-1</sup> and the lag phase ranged from 0.22 to 4.47 h; while on wheat grain presented μ<sub>max</sub> since 0.08 to 11.41 cm<sup>3</sup> day<sup>-1</sup> and lag duration between 0.06 and 8.04 h. The hybrid strain PO<sub>5</sub>xLC<sub>2</sub> and the reconstituted strain of <em>Pleurotus djamor</em> PD<sub>1</sub>xPD<sub>4</sub> showed the highest μ<sub>max</sub> and lowest lag phase on MEA and wheat grain respectively in comparison to the other strains include their parental strains. The results evidenced that the use of hybrid and reconstitued strains of <em>Pleurotus</em> and <em>Lentinula</em> improves the production of edible fungi production.</p> 2019-06-12T00:40:52+00:00 ##submission.copyrightStatement## NEW MODEL OF HYDROLYSIS IN THE ANAEROBIC CO-DIGESTION OF BOVINE MANURE WITH VEGETABLE WASTE: MODIFICATION OF ANAEROBIC DIGESTION MODEL No. 1 2019-08-20T17:31:37+00:00 P. Rivas-García J.E. Botello-Álvarez L.R. Miramontes-Martínez J.J. Cano-Gómez R. Rico-Martínez <p>A new model of the stages of disintegration and hydrolysis, and co-digestion process following the classical Anaerobic Digestion Model No.1 (ADM1) structure is proposed. In the new method, substrate-microorganism relationships are represented using the Contois equation rather than the first order models previously used to represent substrates in the degradation process. This model was validated by assessing the biogas production from the co-digestion of vegetable (V) and manure (M) with variations in the V/M ratio in the feed. The highest biogas and yield levels were obtained when the feed ratio was 50/50 V/M. This finding was reproduced by running simulations of the original and modified ADM1. The original ADM1 explains the low digestibility and utilization of manure for biogas production as a consequence of a slow disintegration or hydrolysis stage, which depends exclusively on the disintegration and hydrolysis constants used. The new model offers a more mechanistic explanation; it assumes unfavorable substrate-microorganism relationships, which cause disintegration to become a limiting factor in the process. In addition, biogas production in the new model is primarily associated with carbohydrate degradation, as well as low concentrations and rapid consumption of intermediary metabolites, which do not favor the proliferation of acetanogenic or methanogenic communities.</p> 2019-06-13T01:24:32+00:00 ##submission.copyrightStatement## A BIOTECHNOLOGICAL INSIGHT TO RECYCLE WASTE: ANALYZING THE SPONTANEOUS FERMENTATION OF SHRIMP WASTE TO DESIGN THE HYDROLYSIS PROCESS OF CHITIN INTO N-ACETYLGLUCOSAMINE 2019-08-20T17:31:38+00:00 J.L. Navarrete-Bolaños I. González-Torres V.H. Vargas-Bermúdez H. Jiménez-Islas <p><em>Vibrio alginolyticus</em>, a native microorganism of the shrimp wastes, was selected to synthesize ß-N-acetylglucosaminidase and produce N-acetylglucosamine by chitin hydrolysis. Successful design was achieving when the culture medium ingredients and fermentation parameters were optimized to maximize the active enzyme content in raw extracts. The results showed that a starter inoculum containing 1.0 × 106 cells/mL mixed with a liquid culture medium supplemented with chitin (35.13 g/L), sodium chloride (27.53 g/L), magnesium chloride (42.71 g/L), sodium sulfate (1.71 g/L), calcium chloride (20.84 g/L), and yeast extract (5.1 g/L) in a stirred tank bioreactor under operating conditions held constant at 26.6 °C, 7.3 pH value, 96.8 rpm and 1.6 VVM allows for obtaining an enzyme preparation with an activity of 0.041 U/mL, which compares favorably against the yield achieved using the reference commercial culture medium and represent three-fold more units of enzyme as compared to those obtained at the shake flask level (0.026 U/mL). These results suggest <em>V. alginolyticus</em> is a strong candidate for producing active chitinases and confirm that the microbial ecology studies for specific microorganisms selection and the optimizing of both the culture medium and fermentation parameters (for the selected microorganism) allow evolve efficiently from the spontaneous to directed fermentations.</p> 2019-06-13T19:47:22+00:00 ##submission.copyrightStatement## OPTIMIZATION FOR THE PRODUCTION OF Verrucodesmus verrucosus BIOMASS THROUGH CROPS IN AUTOTROPHIC AND MIXOTROPHIC CONDITIONS WITH POTENTIAL FOR THE PRODUCTION OF BIODIESEL 2019-08-20T17:31:39+00:00 Y. Sánchez-Roque Y. D. C. Pérez Luna J. Moreira Acosta N. Farrera Vázquez J.P. Sebastian R. Berrones Hernández <p>In the present work <em>Verrucodesmus verrucosus</em> was evaluated in mixed and autotrophic growth conditions as a suitable source of oil for biodiesel production, for this purpose three synthetic media were evaluated a lixiviated coming from a biodigester in three concentrations and the mix between synthetic media and the diferent concentrations of the lixiviated from biodigester, the evaluation of the kinetic parameters of growth was carried. So to, the nitrogen-lipid ratio was determined and lipid extraction. Finally, the fatty acid profile of the total pooled lipids was determined out using gas chromatography mass spectroscopy (GC-MS). The results demonstrate that the maximum cell density was reached in the Guillard medium with 6.0 x 10<sup>4</sup> cells / mL. On the other hand, the results in the production of lipids of the microalgal biomass showed that the BG11 medium with a nitrogen concentration of 0.23%, it is the best, since it produces up to 24.3% of lipids, finally, the Fatty acid profile shows that the highest concentrations of fatty acids in <em>V. verrucosus</em> were palmitic, oleic, stearic, palmitoleic and linoleic with a concentration of 34.9, 22.8, 9.3, 7.0 and 6.8% respectively, indicating the suitability of this species for biodiesel production.</p> 2019-06-14T00:42:49+00:00 ##submission.copyrightStatement## DEVELOPMENT OF A SELF-NANOEMULSIFYING DRUG DELIVERY SYSTEM (SNEDDS) FROM AN INSULIN COMPLEX WITH MODIFIED PHOSPHATIDYLCHOLINE AND MUCOADHESIVE POLYSACCHARIDE COATING AS A POTENTIAL NONE-INVASIVE TREATMENT FOR DIABETES. 2019-08-20T17:31:39+00:00 M.O.F. Muñoz-Correa D.A. Bravo-Alfaro H.S. García R. Garcia-Varela <p>The present work depicts the development of a SNEDDS system for the administration of insulin, in which an insulin complex was formed with enzymatically modified soy phosphatidylcholine, by means of the solvent elimination technique. In addition, sodium alginate and guar gum were added to this system to provide mucoadherence capacities and to increase insulin protection against gastric conditions. SNEDDS were developed from mixtures of surfactant, co-surfactant and oil phase: Cremophor EL, Labrafil M1944CS and Lauroglycol FCC, respectively: obtaining particle sizes between 27.36-50.53 nm and monomodal distribution. Mucoadhesives were added by orbital agitation and particle sizes between 53.1-83.2 nm were obtained. Finally, nanoemulsions were submitted to an in vitro gastric simulation system, were insulin bioavailability was increased to 46.3% in systems that included mucoadhesive coating. These results show that the developed systems can possibly be used for the administration of insulin by oral route as a potential non-invasive treatment for diabetes.</p> 2019-06-20T03:38:09+00:00 ##submission.copyrightStatement## EFFECTS OF CHITOSAN IN THE CONTROL OF POSTHARVEST ANTHRACNOSE OF SOURSOP (Annona muricata) FRUIT 2019-08-20T17:31:39+00:00 A. Ramos-Guerrero R.R. González-Estrada G. Romanazzi L. Landi P. Gutiérrez-Martínez <p>The disease reducing activity of eco-friendly chitosan compound against postharvest anthracnose caused by <em>Colletotrichum gloeosporioides</em>was investigated by tests performed in <em>in vitro</em>and <em>in vivo</em>conditions. In this study, <em>C. gloeosporioides</em>was isolated in pure culture from soursop (<em>Annona muricata</em>) tropical fruit, identified by morphological and molecular methods and then used in experimental tools. The inhibition of <em>C. gloeosporioides</em>mycelial growth, sporulation and conidial germination by chitosan at different concentrations, 0, 0.1, 0.5, 1.0 and 1.5% was evaluated on potato dextrose agar. The application of 1.0 and 1.5% chitosan decreased mycelial growth and sporulation by 90%, and completely inhibited spore germination. The 1.0% of chitosan solutionshown the best performance on <em>in vitro</em>test was monitored for 9 days <em>in vivo</em>on artificially inoculated soursop. Chitosan completely inhibited anthracnose and reduced weight loss of fruit. Quality parameters of fruit (pH, total soluble solids, firmness and titratable acidity) were not affected by chitosan application. Therefore, coatings with 1.0% chitosan could be recommended as on alternative treatment to the application of synthetic fungicides for keeping quality and controlling anthracnose of soursop during storage and shelf life.</p> 2019-06-20T03:43:46+00:00 ##submission.copyrightStatement## PHYTOCHEMICAL PROFILE OF Coryphantha macromeris (Engelm.) Britton & Rose CACTACEAE OBTAINED FROM in vitro CULTURE 2019-08-20T17:31:39+00:00 E. Cabañas-García C. Areche Y.A. Gómez-Aguirre J. Jáuregui-Rincón F. Cruz-Sosa E. Pérez-Molphe-Balch <p>In the last years, the demand for natural products has increased. Different cacti species has demonstrated to be a source for the biosynthesis of functional compounds, as is the case of <em>Coryphantha macromeris</em> (Engelm.) Britton &amp; Rose. The aim of this work was to evaluate the capacity of<em> C. macromeris </em>growing under controlled <em>in vitro</em> conditions for the obtention of secondary metabolites. <em>In vitro</em> cultures of <em>C. macromeris</em> were established and then the phytochemical profile of aerial and root sections was analyzed by means of ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-PDA-HESI-Orbitrap-MS/MS). Under the proposed conditions, 44 metabolites were detected and 43 of them were identified; seven compounds are reported here for the first time for this cacti species. Organic acids (citric, gluconic and tianshic acids), and phenolic acids such as piscidic, ferulic and syringic acid and/or their derivatives were found as the metabolites with the highest relative abundance. Our results suggest that the <em>in vitro </em>culture of <em>C. macromeris</em> represents a potential source for the obtention of selected compounds, as well a useful system for future investigations related with the generation of root, callus and cell suspension cultures for the elicitation and study of high valuable metabolites.</p> 2019-06-20T04:00:02+00:00 ##submission.copyrightStatement## STUDY ABOUT THE USE OF AQUACULTURE BINDER WITH TUNA ATTRACTANT IN THE FEEDING OF WHITE SHRIMP (Litopenaeus vannamei) 2019-08-20T17:31:39+00:00 J. D. Valenzuela Cobos C. J. Vargas Farías <p>The consumption of feed aquaculture (pellets) in juvenile shrimp (<em>Litopenaeus Vannamei</em>) was determined, 3 formulations were used: aquaculture binder with tuna attractant with pellets (M1), commercial binder with pellets (M2), and only pellets (M3). In the study was put 200 g of pellets mixed with the 2 types of aquaculture binders and only pellets, and were put in alternating feeders during the experimentation. Using the mixture 1 (M1) was obtained a consume of 83% of pellets in the feeders of the aquaculture pool, using the mixture 2 (M2) was obtained a consume of 62% of shrimp foods in the feeders, while only using pellets (M3) a consume of 79% was obtained. Differences were found between the results of the 3 mixtures tested for <em>Litopenaeus Vannamei</em>, being the mixture 1 (M1) that presented the greatest consume of pellets in the aquaculture shrimp. The aquaculture binder with tuna attractant (LA) presented the highest content of protein (1.90) and lysine content of 0.37%. The results showed that the aquaculture binder with tuna attraction presented superior organoleptic and nutritional characteristics that are directly related with the feeding of juvenile shrimp (<em>Litopenaeus Vannamei</em>).</p> 2019-07-02T00:28:28+00:00 ##submission.copyrightStatement## ISOENZYMES AND ACTIVITY OF LACCASES PRODUCED BY Pleurotus ostreatus GROWN AT DIFFERENT TEMPERATURES 2019-08-20T17:31:40+00:00 G. Montalvo M. Téllez-Téllez R. Díaz C. Sánchez G. Díaz-Godínez <p><em>Pleurotus ostreatus </em>produces laccase isoforms depending on the conditions in which it grows, it has been suggested that the presence of inducers, the pH of the culture medium as well as the type and concentration of carbon and nitrogen sources promote the production of these isoforms, however, the effect of temperature of <em>Pleurotus ostreatus</em> growth on its production of laccase isoforms has not been evaluated. In this study, <em>Pleurotus ostreatus</em> was grown in solid-state fermentation at different temperatures (10, 15, 20, 25, 30 and 35 °C) and the activity and isoforms number of laccases produced in each bioprocess was determined. At 10 and 35 °C there was no growth of the fungus. The activity of laccases was different in each fermentation, being at 25 ºC where the highest value was observed (20000 U L<sup>-1</sup>). The laccase isoenzymes pattern was also different depending on the incubation temperature of the fungus, it was observed in some times of the culture, 4 isoforms in the fermentations incubated at 15 and 20 ºC, 3 isoforms at 25 ºC and 2 isoforms at 30 ºC. These results show that the growth temperature of <em>Pleurotus ostreatus</em> modifies its patterns of activity and of isoforms of laccases.</p> 2019-07-03T04:02:00+00:00 ##submission.copyrightStatement## STUDY OF AGITATION, COLOR AND STRESS LIGHT VARIABLES ON SPIRULINA PLATENSIS CULTURE IN A VERTICAL STIRRED REACTOR IN STANDARD MEDIUM 2019-08-20T17:31:40+00:00 A. Solis Méndez M. Molina Quintero E. Oropeza de la Rosa D. Cantú Lozano V. L. Del Bianchi <p><em>Spirulina platensis</em>is a helical-shaped photosynthetic cyanobacterium. For its cultivation, it depends on light intensity, nutrients, pH, cell density, temperature, among others. Microalgae are capable of growing in open and closed reactors. In the present work, it was studied microalgae<em>Spirulina platensis</em>growth in a stirred tank reactor (STR), evaluating stirring rate, color and light stress. <em>Spirulina</em><em>platensis</em>was kept in flasks with Schlösser solution at room temperature, orbital shaker and fluorescent lamps. The operating conditions of stirred vertical reactors (vertical axis) were: LED light externally adhered to the reactor walls, 2.5 L of Schlösser solution inoculated with <em>Spirulina platensis</em>resulting in an initial concentration of 0.15 OD and four Rushton agitators. Within the study of rate variable, the highest rate of 114 rpm, showed a productivity (P) of 2.08 mgL<sup>-1</sup>h<sup>-1</sup>, concerning light color variable a high growth was observed in white light with a productivity of 2.85 mgL<sup>-1</sup>h<sup>-1</sup>and regarding stress variable, Flash function showed a productivity 41% lower than standard (white light). It was shown that stirring rate has a positive influence and light stress affects negatively the microalgae growth.</p> 2019-08-18T02:38:15+00:00 ##submission.copyrightStatement## RHEOLOGICAL CHARACTERIZATION OF GUMS-GEL OBTAINED FROM THE PROTEIC ISOLATION OF SESAME (Sesamum indicum) 2019-08-20T17:31:30+00:00 C. Moreno-Santander L.A. García-Zapateiro R. Ortega-Toro <p><em>Sesame is produced in large quantities, being rich in protein so it could offer multiple alternatives for use in industry. Therefore, in this work were studied the obtaining and characterisation of protein isolation of sesame (Sesamum indicum) for the rheological standardisation of a mixed product of protein/polysaccharide gel type with the incorporation of food hydrocolloids. Sesame seeds were ground to obtain oil and flour rich in proteins; the last one was subjected to a solubilization process, separating the flour paste by centrifugation, to determine through a bromatological analysis its chemical composition. Later, the concentration by isoelectric precipitation was made adjusting the pH (4-5), using a factorial design of 23 and three control samples for the elaboration of gums-gel, with xanthan gum and carrageenan. It was found an isolated protein with a concentration of 80.27% of proteins. Regarding formulations that had higher viscosity values were those that contained lower protein content and higher content of gums. As far as dynamic viscoelastic tests are concerned, the different formulations of the product have an elastic rather than viscous behaviour and thus behaves like a gel-like product.</em></p> 2019-06-11T03:19:38+00:00 ##submission.copyrightStatement## SPECTROSCOPIC METHOD (FTIR-ATR) AND CHEMOMETRIC TOOLS TO DETECT COW'S MILK ADDITION TO BUFFALO'S MILK 2019-08-20T17:31:32+00:00 L.K.R. Silva B.R.F. Gonçalves F.F. da Hora L.S. Santos S.P.B. Ferrão <p>The aim of this work was to use different chemometrics methods to detect cow's milk addition in the buffalo’s milk, through the spectroscopic technique Fourier's Transform Infrared associated with Attenuated Total Reflectance (FTIR-ATR). Preparations were made with increasing levels of cow's milk added to the buffalo's milk, ranging from 0%-100%, totalizing 495 samples. 15 peaks were obtained in the spectral region between 4000 cm<sup>-1</sup>-600 cm<sup>-1</sup> through the FTIR, which were submitted to Principal Component Analysis (PCA) and Artificial Neural Network (ANN). The ANN showed up to be more efficient, displaying classification rates of 100% for the reference samples and for most of the groups with the mixture of cow's and buffalo's milk, total classification rate of 95.5% and good prediction with satisfactory correlation and error. The results displayed the potential of the spectroscopic method FTIR-ATR associated with the chemometrics analysis for the detection of the authenticity of buffalo's milk.</p> 2019-06-11T21:43:42+00:00 ##submission.copyrightStatement## RECOVERY OF ANTIOXIDANTS FROM PAPAYA (Carica papaya L.) PEEL AND PULP BY MICROWAVE-ASSISTED EXTRACTION 2019-08-20T17:31:35+00:00 V. Vallejo-Castillo J. Muñoz-Mera M. F. Pérez-Bustos A. Rodriguez-Stouvenel <p>Papaya (<em>Carica papaya</em> L.) has a diversity of bioactive compounds with recognized antioxidant effects. However, obtaining these compounds presents challenges related to extraction, which must be economical, fast and with high efficiency. In the present study, the performance of microwave irradiation was evaluated to recover extracts with a high content of polyphenols, flavonoids, and an effective antioxidant activity from a mixture of papaya peel and pulp. The factors solid:solvent ratio, microwave power, and ethanol-water mixture were evaluated. The results showed that the maximum content of bioactive compounds was reached after 3 minutes of extraction with the optimum conditions of 340W for power, 23.34% for mixture ethanol:water and 80.60 for solid:solvent ratio. The optimal extract presented a concentration of 1186.39 ± 44.49 mg GAE/100gFW for polyphenols and 43.88 ± 6.94 mg CE/100gFW for flavonoids and antioxidant activity of 3920.48 ± 31.97 <sub><img src="/ojs311/public/site/images/vlackened/miu2.png" width="9" height="12"></sub>mol TE/100gFW, values higher than those reported by other authors. It is confirmed that the application of microwaves in the process of extraction of bioactive compounds reduces time, costs and is efficient to obtain extracts of papaya with an effective antioxidant activity.</p> 2019-06-13T01:34:03+00:00 ##submission.copyrightStatement## PRODUCTION OF BIOACTIVE PEPTIDES FROM BOVINE COLOSTRUM WHEY USING ENZYMATIC HYDROLYSIS 2019-08-20T17:31:36+00:00 F.S. Fajardo-Espinoza A. Romero-Rojas H. Hernández-Sánchez <p>Bovine colostrum is an important source of nutritional and immunological factors that are vital for the early development and protection of the newborn. The aim of this study was to evaluate the antioxidant, mineral-binding (iron and calcium), and angiotensin-converting enzyme (ACE) inhibitory properties of the peptides generated through the enzymatic hydrolysis of bovine colostrum whey proteins. The whey proteins were hydrolyzed with pepsin at two pH values (1.3 and 2), and in a sequential hydrolysis system with pepsin and pancreatin. The hydrolysates were separated by ultrafiltration in three fractions with molecular weights of less than 10, from 10 to 30, and more than 30 kDa. The antioxidant and calcium binding activities increased with the hydrolysis and the highest values were obtained in the case of the fractions with less than 10 kDa. The fractions with molecular weights higher than 30 kDa had the best iron binding capacity. A high positive correlation (R=0.9669) was obtained between the degree of hydrolysis and the ACE inhibitory activity.</p> 2019-06-20T03:28:16+00:00 ##submission.copyrightStatement## KINETICS OF LACTIC ACID FERMENTATION FROM SUGARCANE BAGASSE BY Lactobacillus pentosus 2019-08-20T17:31:37+00:00 A. González-Leos M. G. Bustos G. C. Rodríguez-Castillejos L. V. Rodríguez Durán J. A. Del Ángel Del Ángel <p>Sugarcane bagasse is a residue of the sugar industry that presents a high content of hemicelluloses being one of the most abundant and available agricultural residues in Mexico with great potential to be used in fermentations. The bagasse was characterized and chemically treated to obtain samples of hydrolysates which were supplemented with nutrients and fermented with <em>Lactobacillus pentosus</em> to obtain lactic acid. The hydrolysates were vacuum evaporated to increase the initial concentration of sugars until obtain 7.77 gL<sup>-1</sup> of glucose, 64.25 gL<sup>-1</sup> of xylose and 3.67 gL<sup>-1</sup> of arabinose. Under these conditions, lactic acid values were reached 55.437 gL<sup>-1 </sup>(Q<sub>P</sub>= 0.430 gL<sup>-1</sup>h<sup>-1</sup>, Y<sub>P/S</sub>= 0.724 gg<sup>-1</sup>; Y<sub>P/S</sub> theoretical=81.43%) observing a clear inhibition of the product after 120 hours. The aim of this work was the development of fermentation kinetics for the biotechnological obtaining of lactic acid from sugarcane bagasse hydrolysates concentrated and not concentrated with <em>L. pentosus</em>.</p> 2019-07-09T00:44:19+00:00 ##submission.copyrightStatement## REFRIGERATED STORAGE OF HIGH HYDROSTATIC PRESSURE TREATED PITAYA (Stenocereus pruinosus) JUICE 2019-08-20T17:31:38+00:00 B. Quiroz-González M. C. Ybarra-Moncada V. S. Rodriguez-Martinez J. S. Welti-Chanes M. R. García-Mateos J. Corrales-García M. C. Ybarra-Moncada G. Leyva-Ruelas J. A. Torres <p>This work focuses on HHP and storage effects on pectin methylesterase (PME) activity, native microflora, and the physicochemical, nutraceutical, and sensory properties of non-acidified pitaya juice. After 550 and 600 MPa treatments for 16 and 12 min, respectively, pitaya juice was stored 60&nbsp;d at 4±1°C. No aerobic mesophiles were found immediately after HHP treatments, and during storage, counts remained below 2 Log<sub>10</sub> CFU mL<sup>‑1</sup>. In HHP‑treated juice, yeast and molds were undetectable and remained so during storage. After HHP treatments and during storage, no changes were observed in total soluble solids (9.8‑10.0 °Bx), luminosity (4.3‑4.4&nbsp;%), and chroma (18.9-20.7). Depending on treatment condition, HHP lowered PME activity by 59-63&nbsp;%. A further reduction reaching 25&nbsp;% was observed after storage. Acidity, phenolic compounds, betalains concentrations, and antioxidant activity were not affected by HHP but a 43, 10, 14, and 5 % decrease, respectively, was observed after 60 d of storage. Finally, sensorial acceptability of juices was not affected by HHP but increased during storage reflecting an increased sweetness perception associated with lower acidity values. HHP is thus a viable alternative to produce non-acidified pitaya juice with a 60‑d refrigerated distribution shelf life.</p> 2019-07-20T00:38:10+00:00 ##submission.copyrightStatement## EVALUATION OF THE MECHANISM OF OIL UPTAKE AND WATER LOSS DURING DEEP-FAT FRYING OF TORTILLA CHIPS 2019-08-20T17:31:38+00:00 A. Topete -Betancourt J. D. Figueroa E. Morales Sanchez G. Arámbula-Villa J. F. Pérez-Robles <p>Simple equation M<sub>t</sub>/M<sub>∞ </sub>= Kt<em><sup>n</sup></em> is evaluated to describe the Fickian mechanism of oil absorption and water release during the frying of tortilla chips in nixtamalized samples with lime and without lime where M<sub>t</sub>/M<sub>∞</sub> is the fractional solute absorption or release, and n is the diffusional exponent characteristic of the Fickian mechanism that changes with food physical and chemical properties. For the Fickian mechanism, the exponent (<em>n</em>) is ≤0.50, and non-Fickian is 0.5&lt;n&lt;1 for slabs. Moisture releases showed a Fickian mechanism form tortilla chips with lime (<em>n </em>= 0.5) due to water interaction with matrix components and non-Fickian for tortilla chips without lime (<em>n </em>= 0.6). Oil absorption showed a Fickian mechanism for nixtamalization with lime <em>n </em>= 0.4 and for nixtamalization without lime, one of <em>n </em>= 0.3. The larger water diffusion coefficient in the tortilla chip compared to that of oil diffusion indicates that water release and oil absorption during frying is not a simultaneous event. The behavior of the water and oil diffusion is an interesting topic that, in this study, was investigated using a practical equation with potential application in food processing.</p> 2019-07-24T05:16:08+00:00 ##submission.copyrightStatement## IRON REMOVAL FOR KINETIC STUDIES ON FENTON TREATMENTS: A NEW APPROACH BASED ON FERROCYANIDE 2019-08-20T17:31:31+00:00 E. Laverde-Cerda A. Altamirano-Briones P. Zárate-Pozo C. Sandoval-Pauker L. Ramos-Guerrero F. Muñoz-Bisesti P. Vargas-Jentzsch <p>A new approach based on ferrocyanide for iron removal in kinetic studies on Fenton treatments was developed and proposed. The influence of iron precipitation using the ferrocyanide treatment on the measured concentration of two model molecules (phthalic acid and meropenem) was studied. For this purpose, different solutions of phthalic acid and meropenem were prepared. Ferrous sulfate was added to the solutions after the adjustment of the pH value. Then, iron was removed by alkalization (traditional) and ferrocyanide treatments, this for phthalic acid. In the case of meropenem, the removal of iron was performed using only the ferrocyanide treatment due to a chemical modification of the molecule at (highly) alkaline conditions. According to the results, the application of ferrocyanide treatment did not affect the measurement of the concentration of phthalic acid and meropenem after the removal of iron. Moreover, some considerations are provided to apply this method to other molecules.</p> 2019-06-14T00:28:30+00:00 ##submission.copyrightStatement## EXPLORING THE REGENERATION OF MORDENITE CATALYST IN DIMETHYL ETHER CARBONYLATION REACTION 2019-08-20T17:31:33+00:00 M.A. Vázquez-Domínguez P. García-Haro F. Vidal-Barrero P. Ollero de Castro <p><em>Dimethyl ether carbonylation (DME) to produce methyl acetate (MA) over mordenite catalysts is attracting much attention because of its high selectivity. However, acidic mordenite suffers from a fast deactivation (coking) that has not been properly studied. In the present work, we study the regeneration of the catalyst in several cycles aiming to help the future industrial application of mordenite catalysts in MA production. Both diluted and pure air have been successfully tested for the regeneration of the catalyst. The results show that 1) there is no negative effect after several regeneration cycles and 2) there is a slight improvement of catalyst productivity after the first regeneration cycle. A possible explanation to these results, which is highlighted in this work, is that the catalyst structure is not affected during regeneration while there is an initial migration of Al from the mordenite structure to extra-framework positions.</em></p> 2019-06-20T03:49:31+00:00 ##submission.copyrightStatement## ON THE EXPLICIT EXPRESSIONS FOR THE DETERMINATION OF THE FRICTION FACTOR IN TURBULENT REGIME 2019-08-20T17:31:31+00:00 J.R. Pérez-Pupo M.N. Navarro-Ojeda J.N. Pérez-Guerrero M.A. Batista-Zaldívar <p><span lang="EN-US" style="margin: 0px; line-height: 115%; font-family: 'Times New Roman',serif; font-size: 12pt;">Pressure drop in pipelines is commonly calculated by the Darcy-Weisbach formula. To use this formula, the Darcy´s hydraulic friction factor must be known. The best approximation for the Darcy´s friction coefficient in turbulent flow regime, is expressed by the Colebrook-White equation. This equation can only be solved by numerical methods, because it is implicit for the friction coefficient. There are other approximate explicit models for the calculation with different relative errors in comparison to the Colebrook-White equation. In this work, a review of the friction factor explicit correlations is made including, for the first time in an article of this type, 48 equations, 10 of them that had not been reported previously and other explicit equations whose precision does not agree with previous reports or had not been included in review articles on this topic. The precision of these equations was determined by means of the maximum relative error for Reynold´s numbers and relative roughness, considered as the equation´s application range. </span></p> 2019-06-15T05:31:22+00:00 ##submission.copyrightStatement## ENRICHMENT OF LACTOFERRIN BY A SIMPLE PROCESS BASED ON SOLID PHASE EXTRACTION 2019-08-20T17:31:30+00:00 J.L. Sebastián-Nicolás A.E. Cruz-Guerrero A. Castañeda-Ovando G.A. Vázquez-Rodríguez H.M. Hernández-Hernández C.A. Lucho-Constantino L.G. González-Olivares <p>Bovine whey is a promising by-product of cheese-making processes, which one can be extracted high-value compounds, like lactoferrin (Lf). This protein has biological activity, such as antimicrobial, anti-inflammatory and anti-cancer effects. Several methods have been proposed to separate Lf from whey, including ultrafiltration or chromatography affinity. In this work, extraction of Lf was proposed, which was carried out using a matrix of polyacrylamide (PAM) activated with Cu (II) to improve its affinity to lactoferrin. Matrices were prepared with two different %T concentrations (6 and 10); these were characterized, and PAM 10%T showed higher entropy values (higher homogeneity), therefore, it was modified with cupric ion and used in the subsequent extraction stages. FT-IR and SEM analysis supported the functionalization of matrix PAM 10%T; likewise, the role of the copper ion in the extraction procedure. According to SDS-PAGE results, PAM (10%T)-IDA-Cu<sup>2+</sup>-imidazole enabled to reach a lactoferrin recovery around 82.5%; besides, a Lf-enriched fraction (150 µg per gram of powder) was obtained. The method proposed represents an adequate alternative for the recovery of lactoferrin from bovine whey, which is considered a problematic waste.</p> 2019-06-13T20:11:26+00:00 ##submission.copyrightStatement## DETERMINATION OF BIOSORPTION MECHANISM IN BIOMASS OF AGAVE, USING SPECTROSCOPIC AND MICROSCOPIC TECHNIQUES FOR THE PURIFICATION OF CONTAMINATED WATER 2019-08-20T17:31:33+00:00 M.T. Hernandez-Botello J.L. Barriada-Pereira M.E. Sastre de Vicente J.A. Mendoza-Pérez J.J. Chanona-Pérez M.S. López-Cortez D.I. Téllez-Medina <p>Lead (Pb<sup>2+</sup>) and copper (Cu<sup>2+</sup>) are polluting metals due to their toxicity; however, the extraction of these metals is essential for economic development, so it is important to look for efficient and low-cost alternatives that can remove heavy metals from the various bodies of water. One of the alternatives used in this work is biosorption, for which an agroindustrial waste (epidermis from <em>Agave atrovirens</em>) was used to evaluate the affinity of removal of lead and copper in aqueous solutions; in addition, spectroscopy and microscopy techniques were used to elucidate and corroborate the removal and affinity capacity of the agave epidermis for both metals studied. The optimal pH value for the removal of both metals was 3. The adsorption isotherms yielded a q<sub>max</sub> of 25.7 and 8.6 mg/g for lead and copper, respectively. Adjusting to the Langmuir-Freundlich model, the adsorption kinetics were pseudo-second order, and it was found that the equilibrium time was at 140 min. The spectroscopy and microscopy analyses corroborated the affinity between metals and functional groups of the agave, as well as with the elemental analysis, which reported 17.38% of lead and 4.25% of copper.</p> 2019-06-14T14:01:59+00:00 ##submission.copyrightStatement## THIOUREA DETERMINATION FOR THE PRECIOUS METALS LEACHING PROCESS BY IODATE TITRATION 2019-08-20T17:31:35+00:00 D. Calla-Choque F. Nava-Alonso <p>The thiourea leaching process for precious metals recovery has been studied as an alternative process to cyanidation. The accurate and simple determination of thiourea is important to guarantee the efficiency of the process and to evaluate the thiourea consumption during the gold and silver leaching from minerals; however, there is not, until now, any trustable method to determine the thiourea concentration for the high levels used in the extractive metallurgy industry. The present work, performed at CINVESTAV Saltillo, studies thermodynamically and experimentally the thiourea determination by iodate titration in the search of a precise technique appropriate for the high thiourea concentrations used in the leaching of precious metals.</p> <p>The thiourea titration by iodate in acid media permits the precise determination of high thiourea concentrations (up to 10,000 ppm). The acidification of thiourea (CS(NH<sub>2</sub>)<sub>2</sub>) produces protonated thiourea (HCS(NH<sub>2</sub>)<sub>2</sub><sup>+</sup>) which reacts with iodate to form the protonated formamidine disulfide ([CS(NH<sub>2</sub>)<sub>2</sub>]<sub>2</sub><sup>2+</sup>).&nbsp; The presence of oxidant ions like cupric or ferric ions can oxidize the thiourea into formamidine disulfide (FDS<sup>2+</sup>), decreasing the leaching strength of the solution. When zinc dust is added to the solution before the titration, it reduces FDS<sup>2+</sup> by regenerating the thiourea.</p> 2019-06-15T02:44:52+00:00 ##submission.copyrightStatement## VOLTAGE PRODUCTION IN A PLANT MICROBIAL FUEL CELL USING AGAPANTHUS AFRICANUS 2019-08-20T17:31:36+00:00 J.C. Gómora-Hernández J.H. Serment-Guerrero M.C. Carreño-de-León N. Flores-Alamo <p>Due to the existing energetic demand worldwide the search for alternative energy sources is necessary. Bioenergy has been studied in the last decades as a promising energy source and the use of bioelectrochemical devices has become important. In this paper the plant <em>Agapanthus africanus L. Hoffman’s</em> was used to evaluate both growing and voltage generation in an electrochemical device adapted at the root system of the plant. For this, <em>Agapanthus</em> was planted either with or without compost and varying the position of the anode. Growth and voltage generation was monitored throughout all the experiments. All plants showed a satisfactory growth, and the carbon fiber anode position affect neither the vitality of the plant nor the system performance, moreover, the addition of compost (33%v) increased the generated voltage reaching a maximum value of 690 mV. Experimental data indicate a great potential of <em>Agapanthus africanus </em>to generate voltage in a green and sustainable way. Energy obtained from plant-microbial fuel cell can be used to power on low consumption electronics using an electronic device composed by 1.2 V batteries.</p> 2019-06-15T03:07:47+00:00 ##submission.copyrightStatement## EFFECT OF THE WATER TYPE, THE INOCULUM AND THE CONCENTRATION ON THE PHENANTHRENE DEGRADATION IN A FLUIDIZED BED REACTOR USING ACTIVATED CHARCOAL AS A BACTERIAL SUPPORT 2019-08-20T17:31:37+00:00 C. Quintal Franco O. Poot-Cobá A. López-Padilla C. Ponce-Caballero G. Giácoman-Vallejos I. Moreno-Andrade V. R. Góngora-Echeverría <p>The phenanthrene degradation and microbial growth at short times (t ≤ 16 days) using a fluidized bed reactor (FBR) with activated charcoal (AC) as support for the bacterial consortium in different seawater types (sterile and non-sterile) and inoculum additions were studied. The effect of the reactor operating conditions (water type, addition of inoculum, phenanthrene concentration of 112 mg L<sup>-</sup>1, and air flow of 1.5 L min<sup>-1</sup>) and variations in phenanthrene concentration (60, 200, and 600 mg L<sup>-1</sup> at an air flow of 2 L min<sup>-1</sup>) were evaluated. Phenanthrene degradation was improved when an inoculum was added to the seawater (62.5%–69.5% of the initial concentration was degraded); the best microbial growth was observed when an inoculum was added to sterile seawater (constant concentration) and when phenanthrene concentration was 200 mg L<sup>-1</sup>; however, the highest degradation rate values (mg CFU<sup>-1</sup>) were obtained for a phenanthrene concentration of 600 mg L<sup>-1</sup>. Operating conditions and phenanthrene concentration had significant impacts on phenanthrene degradation and microbial growth (P &lt; 0.05). The findings show that the FBR efficiency in phenanthrene degradation responds to a multi factorial operating conditions; however, high efficiencies can be reached if the operating conditions, including inoculum addition, are carefully controlled.</p> 2019-06-16T19:13:23+00:00 ##submission.copyrightStatement## APPLICATION OF PERCOLATION THEORY AND FRACTAL GEOMETRY TO LANDFILL METHANE PRODUCTION 2019-08-20T17:31:38+00:00 C. Aranda-de la Teja A. Domínguez-Ortiz A. Domínguez-Ortiz <p>The estimation of methane generation in landfill is based mainly on first-order chemical kinetics, which is a good theory for gaseous media or in solution, <em>i.e.</em> a homogeneous media; however in landfill, conversions lower than expected yields are observed. In this paper we propose the consideration of the sanitary landfill heterogeneity, through the classic percolation theory, and introducing a&nbsp; &nbsp;factor in first order models to reduce the error of the methane estimations in the landfill. This percolation factor () only considers the degradation of organic matter in methanogenic zones, which we propose immersed in the percolation clusters (including the infinite cluster), so&nbsp; ={1/4,2/3}. When including &nbsp;in the Hoeks model (Hoeks, 1983), and fractal-like Hoeks model (Meraz et al, 2004), conversions of 22-59% and 12-33% are reached at 30 years of closed site, respectively. These ranges are within what was estimated by Bogner and Spokas (1993), 25-40% conversion for the same time period.</p> 2019-06-20T03:57:18+00:00 ##submission.copyrightStatement## MODELLING OF THE ADSORPTION KINETICS OF CHROMIUM (VI) USING WASTE BIOMATERIALS 2019-08-27T19:58:45+00:00 A. Villabona-Ortíz C. N. Tejada-Tovar R. Ortega-Toro <p>The presence of heavy metals in bodies of water is an environmental problem, due to its toxicity and bioaccumulation in ecosystems. The adsorption kinetics of Cr (VI) was studied in a batch system using plantain peels and oil palm bagasse, evaluating the effect of temperature and amount of adsorbent on the process. The bioadsorbents were placed in contact with the solution of Cr (VI) at pH 2 and 100 ppm, taking samples at different times until equilibrium. The kinetics were adjusted to the pseudo-first order, pseudo-second order and Elovich models. It was established that: the increase in temperature favours the process for the plantain peel and decreases the capacity of adsorption for oil palm bagasse; and that a decrease in the amount of adsorbent favours the kinetics for both biomasses studied. The Elovich model describes the behaviour for the plantain peel, while the pseudo-first and pseudo-second-order models do it for the oil palm bagasse when the temperature varies. The Elovich model better approximates the kinetic data by varying the adsorbent dose of both biomasses, suggesting that the process of adsorption of Cr (VI) was controlled by chemisorption.</p> 2019-07-24T05:06:34+00:00 ##submission.copyrightStatement## MICROBIAL AND PHYSICOCHEMICAL PROPERTIES OF UV-C PROCESSED Aloe vera GEL BLENDS AT DIFFERENT pHs USING A CONTINUOUS FLOW UV SYSTEM 2019-08-20T17:31:32+00:00 M.Z. Rodríguez-Rodríguez A. Quintero-Ramos C.O. Meléndez-Pizarro J.A. Meza-Velázquez J.A. Jiménez-Castro M.A. Sánchez-Madrigal M.G. Ruiz-Gutiérrez J.C. Espinoza-Hicks <p>UV-C irradiation doses (12.8, 24.2, 35.8, and 54.6 mJ×cm<sup>-2</sup>) on the physicochemical and microbiological properties of 10% <em>Aloe vera</em> gel at different pHs (3.5, 4.5, and 5.5) were evaluated. An unprocessed treatment (UP) and a short (45 s) thermal treatment (TT) at 90 °C were used as controls. The irradiation doses and pH levels affected (<em>p </em>&lt; 0.05) the elimination of coliforms and aerobic mesophilic microorganisms with the same efficiency as TT. Molds and yeasts were successfully eliminated at doses ≥24.2 mJ×cm<sup>-2 </sup>regardless of pH. Reducing sugars, total polyphenols, and aloin A content decreased as pH increased (<em>p</em> &lt; 0.05). Although, the antioxidant activity was significantly reduced at doses ≥35.8 mJ×cm<sup>-2</sup>. TT and UV-C treatments affected the <em>a*</em> color parameter (<em>p</em> &lt; 0.05), resulting the UV-C with the highest values. In both treatments, a reddish color was present at pH ≥ 4.5. The UV-C treatment resulted in minimal changes in most physicochemical properties, compared to UP treatment. However, TT significantly affected most physicochemical properties of <em>A. vera</em> gel blends. These results suggest that dose of 24.2 mJ×cm<sup>-2</sup> in a continuous flow UV system is a non-thermal alternative for the stabilization of 10% <em>A. vera</em> gel blends at pH of 3.5.</p> 2019-06-20T03:54:20+00:00 ##submission.copyrightStatement## OBTAINING A LACTOSE HYDROLYZED FROM NANOFILTRATION OF SWEET WHEY: CHARACTERIZATION AND PROCESS OPTIMIZATION 2019-08-20T17:31:34+00:00 L.V. Pérez-Escobar A.J. Mosquera-Martínez H.J. Ciro-Velásquez J.U. Sepúlveda-Valencia S.L. Vargas-Díaz <p>La lactosa ha sido un azúcar de limitada aplicabilidad en la industria de alimentos debido a su bajo nivel de dulzura, baja solubilidad y deficiente digestión en la mayoría de la población global. Sin embargo, un alto volumen de producción de este disacárido podría obtenerse de la producción mundial de lactosuero y ser hidrolizado enzimáticamente para generar azúcares más dulces, muy solubles en agua y fácilmente digeribles como la glucosa y galactosa. Este estudio se propuso optimizar el proceso de hidrólisis de una enzima comercial (β-galactosidasa de <em>Kluyveromyces lactis</em>) en un concentrado de lactosa (207 g L<sup>-1</sup>), obtenido por nanofiltración de lactosuero dulce. Un diseño de superficie de respuesta Box-Behnken permitió evaluar la influencia de diferentes factores sobre el porcentaje de hidrólisis, indicando que es posible obtener hasta el 84.5% mediante las siguientes condiciones de proceso: pH (6.11); temperatura (37.20 ºC); concentración de enzima (1.36 g L<sup>-1</sup>) y tiempo (176 min). El hidrolizado obtenido fue analizado; encontrándose minerales como potasio: 0.3 g 100g<sup>-1</sup>, magnesio: 0.020 g 100g<sup>-1</sup>, calcio: 0.060 g 100 g<sup>-1</sup>, fósforo: 0.09 g 100g<sup>-1</sup>), glucosa: 89 g L<sup>-1</sup>, galactosa: 66 g L<sup>-1</sup> y coordenadas CIELAB: L = 32.3, a = -0.5 y b = 15.</p> 2019-07-24T04:59:52+00:00 ##submission.copyrightStatement## SYNTHESIS AND CHARACTERIZATION OF CALCIUM PHOSPHATE NANOPARTICLES AND EFFECT OF THE AGITATION TYPE ON PARTICLES MORPHOLOGY 2019-08-20T17:31:32+00:00 E.A. Flores-Hernández R.H. Lira-Saldívar R. Acosta-Ortiz B. Méndez-Arguello J.I. García-López E. Díaz-Barriga-Castro A. González-Torres M. García-Carrillo <p>This paper reports a rapid, economic and efficient process to prepare calcium phosphate nanoparticles (nFC), also known as hydroxyapatite. The objective of this study was to synthesize, characterize and determine the effect of the agitation type on the production and morphology of nFC. The synthesis was carried out by wet chemical precipitation, with mechanical and magnetic agitation. TEM microscopy indicates that mechanical agitation produced ~ 33% particles with diameter between 15-20 nm, while magnetic stirring formed 29% (12.12% less). The sizes range obtained for both agitations types was 10 to 45 nm, with the predominant size being 15 to 20 nm. The FTIR spectrometry analysis revealed that the nFC obtained are analogous to those reported in the literature. Ζeta potential values of -20 mV to -14 mV were obtained for mechanical and magnetic agitation respectively, suggesting that nFC synthesized by mechanical agitation is more stable in solution. The results obtained reveal that mechanical agitation improves the characteristics of the nanocomposite, so this technique should be validated. We consider that the process reported here could be scalable to produce nFC, which has commercial potential as a nanofertilizer for the agricultural sector</p> 2019-06-18T22:52:54+00:00 ##submission.copyrightStatement## STUDY OF Bi0.5Na0.5TiO3 (BNT) SYSTEM DOPED WITH LANTHANUM (La3+) OBTAINED BY ACETIC ACID ROUTE IN SOL-GEL PROCESS 2019-08-20T17:31:34+00:00 J. M. Yañez-Limón K. M. Moya Canul <p>This work studies the Bi<sub>0.5</sub>Na<sub>0.5</sub>TiO<sub>3</sub> (BNT) system doped with lanthanum (La<sup>3+</sup>) at molar concentrations 0.0, 0.3, 0.6, 0.8, 1.0, 3.0 and 6.0 . The samples were synthesized by the Sol-gel method using the acetic acid route.&nbsp; The bulk samples were calcined at 700 ºC/1hr seeking to obtain the perovskite phase, and finally the samples were sintered at 1050 ºC/1hr, with density values between 90 and 92% with respect to the theoretical density. The La doping effect in the BNT system was analyzed using X-ray diffraction (DRX), Scanning electron microscopy (SEM), Ferroelectric hysteresis curves and Raman spectroscopy. The samples show a crystalline rhombohedral structure and a decreasing behavior of the grain size for La concentrations greater than 0.3%. After the incorporation of 0.6% of lanthanum concentration the presence of the pyrochlore phase of Bi<sub>2</sub>Ti<sub>2</sub>O<sub>7 </sub>is appreciated. &nbsp;The best ferroelectric properties were obtained for BNT doped with lanthanum (La3 +) at 6% in which a rhombohedral structure and traces of pyrochlore phases were obtained. This sample presented a maximum polarization (Pm) of 22.55 µC/cm<sup>2</sup>, remnant polarization (Pr) of 22.06 µC/cm<sup>2</sup>&nbsp;&nbsp; and a coercive field (Ec) of 25 kV/cm.</p> 2019-07-01T03:05:16+00:00 ##submission.copyrightStatement## EFFECT OF COMBINED MICROWAVE-ULTRASOUND IRRADIATION IN THE STRUCTURE AND MORPHOLOGY OF HIDROTALCITE LIKE COMPOUNDS Al/Mg-CH3COO AND ITS EVALUATION IN THE SORPTION OF A REACTIVE DYE 2019-08-20T17:31:35+00:00 A. S. Garzón Pérez S. P. Paredes-Carrera H. Martínez-Gutiérrez J. C. Sánchez-Ochoa R. M. Pérez-Gutiérrez N. Cayetano-Castro <p>Textile effluents contain a great variety of dye residues, their presence in the environment is undesirable since they cause a severe contamination in the aquifers. Different technologies are commonly used in the removal of these kind of dyes, which are often recalcitrant due to their anionic character, such as the sorption with activated carbon, zeolites and recently anionic clays (hydrotalcite-like compounds Al/Mg (HT-Al/Mg)) with relatively good results. The HT-Al/Mg can be synthesized by various methods assisted by treatments in the crystallization stage such as microwave and/or ultrasound irradiation, which allow the control of textural and morphological properties, in addition to reducing the synthesis times. The effects on the texture and morphology properties of HT-Al/Mg with an organic interlaminar anion (CH<sub>3</sub>COO<sup>-</sup>) synthesized by coprecipitation assisted with microwave irradiation, ultrasound and microwave-ultrasound in combined mode are studied. The synthesized materials were evaluated in the sorption of the reactive dye BEZAKTIV Red S-LF with reference to activated carbon. The solids were characterized before and after evaluation by known techniques described below. It was found that the HT-Al/Mg-CH<sub>3</sub>COO irradiated by the combined mode had the highest capacity of removal of the dyes compared to the reference material and when the materials were irradiated separately by microwaves or ultrasound.</p> 2019-07-09T00:21:06+00:00 ##submission.copyrightStatement## GLYCIDYL METHACRYLATE-COMPATIBILIZED POLY(LACTIC ACID)/NANOCLAY/AGAVE FIBER HYBRID BIOCOMPOSITES: EFFECT ON THE PHYSICAL AND MECHANICAL PROPERTIES 2019-08-20T17:31:36+00:00 A. S. Martín del Campo J. R. Robledo-Ortiz M. Arellano C. F. Jasso-Gastinel J. M. Silva-Jara E. J. López-Naranjo A. A. Pérez-Fonseca <p>This study evaluates the effect of agave fiber and nanoclay reinforcers over poly(lactic acid) (PLA) properties. Also, a compatibilizer based on glycidyl methacrylate and PLA was used to enhance the fiber-PLA interaction. The results showed that crystallinity of PLA was increased with nanoclay addition while fiber inclusion decreased it. Tensile and flexural moduli were increased by both reinforcements. The agave fibers affect negatively the tensile and flexural strengths, but they were importantly recovered by the used of the compatibilizer. Even though the nanoclay did not modify the impact strength, it was increased with agave fiber addition. The water absorption results showed that the coupling agent decreases the rate and maximum water absorption of the biocomposites. In general, it was concluded that with a proper combination of both reinforcers (hybridization) and the compatibilizer, it is possible to control the final characteristics of the biocomposite according to the desired or potential applications.</p> 2019-08-02T00:00:00+00:00 ##submission.copyrightStatement## ON THE INTERACTION OF THIOPHENE AND ZEOLITE-Y IN THE THIOPHENE-BASED OLIGOMERS FORMATION 2019-08-20T17:31:37+00:00 V. M. Rivera A. Suarez-Méndez L. I. Pascual-Mathey A. Gutierrez M. A. Vera G. A. Fuentes <p>Due to the inconsistencies in the literature about the structure of thiophene oligomers, formed by the interaction between thiophene and the Brönsted acid sites of zeolite Y, the direct analysis of these oligomeric species is fundamental, mainly to understand how they are made up and their correct structure. The materials used were zeolite Y in its protonic (HY) and sodic (NaY) form. The interaction between thiophene and the zeolitic material was performed by the adsorption of thiophene at room temperature using a solution of thiophene in <em>n</em>-octane (100-700 ppmw), leading to the formation of cationic thiophene oligomers that are trapped inside the cavities of HY, among other non-oligomeric species. The thiophene-zeolite Y interaction occurs through the Brönsted acid sites by two possible routes: <em>i)</em> by electrophilic attack to the pair of free electrons in sulfur, forming oligothiophene whose size is limited by the structure of zeolite and, <em>ii)</em> by interaction with the α-carbon that leads to the formation of thiols and hydrocarbons with carbons with sp<sup>3</sup>and H<sub>2</sub>S hybridization.</p> 2019-08-07T00:00:00+00:00 ##submission.copyrightStatement## A COMPARATIVE STUDY OF MULTI OBJECTIVE OPTIMIZATION ALGORITHMS FOR A CELLULAR AUTOMATA MODEL 2019-08-20T17:31:31+00:00 S. Kar S. Majumdar D. Constales T. Pal A. Dutta <p>Cellular Automata (CA) models can represent dynamic systems which are discrete in space and time that reflects the effect of intrinsic parameters where individual events are considered to occur from randomness. A CA model of two agents’ chemical kinetics has been optimized earlier using NSGA-II based on Genetic Algorithm (GA). But the stochastic nature of the CA model along with its high sensitivity on the model parameters requires extensive investigation using different optimization algorithms. For this purpose, in the current study, four more recently developed and popular optimization algorithms based on GA, called NSGA-IIr, NSGA-IIa, AbYSS, and MOEA/D, have been considered for investigation based on various performance measuring parameters. The study also compares the performances of the algorithms for different computational efforts with an objective to minimize the required number of objective function evaluations. Simulation results show NSGA-IIr as the best choice to optimize the CA model for 75000 objective function evaluations. Such results facilitate the use of stochastic CA models to represent complex (bio)-chemical networks.</p> 2019-06-16T01:32:55+00:00 ##submission.copyrightStatement## PERFORMANCE PROFILES FOR BENCHMARKING OF GLOBAL SENSITIVITY ANALYSIS ALGORITHMS 2019-08-20T17:31:34+00:00 F. A. Lucay T. López-Arenas M. Sales Cruz E. D. Galvez L. A. Cisternas <p>Nowadays, sensitivity analysis (SA) is a methodology commonly used to identify important parameters that determine the behavior of the model. The SA of a model allows to determine how uncertainties in the model responses (outputs) can be assigned to the values of the model parameters (input variables). The related literature indicates that there are several methods to&nbsp;perform SA. This work addresses the benchmarking of four widely used methods for Global SA (GSA): Sobol-Jansen, Sobol-Baudin, Sobol-Owen and Sobol 2007, based on the concept of performance profile introduced by Dolan and Moré (2002) and the extension by Mahajan et al. (2012). For the previous methods, a set of 21 models and their variations were considered, which correspond to various applications in chemical engineering (such as heap leaching, water distribution network, milling, flotation circuit, among others). These comparisons show that the Sobol-Jansen method has the best performance profile because it is the first to perform GSA in 83% of the models considered. The four SA methods analyzed proved to be quite stable since they performed the SA in 100% of the models tested.</p> 2019-07-25T21:01:58+00:00 ##submission.copyrightStatement##