Revista Mexicana de Ingeniería Química <div class="_4wyf">The Mexican Journal of Chemical Engineering &nbsp;(ISSN 1665-2738,&nbsp; issn-e: 2395-8472) 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> en-US <p>By publishing your paper in our journal you are also granting it the copyright of the information that it contains.</p> (Francisco J Valdes Parada) (Francisco J. Valdés-Parada) Sun, 28 Aug 2022 03:09:20 +0000 OJS 60 Chitosan and GRAS substances application in the control of Geotrichum candidum isolated from tomato fruits (Lycopersicum esculentum L.) in the state of Nayarit, Mexico: In vitro tests <p><em>Geotrichum candidum</em> causal agent of tomato sour rot, has the potential to infect a wide variety of fruits and vegetables. In this work, the <em>in vitro</em> antifungal activity of Chitosan (Chi), Potassium Sorbate (PS), Sodium Bicarbonate (SB), and Sodium Carbonate (SC) and their mixtures were evaluated. The PS and SC treatments showed a 100% inhibition of mycelial growth (MG), germination, and sporulation. Regarding SB, 1.5 and 2.0% concentrations inhibited 87.5 and 88.5% of MG and affected germination and sporulation. Chi at 1.0, 1.5, and 2.0% inhibited MG by 63.1, 62.4, and 42.1%, respectively, affecting germination and sporulation. The combination of chitosan at 0.5% + PS 0.5% and Chi 0.5% + SC 0.5% demonstrated 99.3 and 71.4%, inhibition of MG, and affected germination and sporulation. Chi 0.5% + SB 1.5% showed no effect on MG, and at 0.5 and 1.0%, the growth rate of the mycelium increased, as well as sporulation and germination. In conclusion, chitosan and salts are an option for the use of synthetic fungicides in the control of pathogenic fungi in postharvest, with low toxicity, and are friendly to the environment.</p> C.A. Rodríguez-Guzmán, B. Montaño-Leyva, J.A. Sánchez-Burgos, P.U. Bautista-Rosales, P. Gutierrez-Martinez ##submission.copyrightStatement## Sun, 28 Aug 2022 03:15:10 +0000 Identification of a Colletotrichum species from mango fruit and its in vitro control by GRAS compounds <p>The fungus <em>Colletotrichum </em>sp. is the causal agent of anthracnose in mango fruit and leads to substantial postharvest losses (&gt;30 %). Efficient control agents continue to be investigated to reduce the incidence of this pathogen, preferably of a biological-organic nature. The objective of this work was to evaluate the <em>in vitro</em> application of commercial-grade generally recognized as safe (GRAS) compounds as chitosan, hydrogen peroxide, acetic acid, and peracetic acid, in the control of <em>Colletotrichum </em>species isolated from mango fruit. The application of commercial chitosan (1.5 % and 2.0 %) confirmed its antifungal effect, with an average inhibition of 34 %, no significant difference was shown with respect to reactive grade chitosan. Hydrogen peroxide, acetic acid, and peracetic acid completely inhibited the development of <em>C. asianum</em> at concentrations &gt; 1.0 %. Each GRAS agent caused morphological damage to the spores, including loss of turgidity, intracellular disorder, effusion of liquid from the cytoplasm, and total loss of integrity. Scanning electron microscopy confirmed the damage to the mycelia, with collapsed and dehydrated structures due to exposure to the control agents. Overall, commercial GRAS agents showed an <em>in vitro</em> control effect on the growth of <em>C. asianum</em> at different stages of their development.</p> C.L. Moreno-Hernández, M.L. Zambrano-Zaragoza, R.M. Velázquez-Estrada, J.A. Sánchez-Burgos, P. Gutierrez-Martinez ##submission.copyrightStatement## Fri, 09 Sep 2022 23:19:22 +0000 Additive effect of alternative treatment to chemical control of Botrytis cinerea in blueberries <p>The blueberry crop is mainly attacked by the phytopathogen Botrytis cinerea, being very aggressive for this plant, showing resistance to synthetic fungicides. Non-chemical alternatives such as chitosan and salicylic acid have been proposed for its control. Therefore, the objective of this study was to evaluate the combination of these compounds for the control of Botrytis cinerea. The in vitro evaluation showed percentages of fungal growth inhibition of 60% and 100% inhibition of sporulation and germination of the phytopathogen. The micrographs showed damage to fungal structures of B. cinerea under the application of the treatments due to the additive effect demonstrated by combining chitosan and salicylic acid. Likewise, there was a great reactivity when combining these compounds, favoring the attack on the phytopathogen and increasing the in vivo effect by reducing the decomposition rate of blueberries by 60% compared to the control.</p> S. Ramos-Bell, L.G. Hernández-Montiel, R.M. Velázquez-Estrada, J.A. Sánchez-Burgos, P.U. Bautista-Rosales, P. Gutierrez-Martinez ##submission.copyrightStatement## Sat, 10 Sep 2022 16:58:11 +0000 Efficiency parameters that effectively correspond with hydrogen production from VFAs in microbial electrolysis cells <p>Microbial electrolysis cells (MECs) are hybrid systems that include characteristics of bioreactors and electrochemical cells. Primary parameters, such as substrate removal, current density and hydrogen production, and secondary parameters, such as coulombic efficiency, cathodic efficiency and hydrogen yield, determine the performance of MECs. The present work aimed to assess primary and secondary parameters in an MEC fed volatile fatty acids (VFAs) to determine those that most reliably describe the MEC performance in a model setup for hydrogen production. MECs were operated at 0.6 V and fed acetic, propionic and butyric acid mixtures in successive feeding cycles. The main performance parameters were chemical oxygen demand removal COD (84.7 ± 0.5 %), current density (378 ± 7 mA m<sup>-2</sup>) and hydrogen production (267 mL L<sup>-1</sup> d<sup>-1</sup>), which resulted in repeatable and more reliable efficiency parameters when MECs were fed acetate than when they were fed VFA mixtures. Both the current density and hydrogen production curves showed similar inflection points, thus giving accuracy to the cathodic efficiency determination (162.1 % -169.6 %). Hydrogen yield was not a reliable parameter with the three-VFA mixture since hydrogen production and COD removal curves showed no correlation. These findings indicate that MEC assessment should be verified via the correspondence between primary and secondary parameters.</p> B. Cercado, V. Ruiz, G. Buitrón ##submission.copyrightStatement## Sun, 11 Sep 2022 20:43:24 +0000 Heat stress on Fomes culture reduces proteases and improves laccases thermostability <p>The aim of this work was to study the production of laccase and protease by <em>Fomes</em> sp. EUM1 under heat stress when a temperature shift from 35 to 45°C was applied. The highest values of laccase activity were similar and obtained after the temperature shift, 76 and 81.6 U/gids at 35 and 45 °C respectively.&nbsp; For protease activity, at 35°C the peak activity (6.4 U/gids) was obtained at day 7 and maintained until the end of the culture and at 45°C the peak activity (4.3 U/gids) was obtained when the temperature shift was realized (day 6) and decreased until the end of the culture. In the zymogram of laccase activity one band with a molecular weight of 45 kDa was observed with extracts from both temperatures evaluated with slight differences in molecular weight and intensity of the bands at the various days assessed. The thermostability of laccase and protease activities from the enzymatic crude extracts, at the highest temperature assessed (60°C) for laccase activity the inactivation constant was 0.324 h<sup>–1</sup> and 0.277 h<sup>–1</sup> from cultures at 35 and 45 °C, respectively.</p> F.J. Martínez-Valdez, G. Carrillo-Sancén, O. Loera ##submission.copyrightStatement## Tue, 13 Sep 2022 03:15:19 +0000 Ethnopharmacological study of the genus Coffea and compounds of biological importance <p>Coffee is native to Ethiopia and it was used originally as a food and fermented beverage in Arab countries due to its stimulating effect. The “Moka” infusion of green and/or roasted beans then became popular in Europe. The genus <em>Coffea</em> (Rubiaceae) comprises more than 100 species; the best known are <em>C. arabica</em> and <em>C. canephora</em> and their hybrids Colombia, Oro Azteca and Costa Rica 95, which are resistant to the rust fungus. The predominant commercial production (70%) is of <em>C. arabica</em> due to its cup quality, low caffeine content and fine aroma. <em>C. canephora </em>is mainly used as a base for instant coffee. The main consumers are the United States and countries in the European Union. As producers, Brazil and Vietnam stand out; Mexico is the tenth largest producer, with Chiapas being the major producer and Guerrero standing out for its production of organic and specialty coffee by indigenous communities. Coffee beans are rich in phenolic compounds such as chlorogenic acids (CGAs) and alkaloids such as caffeine and trigonelline, the contents of which are reduced after the beans are roasted. Trigonelline and CGAs confer aroma, bitterness and astringency to coffee. The main biological effects of CGAs are associated with its antioxidant, anti-inflammatory and antidiabetic properties, and as neurostimulating for caffeine.</p> J. Gallardo-Ignacio, M.P. Nicasio-Torres, A. Santibáñez, S.L. Cabrera-Hilerio, F. Cruz-Sosa ##submission.copyrightStatement## Tue, 04 Oct 2022 21:40:56 +0000 Selenium accumulation by Lactobacillus isolated from commercial fermented milk: minimum inhibitory concentration and kinetic growth changes <p>Selenium is essential for human health; however, recommended daily intake is not always met. Thus, studies have been carried out on the biogenic production of more bioavailable selenium. It has been demonstrated that certain lactobacilli can metabolize inorganic selenium to transform it into selenoamino acids. This study aimed to add selenium on &nbsp;<em>Lactobacillus casei</em> Shirota and <em>Lactobacillus johnsonii </em>La1, isolated from commercial dairy products through an MRS media fermentation enriched with Na<sub>2</sub>SeO<sub>3</sub> to determine the minimum inhibitory concentration, the changes in the kinetics growth, and the selenium bioaccumulation. The minimum inhibitory concentration (MIC) was determined using the Talmadge and Fitch method. Kinetic changes were calculated by modeling the growth curve, and an inductively coupled plasma (ICP) assay was used to determine selenium accumulation by the cell. The MIC of Na<sub>2</sub>SeO<sub>3</sub> was higher than 190 mg/L in both bacteria, and kinetic changes showed faster growth when media was not enriched. Selenium absorption of 64.50 % was found for <em>Lb. casei</em> Shirota and 75.78 % for <em>Lb. johnsonii </em>La1. Obtained results demonstrated that these lactic acid bacteria bacteria are a potential ingredient in functional food processing to their ability to accumulate selenium.</p> A. Castañeda-Ovando, E. Pérez-Escalante, G.M. Rodríguez-Serrano, X. Martínez-Ramírez, E. Contreras-López, J. Jaimez-Ordaz, J. Añorve-Morga, S. Nieto-Velázquez, J. Ramírez-Godínez, L.G. González Olivares ##submission.copyrightStatement## Fri, 14 Oct 2022 01:10:37 +0000 Modeling process conditions of modified starches to be used as wall materials in the encapsulation by nano-spray drying <p class="p1">In the present work, time-variable modeling of high-energy mechanical grinding (0, 20, 30, 40, 50, 60, 70, and 80<span class="s1">&nbsp;</span>min), was carried out to obtain the best grinding conditions process for obtaining modified starches with applications as wall materials with favorable viscosity and particle size characteristics for the nano-encapsulation of bioactive compounds by means of nano-spray drying. The pasting profile was affected by the different mechanical grinding times, since the maximum viscosity (95 ºC) decreased as the grinding time increased, but this was not the case in the cooling stage (30 ºC) since at times of 30 and 40 min the viscosity was more significant than the maximum viscosity. The modified starches showed larger particle sizes compared to their native counterpart, indicating the formation<span class="s1">&nbsp;</span>of agglomerations. The model presents an adequate fit with respect to the experimental data and the feasible and infeasible conditions of this process are represented.</p> A. Aparicio-Saguilán, D.E. Páramo-Calderón, L.A. Vázquez-León, G. Reynoso-Meza, A. Ramírez-Hernández, R. Colorado-Peralta, J. Carrillo-Ahumada ##submission.copyrightStatement## Tue, 01 Nov 2022 05:28:46 +0000 Effect of SiO2 nanoparticles in the physicochemical, mechanical and structural properties of sweet potato starch edible films <p>In our present work it was evaluated the influence of addition of SiO<sub>2</sub> nanoparticles to sweet potato starch films in the mechanical, structural and physicochemical properties. Two edible films was made, sweet potato starch edible films without SiO<sub>2</sub> nanoparticles (EF) and sweet potato starch films with SiO<sub>2</sub> nanoparticles (DEF). Mechanical properties did not present major difference (p&lt;0.05), but water vapor permeability, solubility and absorption of water decreased. In the FTIR spectra, characteristic peaks shifts were observed in which changes in crystallinity and intermolecular interactions between SiO<sub>2</sub> nanoparticles and starch could be concluded.&nbsp; The addition of SiO<sub>2</sub> to the sweet potato edibles films increased the crystallinity, reduced water vapor permeability without affect its mechanical properties.</p> D. Martínez-Prigadá, L. Acosta-Domínguez, M. Martínez-Minaya, S. García-Díaz, L. Alamilla-Beltrán ##submission.copyrightStatement## Fri, 18 Nov 2022 23:54:02 +0000 Application of Fourier Transform Infrared Spectroscopy (FTIR) in combination with Attenuated Total Reflection (ATR) for rapid analysis of the tequila production process <p>The manufacturing process of tequila made of <em>Agave tequilana </em>Weber var. azul consists of several important process stages such as milling, cooking, fermentation, distillation, and aging. The purpose of this contribution was to characterize five of the most important stages of the tequila production process in a pilot plant by using FTIR-ATR spectroscopy. The results showed that FTIR-ATR spectra of raw juices in the range 4000 and 700 cm<sup>-1</sup>, were mostly composed of absorption peaks associated with water and fructose. The spectra of cooked juices showed the thermal hydrolysis of the fructans to fructose in the interval between 1200 and 800 cm<sup>-1</sup>. The FTIR-ATR spectra of the samples fermented showed a gradual sequence transforming fructose peaks to ethanol peaks during the interval time from 0 to 48 h at 35°C. The spectra obtained from the distillation showed that the intensity of the peaks was a function of the concentration of ethanol in the product distillates. The evolution of the aging of the “<em>tequila blanco</em>” in an oak barrel was monitored for 60 days. The results showed that the region between 1300 and 900 cm<sup>-1</sup> of the FTIR-ATR spectra was associated with the aging process in the oak barrel.</p> P.M. Mondragón-Cortez, E.J. Herrera-López, E. Arriola-Guevara, G.M. Guatemala-Morales ##submission.copyrightStatement## Sun, 28 Aug 2022 03:07:48 +0000 Chemical modification of rice (Oryza sativa) and potato (Solanum tuberosum) starches by silanization with trimethoxy(methyl)silane <p>Rice starch of the A98 variety, with a denomination of origin of the state of Morelos, and potato starch were silanized to modify hydrophobicity and improve functional properties, providing added value to these starch sources and promoting their use in the formulation of biodegradable materials that require a degree of hydrophobicity, such as packaging materials. Fourier transform infrared spectroscopy analysis determined the presence of trimethoxy(methyl) silane in starch. Differential scanning calorimetry was used to determine the thermal properties and morphology was evaluated using scanning electron microscopy while changes in functional properties were assessed by identifying contact angle, swelling power, water absorption capacity, and oil absorption capacity. Hydrophobic silanized starches were obtained: Potato starch showed a contact angle of 132 ° and rice starch, 130 °. They exhibited changes in density and functionality; both swelling power and water absorption capacity were reduced in potato starch but increased in rice starch.</p> A.M. Salgado-Delgado, E. Lozano-Pineda, R. Salgado-Delgado, J.P. Hernández-Uribe, A. Olarte-Paredes, M.J. Granados-Baeza ##submission.copyrightStatement## Sun, 28 Aug 2022 15:28:33 +0000 Investigation of drying kinetics and drying conditions on biochemical, sensory, and microstructural parameters of “Sefri” pomegranate arils (Punica granatum L. a Moroccan variety). <p>The study evaluated the application of four drying temperatures inside a newly developed hybrid indirect solar dryer in forced convection (at 40, 50, 60, and 70°C) compared to a direct solar dryer (Greenhouse) for the processing of the Moroccan Sefri pomegranate arils. The thermodynamical analysis allows characterizing the physical properties of the arils using some parameters such as optimal water activity, net isosteric heat of sorption, and effective moisture diffusivity. The biochemical analysis studied included total proteins, sugars, vitamin C, and total anthocyanins, hygrometric properties, microstructure modification, and sensory evaluation. Generally, drying led to a reduction in all parameters. However, lower drying temperature processes (indirect convective solar drying at 40°C and 50°C) give the best results for pomegranate arils. Greenhouse dried samples had almost the lower quality in all parameters. The color is more preserved at indirect convective solar drying at 40°C. However, indirect convective solar drying at 50°C was most appreciated by consumers with higher scores on the sensory evaluation test. As the first study of the thermodynamic and biochemical investigation of dried pomegranate arils in Morocco, this work intended to be the first step in developing controlled new high-quality products for the Moroccan market.</p> S. El Broudi, N. Zehhar, N. Abdenouri, A. Boussaid, A. Hafidi, H. Bouamama, F. Benkhalti ##submission.copyrightStatement## Sun, 28 Aug 2022 22:44:23 +0000 Structural, physicochemical, and emulsifying properties of pectin obtained by aqueous extraction from red pitaya (Hylocereus polyrhizus) peel <p>This work aimed to carry out a straightforward aqueous extraction of pectin from red pitaya peels (RPP), in a drive to promote the circular economy of the settlements where the fruit of this endemic species grows. The average pectin yield was 11.59 g/100 g dry basis, the degree of esterification was 60.35±1.35%, the galacturonic acid content was 54.36±1.03%, and the protein content of 5.86 ± 0.25%. The RPP pectin was analyzed in terms of physicochemical, functional, and structural features. The FTIR spectrum confirmed that the unveiled pectin structure was consistent with that reported for commercial pectins from different botanical sources. Pectin aqueous dispersions exhibited power-law shear thinning behaviour. Corn oil (10 mL) in 150 mL aqueous pectin solutions (0.12, 0.15, 0.30, 0.60 and 0.90%, w/v) emulsions exhibited increasing emulsifying activity and emulsifying stability with increased pectin concentration. The small It was concluded that the RPP pectin is an alternative potential new source of pectin for use in the formation and stabilization of oil-in-water food emulsions.</p> E. Alpizar-Reyes, J. Cruz-Olivares, S. Cortés-Camargo, M.E. Rodríguez-Huezo, J.O. Macías-Mendoza, J. Alvarez-Ramirez, C. Pérez-Alonso ##submission.copyrightStatement## Wed, 31 Aug 2022 01:38:02 +0000 Swelling, erosion and physicochemical characteristics of plum powder tablets obtained by spray drying <p>Mexican plum juice was spray dried to obtain plum powder to develop tablets as a source of vitamin C and pectins. Plum powder presented poor flow characteristics and low capacity to compaction so different binders were probed. Corn starch (CS), carboxymethyl cellulose (CMC) and sodium alginate (SA) were added in 15 and 30 % w/w and tablets were made at 30 and 40 kN of compression load. Water activity (a<sub>w</sub>), moisture content (%X), color, hardness, disintegration time, % water uptake and erosion were evaluated. Tablets presented acceptable values of a<sub>w</sub> (0.364-0.513) and %X (1.14-2.79), color parameters indicated more presence of yellow-red coloration when maximum compression load was applied. Starch formulations presented shortest disintegration times (4.24-6.43 min) and acceptable hardness to be handled and transported without damage (3.441-4.8618 kgf), CMC and alginate formulations took more time to disintegrate in water however were synergic in acidic medium allowing faster dissolution, compared to water, and high erosion (&gt;80%).</p> P. Guillén-Velázquez, D. Cantú-Lozano, M.P. Rascón-Díaz, M. Jimenez-Fernández, G. Luna Solano ##submission.copyrightStatement## Mon, 12 Sep 2022 03:18:30 +0000 Influence of the feed composition and the spray drying process on the quality of a powdered mixture of blackberry (Rubus glaucus Benth) <p><em>The Castile blackberry (Rubus glaucus </em>Benth<em>) is a fruit rich in active components, which is framed within the context of functional foods, to provide well-being to the human being. The objective of the research was to evaluate the effect of the feed composition and the spray drying process (SD) on the quality of the blackberry powdered mixture (BPM). The response surface methodology was used with a central composite face-centered design (α=1), considering the following independent variables: inlet air temperature (IAT) (140 - 160 °C), outlet air temperature (OAT) (80 - 90 °C), atomizer disk speed (ADS) (20000 - 24000 rpm) and maltodextrin (MD) (5 – 9 %). The dependent variables were water activity (aw), humidity (X<sub>w</sub>), solubility (S), wettability (<u>W<sub>e</sub></u>), hygroscopicity (H), angle of repose (AR), particle size (Span), total phenols (TP), antioxidant activity (ABTS and DPPH), anthocyanins (A), ellagic acid (EA) and product yield (Y). In general, <u>W<sub>e</sub></u> is the most critical variable in BPM, being statistically affected by most of the independent variables and by their linear and quadratic interactions. On the other hand, the experimental optimization of multiple responses defined the independent variables as IAT (159.3 °C), OAT (89.3 °C), ADS (24000 rpm), MD (5.5 &nbsp;%), and the dependent variables as aw (0.166±0.002), Xw (7.10±0.05 %), S (88.01±0.17 %), <u>W<sub>e</sub></u> (54.4±1.3 min), AR (7.4±3.7°), Span (1.69±1.04), TP (4513.1±23.5 mg AGE/100g dry base (db), ABTS (4012.7±34.0 mg TE/100g db), DPPH (5359.4±39.1 mg TE/100g db), A (281.2±29.4 mg C<sub>3</sub>G/100g db), EA (2653.0±155.0 mg/100g db) and Y (46.4±13.2 %). The spray drying (SD) process provides effective protection for the active compounds of the blackberry extract. In addition, it guarantees physicochemical stability for storage.</em></p> M. Cortes-Rodriguez, J.H. Gil-González, R. Ortega-Toro ##submission.copyrightStatement## Thu, 29 Sep 2022 02:10:55 +0000 Effect of the storage relative humidity on the physicochemical properties of corn starch edible films obtained by a combination of extrusion process and casting technique <p>Starch is one of the most used polysaccharides in the formulation of Edible Films (EFs). This work aimed to develop starch-based EFs employing extrusion technology as a pretreatment to casting technique and evaluate the storage relative humidity (RH) effect to determine their possible application as food coating. Corn starch and a mixture of plasticizers (sorbitol and glycerol) were processed in a twin-screw extruder. The casting technique was used for EFs formation. The EFs were conditioned at different storage RH (53, 75, and 100%) for ten weeks. The studied response variables were: puncture resistance (PR), puncture deformation (PD), water vapor permeability (WVP), water solubility (WS), X-ray diffraction patterns, and relative crystallinity. EFs at 53 and 75% RH showed the most stable behavior in PR and PD. Concerning the barrier properties, it was found that EFs stored at 53% RH had the lowest value of WVP and XRD patterns showing that storage time produces crystalline zones by the aging effect. Starch-based EFs obtained by the combination of extrusion-casting and stored at an RH of 53 and 75% presented the best physicochemical properties. Hence, these EFs could be used as coatings of intermediate moisture foods.</p> A. Calderón-Castro, E. Aguilar-Palazuelos, I.L. Camacho-Hernández, M.O. Vega-García, J.J. Zazueta-Morales, PhD, X.A. Ruiz-Armenta, P.R. Fitch-Vargas ##submission.copyrightStatement## Mon, 03 Oct 2022 15:00:49 +0000 Determination of the spreading pressure and shelf-life of spray-dried coffee powder: quality assurance of a water-soluble food <p>In this work, the values of monolayer (<em>M<sub>o</sub></em>) of the GAB model, generalized GAB model, and minimum change in spreading pressure (MCSP) of the adsorbed water were compared to determine the optimal storage conditions of spray-dried coffee powder. The effect of the adsorption models on estimating the water-vapor permeance of the packaging material and the product’s shelf-life was also evaluated. For this, the powder was packed in a plastic film and stored at three temperatures and two relative humidities (RH). As a result, the best physicochemical stability of the powder was achieved at water contents corresponding to MCSP, from 0.01-0.04 g water/g dry solids. It was also observed that the most extended shelf-life was 246 days, obtained at 25 °C/75 HR with a permeance of 1.45 &nbsp;g/m<sup>2</sup>dPa, and the shortest was 8 days at 45 °C/97 HR with a permeance of 4.2 &nbsp;g/m<sup>2</sup>dPa. Additionally, it was determined that the degradation rate tripled ( &nbsp;3) every 10 °C with activation energies greater than 90 kJ/mol. The results show that the spreading pressure contributes to ensure the quality of water-soluble foods.</p> L.A. Pascual-Pineda, A. Guerrero-Hernández, M. Castillo-Morales, R. Salazar, M. Jiménez-Fernández, E. Flores-Andrade ##submission.copyrightStatement## Sat, 15 Oct 2022 03:48:05 +0000 A hydrodynamic model to describe CaCO3 deposit formation in pipelines <p>Calcium carbonate deposition inside of pipes is a widespread problem in aqueous fluid transport systems, where calcium and carbonate ions are dissolved. The present study describes the physical and chemical phenomena of mass transport of the chemical species, from the bulk solution to the pipe walls, inside a straight circular pipe. The mass transfer coefficient is estimated using correlations for developing laminar flow. The controlling mechanism is assigned using the Damköhler number and the model simulation results are analyzed for three scenarios: when mass transfer controls the deposition, by mixed control or by the deposition kinetics. If mass transfer is the controlling mechanism, the deposit was concentrated at the pipe entrance, while with kinetic control, it forms further downstream. This study found that most important factor influencing the deposition process is the bulk and superficial pH values.</p> H. Gómez-Yáñez, G.T. Lapidus-Lavine ##submission.copyrightStatement## Fri, 09 Sep 2022 23:04:41 +0000 Synthesis of non-ionic, cationic, and anionic surfactant from coconut oil for remediation of diesel contaminated soil <p>Nowadays, there is great concern about environmental pollution caused by human activity. The soil represents an ecosystem affected by oil activities. Surfactant soil washing is commonly used to remediate contaminated total petroleum hydrocarbons (TPH) soil. However, most commercial surfactants are derived from petroleum; therefore, new surfactants friendly to the environment are researched.</p> <p>This work synthesized types three green surfactants from coconut oil. FTIR, and <sup>1</sup>H NMR spectroscopy indicated the proposed chemical structures. These surfactants were evaluated in the TPH remotion. The results show a more effective removal of hydrocarbons using the cationic surfactant with 99.3 %, followed by the non-ionic surfactant with 97.5 %, and the anionic surfactant, with 93.7 %.</p> <p>Residual diesel in the soil was characterized and quantified using Gas Chromatography-Mass (GC-MS) and UV-Vis spectroscopy, complying with the maximum permissible limits of TPH in the soil (NOM-138-SEMARNAT/SSA1-2012). The GC results show the removal of several TPHs; however, some differ based on the type of surfactant used in the wash. Soil characterization by SEM-EDS confirmed that there was no significant particle wear. Furthermore, the cationic surfactant was not adsorbed on the soil after washing.</p> E. Vázquez-Vélez, J. Monzón-Mendoza, H. Martínez, B. Campillo ##submission.copyrightStatement## Fri, 02 Sep 2022 01:10:09 +0000 Sugar production by dilute acid hydrolysis of oat bagasse with three different acids: kinetics and thermodynamics <p>Acid hydrolysis is used as a treatment method to hydrolyse the polysaccharides present in biomass to fermentable sugar. In this research the hydrolysis of oat bagasse was studied employing different inorganic acids (HCl, H<sub>2</sub>SO<sub>4</sub> and H<sub>3</sub>PO<sub>4</sub>) at low temperatures (90 – 110 °C) in a long-term process. Sulphuric acid showed a high potential to produce reducing sugars reaching the maximum production yields at 110°C, while hydrochloric acid at 110°C was the most catabolic acid promoting sugars transformation into furfural. FTIR and relative transmittance analyses suggested that major impact on lignin polymer was made by phosphoric acid hydrolysis at Combined Severity Factors (CSF) higher than 1.5. Kinetic constants calculated from conventional Saeman model allowed to determine thermodynamic parameters for each inorganic acid. Decomposition of sugars occurred most frequently when the Activation Energies (Ae) were low than calculated for sugar production, being aldehydes, the most stable products obtained during hydrolysis. Thermodynamic parameters show and endothermic and non-spontaneous oat bagasse hydrolysis reaction for different inorganic acids.</p> J.C. Gómora-Hernández, M. del C. Carreño-de-León, F. Cuellar-Robles, N. Flores-Alamo ##submission.copyrightStatement## Mon, 05 Sep 2022 14:42:19 +0000 Metabolic and kinetic changes of activated sludge because of failures in the aeration system in a WWTP <p>The classic question from wastewater treatment plant (WWTP) operators is, how long can a secondary reactor be kept unaerated after an aeration system failure? Therefore, in the present research, samples of activated sludge (AS) were taken from a WWTP and left without aeration for 12, 18, 24, and 36 h; simulating an aeration failure. Subsequently, the activity of AS lacking aeration was evaluated in batch cultures. The results showed that the lack of AS oxygenation affected its metabolism. For example, the heterotrophic activity stopped completely when AS was not aerated for 24 h. The nitrifying activity, in the experiments from 12 to 24 h without aeration, the ammonium removal did not change, but there was an increase in nitrite concentration. In the 36-h experiment without aeration, the ammonium consumption rate and removal efficiency decreased by 56% and 43%, respectively, regarding the control. N<sub>2</sub>O was produced in the period when the AS was not aerated, which could be responsible for these metabolic and kinetic changes. Finally, this study suggested don't leave for more than 24 h the activated sludge without aeration for a quick recovery or to diminish the damage.</p> I.V. Romualdo-Martínez, A.I. Hernández-Rodríguez, G. González-Blanco, R. Beristain-Cardoso ##submission.copyrightStatement## Fri, 16 Sep 2022 20:38:06 +0000 Analytical and hybrid-neuro-differential approaches for describing contaminant removal from aqueous systems <p>In this study, both analytical and hybrid-neuro-differential formulations were developed for describing the contaminant removal from wastewater by adsorption. The sorption isotherm, expressed as a straight-line equation (single segment or piecewise function) or artificial neural network (ANN), was coupled to the balance equations describing the pollutant transfer in adsorbent and wastewater phases, and their contact interface. The resulting wastewater adsorption remediation model (WARM) is valid for both batch and continuous operations, does not consider a dominant internal or external resistance to mass transfer or instantaneously equilibrated adsorbent, and has an analytical solution when a straight-line isotherm is used. The applicability of current model was tested in the analysis of two experimental datasets from literature describing the removal of the anionic dye direct red 23 (DR23) by graphene oxide (GO) and 4-nitrophenol (4NP) on calcium alginate-multiwall carbon nanotube beads (CAMCNB), where internal and external mass transfer coefficients and sorption isotherm parameters were simultaneously estimated by nonlinear regression. The analytical and hybrid-neuro-differential formulations were further compared with a numerical one where the WARM was coupled to Langmuir isotherm. Besides, the model was also used to explore different scenarios for continuous operation with all tested isotherms. It was demonstrated that the proposed formulations based on straight-line and ANN isotherms achieved a good reproduction of both dynamic and equilibrium experimental data, with similar fitness indices to that obtained with other non-linear equilibrium models.</p> D. Temoltzin-Lobatón, K.H. Estévez-Sánchez, D. Cruz-González, C.E. Ochoa-Velasco, I.I. Ruiz-López ##submission.copyrightStatement## Sat, 17 Sep 2022 01:25:19 +0000 Inhibition of the acetoclastic methanogenic activity by disinfectants used in the washing of pharmaceutical industry equipment <p>The pharmaceutical industry uses different types of disinfectants in the washing processes of different equipment, which become part of the wastewaters generated in the production processes. The nature of these compounds can diminish the biodegradability of the effluents; hence, this is an important issue to consider during the design and operation of treatment processes. This study establishes the kinetic parameters for three commercial disinfectants, using anaerobic sludges as inoculum. The doses for the active principle (quaternary salt) that yield a 50% reduction of the methanogenic inoculum were 1.6X10<sup>-3</sup> kg · m<sup>-3</sup> for benzalkonium, 8.4X10<sup>-3</sup> kg · m<sup>-3</sup> for bactium, and 154X10<sup>-3</sup> kg · m<sup>-3</sup> for anibac. The three disinfectants induced a mixed-type inhibition on the anaerobic biodegradability of sodium acetate, the main precursor of methanogenesis during anaerobic digestion.</p> S.E. Vigueras-Carmona, M.M. Montes-García, J. Pérez-Vargas ##submission.copyrightStatement## Fri, 23 Sep 2022 15:43:24 +0000 Influence of initial copper concentration, pH, and cross-linked alginate-chitosan and alginate-chitosan-Aspergillus australensis composite beads on the adsorption capacity and removal efficiency of copper ions <p>Copper (Cu) is a toxic heavy metal whose concentration must be reduced to values under the environmental standard before discharges can be released into the environment. Due to its characteristics, using different adsorbents for biosorption is a convenient method for removing heavy metals. Alginate and chitosan are biopolymers that have shown high potential as adsorbents. This investigation discusses the influence of pH, initial concentration of copper (Co), and the type of immobilized bead in the adsorption capacity and removal efficiency of copper from synthetic solutions. FT-IR analysis showed cross-linked composite beads of alginate-chitosan (ICB) and alginate-chitosan-<em>Aspergillus australensis</em> (IBB) possess different functional groups. The analysis made with the kinetic models showed that the adsorption mechanism was governed by diffusion through interface and chemical adsorption. Adsorption capacity depends on pH and Co. Maximum average adsorption capacity was 4.46 mg/g at 600 mg/L and pH 4.5 for ICB. Statistical analysis demonstrated that Co, pH, and their interactions significantly affect removal efficiency. Besides, the highest removal efficiency was 36.18% ± 1.87 at pH 4.5, 150 mg/L for IBB. These biomaterials could be a potential adsorbent for removing copper from wastewater.</p> F.A. Dávila-Parra, M. Plascencia-Jatomea, O. Monge-Amaya, A.R. Mártin-García; J. de la Vega Olivas; F.J. Almendariz-Tapia ##submission.copyrightStatement## Sat, 26 Nov 2022 02:29:19 +0000 Study of corrosion in metallic materials during the hydrodeoxygenation of palm oil in continuous fixed-bed reactor <p>In this work, corrosion damage in different metallic materials directly exposed to the corrosive environment generated in the catalytic hydrodeoxygenation (HDO) of palm oil to obtain green diesel in a continuous fixed-bed reactor at pilot plant scale was studied. Coupons were manufactured according to ASTM methods and were placed in holders at the outlet of the catalytic bed. Two experimental sets of 392 and 600 h of exposure time were carried out, keeping temperature and pressure at 340°C and 5 MPa, respectively, and results were reported as corrosion rate. It was found the material with the highest Cr content had the highest corrosion resistance. Similarly, it was noticed the most significant corrosion damage occurred just at the outlet of the catalytic bed. The experimental methodology followed in this work is a new procedure developed for continuous flow processes and could be used in transformation processes studies of biomass or other types of chemical compounds.</p> M. Cruz, G. Marroquín, P.M. Vega-Merino, R. Guzmán, P. Rayo ##submission.copyrightStatement## Wed, 12 Oct 2022 06:04:57 +0000 CO2 capture on an optimally prepared highly microporous KOH-activated carbon from rice husk <p>In this study, rice husk was used as a low-cost agro-waste to produce optimally a high microporous KOH-chemically activated carbon for efficient CO<sub>2</sub> capture. In order to find the optimum conditions to prepare this carbon-based adsorbent, the rice husk was subject to different carbonization temperatures, followed by various KOH impregnation ratios, activation temperatures, and activation times, in absence of an inert atmosphere. All developed carbons were characterized by using different analytical methods. Results showed that the rice husk carbonization at 600 <sup>o</sup>C by 1 hour followed by KOH-chemical activation using a mass impregnation ratio of 1:3 at 600 <sup>o</sup>C during 1 h, produced an activated carbon of microporous structure, with a high surface area of 1384.4 m<sup>2</sup>/g and a high total pore volume of 1.0854 cm<sup>3</sup>/g, these obtained morphological and textural properties were correlated with their exhibited CO<sub>2</sub> adsorption capacity of 110.78 mg/g under atmospheric conditions, measured by the thermogravimetric method. The results indicate that KOH chemical activation under no inert gas conditions as an optimized synthesis route does seem to be a suitable modification technique that offered to prepare with economic feasibility a valuable activated carbon to be potentially used in CO<sub>2</sub> capture technologies.</p> E. Gutiérrez-Bonilla, F. Granados-Correa, G. Roa-Morales, P. Balderas-Hernández ##submission.copyrightStatement## Fri, 14 Oct 2022 01:33:43 +0000 Evaluation of destructive and non-destructive measurement methods to determine the thickness of a titanium coating deposited by physical evaporation <p><em>The purpose of this research is to develop reference Ti-coatings and analyze the thicknesses evaluated via destructive (DT) and non-destructive (NDT) measurement techniques. The Ti coating was deposited on a mirror finished AISI M2 steel by the magnetron process. The nominal value of the coating thickness was 1 μm. The NDT was the X-Ray Fluorescence (XRF) method, the thickness for the portable analyzer was 1.18 ± 0.19 μm and the thickness using the spectrometer XRF was 1.17 ± 0.24 μm. For DT, thickness measurements were carried out in the cross-sections of the Ti-coatings, using the Field Emission - Scanning Electron Microscopy equipped with Energy Dispersive Spectrometer (FE-SEM-EDS). The coating thickness measurements were performed with image analysis of secondary electrons (SE), backscattering electrons (BSC), mapping (MAP) and elemental profiles (LS) using ImageJ and Aztec software. The results of the thickness measurements are SE: 1.12 ± 0.15 μm, BSC: 1.14 ± 0.13 μm, LS: 1.25 ± 0.13 μm and MAP: 1.29 ± 0.6 μm. Variations in the results were identified and estimated in the uncertainty models proposed for each method.</em></p> R. Herrera-Basurto, F. Mercader-Trejo, A. Domínguez-García, G.C. Mondragón-Rodríguez ##submission.copyrightStatement## Sat, 22 Oct 2022 14:15:18 +0000 Evaluation of the use of banana pseudostem with thermoplastic corn starch for the elaboration of biodegradable dishes <p>This project evaluated the use of fiber residues from the banana pseudostem (<em>Musa Paradisiaca </em>L<em>.</em>) with thermoplastic corn starch (<em>Zea Mays</em>) in the production of biodegradable dishes for food use. The homogenized mixture was gelatinized at 60 °C and thermopressed at 150 °C for 20 min. The amounts of thermoplastic starch and polyvinyl alcohol were varied.&nbsp; The raw material and the final product were characterized by physical-chemical, mechanical, and thermal analyses. The lignocellulosic fibers improved the tensile strength, modulus of elasticity, hardness, and viscoelasticity in the dish, also presented hydrophilic character. Degradation increased with the increase of thermoplastic starch. The unit cost per dozen plates was $ 1.63. It is concluded that the residues of fibers from the pseudostem of banana and thermoplastic starch turned out to be an alternative in the elaboration of biodegradable dishes.</p> L. Hernandez-Gil, L. Caldas-Cortez, D. Contreras-López, A. Jiménez-Sánchez ##submission.copyrightStatement## Fri, 25 Nov 2022 16:42:21 +0000 Analysis of the thermal efficiency of flat plate solar air heaters considering environmental conditions using artificial neural networks <p>The variance analysis and Artificial Neural Networks were employed to characterize the thermal efficiency in an Air Solar Heater (ASH), evaluating the effects of the design variables: the depth, material and thickness of the absorber plate and inlet airflow. Using Artificial Neural Networks, it was possible to correlate and estimate the effects of uncontrolled environmental variables on thermal efficiency. Incident solar radiation is the environmental factor with the greatest relevant effect on the thermal efficiency of ASH; due to the inability of the absorber plate to receive, store and transfer the abundant solar energy to the air. The most relevant variables in the design were the material and the thickness of absorbed plate, nevertheless, these variables have opposite behaviors on thermal efficiency under conditions of high and low solar incidence. Under this proposed methodology, it was possible to evaluate and know the effect of the design variables studied, even with the high effect of the prevailing environmental conditions.</p> M. Calderón-Ramírez, J.A. Gomez-Náfate, B. Ríos-Fuentes, R. Rico-Martínez, J.J. Martínez-Nolazco, J.E. Botello-Álvarez ##submission.copyrightStatement## Wed, 12 Oct 2022 05:53:54 +0000 Esterification of oleic acid into biodiesel and use it as fuel in a diesel engine to determine its impact <p><em>In this study, experimentally obtained biodiesel was analyzed as an alternative source of energy from oleic acid, using pure methanol and a solid acid catalyst in an autogenous reactor, the main product obtained was biodiesel, achieving a yield of 96.72 percent and thus demonstrating a greater conversion of free fatty acids (FFA) to methyl esters, allowing them to be studied in a diesel engine. Sulfonation of vulcanized rubber carbon produced the solid acid catalyst. Three control variables were used in the engine for the realization and analysis of the biodiesel obtained vs. commercial diesel in the internal combustion engine. Pure commercial diesel (PDI), biodiesel-diesel blend (50/50), and pure biodiesel (MES). The combustion tests show that there is no significant variation in the characteristics and performance of said tests; however, in the gaseous combustion products, significant reductions in carbon monoxide, unburned hydrocarbon, and an increase in greenhouse gas emissions were achieved. The greenhouse effect. nitrogen oxide when using the (PDI) versus the (MES). When MES and PBM were tested in a laboratory engine, the amount of NOx, CO, HC, and smoke emissions were reduced.</em></p> M. Sánchez-Cárdenas, L.A. Sánchez-Olmos, F. Trejo-Zárraga, k. Sathish-Kumar ##submission.copyrightStatement## Fri, 25 Nov 2022 20:30:46 +0000