Ingeniería Química-Pregrado

Permanent URI for this collectionhttps://dspace-test.ucuenca.edu.ec/handle/123456789/292

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Obtención de una película plástica biodegradable a partir de la gelatinización de almidón de zapallo reforzada con fibras de celulosa
(Universidad de Cuenca, 2023-10-30) Valdez Llivisaca, Cesar Ismael; Vanegas Peña, María Eulalia
The production of biopolymers represents a promising solution to the increasing pollution caused by petroleum-derived plastics. Among these, polymeric compounds obtained from starch are of great interest, due to their easy elaboration, adaptability to existing manufacturing processes and low raw material cost; however, compared to traditional plastics, their properties are not very favorable for their use at industrial level. In the present work, a biodegradable starch film was obtained using the wet molding method, from an uncommon and locally abundant raw material, such as pumpkin, together with glycerol (plasticizer) and cellulose fibers (reinforcement) obtained from sugarcane bagasse. In addition, the influence of the components was evaluated by means of a factorial analysis 2 . This film was characterized by measuring its mechanical and thermal properties, water absorption, vapor permeability, functional group analysis and degradability. The results showed that 3% starch by weight, 50% glycerol and 8% cellulose in relation to the weight of starch, the latter being the factor with the greatest influence as the best formulation. The film presented a low degradation rate, but exhibited favorable properties for this type of composites, such as a tensile strength of 24.29 MPa, elongation of 6.38%, water absorption of 44.81% and a permeability of 0.46x10 3 g/m∙s∙Pa. These values, however, will need to be further improved to compete with traditional plastics.
Evaluación microbiológica de la sección de cárnicos en un mercado de Cuenca-Ecuador: Propuestas de mejora higiénico-sanitarias
(Universidad de Cuenca. Facultad de Ciencias Químicas, 2025-11-10) Arias Batallas, Jorge Andrés; Pucha Cabrera, Geovanna Mercedes; Zúñiga García, Daniela Estefanía
Food safety in Ecuador's municipal markets is compromised by poor hygiene practices during the handling of meat products. One of the problems is the presence of microbiological contaminants on inert surfaces such as knives, cutting boards, scales, and saws. The objective of this study was to perform a microbiological analysis of these surfaces in a municipal market in the city of Cuenca, as well as to design and verify a Standard Sanitation Operating Procedure (SSOP) in the intervention area. 100% of cutting boards, 83.3% of scales, 75% of knives, and 50% of cutting saws were contaminated with total coliforms. On the other hand, 100% of cutting boards, 58.3% of scales, 43.8% of knives, and 50% of saws were contaminated with E. coli. In addition, 68% of retailers adopted the suggested hygiene operating procedure. These results show that cleaning and disinfection processes need to be reinforced and that monitoring and ongoing training should be implemented. The results showed high levels of total coliform contamination on all surfaces studied, exceeding regulatory limits. A significant presence of E. coli was detected, indicating failures in cleaning processes. The implementation of the SOP is proposed as an effective and replicable approach to improving food safety in meat sales environments at the market level.
Formulación de galletas de chocolate con harina y grasa de chontacuro (Rhynchophorus palmarum): una estrategia para la valorización de recursos alternativos
(Universidad de Cuenca, 2025-09-17) Peláez Vera, Ricardo Alexander; Aray Rodas, Neil Sebastián; Donoso Moscoso, Silvana Patricia
This research project aimed to formulate cookies using flour and fat from the chontacuro (Rhynchophorus palmarum), evaluating their sensory and bromatological characteristics. Four formulations were prepared with varying proportions of chontacuro flour (0%, 25%, 50%, and 100%), while maintaining a constant amount of insect fat. The cookies underwent sensory evaluation (color, smell, taste, and texture), with the 100% chontacuro flour sample receiving the highest acceptance. This formulation was analyzed and showed a protein content of 14.57%, considerably higher than that of conventional commercial cookies. The results demonstrate that chontacuro is a viable ingredient from nutritional, sensory, and sustainability perspectives. The main challenge for its mass production is the high cost, linked to traditional harvesting methods. However, this could be mitigated through controlled farming. This proposal offers a promising alternative to tackle food insecurity, promote rural economies, and reduce the environmental impact of the conventional food industry.
Encapsulación de polifenoles presentes en el extracto de Desmodium spp. mediante la técnica de gelificación iónica
(Universidad de Cuenca, 2025-09-09) Buñay Chimbaina, Ana Gabriela; Zhimnay Sánchez, Karen Stephanie; Vanegas Peña, María Eulalia
This study evaluated the microencapsulation of phenolic compounds from Desmodium spp. plant extract using ionic gelation, with sodium alginate as the matrix and calcium chloride as the crosslinking agent. A 2² factorial design was applied to analyze the effect of their concentrations on the morphological and functional properties of the microcapsules. Four treatments were formulated; treatment (A2_C3) showed the largest and smallest sizes before and after the drying process, respectively, highlighting the influence of higher biopolymer concentration on the structure and behavior of the microcapsules. Treatments (A2_C3) and (A2_C5) achieved better sphericity and structural stability, with the latter reaching the highest encapsulation efficiency (50.82%). ANOVA analysis revealed that alginate concentration had a statistically significant effect on microcapsule size, while calcium chloride and the interaction between both factors were not significant. Regarding encapsulation efficiency, none of the factors nor their interaction showed statistically significant differences. In the release assays, a greater release of polyphenols was observed in the basic medium (pH 9.2), following a zeroorder kinetic model, characterized by a constant release rate. In contrast, in the acidic medium (pH 2.03), the release was lower and followed the Higuchi model, indicating a Fickian diffusion mechanism without matrix erosion. The results confirm that the system is viable; however, improvements in the formulation are needed to optimize encapsulation efficiency.
Adsorción de diclofenaco e ibuprofeno del agua usando bagazo de caña de azúcar y cáscara de cacao hidrolizado
(Universidad de Cuenca, 2025-09-08) Barzallo Redrovan, Joe Stiven; Guiracocha Orellana, Nathaly Carolina; Peñafiel Herrera, María Eulalia
It was evaluated the adsorption of diclofenac and ibuprofen, two pharmaceuticals considered emerging contaminants, using modified agro-industrial residues as adsorbents: hydrolyzed sugarcane bagasse and cocoa shell. Experiments were carried out in batch reactors and fixed- bed columns to analyze removal efficiency under equilibrium and continuous flow conditions. In the batch system, the effects of adsorbent dosage, pH, initial concentration, and contact time were studied. Experimental data were fitted to kinetic models (pseudo-first order, pseudo- second order, and intraparticle diffusion) and equilibrium models (Langmuir, Freundlich, BET, and Dubinin–Radushkevich). The pseudo-second-order model provided the best fit (R² > 0.90), indicating that both chemical and physical interactions contribute significantly to the process. In fixed-bed columns, the influence of adsorbent mass and flow rate on breakthrough curves was evaluated. The Thomas, Bohart–Adams, Yoon–Nelson, and Dose–Response models were applied, with the latter showing the best correlation (R² > 0.99). For diclofenac, sugarcane bagasse exhibited the highest adsorption capacity (q₀ = 1.31 mg/g), while for ibuprofen the best performance was obtained with cocoa shell (q₀ = 0.86 mg/g), both under specific mass and flow conditions. The findings confirm that these agro-industrial by-products, being low-cost, readily available, and environmentally sustainable, represent a promising alternative for water treatment technologies aimed at the removal of pharmaceutical pollutants.
Obtención de clara de huevo en polvo, mediante secado por aspersión, una propuesta tecnológica para el aprovechamiento de materia prima secundaria en una industria artesanal de elaboración de quesadillas
(Universidad de Cuenca, 2025-09-07) Ochoa Barrera, Pedro José; Andrade Muñoz, Diana Jesús
This study evaluated the technical and operational feasibility of obtaining egg white powder through spray drying using maltodextrin as an encapsulating agent, aiming to promote the sustainable utilization of poultry by-products generated by the artisanal quesadilla industry in Cuenca. Preliminary tests revealed clogging in the atomization system when processing liquid egg white without an encapsulant, which led to the incorporation of maltodextrin at 10% and 15% concentrations. A factorial design was applied to determine optimal processing parameters, resulting in the best conditions being an inlet temperature of 140 °C, feed rate of 12.5 mL/min, and 15% maltodextrin. Under these parameters, the final product showed a moisture content of 7.01%, protein content of 88.57% (wet basis), total carbohydrates of 2.13%, and fat content of 1.69%, complying with the NTE INEN 1973 standard for egg products. Microbiological analysis confirmed the absence of Salmonella spp. and low yeast and mold counts, ensuring product safety. The process yield was 12.29 %, higher than previous studies without encapsulants (6.3%, 7.69%, and 10% at 120 °C, 140 °C, and 160 °C, respectively). These results demonstrate that spray drying with maltodextrin addition is an efficient technological alternative for producing high-quality nutritional and functional egg white powder, fostering sustainable practices and the valorization of by-products in the local food industry.
Elaboración de membranas poliméricas a base polietilenotereftalato (PET) reciclado con nanotubos de carbono mediante electrohilado
(Universidad de Cuenca, 2025-09-01) Aguirre Sanmartin, Pedro Xavier; Vera Cabezas, Luisa Mayra
One of the problems faced by the scientific community is plastic pollution, as plastics have the potential to cause significant harm to the environment and human health. Therefore, it is important to add value to them through recycling. In this work, three polyethylene terephthalate (PET) membranes were created using the electrospinning technique. For the first membrane, only trifluoroacetic acid (TFA) was used as the solvent; in the second, a mixture of TFA and dichloromethane (DCM) in a 55:45 w/w ratio was used; and in the third, the same ratio was used, but multi-walled carbon nanotubes (MWCNTs) were added at a concentration of 3,72% w/w relative to the weight of the polymer. The membrane was electrospun at a voltage of 20 kV, a flow rate of 3.5 ml/h, and with a needle of 0.7 mm outer diameter. The membranes were characterized using atomic force microscopy (AFM) in non-contact mode (NCM) and electrostatic force microscopy (EFM). These analyses revealed that the incorporation of nanotubes altered the membrane’s morphology. Starting from an average fiber diameter of 1339 μm and an average pore diameter of 0.235 μm, a 37.74% decrease in fiber diameter and a 43.89% increase in pore size were observed. Additionally, it was confirmed that the membrane exhibited higher electrical conductivity compared to the original membrane, suggesting its potential application in water treatment, and biogas production.
Diseño y construcción de un reactor para el tratamiento de aguas residuales del proceso de tintura en la industria de la paja toquilla, empleando radiación UV y nanopartículas de dióxido de titanio como catalizador
(Universidad de Cuenca, 2025-09-08) Jiménez Alvarado, Julieth Maricela; Sigüenza Brito, Karen Juliana; Montero Izquierdo, Iván Andrés; Pinos Vélez, Verónica Patricia
This study addresses the design, construction, and evaluation of a batch reactor for the photodegradation of wastewater from the dyeing of toquilla straw hats. The objective was to develop an efficient and energy-efficient system, applying advanced oxidation technologies such as the photo-Fenton process with titanium dioxide (TiO₂) doped with ferric chloride (FeCl₃) as a catalyst. The reactor, constructed of 4 mm borosilicate glass to take advantage of its UV transmission and thermal resistance, has an operating volume of 850 mL and dimensions of 10.2 cm in diameter by 14 cm in height. A stirring system with a stainless-steel propeller and acrylic baffles was incorporated, along with UV LED lighting (365 nm) monitored with a sensor UV GUYA -S12SD and Arduino Uno board. Different concentrations of FeCl₃ were evaluated, determining that the optimal Fe+3 support is 5% and the ideal catalyst mass of 5 g for the working volume. Decolorization tests showed removal rates of over 50% in six hours for red aniline at 50, 30, and 20 ppm; for black aniline, the test at 50 ppm alone also exceeded 50% at the same time. The projection for red aniline at 50 ppm indicated that 90% dye removal is possible after 23 hours of operation. The developed system enables effective and sustainable treatment of wastewater from the artisanal industry, optimizing resources and energy.
Elaboración de un queso análogo sin el empleo de proteína de origen animal, hecho a base de amaranto dirigido para el consumo de personas con intolerancia a la lactosa
(Universidad de Cuenca, 2025-09-09) Alcocer Idrovo, Mercedes Scarlet; Minga Seminario, Paula Cristina; Peña González, Silvia Alexandra
Given the increasing prevalence of lactose intolerance, there is a growing need to develop food alternatives that replace conventional dairy products without compromising their nutritional and sensory properties. This research aimed to formulate a cream-type cheese analogue based on amaranth (Amaranthus caudatus L.) plant-based beverage, intended for consumers with lactose intolerance. The study followed a quantitative-experimental approach, structured into three phases: physicochemical characterization of the plant-based beverage, product formulation through pilot tests, and sensory acceptability analysis using a completely randomized block design. Five experimental formulations were developed and evaluated by 75 lactose-intolerant consumers using hedonic scales. Treatment T5 obtained the highest acceptance, particularly for attributes such as flavor, texture, and appearance. The physicochemical analysis of this formulation showed a moisture content of 65%, fat content of 35%, and protein content of 1.7%. To assess its industrial feasibility, a Process Flow Diagram (PFD) was designed, integrating the key technological stages and required equipment under criteria of efficiency, hygiene, and scalability. Results demonstrated that amaranth-based beverage is a suitable matrix for analogue products and that the developed cheese offers competitive sensory qualities and commercial potential. It is concluded that the proposed formulation not only meets nutritional and technological requirements but also represents a sustainable, functional, and inclusive alternative for the food industry.
Obtención de un suplemento soluble a base de calostro saborizado con panela y canela (Cinnamomum verum Presl) mediante secado por aspersión
(Universidad de Cuenca, 2025-09-08) Romero Carrión, Shelly Micaela; Andrade Muñoz, Diana Jesús
The objective of this work is to develop a functional soluble supplement based on colostrum flavored with panela and cinnamon (Cinnamomum verum Presl) using spray drying, with the aim of taking advantage of its nutritional value and extending its shelf life. The research focuses on recovering this resource through a process that allows it to be converted into an accessible and functional supplement, considering that its availability in the domestic market is limited. To this end, a premix was developed by adjusting the proportions of each ingredient and controlling the Brix degrees. The optimal formulation obtained was 77% colostrum, 12% panela, and 11% maltodextrin, with a constant cinnamon content of 2.786%. This combination allowed a desired value of 27 °Brix to be achieved. Subsequently, the appropriate parameters for the LabPlant® SD-Basic Spray Dryer equipment were determined, establishing an inlet temperature of 100 °C and a feed rate of 6.3 mL/min as optimal conditions. Under these conditions, a powder with low moisture content (2.01%) and water activity (0.17) was obtained. In addition, the protein content was evaluated before and after drying (9.018% and 16.911%, respectively), and physicochemical and microbiological analyses were performed, with values found to be within the ranges established by standards NTE INEN:2016 and NTE INEN 298:2011, demonstrating its quality and safety.
Elaboración de cerveza artesanal con levadura silvestre y comparación de parámetros frente a levadura comercial
(Universidad de Cuenca, 2025-09-08) Aucapiña Rodriguez, Juan Javier; Ramirez Romero, Ramiro Jose; Astudillo Ochoa, Gonzalo Javier
In this study, microbiological techniques were proposed for isolating a pure culture of non-conventional yeasts present in sourdough, which is prepared with a mixture of flour and water and subsequently fermented under ambient conditions. Several culture media were prepared, initially employing peptone, sucrose, and dextrose. Among the evaluated media, sucrose proved to be the most efficient in terms of yeast growth. This yeast culture was used as the fermenting agent in the production of a batch of American pale ale craft beer. The resulting beer was analyzed through physicochemical tests including alcohol content, turbidity, specific gravity, density, and degrees Plato; and organoleptic characteristics such as flavor, color, bitterness, aroma, and foam—compared with a craft beer brewed using conventional brewer’s yeast (Saccharomyces cerevisiae). With the microbiological culture obtained, a batch of craft beer was successfully produced. Organoleptic analysis showed that the use of non-conventional yeasts resulted in acceptable sensory characteristics for aroma, color, and flavor. However, other sensory traits suggested that these yeasts did not enhance bitterness or foam formation. Moreover, physicochemical comparison revealed lower alcohol production, increased turbidity, and reduced utilization of fermentable sugars by the microorganisms, as evidenced by the small difference in °Plato between the start and end of fermentation.
Evaluación de la eficiencia de absorción de vermifiltros para la remoción de ciprofloxacina
(Universidad de Cuenca, 2025-09-08) Bojorque Palacios, Juliana Marcela; Merchan Ordoñez, Karen Mabel; Guanuchi Quito, Alexandra Elizabeth
The existence of pollutants whose consequences are not directly detectable poses an environmental crisis. These are known as emerging pollutants. Drugs are among them, such as ciprofloxacin (CIP). This drug is absorbed in the intestinal tract, where 40% to 50% is not metabolized and is excreted as feces and urine, reaching wastewater that is treated inefficiently and nonspecifically. Therefore, vermifiltration is proposed, a technology based on the removal of contaminants by Eisenia foetida worms due to their bioactivity, rapid acclimatization, high reproductive capacity, and survival. These worms consume the drug, transforming 60% into humus and using the rest in cellular processes. The objective of this research is to evaluate the absorption efficiency of this technology for the removal of ciprofloxacin from water. Two laboratory-scale filters were constructed, one with worms (vermicomposting filter) and the other called a control or blank filter, to make comparisons between the two objects. The study will be carried out with synthetic domestic wastewater containing 2 ppm of the drug. Using solid-phase extraction (SPE) and high-performance liquid chromatography (HPLC), a removal percentage of up to 97.99% of CIP was obtained, of which 3.5% was due to the effect of the worms, thus concluding that it is a viable method. However, further research is needed to explore greater results from the test organism.
Uso de la transglutaminasa (TG) en la formulación de jamón de pierna de cerdo con reducción parcial de los fosfatos
(Universidad de Cuenca, 2025-09-05) Avilés Abadie, Doménica Stephany; Astudillo Segovia, Servio Rodrigo
This study aimed to evaluate the impact on the sensory quality of pork leg ham by incorporating transglutaminase and partially reducing phosphates. Five formulations with varying ratios of transglutaminase and phosphates were developed, following the requirements of the Ecuadorian technical standard INEN 1338:2016. A sensory analysis was conducted with 50 convenience-selected panelists using affective tests and a hedonic scale. Results were analyzed through ANOVA in RStudio, and Tukey’s post hoc test was applied to compare means. The optimal treatment (T2), that contained 5 g of transglutaminase and 1 g of phosphates, achieved the highest acceptance and texture ratings. Additionally, microbiological, bromatological, cost, and shelf-life stability analysis were conducted on the optimal treatment. The product met microbiological safety limits shown by INEN standards. The bromatological analysis showed a protein content of 16.24%, fat of 4.8%, and moisture of 76%, classifying it as a type 1 product. The estimated production cost was $1.67 per 200 g package, showing potential market profitability. Lastly, the shelf-life evaluation under 25 °C and 50% relative humidity showed that the product remained safe for consumption for up to 30 days.
Reemplazo de proteína cárnica por proteínas alternativas no cárnicas, para la elaboración de embutidos escaldados
(Universidad de Cuenca, 2025-09-03) Yugsi Pangol, Lizbeth Alexandra; Astudillo Segovia, Servio Rodrigo
This research project aimed to develop a non-meat Vienna-type sausage using alternative proteins such as soy and egg albumin, addressing the growing demand for healthier, more sustainable foods aligned with modern dietary trends. Several formulations were developed and evaluated through sensory analysis using consumer surveys, selecting the sample with the highest acceptance. Based on this preferred formulation, bromatological, microbiological, and economic analyses were carried out to validate its feasibility as an alternative to traditional meat-based sausages. The results showed that the selected sample presented a superior nutritional profile, with higher protein content and lower fat content compared to the pork-based counterpart, while also meeting current food safety regulations. Regarding preservation, complementary strategies were applied to improve the product’s microbiological and sensory stability, achieving an appropriate shelf life under refrigerated conditions. Finally, the cost analysis revealed a significant reduction in production costs compared to the traditional formulation, reinforcing its industrial feasibility. In summary, this study demonstrates that it is possible to develop a scalded sausage based on non-meat proteins with competitive quality, safety, functionality, and cost, confirming its potential as an innovative food product for the current market.
Aprovechamiento de subproductos provenientes del despiece de canales avícolas como materia prima en la elaboración de productos cárnicos
(Universidad de Cuenca, 2025-09-05) Rivadeneira León, Karen Lizbeth; Astudillo Segovia, Servio Rodrigo
This study implemented an efficient process in a meat industry to valorize poultry by-products through mechanical deboning, evaluating the technological, nutritional, and economic quality of the obtained Mechanically Deboned Meat (MDM). Two formulations were compared: MDM A (80% breast meat) and MDM B (necks, wings, frames), processed under different pressure combinations (6 and 11 bar) and mass flows (350, 400, 450 kg/h). MDM B achieved a higher yield (67.84%), influenced by its high moisture content (75.92%). MDM A showed a moderate yield (57.86%) but superior bromatological quality, with higher protein (14.99%) and fat (12.32%) content, as well as greater profitability ($0.60/kg vs. $0.51/kg for MDM B). Both complied with microbiological safety requirements. It is concluded that MDM A is the most suitable option for manufacturing meat products such as sausages, as it combines better nutritional, functional, and economic attributes.
Estudio de la decoloración de colorantes en aguas residuales provenientes de la industria de paja toquilla mediante procesos de oxidación avanzada empleando como catalizador ferrita de zinc preparada con pilas usadas
(Universidad de Cuenca, 2025-09-04) Loayza Cueva, Camila Maite; Pinos Vélez, Verónica Patricia
This work evaluates the decolorization of wastewater from artisanal toquilla straw dyeing through photocatalysis and photo-Fenton processes, using zinc ferrite synthesized from commercial reagents and alkaline batteries as catalysts. The ferrites were prepared and characterized by assessing their structure, surface area, and porosity. It was observed that the battery-derived ferrite has a lower surface area but larger pores, which influences its catalytic activity. Photocatalysis experiments resulted in removals of the aniline red dye below 2%, whereas the photo-Fenton process achieved removals of 33.4% for ferrite from commercial reagents and 40.2% for battery-derived ferrite within 3 hours. Statistical analysis using ANOVA and post hoc tests found statistically significant differences between the decolorization percentages achieved with the photo-Fenton method, but no significant differences were observed by ferrite type in photocatalysis. The kinetic study revealed that the degradation follows a pseudo-first order model with an average rate constant of 0.003 min-1 and a 22 factorial design showed that both the catalyst amount and H2O2 dosage affect the efficiency. These results identified the most efficient treatment as the photo-Fenton process using ferrite obtained from alkaline batteries, confirming that this ferrite is a viable catalyst for wastewater treatment.
Modelamiento de la producción de bioetanol a partir de la holocelulosa obtenida mediante refinamiento catalítico de cáscara de cacao y su posterior hidrólisis enzimática y fermentación alcohólica
(Universidad de Cuenca, 2025-09-04) García Pesantez, Claudia Belén; Iturralde Vela, Samanta Katherine; Delgado Noboa, Jorge Washington
In this study, a process was developed for the production of bioethanol from holocellulose extracted from cacao husk (Theobroma cacao L.), employing a catalytic pretreatment based on the Lignin-First approach, followed by enzymatic hydrolysis and alcoholic fermentation. The main objective was to evaluate the efficiency of catalytic refinement in sugar conversion and to optimize the enzymatic hydrolysis conditions. Three experimental runs were carried out using different concentrations of cellulases from Trichoderma reesei (Celluclast) (0.1, 0.2, and 0.3 mL/g) and hemicellulases from Aspergillus niger H2125 (0.1 and 0.3 g/g). The highest sugar release was achieved at the highest enzyme concentrations, reaching 489.967 mg/g, while the fermentation efficiency was 88.62%, resulting in a bioethanol yield of 3.36 g/L, equivalent to 112 g/kg of dry biomass. Although no significant differences in sugar release were observed compared to non-catalyzed samples during the hydrolysis stage, the catalytic treatment significantly enhanced the fermentability of the substrate. Furthermore, the kinetic behavior of the fermentation process was modeled using the modified Gompertz equation, yielding a determination coefficient (R2) of 0.97, thus validating the consistency between the experimental data and the simulation performed in MATLAB. The results confirm that catalytic pretreatment is a viable strategy to increase the efficiency of bioethanol production from lignocellulosic biomass; however, further optimization is recommended to reduce losses and minimize the formation of inhibitory compounds.
Formulación de un medio de cultivo enriquecido con extractos de microalgas para el desarrollo y crecimiento de Cattleya híbrida con herramientas de diseño experimental
(Universidad de Cuenca, 2025-09-01) Barrera Siguenza, Amanda Marcela; Cazar Ramírez, María Elena
This study evaluated the potential of microalgae extracts as a nutrient source in in vitro culture media for the growth and development of orchids of the genus Cattleya. A 2³ factorial design was used to analyze the effect of the combination of algae extract and the growth hormones α-naphthaleneacetic acid (NAA) and 6-benzylaminopurine (BAP) on sprout, leaf, and root growth of Cattleya seedlings under controlled conditions. The results showed that the addition of algae extract together with NAA significantly promoted root development, while the combination of microalgae extract with NAA and BAP enhanced leaf length, demonstrating a positive interaction in growth. In contrast, no significant effects were observed on shoot length, which remained stable across treatments. The characterization of the microalgae extract showed an ash content of 15.1%, phosphorus content of 1.2%, and nitrogen content of 5%, confirming its richness in essential nutrients for plant development. These findings confirm that microalgae extracts can be used as sustainable biostimulants in in vitro cultures, improving the propagation efficiency of orchids and contributing to their conservation under controlled conditions.
Evaluación de las propiedades antimicrobianas de hidrolatos de urtica dioica y eucalyptus globulus para la desinfección de aguas residuales provenientes de un vermifiltro
(Universidad de Cuenca, 2025-09-01) Quinde Quito, Cynthia Ximena; Toledo Medina, Jaira Tatiana; Guanuchi Quito, Alexandra Elizabeth
This study presents a comparative evaluation of the efficacy of hydrosols obtained from Urtica dioica (nettle) and Eucalyptus globulus (eucalyptus) as a natural and sustainable alternative for the removal of total coliforms, fecal coliforms, and amoebae present in domestic wastewater treated through a vermifiltration system. The hydrosols were obtained using the steam distillation extraction method. Six treatments with varying concentrations and contact times were tested, achieving removal efficiencies of 90 % to 100 % for total coliforms, 90 % to 100 % for fecal coliforms, and 85.71 % to 100 % for amoebae. The antimicrobial efficacy of the treatments was attributed to the presence of flavonoids, tannins, terpenes, phenolic compounds, and carotenoids, as supported by the literature review. The most effective treatments were T2, consisting of 70 % aqueous eucalyptus extract with a 3- hour contact time and a cost of USD 0.94; and T4, with 50 % aqueous eucalyptus extract and a 4-hour contact time at a cost of USD 0.91. Both treatments achieved 100 % removal of the target microorganisms, positioning them as the most viable and effective disinfection alternatives for the treatment of domestic wastewater.
Uso de biocarbón obtenido del bagazo de caña en la remoción de cromo hexavalente de soluciones acuosas
(Universidad de Cuenca, 2025-09-01) Shinin Espinoza, Michelle Stephany; Vivanco Troya, Paúl Emerson; Vera Cabezas, Luisa Mayra
Cr(VI) contamination, a toxic and carcinogenic heavy metal, is a critical environmental problem in Ecuador, especially in the tanning industry, which generates effluents with high concentrations of this pollutant. Given the limitations of conventional treatment methods, this research evaluates biochar obtained from sugarcane bagasse as a potential adsorbent for the removal of Cr(VI) from aqueous solutions. The bagasse was subjected to slow pyrolysis under an inert atmosphere to obtain a carbonaceous material with high porosity and surface area. Biochar characterization included particle size analysis, FTIR spectroscopy, BET analysis, and zero-charge point analysis. Adsorption tests were performed in batches, varying parameters such as contact time, pH, and adsorbent dosage, and kinetic and equilibrium models were applied to describe the adsorption mechanism. The results show a removal efficiency greater than 90% under optimal conditions and a suitable contact time of 30 minutes. By fitting the experimental data to kinetic and equilibrium models, a favorable dual adsorption mechanism was determined: chemisorption and physisorption; additionally, an initial phase limited by intraparticle diffusion, followed by a phase limited by the boundary layer and/or by the approach to equilibrium. Therefore, it is concluded that sugarcane bagasse biochar represents a sustainable, economical, and efficient alternative for the treatment of water contaminated with Cr(VI), promoting the valorization of agroindustrial waste and contributing to the mitigation of the environmental impact of the tanning industry.

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