Ciencia e Ingeniería en Alimentos y Biotecnología

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Subject: search.filters.subject.ACTIVIDAD ANTIMICROBIANA

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    Evaluación del efecto antiproliferativo de la cefalexina cargada en nanopartículas de quitosano sobre células de cáncer de próstata
    (Universidad Técnica de Ambato. Facultad de Ciencia e Ingeniería en Alimentos y Biotecnología. Carrera de Biotecnología, 2026-01) Rodríguez Guaño, Justin Damián; Núñez Villacís, Lorena de los Ángeles
    Prostate cancer is one of the leading causes of morbidity and mortality among men worldwide, driving the search for more effective and less toxic therapeutic alternatives than conventional treatments. In this context, the present study evaluated the antiproliferative effect of cefalexin, a β-lactam antibiotic with emerging anticancer potential, nanoencapsulated in chitosan for its application in PC-3 prostate cancer cells. The nanoparticles were prepared through ionic gelation with tripolyphosphate, resulting in a stable and homogeneous nanostructured system. FT-IR characterization confirmed the drug encapsulation by the modification of characteristic bands, while encapsulation efficiency and drug content demonstrated that the system retains a significant amount of cefalexin. SEM microscopy revealed spherical nanoparticles with a uniform surface, reaffirming the quality of the nanocarrier. In biological assays, free cefalexin showed antiproliferative capacity dependent on concentration and time; however, its nanoencapsulated version achieved a significantly greater cytotoxic effect. Cells treated with nanoparticles showed a notable reduction in viability, along with morphological alterations characteristic of apoptosis and necrosis, confirming better internalization and effective drug release. Higher concentrations caused severe cellular damage, demonstrating that the cefalexin-chitosan combination enhances anticancer activity against the PC-3 cell line. These results demonstrate that the nanoencapsulation of cefalexin in chitosan substantially improves its antiproliferative activity, positioning this system as a promising candidate in the fields of drug repositioning and oncological nanomedicine.
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    Evaluación de la capacidad inhibidora del aceite esencial de tomillo (Thymus vulgaris) microencapsulado en la conservación de la carne de pollo (Gallus gallus domesticus)
    (Universidad Técnica de Ambato. Facultad de Ciencia e Ingeniería en Alimentos y Biotecnología. Carrera de Alimentos, 2026-01) Jácome Vizuete, Steven Daniel; López Hernández, Orestes Darío
    The preservation of chicken meat (Gallus gallus domesticus) in the Ecuadorian food industry presents a constant challenge due to its high susceptibility to microbial spoilage and high consumption. Finding a way to extend shelf life is crucial. Therefore, by applying the microencapsulation technique, the aim is to influence the inhibitory effect of thyme essential oil (Thymus vulgaris). The methodology begins with microencapsulation using proportions of gum arabic and maltodextrin. To verify proper microencapsulation, Fourier transform infrared spectroscopy (FTIR) was performed on all samples. The microencapsulated product was used as an inhibitor, dissolved in solutions at different concentrations in which the chicken meat was immersed for three different durations, resulting in a total of 10 treatments, including the control. Statistical tools were used for data comparison (Statgraphics 19) and it was concluded that treatment 9 has a higher percentage of germicidal efficiency, which was tested against a control treatment to determine the shelf life at zero degrees Celsius, resulting in 3 days for the control treatment and 10-11 days for the chicken meat samples with the best treatment.
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    Evaluación de la capacidad inhibidora del aceite de tomillo (Thymus vulgaris) en la conservación de la carne de pollo (Gallus gallus domesticus)
    (Universidad Técnica de Ambato. Facultad de Ciencia e Ingeniería en Alimentos y Biotecnología. Carrera de Alimentos, 2025-07) Chugchilán Caiza Liliana Estefania; Lascano Sumbana Alexandra Virginia
    This research aims to harness the potential of thyme essential oil (Thymus vulgaris) as an inhibitory agent to prevent spoilage in chicken meat (Gallus gallus domesticus). The growing demand for natural alternatives to synthetic preservatives in the food industry has driven research into essential oils as biopreservatives. Food safety is an increasingly important issue, regardless of advancements in public health and food preservation. Chicken meat is a nutritious food, but its high water and nutrient content makes it more susceptible to contamination and oxidation, which limits its shelf life. The employed methodology consisted of applying thyme essential oil (Thymus vulgaris) as an inhibiting agent in the different solutions, the immersion method was applied to refrigerated chicken stored at four degrees Celsius, in the different concentrations and times of thyme essential oil, which allowed for maintaining the chicken´s characteristics for a longer time, as well as reducing its microbial load in the case of mesophilic aerobes and Escherichia coli. It was concluded the thyme essential oil is a good viable and safe alternative for extending the shelf life of chicken meat, reducing the microbial load while maintaining its organoleptic properties, thus contributing to the development of safer and more natural food for consumer health.
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    Uso de suelos supresivos como tratamiento biológico para controlar la infección de Mildiu (Peronospora variabilis Gaum.) en el cultivo de quinua (Chenopodium quinoa Willd.)
    (Universidad Técnica de Ambato. Facultad de Ciencia e Ingeniería en Alimentos y Biotecnología. Carrera de Biotecnología, 2025-07) Tapia Chicaiza Dayana Abigail; Sánchez Garnica Manoella Alejandra
    Quinoa (Chenopodium quinoa Willd.) cultivation faces a significant threat from downy mildew (Peronospora variabilis Gaum.), a disease capable of reducing yields by up to ninety percent, which represents a serious obstacle to food security in high-altitude regions. To address this issue, the use of suppressive soils as a biological treatment was proposed, offering an ecological and cost-effective alternative to synthetic fungicides. The research was conducted through a comparative analysis between suppressive and conducive soils, evaluating their physicochemical and microbiological characteristics, including metagenomic analysis to identify the present microbial diversity. A bio-input was developed from the suppressive soil and evaluated through in vitro tests to determine its biocontrol capacity against P. variabilis and later validated under greenhouse conditions through inoculation in quinoa plants. The results revealed that the suppressive soil exhibited a slightly more acidic pH, higher organic matter content, and significantly greater beneficial microbial diversity, conditions that favor the establishment of antagonistic microorganisms. The formulated bio-input completely inhibited the pathogen's growth in laboratory conditions, and in greenhouse trials, the treated plants achieved one hundred percent survival, in contrast with the high mortality observed in the control groups. This confirmed that the use of suppressive soils and derived bio-inputs, supported by microbiological analysis with a metagenomic approach, represents an effective, sustainable strategy aligned with the principles of ecological agriculture for the control of downy mildew in quinoa.
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    Uso de suelos supresivos como tratamiento biológico para controlar la infección de Mildiu (Peronospora variabilis Gaum.) en el cultivo de quinua (Chenopodium quinoa Willd.)
    (Universidad Técnica de Ambato. Facultad de Ciencia e Ingeniería en Alimentos y Biotecnología. Carrera de Biotecnología, 2025-07) Narvaez Quilligana Leslie Nicole; Sánchez Garnica Manoella Alejandra
    BIOTECNOLOGÍA AGRÍCOLA, FITOPATOLOGÍA, SUELOS SUPRESIVOS, CONTROL BIOLÓGICO, ACTIVIDAD ANTIMICROBIANA, BIOINSUMOS, MILDIU, QUINUA, PERONOSPORA VARIABILIS Abstract: Quinoa (Chenopodium quinoa Willd.) cultivation faces a significant threat from downy mildew (Peronospora variabilis Gaum.), a disease capable of reducing yields by up to ninety percent, which represents a serious obstacle to food security in high-altitude regions. To address this issue, the use of suppressive soils as a biological treatment was proposed, offering an ecological and cost-effective alternative to synthetic fungicides. The research was conducted through a comparative analysis between suppressive and conducive soils, evaluating their physicochemical and microbiological characteristics, including metagenomic analysis to identify the present microbial diversity. A bio-input was developed from the suppressive soil and evaluated through in vitro tests to determine its biocontrol capacity against P. variabilis and later validated under greenhouse conditions through inoculation in quinoa plants. The results revealed that the suppressive soil exhibited a slightly more acidic pH, higher organic matter content, and significantly greater beneficial microbial diversity, conditions that favor the establishment of antagonistic microorganisms. The formulated bio-input completely inhibited the pathogen's growth in laboratory conditions, and in greenhouse trials, the treated plants achieved one hundred percent survival, in contrast with the high mortality observed in the control groups. This confirmed that the use of suppressive soils and derived bio-inputs, supported by microbiological analysis with a metagenomic approach, represents an effective, sustainable strategy aligned with the principles of ecological agriculture for the control of downy mildew in quinoa.
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    Análisis de la capacidad antimicrobiana de un péptido obtenido en un sistema de expresión Escherichia coli J53 frente a cepas de Staphylococcus spp.
    (Universidad Técnica de Ambato. Facultad de Ciencia e Ingeniería en Alimentos y Biotecnología. Carrera de Biotecnología, 2025-02) Llambo Charco, Darwin Marcelo; Garcés Moncayo, María Daniela
    Pathogenic microorganisms of the Staphylococcus spp. genius have represented one of the main causes of infections in nosocomial environments, immunosuppressed population, and patients with medical devices. The S. aureus strain has been particularly worrying due to its increasing resistance to antibiotics such as methicillin (MRSA) and certain beta-lactams such as cephalosporin and penicillin due to the presence of the mecA gene. Obtaining proteins from expression systems is a viable alternative for the development of new therapeutic avenues for infections caused by the Staphylococcus spp. genus. This research project was developed with the aim of analyzing the antimicrobial capacity of the peptide Alpha-1-Purothionine obtained in an E. coli J53 expression system against strains of S. aureus and coagulase-negative S. (CoNS). The process began with the cellular chemically competent of the host, induction with IPTG and the analysis of the expression by means of SDS PAGE, where a certain level of basal expression is evident. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were evaluated. Finally, it was determined that the peptide presented antimicrobial properties, inhibiting the growth and development of the S. aureus and CoNS strains through colorimetric verification using the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC), showing values of 8,5 micrograms per millimeters for S. aureus and 17,0 micrograms per millimeters for CoNS.
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    Uso de las propiedades antimicrobianas del quitosano contra patógenos alimentarios
    (Universidad Técnica de Ambato. Facultad de Ciencia e Ingeniería en Alimentos y Biotecnología. Carrera de Alimentos, 2025-02) Flores Barona, Joselyne Anabell; Sánchez Garnica, Manoella Alejandra
    This study focuses on the antimicrobial properties of chitosan to combat foodborne pathogens present in fresh cheeses, a significant public health problem due to foodborne illnesses. Pathogens such as Escherichia coli and Staphylococcus aureus are responsible for numerous foodborne infections, highlighting the need for effective alternatives to synthetic preservatives. The main objective of this study was to evaluate the efficacy of chitosan as an antimicrobial agent against these pathogens. The methodology included the determination of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) by microdilution and disc diffusion techniques. Chitosan solutions were prepared, and their effects on E. coli and S. aureus strains isolated from fresh cheeses were evaluated. The results showed that chitosan had an MIC of 165 micrograms per millilitre for E. coli and 10 micrograms per millilitre for S. aureus, indicating an increased susceptibility of gram-positive bacteria. In addition, inhibition percentages of 62.5 percent for E. coli and 60 percent for S. aureus were observed. The most relevant findings suggest that chitosan is a promising natural preservative capable of inhibiting the growth of food pathogens, which could improve food safety and extend the shelf life of dairy products such as fresh cheeses without compromising their quality. Further studies are recommended to optimize its application in the food industry.
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    Evaluación de la actividad antimicrobiana in vitro de aceites esenciales frente a microorganismos patógenos y del deterioro de alimento
    (Universidad Técnica de Ambato. Facultad de Ciencia e Ingeniería en Alimentos y Biotecnología. Carrera de Biotecnología, 2025-02) Chango Chimborazo, Yajaira Estefania; Arancibia Soria, Mirari Yosune
    Essential oils (EOs) are volatile compounds, rich in secondary metabolites such as monoterpenes and sesquiterpenes, noted for their antimicrobial activity, attributed to their hydrophobicity and high concentration of active phenols (thymol, carvacrol, and eugenol). These compounds alter the integrity of microbial membranes, increasing their permeability and generating oxidative stress. The agar diffusion method is used to categorize antimicrobial activity into four levels (+++; fully inhibited, ++; partially inhibited, +; slightly inhibited, and -; no inhibition). However, this method presented limitations due to the volatility and hydrophobicity of EOs, which affected their uniform diffusion. The in vitro evaluation of 50 EOs against 12 microorganisms revealed greater efficacy against Gram-positive bacteria due to their more permeable cell wall. Although Gram-negative bacteria are more resistant due to their complex outer membrane. EOs such as thyme and oregano were able to inhibit them thanks to their bioactive compounds. In contrast, anaerobic Clostridium perfringens showed complete resistance, likely due to their spore-forming capacity and the reduced production of reactive oxygen species (ROS) in the absence of oxygen, which limits the antimicrobial action of EOs. In fungi, thyme and cinnamon showed significant activity, while against beneficial bacteria the action was minimal. Their efficacy depends on the active compounds, oil volatility, and experimental conditions. Finally, EOs represent a sustainable and natural alternative as antimicrobial agents, aligning with the Sustainable Development Goals (SDGs). Their application in the food and pharmaceutical industries can improve food safety and meet the demand for natural preservatives in consumer products.
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    Evaluación de las propiedades antimicrobianas del hongo cola de pavo (Trametes versicolor (L.) Lloyd) y su aplicación como conservante en queso fresco
    (Universidad Técnica de Ambato. Facultad de Ciencia e Ingeniería en Alimentos y Biotecnología. Carrera de Alimentos, 2025-02) Arteaga Teneda, Andrés Leonardo; Sánchez Garnica, Manoella Alejandra
    The excessive consumption of processed foods with high levels of chemical additives has generated concern owing to the potential adverse effects on human health in both the short and long term. In this context, fungi have been proposed as promising alternatives for the production of natural food additives because of their functional and beneficial properties, as well as their ability to replace synthetic additives. For this purpose, a methanolic extract of the turkey tail fungus (Trametes versicolor (L.) Lloyd) was developed using the maceration method, which achieved the extraction of secondary metabolites together with the solvent methanol. The antimicrobial properties of the extract were evaluated using the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) against Escherichia coli ATCC 11775 and Staphylococcus aureus ATCC 25923, using resazurin as an indicator, which allowed the observation of coloration changes. For food application, a fresh cheese was developed incorporating the fungus extract, and its shelf life was determined by counting colony forming units (CFU) per gram of Enterobacteriaceae for 5 days. In addition, the Arrhenius equation was used to predict its stability by comparing it with a traditional preservation method such as brine. The T. versicolor extract exhibited antimicrobial properties, as evidenced by the inhibition of the growth of the studied strains of E. coli and S. aureus, as confirmed by MIC and BMC assays. Likewise, the extract showed preservative effects in fresh cheese that were comparable to those obtained with brine, according to the results obtained through the prediction of shelf life based on the Arrhenius equation.
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    Eficiencia del almidón de chonta (Bactris gasipaes) como agente encapsulante sobre la actividad antimicrobiana de la doxiciclina
    (Universidad Técnica de Ambato. Facultad de Ciencia e Ingeniería en Alimentos y Biotecnología. Carrera de Biotecnología, 2025-02) Aponte Urrutia, Kerly Anais; López Hernández, Orestes Darío
    Doxycycline is an antibiotic of great interest in the health area, since it serves as a treatment for a variety of bacterial infections, but it has a drawback since it tends to degrade very easily at the time of its production, that is why new alternatives have been sought to preserve its bioactive components and protect it from contamination and even increase its bioavailability with the help of microencapsulation which is a technique that uses encapsulating materials such as natural polymers in order to generate greater effectiveness in encapsulation. For this, three suspensions were made with different proportions, using analysis techniques and verification of microencapsulation efficiency which were, performance analysis, statistical analysis, thermograms by means of differential scanning calorimetry (DSC) and antimicrobial evaluation, which was carried out by means of antibiograms of diffusion disks in Müller Hinton agar, to determine the inhibition of the microencapsulate against the E. coli bacteria. Through the different analyses carried out, it was obtained that the best performance and inhibition halos were given in the proportion 20:80, in addition to this, through the thermograms it was possible to observe the melting peaks where it was also represented that the best curve was that of the proportion 20:80. This is thanks to the fact that with a higher polymeric load, the percentage of microencapsulation efficiency increases. This could also be observed with the help of an-ANOVA analysis, which allowed the most significant performance to be seen through statistical graphs.