Química
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Item Análisis estructural y supramolecular del compuesto (e)-3',6'-dihidroxi-2-((pyridina-2-yl metileno) amino) spiro[isoidolina-1,9'-xanteno]-3-ona(Universidad Santiago de Cali, 2019) Cardona Restrepo, Camila; Fernando D¨vries, RichardThe crystalline structure of the compound (E) -3 ',6'-dihydroxy-2-((pyridine-2-and methylene) amino) spiro [iso-idoline-1,9'-xanthene] -3-one was solved and refined, using single crystal X-ray diffraction data. It was found that the compound crystallized in the triclinic P-1 space group. its unit cell present two molecules per asymmetric unit, which correspond to molecular conformers. Moreover, an analysis to determine the intermolecular interactions from the crystalline system was performed. It was observed that the crystal packing is formed mainly by hydrogen interactions type O-H••• N, and C-H•••O. Finally, the supramolecular interactions of the dimer were quantified using fingerprint plots, obtaining values of 41.4%, 12.9%, 11.1% and 10.4% for interactions type H•••H, C•••H, O•••H, H•••C respectively. The aforementioned diagrams were compared with the obtained for structurally similar molecules; their forms confirmed the differences at the supramolecular level of the compounds analyzed. With this project, it was possible to determine the structural and supramolecular characteristics of the compound. In addition, were acquired the basic concepts related to crystallography and supramolecular chemistry, both at a theoretical and experimental level.Item Aplicación de la ecuación de Schrödinger en el estudio del movimiento de moléculas diatómicas(Universidad Santiago de Cali, 2019) Bueno Barbosa, Douglas Andrés; Parada Valencia, AlexanderUnderstanding the physiochemical phenomenon at the subatomic level is very important in order to know the behaviour of the matter these energy scales. It is necessary to use the Schrödinger equation in the order to describe chemical and physically the molecules. Throughout of the development of this work, we addressed the study of the Schrödinger equation and applications in the movement of diatomic molecules. The interaction potential is described by this equation, as well as the translational, rotational and vibrational energies of each molecule. Likewise, the Hamiltonian is studied in a general way, and particularly for the hydrogen molecule. We learned the main knowledge relating with Quantum Chemical and after that we focus in the study of some diatomic molecules no studied in the literature until now. Then, a phenomenological study was carried out for the BrCl molecule.Item Aplicación de la espectroscopia de infrarrojo cercano (NIRS) en productos cárnicos(Universidad Santiago de Cali, 2024) Rosero Martínez, José Miguel; Castro Narváez, Sandra Patricia (Directora)An approximation is made to near infrared spectroscopy (NIRS) as a tool for evaluating the quality and authenticity of meat products. Given the growing demand for organic meat products and the need to guarantee their integrity, NIRS stands out as an effective alternative to traditional methods. The methodology employed included literature review, data analysis and method comparison, highlighting the importance of developing more robust calibration and standardization techniques. Quality parameters that NIRS can assess, such as moisture, fat, protein, color and pH, were identified, demonstrating its ability to provide rapid and non-destructive results. Comparison between NIRS and traditional techniques such as proximate analysis revealed that NIRS offers significant advantages in terms of speed and reduced need for sample preparation. However, limitations have been identified, including the need for specific calibrations for each type of meat and the dependence on the quality of the equipment used. Recommendations include advancing the development of calibration techniques and exploring the integration of NIRS technology in real-time computing environments.Item Aplicación del diseño de mezclas en la formulación de sidra de manzana(Univerisad Santiago de Cali, 2020) Ramírez Naranjo, Nathalia; Sinisterra Amú, Diana; Ramirez Navas, Juan SebastiánCider is a drink with very marked characteristics with respect to other spirits; It has abundant carbon dioxide, but produces less foam than a regular beer, acquires shades of yellow in transparent and bright appearance. (Drilleau, 2005). Cider. 2. The objective of this research was to evaluate the ratio of cider mixtures from three varieties of apple (Malus Domestica): Gala, Golden and Green. This mixing design consisted of applying a planning and analysis methodology which could ensure that we obtain the knowledge and solutions. The adoption of this methodology aims to assess the influence of each component of the formulation on the selected response varieties. For this purpose, different physicochemical tests were performed on each mixture obtained: (pH, Density, Volatile Acidity, alcoholic Strength and Sugar Percentage) and from which the expected results were obtained with an average of pH between 3.6 - 3.8; Density between 0.99-1.02 g/mL; Volatile Acidity between 0.04 -0.09 g/L; Alcohol content between 0.73 - 2.4 %V; Microbiological: (Count of aerobic bacteria and mesophylls, mold count, yeast count and total coliforms) whose result of each test was <10 UCF/mL and Sensory Analysis in which preference was found for the sample called B, corresponding to the mixture 0,1/2,1/2 being this the mixture between green apple and gallium apple. The results obtained in each test were expected indicating that the drink does meet the requirements established by the Colombian technical standard NTC 222 and NTC 708, concerning alcoholic beverages and their general definitions, alcoholic beverages (Fruit wines) respectively.Item Avances en Materiales Electrocrómicos: Perspectiva Industrial en Colombia(Univerisad Santiago de Cali, 2021) Hurtado Palacios, Luis Felipe; Castro Narváez, Sandra PatriciaItem Calibración en harina de arroz blanco para la determinación de las variables de SB y BD del perfil de viscosidad por la técnica espectroscopía de reflectancia en el infrarrojo cercano (NIRS)(Universidad Santiago de Cali, 2023) Giraldo Ossa, Erika Fernanda; Orduña Ortega, Julieth; Loaiza de la Pava, Jhoana KaterineCurrently, the importance has increased for the genetic improvement program of the Latin American Irrigated Rice Fund (FLAR) to evaluate the quality of rice through quick, economical, environmentally friendly tools that require a minimum of preparation for your analysis. Given the above, the possibility of using the NIRS near-infrared spectroscopy technique (400-250nm) was studied through the development of a calibration equation to measure the Breakdown (BD) and Setback (SB) variables, which currently are evaluated in the Rapid Visco Analyzer RVA equipment (by its name in English), these viscosity variables of rice starch allow us to associate the cooking quality of the grain. The implementation of this technique seeks to facilitate the analysis of early generation rice lines, since currently, due to the capabilities of the RVA, it is only possible to evaluate advanced lines. The calibration was carried out on a set of 196 samples with a mathematical treatment “2,16,32,1”, an MPLS partial least squares regression model and SNV and Detrend smoothing, where the following statistical data of the variables were obtained. viscosity of BD and SB which were RSQ calibration (0.864 and 0.853), SEC (129.580 and 234.552), 1-VR (0.786 and 0.761), SECV (350.939 and 635.427) and RPD (2.168 and 2.049) respectively. Subsequently, the developed equation was verified through internal and external validation, obtaining the following internal RSQ statistics (0.822 and 0.808) and a SEP (151.909 and 309.770), RSQ external (0.791 and 0.531) and a SEP (210.444 and 944.374) respectively for the BD and SB variables. The calibration equation presents a good prediction for routine evaluation in early generation samples for the BD variable.Item Calificación de un dispositivo de inmersión para así realizar recubrimientos de TiO2/Hidroxiapatita sobre superficies metálicas(Universidad Santiago de Cali, 2019) Martínez Bellaiza, Daniela; Morales Morales, Jimmy Alexander; Castillo Ayala, Jorge EnriqueEl método de inmersión o “Dip-Coating” es utilizado para la obtención de películas delgadas sobre diferentes superficies y con un amplio rango de aplicación; este consiste en la inmersión y posterior extracción de un sustrato dentro de una solución precursora para la formación de la película. En este trabajo se realizó la calificación de un dispositivo de inmersión de bajo costo elaborado en la Universidad Santiago de Cali y se ejecutaron recubrimientos sobre sustratos de acero inoxidable con TiO2/Hidroxiapatita por la técnica de química húmeda. Para la calificación se evaluaron parámetros de velocidad y tiempo de inmersión, abordando la calificación de instalación, desempeño y diseño (IQ, PQ y QD respectivamente); la síntesis de Hidroxiapatita se realizó por precipitación controlada y se analizaron las muestras secas por IR/ATR y TGA-DSC obteniendo unos picos característicos del compuesto y un buen comportamiento térmico, además se analizaron los revestimientos realizados utilizando técnicas espectroscópicas obteniendo los depósitos esperados en los sustratos y obteniendo una relación de Ca/P de 1,57.Item Capacidad antioxidante de la semilla de aguacate (Persea Americana Mill) variedad Hass en distintos grados de germinación(Univerisad Santiago de Cali, 2020) Rodriguez Sanchez, Yuly; Ramirez Navas, Juan SebastiánThe avocado seed has in its chemical composition active phytocomposites; but the food industry has been limited only to the use of pulp, discarding the avocado seed. Increasing volumes of this agroindustrial remnant are expected to be generated inevitably; as a result of the growing interest in products derived from the fruit. In this study, the total phenolic content and antioxidant activity in 4 stages of avocado germination were analyzed using spectrophotometric reference methods. The total phenolic content was determined by an internal reference material of gallic acid. The antioxidant activity is referred to as the stable free radical 1,1-diphenyl-2-picrilhydrazil. The results obtained show that the antioxidant capacity increases in each stage of germination.Item Caracterización fisicoquímica de tres aceites de cocina usados para freír diferentes alimentos y los respectivos biodiesel obtenidos por transesterificación en la ciudad santiago de cali, colombia.(Universidad Santiago de Cali, 2024) Guerra Cuaran, Lina Alexandra; Bonilla Ramírez, Luis Fernando; Tusso, Ricardo Andrés; Zambrano Salgado, Yesid FabiánThe increase in global energy demand and the environmental concerns related to the use of fossil fuels, creates the need to find more sustainable alternatives, highlighting the relevance of biofuels to reduce dependence on oil. This study focuses on obtaining three types of biodiesel from Used Cooking Oils (UCO), from the frying of empanadas, fritters, breaded chicken and a new palm oil biodiesel used as a reference. Physicochemical tests were carried out to characterize the oils and biodiesel obtained to evaluate their potential as biofuel. Their yield was determined and 93.1% fritters, 87.5% empanadas and 90.6% breaded chicken were obtained. Based on the results of the characterization and their yield, it was determined that the biodiesel from the breaded chicken ACU has the greatest potential as biofuel and the biodiesel from the breaded chicken ACU proved to be the least suitable for such use.Item Caracterización fisicoquímica funcional del Almidón extraído de la papa china (Colocasia Esculenta) cultivada en el pacífico colombiano(Universidad Santiago de Cali, 2019) Hurtado Herrera, Janer Guillermo; Castillo Ayala, Jorge EnriqueThe evaluation of the physicochemical and functional properties of the starch extracted from the Chinese potato tubers (Colocasia esculenta) from the municipality of Timbiquí and López de micay – Cauca was carried out. The granules had particle size around (3.5-7.8 µm in diameter for sample 1 and 3.5-7.0 µm in diameter for sample 2); a high content of % amylose (67.6 and 70.7 respectively for M1 and M2) was found compared to other botanical sources, through the colorimetric method recommended by ISO 6647. The gelatinization temperatures were (78, 6 and 81.9 ° C, respectively) by heating a solution of the starch until a stable paste formed for a few seconds. The samples showed low water solubility (0.13 M1 and 0.23 M2 g / 100 mL) and a high water retention capacity (280.3 and 391.7% at 60 ° C) compared to 226% of the cassava and 162.8% for sago: which makes it a good quality starch. The gel pastes when subjected to a % processing of light at 650 nm in a Thermo Evo 201 UV spectrophotometer was (3.4 and 4.1%) respectively. Comparing these characteristics found in this tuber with other sources of starch commonly used in the industry, it is concluded that it can be used as a promising alternative in the food industry; In addition to having a high amylose content, it is a resistant starch, providing physiological health benefits.Item Caracterización fisicoquímica y funcional del almidón extraído de la papa china (Colocasia esculenta) cultivada en el pacífico colombiano(Universidad Santiago de Cali, 2020) Hurtado Herrera, Janer Guillermo; Castillo Ayala, Jorge EnriqueThe evaluation of the physicochemical and functional properties of the starch extracted from the Chinese potato tubers (Colocasia esculenta) from the municipality of Timbiquí and López de micay – Cauca was carried out. The granules had particle size around (3.5-7.8 μm in diameter for sample 1 and 3.5-7.0 μm in diameter for sample 2); a high content of % amylose (67.6 and 70.7 respectively for M1 and M2) was found compared to other botanical sources, through the colorimetric method recommended by ISO 6647. The gelatinization temperatures were (78, 6 and 81.9 ° C, respectively) by heating a solution of the starch until a stable paste formed for a few seconds. The samples showed low water solubility (0.13 M1 and 0.23 M2 g / 100 mL) and a high water retention capacity (280.3 and 391.7% at 60 ° C) compared to 226% of the cassava and 162.8% for sago: which makes it a good quality starch. The gel pastes when subjected to a % processing of light at 650 nm in a Thermo Evo 201 UV spectrophotometer was (3.4 and 4.1%) respectively. Comparing these characteristics found in this tuber with other sources of starch commonly used in the industry, it is concluded that it can be used as a promising alternative in the food industry; In addition to having a high amylose content, it is a resistant starch, providing physiological health benefitsItem Caracterización térmica y espectroscópica de sulfato de calcio dihidratado y sulfato de calcio hemihidratado(Universidad Santiago de Cali, 2024) Correa Castaño, Leonel; Gutiérrez Moreno, Nini Johanna (Director); Castillo Gómez, Duván Fernando (Director)The main objective of the present work was the thermal and spectroscopic characterization of calcium sulfate dihydrate and hemihydrate. Differential scanning calorimetry (DSC) and thermogravimetry (TGA) thermal analysis techniques were applied, finding characteristic peaks at 102 °C for the hemihydrate, 52.5 and 126.7 °C for the dihydrate. TGA showed a weight loss of 1.5% at 38.27 °C, 3% at 73.14 °C and 8.5% at 110 °C for the hemihydrate, the dihydrate showed weight losses of 17% at 56 °C, 31.6% at 110 ° C and 41.4% at 130 °C. Analysis by FT-IR revealed absorption bands between 3700 and 3500 cm-1 typical of the water molecules present and bands between 1200 and 900 cm-1 characteristic of the S=O double bond. The 20.72°, 23.38° and 29.14° for the dihydrate form. The determination of heavy metals by atomic absorption showed concentrations below 60 ppm in Na, Fe, Pb, As and Cd. The micrographs taken by SEM revealed the morphology of the crystals for the study compounds, exposing a varied number of sizes. It was found that the product has high purity, without the presence of anhydrites and low concentrations of metals such as Na, Fe, Pb, As and Cd.Item “Caracterización y determinación de polifenoles, flavonoides y actividad antioxidante por diferentes tipos de extracción en catharanthus roseus l. g don”.(Universidad Santiago de Cali, 2020) Sánchez Marín, Mónica María; López Parra, Lizbeth LorenaItem Conversión catalítica de alcohol fusel y etanol utilizando perovskitas del tipo LaM2+O3 como catalizadores(Univerisad Santiago de Cali, 2022) Rojas Rivas, Sofia; Orduña Ortega, Julieth; Mora Vargas, Jorge AndrésCurrently, the development of more environmentally friendly methodologies to produce value-added compounds (PVA) from renewable raw materials has been increasing, mainly for the production of derivatives from fossil sources. Among these raw materials, the products obtained from the industrial processing of sugar cane become important substrates for obtaining these compounds. Fusel alcohol (mixture of different low molecular weight alcohols), obtained as a by-product in the process of obtaining bioethanol via fermentation routes has become a raw material little explored to produce PVA. In addition, its use as a substrate in the Guerbet reaction (RG) has not yet been investigated, therefore, in this work it was proposed catalytic conversion by RG to obtain PVA, added, experiments were performed with ethanol, since this has already been used in GR with heterogeneous catalysts. For this, the use of catalysts possessing acid/base and hydrogenation/dehydrogenation properties such as perovskite type materials are necessary. For this reason, the synthesis, characterization (DRX, Raman, TGA, FTIR and SEM) was performed and use as heterogeneous perovskite catalysts of type LaM2+O3 where M2+ = Cu2+ or Co2+ in the catalytic conversion of fusel alcohol and ethanol using a low pressure fixed bed reactor in order to determine its influence on the type of pervoskitas and how it varies depending on the reaction conditions, added, the products obtained in both reactions were identified by means of CG-EM. They were obtained as main products in the reaction with fusel alcohol alkenes, aldehydes, ketones, alcohols and esters, on the other hand, in the reactions with ethanol, acetaldehyde and 1-butanol was obtained, among other products due to secondary reactions. In the first case, it is necessary to continue the investigation in order to determine some possible routes of formation of the mostly obtained compounds; in the second instance, reactions tended to follow the Guerbet reaction path along with secondary reactions based on the hydrogenation and dehydrogenation of molecules.Item Correlación instrumental y sensorial de la calidad de una muestra de yogurt de la empresa fructilacteos(Universidad Santiago de Cali, 2019) Giraldo, María, Camila Erazo; Ramírez Navas, Juan SebastiánGreek yogurt samples from the company fructilácteos of campo were sensorially characterized by a semi-trained panel. Likewise, a study of the physical-chemical parameters of the same was carried out. The objective was to correlate the sensory parameters with the instrumental ones (viscosity, syneresis, pH, acidity, soluble and total solids) to identify the instrumental parameters that approximate the sensations experienced when consuming fructilácteos Greek yogurt (YGF). On the sensory side of the panelists, there was a preference for YGF for its attribute of creaminess and acidity, while on the part of the consumer a preference of 58% was observed by the YGC, mostly male consumers, however in the instrumental parameters it is revealed that most of them enter the established limit, minus the parameter of viscosity, which was 1.02.Item Crecimiento de una barrera electroquímica por la electrolisis oxidativa de 2-aminotiazoles y derivados 4-x-fenil(Universidad Santiago de Cali, 2019) Patiño Izquierdo, José Luis; Morales Morales, Jimmy Alexander; Flórez López, EdwinSe realizó el seguimiento electroquímico de los compuestos 4-(4-X-fenil)-2-aminotiazol [ X = 1a -CH3, 1b -NO2 , 1c 2-amino-5-metil-4-feniltiazol y 1d 5-(4-Bromofenil)-oxazol-2- ylamina] a través de voltamperométrica cíclica utilizando como electrodo de trabajo carbón vítreo, electrodo de referencia Ag/Ag+ y como contra electrodo espiral de platino; se estudió el efecto que producen variables como el electrolito soporte, concentración, velocidad de barrido, sustituyente y temperatura durante la electro-oxidación de cada compuesto. Se evidenció que el tamaño del electrolito soporte influye en los valores de potencial y corriente pico. La velocidad de barrido como la concentración modifican proporcionalmente los valores de corriente pico. Por otra parte, el cambio de temperatura afecta los procesos de transferencia electrónica modificando las señales de oxidación. Se evidenció que un sustituyente electro-donador facilita la oxidación del compuesto y uno electro-atractor la dificulta. Por último, se evidencio durante la electrolisis oxidativa el crecimiento de una barrera electroquímica influenciada por cambios estructurales.Item Cuantificación de sulfitos en las etapas de cocimiento y fermentación de cerveza y evaluación de su efecto sobre las propiedades sensoriales(Universidad Santiago de Cali, 2024) Caicedo Roldan, Daly Dayanna; Tusso, Ricardo Andres; Agredo, William AlexanderThis research addressed the low production of sulfites in the Corona brand of Cervecería del Valle, which resulted in non-compliance with the quality indicator known as the flavor stability index (FSI) and caused negative economic impacts. To resolve this situation, trials were conducted that modified parameters in the fermentation and brewing stages. The evaluated variables included the amount of ZnCl₂, which improved fermentation; the time and temperature of diacetyl release, which increased interaction with the yeast; and the amount of air injected into the wort, which elevated the concentration of SO₂. As a result, SO₂ values exceeding 3 ppm were obtained, acting as an antimicrobial and antioxidant agent that preserves the freshness of the beer. Additionally, FSI compliance was achieved at 95%, ensuring a high-quality product that meets consumer expectations and remains competitive in the market.Item Cuantificación por HPLC de Trans-resveratrol en la uva Isabella (vitis labrusca) cultivadas en la Unión-Valle del Cauca(Universidad Santiago de Cali, 2019) Ospina Ramírez, Stephanie; Castillo Ayala, Jorge EnriqueThe Isabella grape (Vitis labrusca) is a variety that has been optimally adapted to the climatic conditions of La Unión-Valle del Cauca, and has had good acceptance in local markets. Currently the grape is consumed fresh and its phenolic content is unknown. According to epidemiological studies, the presence of bioactive compounds with antioxidant capacity such as trans-resveratrol, can exert a protective effect against some diseases such as cancer and cardiovascular disorders. For this reason, with this work the quantification of the trans-resveratrol present in the epicarp of the Isabella grape (Vitis labrusca) grown in La Unión-Valle del Cauca is performed, using high efficiency liquid chromatography (HPLC) with ultraviolet detector. It will ensure that the method to follow complies with the evaluation parameters (linearity, precision and accuracy). It is also intended to contribute to a methodological proposal for the extraction (liquid-liquid with acidified methanol) and purification of trans-resveratrol.Item Degradación de Ampicilina, Catecol y el colorante naranja II, a partir de residuos de CdS obtenidos de prácticas convencionales de química inorgánica(Universidad Santiago de Cali, 2019) Vidal Ruíz, Victor Alfonso; Avila Torres, YennyThe elimination of orange dye, catechol and ampicillin (products present in waste from practical work of organic chemistry and biochemistry), was carried out with cadmium sulfide (CdS). This inorganic material was obtained from of residues of acid- base Pearson's practices in the laboratories of inorganic and analytical chemistry. Cadmium sulfide is a semiconductor with a GAP 2.4-2.6 ; which allows its use as a photocatalyst in the visible region and enhances its application in the degradation of organic matter. An important source of this type of materials are the conventional practices at the laboratory level, where it is possible to obtain residues such as PbS and CdS; which are generally underutilized. In this article, the impure CdS residue was purified and characterized as was reported, previously. Subsequently, organic labs and has obtained the best parameters at pH neutral for the elimination of orange II. This behavior was compared with the transformation of catechol and ampicillin as neutral and zwitterion molecules. H2O2, KI and acetonitrile as solvent, were added in to order to evaluate synergistic effects and establish the role of the semiconductor, (huecos) h+ and OH-. This work is a contribution to the reuse of waste in teaching laboratories, which promote the recirculation water contaminated with this type of organic compounds and allows for the student to design experimental protocols that allow him to use two types of organic and inorganic waste.Item Degradación del Fluconazol mediante Foto-Fenton: Aplicaciones en la agroindustria(Universidad Santiago de Cali, 2023) Martínez Sarria, Nicoll Andrea; Obeso Hurtado, Evelin Tatiana; Castro Narváez, Sandra Patricia (Directora)Fluconazole (FCZ) is one of the most widely used fungicides to combat plant pathogens which has a Fluconazole (FCZ) is one of the most widely used fungicides to combat plant pathogens which has a low degradation rate making it an emerging contaminant. The monitoring of FCZ photooxidation by UV-vis spectroscopy under different conditions such as pH, wavelength, contaminant vs. hydrogen peroxide ratio (FCZ:H2O2) and concentration of ions such as iron (II), sulfate, carbonate and phosphate establish pseudo first order kinetics by graphical method with rate constant between 0.1796 to 0.0604 min-1 and half-life between 2.41 and 11.40 min, depending on pH, FCZ:H2O2 ratio and type of ion present in the sample. The addition of carbonate (200 mg/L) to the FCZ sample evidenced a removal rate higher than 99% in 25min at pH 2.0 and a 1:4 FCZ:H2O2 ratio. Gas chromatographic studies coupled to mass detector (GC-MS) establish the obtaining of low molecular weight by-products.