Determination of banned sudan dyes in culinary spices through spectroscopic techniques and multivariate analysis

La presente tesis esta focalizada en el desarrollo de métodos analíticos para determinar la adulteración de especias culinarias con colorantes Sudan I, II, III y IV. Estos colorantes están prohibidos como aditivos para uso alimentario por la legislación europea ya que son carcinógenos. Las metodologías analíticas desarrolladas están basadas en el uso de técnicas espectroscópicas como UV-visible, Resonancia Magnética de protón y Raman junto con tratamiento multivariante de los datos obtenidos. En relación al análisis multivariante, como principal objetivo se planteó el establecimiento de modelos de clasificación y posteriormente se utilizaron diversas herramientas quimiométricas con el objetivo de mejorar los resultados de clasificación: análisis exploratorio de datos, métodos de selección de variables y procesamiento de espectros, estrategias de fusión de datos y métodos de transferencia (estandarización).This thesis is focused at developing multivariate analytical screening methodologies for determining the adulteration of culinary spices with Sudan I, II, III and IV dyes. Such dyes are prohibited to be used as additive in foods according to the European legislation because they are Class 3 carcinogens. The proposed methodologies are based on the use of spectroscopic techniques such as UV-Visible, 1H-NMR and Raman along with multivariate data treatment. The applied chemometric tools include the establishment and application of supervised classification techniques combined with exploratory data analysis, data processing and variable selection techniques to extract the maximum possible information from the spectral data. Otherwise some strategies to improve the classification have been evaluated such as data fusion strategies and multivariate transfer (standardization) methods

Synchronous fluorescence and multivariate classification analysis as a screening tool for determining Sudan I dye in culinary spices

Spices are a globally traded commodity which has been found to be adulterated with forbidden Sudan dyes. This work proposes a screening method for determining the adulteration of paprika varieties (mild, hot and smoked) with Sudan I dye, based on constant-wavelength synchronousfluorescence spectros-copy with multivariate classification. Different wavelength-intervals (Dl) were evaluated. Classification models were built with Partial Least Squares-Discriminant Analysis (PLS-DA) at two Sudan I dye con-centration levels (1 and 5 mg/L) and they were tested with samples at a lower level (0.5 mg/L). Classification results were quite satisfactory when a strategy based onfirst-derivative spectra was used for improving classification results. nm was chosen as the optimum wavelength interval giving a 100% of sensitivity and specificity. These results are promising because the risk of assigning adulterated samples as safe to be consumed is highly minimized. The proposed method is feasible, rapid and simple taking advantage of Sudan Ifluorescence phenomena in a direct way.Fil: Di Anibal, Carolina Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Rodríguez, María Sol. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Albertengo, Liliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; Argentin

UV-Visible Spectroscopy and Multivariate Classification as a Screening Tool to Identify Adulteration of Culinary Spices with Sudan I and Blends of Sudan I + IV Dyes

This work propose a feasible, rapid, and simple method for detecting culinary spices adulterated either with Sudan I dye or blends of Sudan I + IV dyes at three concentration levels. The method is based on the use of UV-visible spectroscopy with multivariate analysis. Four types of spices were studied: three paprika varieties (mild, hot, and smoked) and a spice commonly consumed in Argentina called aji molido. Principal components analysis was firstly applied as an exploratory analysis and then, two classification techniques were used: K-nearest neighbors (KNN) and partial least squares-discriminant analysis (PLS-DA). Three classes were defined: unadulterated samples and adulterated samples with Sudan I or blends of Sudan I + IV dyes at 1, 2.5, and 5 ppm (mg L−1). Classification techniques gave satisfactory results: between 89 and 100 % for PLS-DA and between 83 and 92 % for KNN. The sensitivity and specificity of the models were above 83 %. It has to be highlighted that none of the adulterated samples were assigned as unadulterated, which is very positive because of the implication that these results have on consumer health. The capability of detecting mixtures of Sudan dyes is a very important advantage because each Sudan dye generates different hazardous metabolites in human body so their toxicity may be enhanced by the simultaneous presence of such dyes.Fil: Di Anibal, Carolina Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Rodriguez, Maria Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Albertengo, Liliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; Argentin

Screening and evaluation of variables for determination of sulfonylurea herbicides in water samples by capillary zone electrophoresis

A simple and rapid capillary electrophoretic method was developed for the simultaneous determination of two sulfonylurea herbicides in water samples: metsulfuron-methyl (MSM) and nicosulfuron (NS). These herbicides are widely used in agricultural practices and their residues represent potential environment pollutants in waters and soils. The effect of the pH of the background electrolyte solution (BGE), the percentage of methanol in the BGE and the separation voltage were studied on the resolution of MSM and NS. A 23 factorial design was used to identify the main factors which significantly influenced the separation of these compounds. Other parameters were evaluated by the univariate method. The experimental results show that using a BGE composed of 25 mmol·L−1 sodium borate and 3% (v/v) of methanol at pH 8.5 and applying 15 kV, satisfactory analysis time and resolution between peaks can be obtained. The linear range for both analytes was 0.1–2.0 µg·mL−1. The detection limits were 0.034 µg·mL−1 for MSM and 0.044 µg·mL−1 for NS. Surface water and groundwater samples were analyzed applying the new method, and the obtained results presented satisfactory recovery percentages (82%–102%).Fil: Springer, Valeria Haydee. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Di Anibal, Carolina Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Lista, Adriana Guillermina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; Argentin

Determination of grated hard cheeses adulteration by near infrared spectroscopy (NIR) and multivariate analysis

Cheese is a dairy product of massive consumption and is commonly commercialised as grated cheese. Adulteration of cheese reduces its quality and consequently, decreases its nutritional value. This work proposes an analytical tool to determine the adulteration of cheeses with higher levels of additives than those permitted (cellulose and silicon dioxide) and non-authentic substances used to increase weight and volume such as wheat-flour, wheat-semolina and sawdust. The proposed methodology is based on near infrared spectroscopy (NIR) and multivariate classification analysis. Excellent classification results were obtained with partial least squares discriminant analysis (PLS-DA) as adulterated samples were discriminated from original (unadulterated) samples. The prediction ability was assessed with adulterated commercial grated cheeses. The screening tool represents a fast, reliable and affordable way to perform quality control of grated cheeses to avoid consumer deception based on nutritional detriment and misleading labelling.Fil: Visconti, Lucas Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Rodriguez, Maria Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Di Anibal, Carolina Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; Argentin

Chemical composition and nutritional value of Argentine commercial edible mushrooms

The chemical composition and nutritional value of four edible mushroom varieties (Champignons, Portobellos, Girgolas and Shiitakes) commonly cultivated and consumed in Argentina was determined. Chemical composition includes water content, crude protein, lipids, ash, carbohydrates, mineral composition and bioactive components (dietary fiber, chitin content and phenolic compounds). Results show that edible mushrooms are rich sources of water and carbohydrates and have low amounts of lipids. Also, they are rich in potassium and phosphorus whereas have a low content of sodium. The composition of bioactive components reveals that mushrooms are rich in fiber and have an interesting amount of total phenolic compounds that could assure an antioxidant capacity. Chitin content is an important part of total fiber and in this work a new method for chitin isolation is proposed. Multivariate analysis (Principal Component Analysis) was applied to discriminate among the different mushrooms varieties and to establish relationships among samples and nutritional parameters.Fil: Di Anibal, Carolina Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química del Sur; Argentina. Universidad Nacional del Sur; ArgentinaFil: Farenzena, Sonia Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química del Sur; Argentina. Universidad Nacional del Sur; ArgentinaFil: Rodriguez, Maria Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química del Sur; Argentina. Universidad Nacional del Sur; ArgentinaFil: Albertengo, Liliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química del Sur; Argentina. Universidad Nacional del Sur; Argentin

A simple method to quantify azo dyes in spices based on flow injection chromatography combined with chemometric tools

Para Red (PR) and Sudan dyes have been illegally used as colorants to adulterate certain foods by enhancing their red/orange colour. In addition, they are toxic and carcinogenic. This work presents the development of a simple flow injection chromatographic method combined with chemometric tools to perform the determination of PR, Sudan I (SI) and Sudan II (SII) in food samples. The flow chromatographic system consisted of a low-pressure manifold coupled to a reverse phase monolithic column. A Partial Least Square (PLS) model was applied to resolve overlapped absorption spectra registered for each dye at the corresponding retention time. The relative errors of calibration (RMSECV, %) were 0.49, 0.85 and 0.23, and the relative errors of prediction (RMSEP, %) were 1.12, 0.75 and 0.33 for PR, SI and SII, respectively. The residual predictive deviation (RPD) values obtained were higher than 3.00 for all analytes. The method was successfully applied to quantify the dyes in six different commercial spices samples. The results were compared with the HPLC reference method concluding that there were no significant differences at the studied confidence level (α = 0.05). The proposed method can be used to rapidly determine the analytes in a simple, reliable, low-cost and environmentally-friendly mannerFil: Nussbaum, Luana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; Argentina. Universidad Nacional del Sur. Departamento de Química; ArgentinaFil: Llamas, Natalia Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; Argentina. Universidad Nacional del Sur. Departamento de Química; ArgentinaFil: Chocholous, Petr. Charles University In Prague. Faculty of Pharmacy; República ChecaFil: Rodriguez, Maria Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; Argentina. Universidad Nacional del Sur. Departamento de Química; ArgentinaFil: Sklenárová, Hana. Charles University In Prague. Faculty of Pharmacy; República ChecaFil: Solich, Petr. Charles University In Prague. Faculty of Pharmacy; República ChecaFil: Di Anibal, Carolina Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; Argentina. Universidad Nacional del Sur. Departamento de Química; ArgentinaFil: Acebal, Carolina Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; Argentina. Universidad Nacional del Sur. Departamento de Química; Argentin

Adaptación de un trabajo científico a un trabajo practico de laboratorio para favorecer la integración de conceptos previos

Esta propuesta didáctica consiste en la adaptación de un trabajo científico en un trabajo práctico de laboratorio. Particularmente, los estudiantes decidieron determinar ciclamato de sodio en diferentes bebidas de bajo contenido calórico. Para ello, transformaron un método turbidimétrico automatizado mediante la técnica de inyección en flujo (FIA) en un método en batch. De esta manera, los estudiantes desempeñaron un papel más activo en su aprendizaje utilizando los conocimientos aprendidos en otras asignaturas previas.Fil: Pistonesi, Denise Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Moreno, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Ávila Orozco, Francisco David. Universidad Nacional del Sur. Departamento de Química; ArgentinaFil: Di Anibal, Carolina Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Domini, Claudia Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Garrido, Mariano Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaXI Jornadas Nacionales y VIII Jornadas Internacionales de Enseñanza de la Química Universitaria, Superior, Secundaria y TécnicaBuenos AiresArgentinaAsociación Química Argentin

NIR-based Sudan I to IV and Para-Red food adulterants screening

Spices are added in order to enhance the organoleptic characteristics of food and culinary dishes, making them more attractive for consumers. The use of illicit cheap colourants might be profitable along the food supply chain, posing undue risks to human health. This work evaluates the feasibility of NIR spectroscopy with chemometrics as a rapid, simple, non-destructive and affordable screening tool to determine the presence of Sudan I, II, III, IV and Para-red dyes in paprika. The dataset comprised unadulterated and adulterated samples with the five studied dyes at different concentration levels. Several multivariate classification models were built with Linear Discriminant Analysis (LDA) and different machine learning techniques. Preliminary results show that a classifier based on only six wavenumbers is able to determine the presence of some of these dyes in food samples in levels that may represent risk to human health. Sensitivities and specificities above 90% were obtained in almost all cases. These results show the feasibility of inexpensive and portable devices that can be useful for screening out adulterated stock along the food chain supply.Fil: Trentanni-hansen, Gimena Jessica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Almonacid, Jonathan Samuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; ArgentinaFil: Albertengo, Liliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Rodriguez, Maria Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Di Anibal, Carolina Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Delrieux, Claudio Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras; Argentin

Composite films with UV barrier capacity to minimize flavored waters degradation

Secondary packages for commercial flavored waters were developed from composite films to reduce beverage UV degradation. Bottle packs of orange and grapefruit flavored waters (OFW and GFW), were wrapped with films based on high density polyethylene, poly(styrene-b-butadiene-b-styrene), and thermoplastic corn starch (0 and 5% w/w bentonite). A commercial protective film (CPF) was employed as reference. Packs were placed in a UV chamber, and the effect of radiation on beverages was evaluated by colorimetry, UV–vis spectroscopy, vitamin C content (VCC), and total phenolic compounds (TPC). Wrapping films minimized OFW color variation, being this effect more evident employing composite films and comparable to CPF. Use of composite materials as secondary packages reduced the oxidative degradation of natural juices compounds, which is the main responsible of the changes observed by UV–vis spectroscopy. VCC in both flavored waters was too low, therefore after 6 days UV irradiation it could not be detected. Regarding TPC, no protective effect of all studied films was evidenced. Composite films containing 5% w/w bentonite increased UV barrier capacity of studied matrices, being the protective effect more efficient than the corresponding to CPF.Fil: Passaretti, María Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería Química; ArgentinaFil: Ninago, Mario Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Aplicadas a la Industria. Departamento de Física y Matemática; ArgentinaFil: Di Anibal, Carolina Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; Argentina. Universidad Nacional del Sur. Departamento de Química; ArgentinaFil: Pacheco, Consuelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería Química; ArgentinaFil: Vega, Daniel Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Física del Sur. Universidad Nacional del Sur. Departamento de Física. Instituto de Física del Sur; ArgentinaFil: Villar, Marcelo Armando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería Química; ArgentinaFil: Lopez, Olivia Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina. Universidad Nacional del Sur. Departamento de Química; Argentin