Elaboración de películas plásticas flexibles a partir de polímeros naturales como una alternativa de empaque y la evaluación de sus propiedades

Tesis (Doctorado en Ciencias con Especialidad en Biotecnología) UANLUANLhttp://www.uanl.mx

Degradation kinetics and thermodynamic analysis of betalains on microencapsulated beetroot juice using maltodextrin and sweet potato starch

Natural colorants have become important due to the health-benefits for humans. In that sense, it is important to evaluate the degradation kinetics of these components, in order to establish the stability under different processing and/or storage conditions. This study provides experimental and simulated results about the degradation of betalains in microencapsulated beetroot juice. Maltodextrin solution (MDX 10%) and sweet potato starch solution (SPS 2%) in proportions of 40MDX:60SPS, 20MDX:80SPS and 0MDX:100SPS were used as microencapsulating agents. The thermal degradation of betalains in the microencapsulated powders was evaluated at three temperatures (6, 19 and 30 °C) in order to predict the behavior under different conditions, using the first-order kinetic model. The kinetic parameters were identified using linear regression on the logarithmic curves of the experimental data to obtain the Arrhenius equations. The highest content of betalains was 2.58 mg/g and the lowest activation energy value was 48.71 KJ/mol, with both values corresponding to the powder that was microencapsulated with 20MDX:80SPS. The above results suggest high betalain stability in this powder, since there was less sensitivity to temperature in comparison to the rest of the powders. Additionally, some thermodynamic parameters were evaluated, which confirmed that the process is non-spontaneous and irreversible. The results obtained from this study, could be a useful tool to predict the minimal losses during processing, and gives the possibility to improve and select the food products where this kind of natural colorant can be applied.Natural colorants have become important due to their health benefits for humans. In that sense, it is important to evaluate the degradation kinetics of these components, in order to establish stability under different processing and/or storage conditions. This study provides experimental and simulated results about the degradation of betalains in microencapsulated beetroot juice. Maltodextrin solution (MDX 10%) and sweet potato starch solution (SPS 2%) in proportions of 40MDX:60SPS, 20MDX:80SPS and 0MDX:100SPS were used as microencapsulating agents. The thermal degradation of betalains in the microencapsulated powders was evaluated at three temperatures (6, 19 and 30 °C) in order to predict the behavior under different conditions, using the first-order kinetic model. The kinetic parameters were identified using linear regression on the logarithmic curves of the experimental data to obtain the Arrhenius equations. The highest content of betalains was 2.58 mg/g and the lowest activation energy value was 48.71 KJ/mol, with both values corresponding to the powder that was microencapsulated with 20MDX:80SPS. The above results suggest high betalain stability in this powder since there was less sensitivity to temperature in comparison to the rest of the powders. Additionally, some thermodynamic parameters were evaluated, which confirmed that the process is non-spontaneous and irreversible. The results obtained from this study could be a useful tool to predict the minimal losses during processing and give the possibility to improve and select the food products where this kind of natural colorant can be applied

Avances en las investigaciones sobre la encapsulación mediante gelación iónica: una revisión sistemática

Encapsulation, a technology that creates a barrier between a compound of interest and the environment, improves the physicochemical stability of products during processing and/or storage. Therefore, it helps to reduce the degradation of compounds of interest, masks undesirable odors and flavors, controls the release of the bioactive compound, and can increase its bioaccessibility and bioavailability. The objective of this review was to collect and discuss recent scientific literature about encapsulation by ionic gelation of bioactive compounds, microorganisms, and enzymes, as well as its use in different applications of scientific and/or industrial interest in several fields. A literature review was carried out in indexed databases using descriptors such as capsule size, encapsulation efficiency, mixture matrices, sodium alginate, and ionic gelation. The results show that using of this kind of encapsulation offers variable advantages regarding the bioavailability of bioactive compounds, the stability of different compounds, the improvement of physical characteristics, the release of compounds, and the protection against adverse environmental effects. In conclusion, the ionic gelation method can have a wide range of applications to encapsulate food ingredients, microorganisms, drugs, etc. This review can guide further research into ionic gelation because it examines the diversity of its applications.La encapsulación es una tecnología que proporciona barreras entre los compuestos de interés en un producto y el medio ambiente. Ella brinda una mejor estabilidad fisicoquímica durante el procesamiento y/o almacenamiento del producto, por lo tanto, ayuda a tener una menor degradación de los compuestos de interés, enmascara olores y sabores indeseables, controla la liberación del principio activo y puede incrementar su bioaccesibilidad y su biodisponibilidad. El objetivo de esta revisión fue recopilar y discutir la literatura reciente enfocada en investigaciones científicas sobre la encapsulación mediante gelación iónica de compuestos bioactivos, de microorganismos, de enzimas y su uso en diferentes aplicaciones de interés científico y/o industrial. La revisión bibliográfica se realizó en las principales bases de datos indexadas, utilizando descriptores como tamaño de cápsula, eficiencia de encapsulación, matrices mixtas, alginato de sodio y gelación iónica. De acuerdo con los resultados se observó que la utilización de este tipo de encapsulación presenta ventajas muy variables que se centran en la mejora de diversos factores como la biodisponibilidad de compuestos bioactivos, estabilidad de diferentes compuestos, características físicas, liberación del compuesto de interés y la protección contra efectos ambientales adversos. En conclusión, existe una amplia gama de aplicaciones que puede tener la metodología de gelación iónica para encapsular ingredientes alimenticios, microorganismos y fármacos, entre otros. Finalmente, el estudio pretende que esta revisión sea de utilidad en la dirección de investigaciones sobre gelación iónica, debido a la diversidad de aplicaciones abordadas durante la investigación

GC/MS Analysis of Some Extractives from Eichhornia crassipes

Eichhornia crassipes (water hyacinth) is an invasive weed that causes serious issues for rivers, lakes, and other reservoirs around the world, although it can be an excellent source for bioactive compounds such as phytosterols and some steroids found in many plants. In this study, water hyacinth samples from both Durango and Distrito Federal in Mexico were collected. Ascendant extracts (cyclohexane, hexane, acetone, and methanol) from their leaves, stems, and roots were analyzed. Using boron trifluoride (~10% [~1.3 M] in 1-butanol), all extracts were derivatized. Twenty-four derivatized samples were analyzed using a gas chromatography-mass spectrometry (GC/MS) method. Twenty carboxylic acids were found, as well as squalene, which was found in nine extract samples: four cyclohexane extracts, one hexane extract, three acetone extracts, and two methanol extracts. A compound not reported before, Beta-stigmasterol, was identified on three hexane extracts, an acetone extract, and a methalonic extract. Spirostane in acetone root extract and cholestane in cyclohexane stem-leaf extract were also identified

Screening of native yeast from Agave duranguensis fermentation for isoamyl acetate production

In this work, fifty yeast strains, isolated from the spontaneous alcoholic fermentation of Agave duranguensis to produce mezcal, were tested using the double coupling system. These yeasts were from the genera Pichia, Torulaspora, Saccharomyces, Kluyveromyces, Deckera, Hanseniaspora, and Candida. P. fermentans ITD00165 was the best isoamyl acetate producer, yielding 0.38 g/L of ester after incubation for 24 h, while K. marxianus ITD00211 produced 0.32 g/L of ester. Thus P. fermentans TD00165 could be considered as an excellent choice for use in optimization studies of the culture medium and bioreactor operating conditions to develop a process for biotechnological production of isoamyl acetate

Microorganism degradation efficiency in BOD analysis formulating a specific microbial consortium in a pulp and paper mill effluent

"Pulp and paper mills are a major source of pollution, generating huge amounts of intensely colored effluent that goes to the receiving end of a wastewater treatment plant. The biochemical oxygen demand test (BOD5) relies heavily on the microorganism metabolic capability added to the test as seeding material. The seeding material in the testing is obtained from sewage sampling or from commercial sources. Specific organic pollutants that are present in paper and pulp mill effluent can only be degraded by specific microbes; therefore, common sewage or synthetic seed may lead to erroneous BOD5 estimations. In this study, specific microbial species were selected to evaluate their degradation efficiency, both individually and in combination. The microorganisms selected in the formulated seed exhibit BOD5 in a reproducible and synergistic manner. The formulation of this specific microbial consortium can be used to develop bioremediation strategies.

Natural pigments of plant origin: Classification, extraction and application in foods

Color is the first attribute that influences the acceptance of foods as they become more attractive to consumers when they are more intense and uniform. In recent years, the interest of producers and consumers in purchasing products containing natural ingredients have constantly increased. Natural pigments are commonly extracted from fruits and vegetables, and have been proven to provide health benefits to reduce the risk of diseases such as type-1 diabetes, obesity, and coronary diseases. Additionally, advanced extraction and encapsulation technologies that make food matrices more efficient are useful tools for improving the use of these pigments. In this review, the state-of-the-art of pigments such as carotenoids, anthocyanins, and betalains of plant origin are discussed, including their main sources of production and the factors that affect their physicochemical stability. In addition, different extraction methods are discussed, listing their advantages and disadvantages, and providing some applications of natural pigments in food.The author Azucena Rodríguez-Mena thanks the Consejo Nacional de Ciencia y Tecnología CONACyT for the scholarship granted (No. 884709) for Doctoral studies in Biochemical Engineering at the Tecnológico Nacional de México/Instituto Tecnológico de Durango.Peer reviewe