Influencia de un recubrimiento comestible adicionado con antioxidantes sobre las características post-mortem en filetes de carpa común (Cyprinus carpio) almacenado a bajas temperaturas

Tesis de doctoradoEl pescado es una fuente importante de proteína de alta calidad y de fácil digestión, cuenta con aminoácidos esenciales (lisina, metionina, cistina, treonina y triptófano), además de ácidos grasos insaturados que pueden tener un efecto hipocolesterolémico. El contenido de grasa, puede presentar consecuencias tecnológicas post-mortem, debido a las reacciones de oxidación, repercutiendo en las características sensoriales, tales como color y olor. Las proteínas son también susceptibles a estas debido a la formación de especies reactivas de oxígeno (EROs) generadas durante la crianza, procesamiento y almacenamiento, así como por la actividad microbiana y enzimática propias del pescado. Se ha observado una correlación importante entre la oxidación proteínica y la textura, siendo ésta un factor determinante para la aceptación por parte del consumidor. Es posible reducir los efectos de la oxidación durante el almacenamiento, mediante la combinación de técnicas de conservación como el control de temperaturas, disminuyendo las reacciones de degradación por acción enzimática y microbiológica, además del empleo de recubrimientos comestibles (RC); los cuales mantienen la humedad en los tejidos y disminuyen la transferencia de oxígeno; pueden ser vehículos de diversos compuestos, como antioxidantes y/o antimicrobianos, formando un material de empaque bioactivo. Dentro de los productos cárnicos empleados para el uso de estas tecnologías de conservación se encuentran las especies acuícolas, especialmente aquellas de importancia económica como lo es la carpa común (Cyprinus carpio). El objetivo de este trabajo fue determinar la influencia de un RC adicionado con antioxidantes en filete de Cyprinus carpio, evaluando las características bioquímicas, fisicoquímicas, texturales, microbiológicas y nutrimentales durante su vida útil permitida para su consumo. Encontrándose una prolongación durante el almacenamiento, a temperaturas de congelación de las características fisicoquímicas y nutrimentales, presentando un efecto protector en lisina, al final de 5 meses de almacenamiento, mientras que las especies con RC en los tratamientos en refrigeración presentan cargas microbianas menores, así como disminución de los productos de oxidación, comparado con aquellos en los que no se emplearon RC

USO DE LA TÉCNICA TKJ EN LA PLANEACIÓN PROSPECTIVA DE UN PROGRAMA INTEGRAL DE FORTALECIMIENTO DEL POSGRADO EN INGENIERÍAS

This article describes, in general, the use of the Team Kawakita Jiro (TKJ) technique to carry out a prospective planning in order to prepare the Integral Program for strengthening the Studies of The Master's Studies in Engineering of the Instituto Tecnológico de Ciudad Juarez (ITCJ), Mexico, in order to redefine the academic structure that such studies must have for the continuous improvement of the quality of these. The TKJ exercise obtained information that would enable graduate management to perform an analysis of Strengths and Weaknesses, and an Analysis of Opportunities and Threats (FODA). The TKJ exercise was also concluded in a vision and mission of the postgraduate course, more consistent with the reality of its surroundings

Thermal Uhlmann phase in a locally driven two-spin system

We study the geometric Uhlmann phase of mixed states at finite temperature in a system of two coupled spin-$\frac 1 2$ particles driven by a magnetic field applied to one of the spins. In the parameter space of temperature and coupling, we show the emergence of two topological Uhlmann phase transitions when the magnetic field evolves around the equator, where a winding number can characterize each temperature range. For small couplings, the width of the temperature gap of the non-trivial phase is roughly the critical temperature $T_c$ of one-dimensional fermion systems with two-band Hamiltonians. The first phase transition in the low-temperature regime and small values of the coupling corresponds to the peak of the \textit{Schottky anomaly} of the heat capacity, typical of a two-level system in solid-state physics involving the ground and first excited states. The second phase transition occurs at temperatures very close to the second maximum of the heat capacity associated with a multilevel system. We also derive analytical expressions for the thermal Uhlmann phase for both subsystems, showing that they exhibit phase transitions. In the driven subsystem, for minimal $g$, a topological phase transition phase appears at $T_c$ again. However, for larger values of $g$, the transitions occur at lower temperature values, and they disappear when the coupling reaches a critical value $g_c$. The latter is not the case for the undriven subsystem, where at low temperatures, a single phase transition occurs at $g_c$. Nevertheless, as the temperature rises, we demonstrate the emergence of two phase transitions defining a coupling gap, where the phase is non-trivial and vanishes as the temperature reaches a critical value.Comment: 11 pages, 13 figure

Delivery systems made of natural-origin polymers for tissue engineering and regenerative medicine applications

There is an emergent need in the development of more specific and effective therapeutic agent carriers to help on the regeneration of a plethora of tissues. The ultimate aim of bioactive factors delivery systems development is to improve the human health with the fewest possible adverse reactions. While there have been many polymeric scaffolds and matrices with different forms and compositions developed to load and deliver bioactive factors, the delivery strategy should be established based on the type of molecules to deliver and mechanisms to control their release. As most bioactive factors such as proteins and genes are water-soluble, natural polymers are more favored than synthetic ones for this purpose. A core-shell structuring of biomaterials (in the cases of particles or fibers) where water-based polymers being placed in the inner core part may be the most common design principal to secure bioactive factors during the processing of synthetic drug delivery scaffolds.(undefined)info:eu-repo/semantics/submittedVersio

Effect of Chitosan Edible Coating on the Biochemical and Physical Characteristics of Carp Fillet (Cyprinus carpio) Stored at −18ºC.

The effect of an edible coating (EC) with 1.5% chitosan as an additive, on common carp (Cyprinus carpio) fillet, was determined evaluating the biochemical, physicochemical, textural, microbiological, and nutritional characteristics periodically during its hydroperoxides content (HPC) (0.8324 nM hydroperoxides/mg of protein versus 0.5540 nM/mg with regard to the EC sample), as well as protein carbonyl content (PCC) (0.5860 nM versus 0.4743 nM of reactive carbonyl groups/mg of protein of noncoated material), keeping properties for a longer period of time, and a lower protein solubility (7.8 mg of supernatant protein/mg of total microbialgrowth,thecountwas2.2×10 CFU/gofsampleinmesophilesversus4.7×10 intheECsample.Theresultsindicatethat the use of EC added with chitosan maintains the quality of the product regarding lipid and protein oxidation until fourth month of storage, maintaining moisture content without variation for at least 3 months, and inhibits microbial growth up to 2 logarithmic units, during five months of frozen storage

Effects of peppermint extract and chitosan-based edible coating on storage quality of common carp (Cyprinus carpio) fillets

Artículo internacional en revista indizadaEdible coatings have recently been developed and applied to different food matrices, due to their numerous benefits, such as increasing the shelf life of foods, improving their appearance, being vehicles of different compounds, such as extracts or oils of various spices that have antioxidant and antimicrobial activity, as well as being friendly to the environment. The objective of this research was to develop a new edible coating based on chitosan enriched with peppermint extract and to evaluate its effectiveness to inhibit microbial development in vitro and improve both the quality and shelf life of common carp (Cyprinus carpio) during refrigerated storage (4 ± 1 C). Three treatments were used: edible coating (C + EC), edible coating +, 5% chitosan (C + ECCh) and edible coating + 1.5% chitosan + 10% peppermint (C + ECChP). Prior the coating carp fillets; the antibacterial activity and antioxidant capacity were evaluated in the peppermint extract and coating solutions. After coating and during storage, the following were determined on the fillet samples: microbiological properties, observed for ECP, an inhibition halo of 14.3 mm for Staphylococcus aureus, not being the case for Gram-negative species, for ECCh, inhibition halos of 17.6 mm, 17.1 mm and 16.5 mm for S. aureus, Salmonella typhimurium and Escherichia coli, respectively; for the ECChP, inhibition halos for S. aureus, S. typhimurium and E. coli of 20 mm, 17 mm and 16.8 mm, respectively. For the physicochemical characteristics: an increase in solubility was observed for all treatments during storage, reaching 46.7 mg SN protein/mg total protein for the control, and values below 29.1 mg SN protein/mg total protein (p C + ECCh > C + ECChP, respectively at the end of storage. For the pH, maximum values were obtained for the control of 6.4, while for the fillets with EC a maximum of 5.8. For TVB-N, the fillets with different CE treatments obtained values (p C + E C > C + ECCh > C + ECChP respectively). Total phenolic compounds in the aqueous peppermint extract were 505.55 mg GAE/100 g dried leaves, with 98.78% antioxidant capacity in the aqueous extract and 81.88% in the EC. Biomolecule oxidation (hydroperoxide content) had a significant increase (p < 0.05) in all treatments during storage, 1.7 mM CHP/mg protein in the control, to 1.4 in C + EC, 1.27 in C + ECCh and 1.16 in C + ECChP; TBARS assay values increased in the different treatments during refrigerated storage, with final values of 33.44, 31.88, 29.40 and 29.21 mM MDA/mg protein in the control; C + EC; C + ECCh and C + ECChP respectively. In SDS -PAGE a protective effect was observed in the myofibrillar proteins of fillets with ECChP). The results indicate that the C + ECCh and C + ECChP treatments extend the shelf life of 3–5 days with respect to microbiological properties and 4–5 days with respect to physicochemical characteristics. A reduction in lipid and protein oxidation products was also observed during refrigerated storage. With these findings, this is considered a promising method to increase the shelf life of fish fillets combined with refrigeration and we are able to recommend this technology for the fish processing industry.Consejo Nacional de Ciencia y Tecnologí