Self cooling bag-in-box package and method of manufacturing the same

[SPA] Esta patente se refiere a un envase bag-in-box autoenfriante, compuesto por: (1) un envase flexible (bag), que contiene un alimento líquido o una bebida, u otro producto líquido; (2) una camisa de enfriamiento o evaporador, construida con una pared flexible y que rodea al envase anterior; (3) un adsorbedor contenido en una caja con paredes flexibles, separada e independiente de la anterior; y (4) un envase rígido (box), que contiene el conjunto anterior, formado por la bolsa con el producto líquido, la camisa de refrigeración, y el adsorbedor. Este envase rígido o box podrá tener una forma cilíndrica, de barril, o de caja en forma de paralelepípedo, o cualquier otra forma. La citada camisa de refrigeración y el adsorbedor está separada por medio de una válvula o una película unida o termosellada a la boca del evaporador, de modo que cuando se abre esta válvula o se rompe este sello comienza el proceso de enfriamiento del alimento líquido, ya que en la citada camisa tiene lugar la evaporación a vacío de un refrigerante, preferentemente agua, siendo adsorbidos los vapores de este refrigerante en el material adsorbente contenido en el adsorbedor, que se mantiene también a vacío. [ENG] This patent refers to a self-cooling bag in box package, that is made up of: (1) a flexible package (bag), that contains a liquid food or a drink, or another liquid product; (2) a cooling jacked or evaporator, constructed with a flexible wall and that surrounds to the cited flexible package; (3) an adsorber contained in a box with flexible walls, separated and independent of the previous one; and (4) a rigid package (box), that contains the previous set, formed by the bag with the liquid product, the coolant jacket, and the adsorber. This rigid package or box will be able to have a cylindrical shape, of barrel, or a shape of parallelogram, or any other shape. The mentioned coolant jacket and the adsorber are separated by means of a valve or a thermal sealed film to the mouth of the evaporator, so that when is opened this valve or breaks this seal begins the process of cooling of the liquid food, since within the mentioned jacked, the evaporation at vacuum takes place, of a coolant, like the water, being adsorbed the steam of this coolant in the contained adsorbent material in the adsorber, that also stays at vacuum.A la empresa Damm S.A. por su financiación y colaboración en la realización de estos trabajos

Modelización y optimización de sistemas de autoenfriamiento de envases alimentarios por adsorción a vacío

El objetivo general de este proyecto es desarrollar un sistema de autoenfriamiento de envases de alimentos líquidos optimizando la tecnología de enfriamiento por adsorción a vacío. Para ello se analizarán, seleccionarán y optimizarán las tecnologías existentes de autoenfriamiento de bebidas envasadas, desde el punto de vista técnico (facilidad de miniaturización y simplicidad, a la vez que efectividad) e higiénico, y de seguridad alimentaria. Se reproducirá el comportamiento termodinámico de cada una de las alternativas posibles, mediante prototipos, utilizando sistemas adecuados de medición, para poder desarrollar un modelo matemático del sistema que contemple por un lado el proceso exotérmico que tiene lugar en el adsorbedor, y por otro el proceso de evaporación. Se analizarán las ventajas e inconvenientes de cada una de las alternativas seleccionadas, para ser aplicadas en envases activos autoenfriantes en bebidas.Son muchas las personas a las que quiero agradecer que me hayan apoyado durante la realización de este trabajo: Antonio López Gómez y Arturo Esnoz Nicuesa, directores de este trabajo por el apoyo, el ánimo y los consejos brindados. A mis compañeros del Departamento de Ingeniería de los Alimentos y del Equipamiento Agrícola, Yulisa, Antonio, Mari Ángeles, Fayiny, y May. A la empresa Damm, S.A. por su financiación y colaboración en la realización de este trabajo

Guidelines for the design of (optimal) isothermal inactivation experiments

Kinetic models are nowadays a basic tool to ensure food safety. Most models used in predictive microbiology have model parameters, whose precision is crucial to provide meaningful predictions. Kinetic parameters are usually estimated based on experimental data, where the experimental design can have a great impact on the precision of the estimates. In this sense, Optimal Experiment Design (OED) applies tools from optimization and information theory to identify the most informative experiment under a set of constrains (e.g. mathematical model, number of samples, etc). In this work, we develop a methodology for the design of optimal isothermal inactivation experiments. We consider the two dimensions of the design space (time and temperature), as well as a temperature-dependent maximum duration of the experiment. Functions for its application have been included in the bioOED R package. We identify design patterns that remain optimum regardless of the number of sampling points for three inactivation models (Bigelow, Mafart and Peleg) and three model microorganisms (Escherichia coli, Salmonella Senftenberg and Bacillus coagulans). Samples at extreme temperatures and close to the maximum duration of the experiment are the most informative. Moreover, the Mafart and Peleg models require some samples at intermediate time points due to the non-linearity of the survivor curve. The impact of the reference temperature on the precision of the parameter estimates is also analysed. Based on numerical simulations we recommend fixing it to the mean of the maximum and minimum temperatures used for the experiments. The article ends with a discussion presenting guidelines for the design of isothermal inactivation experiments. They combine these optimum results based on information theory with several practical limitations related to isothermal inactivation experiments. The application of these guidelines would reduce the experimental burden required to characterize thermal inactivation.</p

On the use of in-silico simulations to support experimental design: A case study in microbial inactivation of foods

The mathematical models used in predictive microbiology contain parameters that must be estimated based on experimental data. Due to experimental uncertainty and variability, they cannot be known exactly and must be reported with a measure of uncertainty (usually a standard deviation). In order to increase precision (i.e. reduce the standard deviation), it is usual to add extra sampling points. However, recent studies have shown that precision can also be increased without adding extra sampling points by using Optimal Experiment Design, which applies optimization and information theory to identify the most informative experiment under a set of constraints. Nevertheless, to date, there has been scarce contributions to know a priori whether an experimental design is likely to provide the desired precision in the parameter estimates. In this article, two complementary methodologies to predict the parameter precision for a given experimental design are proposed. Both approaches are based on in silico simulations, so they can be performed before any experimental work. The first one applies Monte Carlo simulations to estimate the standard deviation of the model parameters, whereas the second one applies the properties of the Fisher Information Matrix to estimate the volume of the confidence ellipsoids. The application of these methods to a case study of dynamic microbial inactivation, showing how they can be used to compare experimental designs and assess their precision, is illustrated. The results show that, as expected, the optimal experimental design is more accurate than the uniform design with the same number of data points. Furthermore, it is demonstrated that, for some heating profiles, the uniform design does not ensure that a higher number of sampling points increases precision. Therefore, optimal experimental designs are highly recommended in predictive microbiology.</p