9 research outputs found
Development and validation of a computational model for steak double-sided pan cooking
The objective of this study was to develop and validate a numerical model to adequately simulate the double-sided pan cooking of beef in a domestic environment. The proposed model takes into account the heat flow from the pan to the meat and the moisture transfer, simultaneously with the meat deformation. The model considers the swelling pressure gradient caused by the shrinkage of the meat fibers and connective tissue due to the denaturation of proteins and the loss of the water holding capacity during cooking. The model results were successfully verified with experimental data of the central temperature and weight loss recorded during cooking for three degrees of doneness. The measured experimental temperatures at the center of the meat were 30 ± 3 °C (very rare), 44 ± 3 °C (rare) and 57 ± 2 °C (done) for a 19 mm steak thickness. Meanwhile, their water losses were 4 ± 2 %, 8 ± 1 % and 11 ± 2 %, respectively. The root mean squared errors of the model predictions were 2.16 °C (very rare), 3.56 °C (rare) and 4.57 °C (done) for the central temperature and 1.48 %, 2.08 % and 2.40 %, respectively for the water loss. The model also correctly predicts cooking times for steaks of different thicknesses, taking weight loss as a reference to set this time. The proposed model is postulated as a useful cooking assistance tool to estimate the optimal cooking time according to consumer preferences
Color changes in beef meat during pan cooking: kinetics, modeling and application to predict turn over time
The kinetics of heat-induced color changes in beef meat was determined and implemented in a numerical model for doublesided
pan cooking of steak. The CIELab color space was used to obtain the lightness (coordinate L∗ ) and the reddish tone
(coordinate a∗ ) of the cooked meat. L∗ was the CIELab coordinate that contributed the most to the change in the absolute
color. Two response surfaces were found to describe the evolution with time and temperature of both color coordinates, L∗
and a∗ . The model results were successfully verified with experimental data of the two coordinates along the thickness of
the meat for three degrees of cooking. The Root-Mean-Squared Errors (RMSE) for coordinate L∗ were 5.17 (very rare), 2.02
(medium rare) and 3.83 (done), and for coordinate a∗ 1.44 (very rare), 1.26 (medium rare) and 0.89 (done). The applicability
of the model for practical cooking purposes was illustrated by determining the optimum turn over time to achieve a similar
color profile on both sides of the meat. The turn over time depended on the desired degrees of cooking, and were comprised
between one-half and two-thirds of the final cooking time, increasing from very rare cooking degree to done cooking degree
Towards domestic cooking efficiency: A case study on burger pan frying using experimental and computational results
It is well known that the use of efficient domestic cooking appliances and equipment can not only save energy, but also improve the quality of the food being prepared. This work raises the question of whether cooking procedures can also contribute to this energy efficiency. Focusing on burger pan frying, experimental data were used to develop a model able to predict cooking outcomes under different power levels supplied by an induction hob. The proposed model takes into account not only the heat consumed by water evaporation in the contact region but also the shrinkage process of the hamburger. A new formulation based on the multiplicative decomposition of the strain deformation gradient is proposed to describe the observed decoupling between weight and volume loss during the process. The model properly predicts temperature, moisture loss and shrinkage, and allows elucidation of the effects of supplying different amounts of energy on the final water content
Effect of the Consumption of Alcohol-Free Beers with Different Carbohydrate Composition on Postprandial Metabolic Response; 35268021
Background: We investigated the postprandial effects of an alcohol-free beer with modified carbohydrate (CH) composition compared to regular alcohol-free beer. Methods: Two randomized crossover studies were conducted. In the first study, 10 healthy volunteers received 25 g of CH in four different periods, coming from regular alcohol-free beer (RB), alcohol-free beer enriched with isomaltulose and a resistant maltodextrin (IMB), alcohol-free beer enriched with resistant maltodextrin (MB), and a glucose-based beverage. In the second study, 20 healthy volunteers were provided with 50 g of CH from white bread (WB) plus water, or with 14.3 g of CH coming from RB, IMB, MB, and extra WB. Blood was sampled after ingestion every 15 min for 2 h. Glucose, insulin, incretin hormones, TG, and NEFAs were determined in all samples. Results: The increase in glucose, insulin, and incretin hormones after the consumption of IMB and MB was significantly lower than after RB. The consumption of WB with IMB and MB showed significantly less increase in glucose levels than WB with water or WB with RB. Conclusions: The consumption of an alcohol-free beer with modified CH composition led to a better postprandial response compared to a conventional alcohol-free beer. © 2022 by the authors. Licensee MDPI, Basel, Switzerland
Obstáculos para la movilidad académica con el programa Erasmus+: Diferencias entre grados universitarios [Barriers to academic mobility with Erasmus+ programme: Differences between bachelor degrees]
Pese al interés creciente que presenta la movilidad académica internacional de los estudiantes universitarios europeos para su inserción profesional posterior, el porcentaje de estudiantes españoles que participan en el programa Erasmus es todavía pequeño. El objetivo de este trabajo fue determinar los principales obstáculos para la movilidad Erasmus percibidos por estudiantes de grado que no han participado en este programa, valorando la existencia de diferencias en función del grado (Sanitario vs. Ciencias Sociales). Se utilizó una encuesta auto-administrada elaborada para un estudio europeo previo en el que participó España. Los resultados muestran el impacto, a nivel general, de la falta de información sobre temas relevantes como: la calidad de la educación en el extranjero, o cómo van a ser evaluados, así como, las barreras económicas por becas insuficientes y retrasos en el pago de las mismas. Los obstáculos que mejor diferencian a los estudiantes de ambos grados están relacionados con la ordenación académica del grado, en concreto, bajo nivel de formación en inglés y presencia de asignaturas anuales, además de características personales del estudiante. Para incrementar la participación, se debería incidir en informar más y comunicar mejor además de incluir modificaciones en el programa académico de los grados que faciliten la movilidad internacional.
[Despite the growing interest that presents academic international mobility for European University students for their later in life job prospects, the rate of Spanish students participating in the Erasmus programme is still small. The objective of this research was to determine the main barriers perceived by bachelor students who had not participated in the Erasmus programme assessing the differences between two bachelor degrees (Health vs. Social Sciences). A self-administered survey including reasons not to participate was used that had been set up for a previous European study including Spain. Results reveal the overall impact of lack of information on relevant issues such as the quality of university education system abroad and how they will be evaluated as well as financial barriers such as insufficient Erasmus grants or delays in the first grant payment. The barriers that better differentiate both bachelor degrees students are related to the bachelors’ curriculum i.e. insufficient training in English and presence of annual (vs. semester) courses as well as personal features. To increase participation, the focus should be on improving information and communication both on academic and financial issues, and changes in the bachelors’ curricula.