Caracterización del salado de lomo de vacuno mediante tecnologías ultrasónicas

Abstract

[EN] In recent years, the agri-food sector has shown growing interest in the development of methods and technologies capable of controlling and monitoring in a non-invasive way and in real time quality parameters at the level of the production line, this being an aspect closely linked to movement of Industry 4.0. In this context, ultrasonic technologies represent a lowcost alternative for the characterization of food in production lines. Specifically, conventional contact ultrasonic technologies have been used successfully to characterize both the composition and the textural properties of different meat products, such as sobrasada and cured ham. However, its use at an industrial level has been hampered by the need for contact between the sample and the transducers. On the contrary, the use of new ultrasonic technologies with air coupling allow the measurement to be carried out without contact, facilitating its industrial implementation. Thus, the general objective of the present work was to determine the feasibility of using non-contact ultrasound for the characterization of texture and compositional changes during the salting of beef loin fillets, comparing it with contact ultrasonic technologies. To achieve the objective of this work, contact (1 MHz) and non-contact (380 kHz) ultrasonic measurements have been performed on previously thawed beef fillets. The samples have been subjected to different dry salting times from 1 to 24 h. Ultrasonic parameters of interest were determined such as the ultrasonic speed, from the variation of the flight time, and the maximum amplitude of the signal for both contact and non-contact measurements. The salting process was characterized by the evolution of different physical-chemical parameters such as chloride content, humidity, activity and water retention capacity and different textural parameters, such as hardness and relaxation capacity. Finally, relationships were established between the ultrasonic parameters and the changes in the content of salt, moisture and textural parameters. The experimental results have shown that the ultrasonic parameters obtained from both techniques used have shown to be sensitive to the salting process of beef fillets and the associated compositional and textural changes. In this way, the speed obtained with contact ultrasound was satisfactorily related to the salt content (R2 = 0,898), humidity (R2 = 0,903) and hardness (R2 = 0,813) from linear models. The ratio of variation in flight time obtained with non-contact ultrasound between salty and fresh samples was related to salt and moisture content (R2 = 0,697), relaxation capacity (R2 = 0,788) and hardness (R2 = 0,936). In addition, the amplitude ratio for the signals of salty and fresh samples obtained with noncontact ultrasound showed a satisfactory relationship with the moisture content (R2 = 0,773) and salt (R2 = 0,805). Finally, it can be concluded that non-contact ultrasonics can be considered as a technique with enormous potential to be applied in production lines and characterize the salt content of raw-cured meat products and their texture

[ES] En los últimos años, el sector agroalimentario ha apostado por el movimiento tecnológico de la industria 4.0 con el desarrollo de métodos y tecnologías capaces de controlar y monitorizar parámetros de calidad a nivel de línea de producción. Las tecnologías ultrasónicas representan una alternativa de bajo coste para la caracterización de alimentos en las líneas de producción. En concreto, las tecnologías ultrasónicas convencionales por contacto se han utilizado con éxito para la caracterización de tanto la composición como las propiedades texturales de diferentes productos cárnicos, como son la sobrasada y el jamón curado. Sin embargo, su uso a nivel industrial se ha visto dificultado por la necesidad del contacto entre la muestra y los transductores. Por el contrario, el uso de nuevas tecnologías ultrasónicas con acoplamiento por aire permiten realizar la medida sin contacto facilitando su implementación industrial. El objetivo del presente trabajo pretende determinar la viabilidad del uso de los ultrasonidos sin contacto para la caracterización de textura y cambios composicionales durante el salado de filetes de lomo de vacuno comparándolo con las tecnologías ultrasónicas por contacto. Para alcanzar el objetivo de este trabajo, se van a realizar medidas ultrasónicas con y sin contacto en lomos de ternera previamente descongelados. Las muestras se someterán a diferentes tiempos de salado en seco desde 1 a 24 horas. Las señales ultrasónicas se analizarán tanto en el dominio temporal como en el de frecuencia para determinar diferentes parámetros, tales como la velocidad y la atenuación ultrasónica. El proceso de salado se caracterizará mediante la evolución de diferentes parámetros físico-químicos como son el contenido de cloruros, actividad de agua (aw), contenido de humedad o capacidad de retención de agua. Finalmente, se establecerán relaciones entre los parámetros ultrasónicos y los cambios en los contenidos de sal, humedad y los parámetros texturales.