Study of the application of ultra high pressure of homogenization treatments in apple juice
- Autores: Angela Suarez Jacobo
- Directores de la Tesis: Ramón Gervilla Fernández (dir. tes.), J. Saldo (dir. tes.)
- Lectura: En la Universitat Autònoma de Barcelona ( España ) en 2011
- Idioma: español
- Tribunal Calificador de la Tesis: Peter Butz (presid.), María Manuela Hernández Herrero (secret.), Avelina Fernández García (voc.)
- Materias:
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- Resumen
This thesis project was focused to apply a non-thermal technology; such a continuous Ultra-High-Pressure Homogenization (UHPH) is, for the conservation of apple juice with the aim to obtain safe foods without losses of nutritional value.
Particularly, this non-thermal technology consist of an UHPH machine that is capable of apply pressures of up to 400 MPa by using a special homogenizing system. During the processing, the elimination of microorganisms was carried without affecting the nutritional value of the juice, making this system a real substitute for the traditional thermal processing, by addition of less energy consumption and producing less waste.
The first part of this research thesis was carried out to ensure the safety of the UHPH process by looking the optimal condition to destroy endogenous and pathogenic microorganisms of the product. The effect of UHPH on the enzyme inactivation, functionality and nutritional characteristics, as well as the possibility of the inactivation or generation of toxic compounds was also studied.
The second part consisted of the application of the optimum UHPH-treatment selected, which effectively reduces the microbiological activity in the juice thereby contributing to an extension of its shelf life without pasteurization step. In this case the UHPH machine was connected to an aseptic tank, which was connected to an aseptic packaging machine (Tetra Pak ®), in order to simulate the industrial processing. Studies on changes during the shelf-life, on generation of toxic or carcinogenic compound as well as the acceptability to consumers of the aseptically packaged UHPH treated-apple juice were conducted.
