Tesis doctoral de ángel Roberto Marsellés Fontanet
The effect of pulsed electric fields as a preservation method on grape juice was studied. Its effects were measured on typical grape juice properties such as brix degrees, ph, acidity, electrical conductivity, microbial and enzymatic activities, and some bioactive compounds like vitamin c and polyphenol contents or antioxidant activity. The obtained values were compared with the current preservative reference technology, which is the heat processing. It was also analysed the effect of pef on the evolution of specific compounds throughout the wine making process from juice to ageing. the study was carried out in 4 phases. It was observed a clear reduction of the microbial populations of both, inoculated and natural flora, as well as the oxidant enzymatic activities of grape juice. Besides, these effects were optimised taking into account the pef processing device and the food product. The comparison of both treatments revealed that the pef treatment yielded milder values of the variables than the thermal treatment. Therefore it could be used in juice and wine making without a negative impact on the quality of the product. the main conclusion inferred from the study is that on three commonly used catalan varieties pef processing is a feasible technology to preserve grape juice. New data coming from different varieties and years should broaden this conclusion.
Datos académicos de la tesis doctoral «Conservación del mosto de uva con pulsos eléctricos de alta intensidad de campo«
- Título de la tesis: Conservación del mosto de uva con pulsos eléctricos de alta intensidad de campo
- Autor: ángel Roberto Marsellés Fontanet
- Universidad: Lleida
- Fecha de lectura de la tesis: 08/04/2011
Dirección y tribunal
- Director de la tesis
- Olga Martin Belloso
- Tribunal
- Presidente del tribunal: vicent Gimeno añó
- anna Puig pujol (vocal)
- silvia Bendicho porta (vocal)
- núria Grigelmo Miguel (vocal)