Servizio Comunitario di Informazione in materia di Ricerca e Sviluppo - CORDIS

Study of a process for the production of superior quality juices

The juice clarification process involving microfiltration and ultrafiltration can be used to separate pulp from juice, making it possible to stabilize the juice using a thermal treatment, limiting the strong treatment to pulp only. The control of enzymic activities in the permeate using ultrafiltration enables successful microbiological sterilization of the clarified juice.

The cold concentration process involving evaporation can produce juice with characteristics very close to fresh juice, but with a commercialization continuous throughout the year at costs which are comparable to the traditional product. The concentrated frozen orange juice can be 100% regenerated and is used to produce the nectars that are diluted. The production of soft drinks makes use of a relatively low amount of juice.

The membrane extraction technique involves concentration whereby water vapour is removed from juice as the liquid flows downstream over a porous hydrophobic membrane; due to the hydrophobicity neither the juice nor the extractant liquid pass through the membrane and a thin layer of gas, housed in pores, separates the two liquids. If the water vapour pressure in juice is greater than that of the extractant, water diffuses in vapour form from the juice to the extractant. Highly concentrated brines can be used as an extractant, but other compounds can be more effective. With this technique it is possible to work at very low temperatures, preventing thermal damage to the product: It is important to stress that the use of this membrane method does not involve flavour loss. The concentration technique can be applied to other fruits, to wine making, to cheese production and in biotechnology.

Reported by

Cre Casaccia Anguillarese 301
00060 Roma
See on map