A rheological approach to extruder design for liquorice extracts

Autori: D. Gabriele, S. Curcio, B. de Cindio
Presentato al: Southern Europe Conference on Rheology
Anno: 1999
Volume: 2
Issue: Unico
Casa Editrice: SIR-Cuen Napoli
Lingua: English


Abstract
Rheology has become a very important factor in the industrial production of liquorice based products due to the difficulty to process this complex material. Therefore rheological characterisation of liquorice extracts has been performed and the results were applied in trying to improve traditional liquorice plants.
Liquorice production process is essentially based on four unit operations. Raw materials, i.e. the roots of two plants which are called Glycyrrhiza Glabra and Rigulizia Cordara, are ground in a hammer mill. A certain amount of water, five parts of water for one part of liquorice, is added to the coarse root powder so that a fluid pulp is obtained. This mixture of liquorice root powder and water is then fed to the extraction plant where it remains just for the time that is necessary to extract the most valuable compounds (Glycyrrhizin and other sugars, proteins and mineral salts). The operating temperature of the extraction plant is about equal to 110 °C. A solution with a concentration of 40 g/l of liquorice is thus obtained; the solid residue, that is called "liquorice-husks" is pressed before being discharged. The concentration plant is actually composed by multiple effect evaporators (primary concentrators) and by some heated stirrers (secondary concentrators). In particular, the first effect operates at a temperature of 110° C, whilst the second one is maintained at a temperature less than 60° C. At these temperatures there is a thermal damage due to the partial denaturation of the more thermal sensitive compounds.


Attenzione la lettura completa dell'Abstract e il download dei file è riservata esclusivamente ai Soci dell'Associazione Italiana di Reologia.

Se sei un Socio ti preghiamo di effettuare il login se non lo hai già fatto

Nel caso non fossi un Socio dell'Associazione Italiana di Reologia ti preghiamo di visitare la sezione "Iscriviti all'Associazione" per procedere alla registrazione