Tesis doctoral de Justyna Warczok
From consumers point of view the food fresh-like appearance is a primary criterion in making a purchase decision. In response to consumer demand, research in the food industry aims to develop mild food preserving methods. a promising pre-treatment method is osmotic dehydration (od), which is the subject of this study. Osmotic dehydration provides a high quality product with a high content of naturally occurring vitamins and microelements. od involves soaking foods (fruit, vegetables, fish and meat) in a hypertonic (osmotic) solution i.E. Concentrated sugar, salt, alcohols or soluble starch solutions, which partially dehydrates the food. During the process, two major simultaneous counter-current flows occur: the solute is transferred from the solution into the food and water flows out of the food into the solution, which is stronger than the previous one. Despite the advantages of od and its simplicity, the industrial application is bottlenecked by the problem of how to manage the spent solution. Thus, from the process and economic point of view it is necessary to find an effective recycling method. the main objective of the present study is to evaluate membrane separation processes that reconcentrate osmotic dehydration spent solutions. The reconcentration is performed using nanofiltration, direct osmosis and osmotic membrane distillation. The nanofiltration (nf) process is carried out using a cross-flow filtration plant with flat sheet and tubular membranes. Direct osmosis is studied in two modes: off-site and on-site. During off-site direct osmosis (off-site do), osmotic and stripping solutions are brought into contact in a membrane module. During on-site direct osmosis (on-site do), however, the osmotic solution is reconcentrated at the same time as the osmotic dehydration process. off-site do was performed using nf membranes and nacl as the stripping solution (ss), while on-site do was performed with a microfiltration membrane and
Datos académicos de la tesis doctoral «Concentration of osmotic dehydration solutions using membrane separation processes«
- Título de la tesis: Concentration of osmotic dehydration solutions using membrane separation processes
- Autor: Justyna Warczok
- Universidad: Rovira i virgili
- Fecha de lectura de la tesis: 02/12/2005
Dirección y tribunal
- Director de la tesis
- Carme GÁ¼ell Saperas
- Tribunal
- Presidente del tribunal: María nne Nystrí¶m
- ane Urtiaga mendía (vocal)
- Mª amparo Chiralt boix (vocal)
- laura Palacio martínez (vocal)