Influence of constant and variable pressure on water absorption capacity of dried strawberries
 okładka_kolor_2.jpg)
|
|
||||||||
PDF 132.6 KB
|
|||||||||
| Authors: | Dariusz Piotrowski1, Anita Godlewska1 1Department of Food Engineering and Process Management, Faculty of Food Science, SGGW – Warsaw University of Life Sciences ul. Nowoursynowska 159C, 02-776 Warszawa |
||||||||
|---|---|---|---|---|---|---|---|---|---|
| Abstract : | This work presents the influence of the method used for vacuum drying on the dry matter content and water absorption capacity of dried strawberries. Calibrated frozen and defrosted strawberries variety Senga Sengana were used in the research. Vacuum drying was carried out twice at preset temperature of 70°C under pressure of 4 and 16 kPa and with a step change of pressure from 4 to 16 kPa. Pressure was changed, as well as the dryer, through either the vacuum-convective or the convective-vacuum drying method, after 4 and 5 hours respectively. The dry matter content and water absorption capacity were determined in strawberries. The dry matter content of strawberries after drying processes with the step change of pressure from 4 to 16 kPa and both fixed levels of pressure did not differ significantly. However, vacuum-convective drying resulted in statistically lower dry matter content. In spite of the introduction of step increase of pressure from 4 to 16 kPa the water absorption capacity was comparable for dried fruits under 4 kPa pressure. The lowest water absorption capacity of vacuum-convective dried strawberries in relation to absorption results of dried fruits obtained under 4 kPa pressure or by convective-vacuum method indicated the existence of structural differences between products. |
||||||||
| Keywords : | vacuum drying, variable pressure, combined drying, statistical analysis | ||||||||
| Language : | English | ||||||||