Changes in respiration rate and physical properties of strawberries due to osmotic dehydration and storage

The effect of osmotic dehydration on the respiration rate (R) and the mechanical and optical properties of strawberry halves were evaluated throughout six days at 10 degrees C. Two different dehydration levels (15 and 20 degrees Brix) were considered, by applying (PVOD) or not (OD) a vacuum pulse and with and without calcium addition. Dehydrated samples showed a faster drop in R than non-treated samples, thus indicating a faster development of senescence. PVOD implied a greater reduction of O-2 consumption. Calcium addition slightly reduced R. Osmotic treatments provoked a decrease in the puncture forces, especially in samples with 20 degrees Brix, as a consequence of the structural collapse caused by treatments. After storage, calcium addition and PVOD treatments had beneficial effects on the maintenance of the sample texture. Colour of treated strawberries was modified, mainly in the parenchyma zone, when changes in the sample porosity were greater due to the treatment (vacuum impregnation). (C) 2009 Elsevier Ltd. All rights reserved.