Study of the influence of osmotic dehydration and freezing on the volatile profile of strawberries

The effect of osmotic process conditions on the volatile fraction of strawberries was studied, as well as the effect of freezing and frozen storage. Osmotic treatments were carried out on strawberries in sucrose solutions up to 20 degreesBrix, at atmospheric pressure (OD), and by applying a vacuum pulse (PVOD). Volatile compounds of fresh, dehydrated, and frozen-stored (at -18 degreesC for 1 mo) samples were obtained by simultaneous distillation-extraction. Osmotic treatments caused an increase in ester concentration and, in some cases, in furaneol less marked in PVOD. Freezing implied losses in all components, although in pre-dehydrated samples the concentration of some esters (and furaneol) remained greater than in the fresh samples.