Influence of dehydration-rehydration process on rheological properties of liquid fruit foods

Abstract

The effects of the dehydration-rehydration process on the recovering of the original rheological characteristics of the re-hydrating solution were studied. Four different fruit fluid products were investigated: apricot, banana purees, non-pureed citrus fruits, i.e mandarin juice and lemon treacle, respectively. The static rheological behavior of both pureed and non-pureed products was measured for the raw material, i.e. before the drying process, and after the rehydration procedure. First of all, the results show that rehydrated materials have different rheological behaviors from fresh ones, especially in the case of starch added non-pureed products. Such differences can be due to both the stress conditions induced by mechanical drying and successive rehydration or to other factors such as, for example, the starch addition. These results were relevant to quantify the rehydration efficacy of pureed and non-pureed foods, suggesting than more than just one parameter should be controlled for liquid foods when the rehydration procedure is carried out.

Keywords

rehydration of liquids / food rheology / fruit purees / starch addition

References

[1] MujumdarA. S.Handbook of Industrial Drying [M], 1995, New York, Marcel Dekker

[2] RattiC.. Hot air and freeze-drying of high-value foods: A review [J]. Journal of Food Engineering, 2001, 49: 311-319

[3] LewickiP.. Some remarks on rehydration of dried foods [J]. Journal of Food Engineering, 1998, 36: 81-87

[4] KrokidaM. K., MaroulisZ. B., SaravacosG. D.. The effect of the method of drying on the color of dehydrated products [J]. International Journal of Food Science and Technology, 2001, 36: 53-59

[5] AhmedJ., ShivhareU. S., Debnath. Color degradation and rheology of green chili puree during thermal processing [J]. International Journal of Food Science and Technology, 2002, 37: 57-63

[6] KrokidaM. K., MaroulisZ. B.. Structural properties of dehydrated products during rehydration [J]. International Journal of Food Science and Technology, 2001, 36: 529-538

[7] MastrocolaD., BarbantiD., Dalla RosaM., et al.. Physicochemical characteristics of dehydrated apple cubes reconstituted in sugar solution [J]. Journal of Food Science, 1998, 63: 495-498

[8] SanjuanN., SiamiS., BonJ., et al.. Modelling of broccoli stems rehydration process [J]. Journal of Food Engineering, 1999, 42: 27-31

[9] PeronaP.. An experimental investigation of laminar-turbulent transition in complex fluids [J]. Journal of Food Engineering, 2003, 60: 137-145

[10] SikoraM., MzurkiewicsJ., TomasikP., et al.. Rheological properties of some starch-water-sugar system [J]. International Journal of Food Science and Technology, 1999, 34: 371-383