Effect of air drying temperature on the quality of rehydrated dried red bell pepper (var. Lamuyo)

Red pepper samples (Capsicum annuum L.) were dried at four air inlet temperatures from 50 to 80 degrees C and rehydrated in water at 30 degrees C to study the influence of air drying temperature on the quality and microstructural properties of the rehydrated tissue. A determination was made on the effects of sample pretreatment on the drying process; samples were immersed in a solution containing NaCl, CaCl2 and Na2S2O5 prior to drying at 70 degrees C. At the end of the rehydration process several quality parameters were analyzed, including the rehydration ratio, water retention capacity, colour, firmness, vitamin C content and microstructure. The results showed that the best quality product was obtained when samples were pretreated before drying. Microscopic examination of the rehydrated pepper samples suggested that damage to cellular structure was minimized by pretreatment of samples; the resulting rehydrated peppers displayed comparatively improved vitamin C retention, colour, and firmness. (C) 2007 Elsevier Ltd. All rights reserved.