Changes in the quality of dehydrated broccoli stems during storage
2000
SanJuan, N. | Benedito, J. | Bon, J. | Mulet, A.
Dehydrated broccoli stems were studied during storage at different temperatures, namely 5, 15, 25 and 40 degrees C. The parameters studied were rehydration capacity, texture of the rehydrated product and chlorophyll content. A diffusional model was used to study the rehydration process, yielding good agreement with the experimental data when the equilibrium moisture and the effective diffusivity were identified. Samples stored at 5 degrees C showed little change in any of the parameters studied during the storage time considered (427 days). At 15 and 25 degrees C the equilibrium moisture and the effective diffusivity varied linearly. At 40 degrees C, sharp changes were observed up to 115 days, the equilibrium moisture decreasing and the effective diffusivity increasing. From this time on, both values showed moderate changes. With reference to texture, samples stored at 5, 15 and 25 degrees C showed a similar trend without significant changes during the whole period, the textural values increasing with temperature. At 40 degrees C the texture suffered a sharp increase up to 145 days, then changes were negligible. Chlorophyll content degradation was increased with temperature. As a result of a calorimetric study a second-order transition was observed at 34 +/- 1 degree C. This fact can contribute to the interpretation of the different tendencies observed in all the parameters studied at 40 degrees C.
显示更多 [+] 显示较少 [-]