No abstract

No abstract

Grape pomace components (seed and skin) were separated in a fluidized bed system based on their aerodynamic behavior. The Weibull equation was used to explain the elutriation history. Seed dehydration was characterized by a first period of constant drying rate and a second period in which drying rate decreased following Fick's liquid molecular diffusion model. The order of magnitude of heat and mass transfer parameters, both internal and external, was similar to those reported in the literature.

Two Mexican wheat varieties conditioned to three initial moisture levels (17, 25 and 37% dry basis) were dried with air at 40, 60, 80 and 100 C for 60 min periods in a laboratory scale fluidised bed system. Drying kinetics and activation energy was determined. Weight per hectolitre, wheat hardness, total protein content, dough mixing time and loaf volume were analysed. The results showed that the initial moisture content and drying velocity lowered the activation energy necessary to extract water from the grain. The effect of temperature and moisture content in the grain were the most important factors to control damage during drying. The hard wheat variety was less susceptible to heat damage than the soft variety, probably due to its higher protein content and harder texture. Weight per hectolitre, wheat hardness and drying did not considerably modify total protein content. Conversely, mixing time and loaf volume showed changes directly related to heat treatment severity. Fluidised bed drying at 40 and 60 C

The aim of this present study was to investigate the degradation of Rhodamine B (RhB) in aqueous solution under the influence of ultrasound irradiation. An ultrasonic reactor was used to investigate the effect of different operational parameters such as dye initial concentration, ultrasound power, pH and electrical conductivity. The results showed an increase in decolourization rate with decreasing pH, but colour removal efficiency decreased with increasing initial dye concentration. It was found that an optimum electrical conductivity of the solution exists on enhancing the degree of RhB degradation. Sonolytic degradation data from the present and other works in the literature were analysed by Langmuir-type kinetics. The apparent reaction rate constant was strongly influenced by both irradiation power density and frequency, and based on the experimental data a mathematical correlation between them was obtained.