Drying of orange seeds representing waste products from juice processing was studied in the temperatures of 40, 50, 60 and 70 °C and drying velocities of 0.6, 1.0 and 1.4 m/s. Experimental drying kinetics of orange seeds were obtained using a convective air forced dryer. Three thin-layer models: Page model, Lewis model, and the Henderson-Pabis model and the diffusive model were used to predict the drying curves. The Henderson-Pabis and the diffusive models show the best fitting performance and statistical evaluations. Moreover, the temperature dependence on the effective diffusivity followed an Arrhenius relationship, and the activation energies ranging from 16.174 to 16.842 kJ/mol

The purpose of this study was to investigate how the properties of Mexican kefir grains (MKG) are affected by the operating parameters used in the freeze-drying process. The factors investigated were the freezing time (3–9 h), freezing temperature (−20 to −80 °C), pressure (0.2–0.8 mbar), and lyophilization time (5–20 h). The maximum range of change and one-way analysis of variance showed that lyophilization time and freezing time significant affects (p < 0.05) the response variables, residual moisture content and water activity, and pressure had a significant effect on the color difference and survival rate of probiotic microorganisms. The best drying conditions were a freezing time of 3 h, a freezing temperature of −20 °C, a pressure of 0.6 mbar, and a lyophilization time of 15 h. Under these conditions, we obtained a product with residual moisture content below 6%, water activity below 0.2, and survival rates above 8.5 log cfu per gram of lactic acid bacteria and above 8.6 log for yeast.

The influence of spray drying conditions on the energy required, production cost, and physicochemical characteristics of cheese whey was researched. The factors investigated were the inlet air temperature (180–220°C), outlet air temperature (80–100°C), and silica and maltodextrin (DE-10) as additives at 2 and 5% (w/w), respectively. Analysis of variance revealed that the inlet and outlet air temperatures, and the addition of additives had significant effects (p < 0.10) on the response variables. The best drying conditions were a T_inlet of 180°C, T_outlet of 80°C, and the addition of 5% additive material. Under these conditions, 0.2165 kg/h of dried product was obtained, with a moisture content of 2.08% and water activity of 0.125, and the product cost was $17.06 kg with an energy consumption of 2.0490 kW · h/kg of dry product.