Emulsified films based on carboxymethyl cellulose containing macro (ME) and nanoemulsion (NE) of cinnamon essential oil at different concentration were prepared. The dynamic light scattering (DLS) results showed intensified in input energies to emulsion solution led to reducing droplet size (D_z) and heterogeneity (PdI). The microstructure of films were analyzed by scanning electron microscopy (SEM), images showed more different structure due to different stabilization behavior of ME and NE in film forming solutions during drying. Increasing in porosity of macroemulsion films and tortuous pathway of nanoemulsion films, caused to water vapor permeability (WVP) of control films from 2.59 × 10 ^-9 g / m s Pa increased to 4.43 × 10 ^-9 g / m s Pa and decreased to 1.80 × 10 ^-9 g / m s Pa in the macro and nanoemulsion films respectively. Plasticizing nature of cinnamon essential oil also higher surface to volume ratio and more interruption interaction between biopolymer chains produced more flexible emulsified films with enhancing in strain at break (SAB) from 53.56 % in control film to 80% and 94.77% in ME and NE films respectively.
 

The purpose of this study was to produce red beetroot pulp powder using foam-mat drying technique and to investigate the effect of foam thickness on drying kinetics and physicochemical and microstructural properties of the resulting powder. To prepare foam, ovalbumin as foaming agent at a concentration of 2% (w / v) was added to the red beetroot pulp and was stirred for a specific time and speed. Prepared foam was spread on aluminum plates at thicknesses of 5, 6 and 7 mm and then dried in a hot air cabinet dryer at 50 ºC and constant air velocity of 1 m/s. Results showed that increasing foam thickness from 5 to 7 mm had no significant effect on moisture content and moisture ratio but significantly (p <0.05) reduced the drying rate by about 29.63%. The effective moisture diffusion coefficient was significantly affected by the foam thickness and ranged between 5.550 × 10⁻⁹ and 7.388 × 10⁻⁹ m²/s. Also, with increasing foam thickness, due to increasing drying time and more denaturation of proteins, an increase in Carr index and Hausner ratio was observed, resulting in a decreasing trend in the flowability of the powders. Bulk and tapped densities of powders were significantly decreased due to the change in moisture content, caused by the increase in foam thickness. Thickness had no significant effect on water solubility index and water absorption index. The microstructure analysis of the produced powders by field emission scanning electron microscope showed that with increasing foam thickness, cracking and surface roughness of powder particles increased. The results of this study and further studies can lead to optimization of red beetroot powder production as a natural food coloring and better preservation of its nutritional and functional properties.