Cereal and whole grain products are an important source of dietary fiber in the human diet. Since the milling process highly influences the proportions of the different cell types in the bran, it is expected that brans originating from different genetic/agricultural backgrounds and produced by different processes have different chemical composition. Wheat (Triticum aestivum) bran has not been studied in Latvia, therefore the aim of the present study was to analyze physical – chemical characteristics of wheat bran from Latvia’s industrial mills. Four bran samples were collected from two industrial mills: Stock Company ‘Dobeles dzirnavnieks’ and SC ‘Rigas dzirnavnieks’. All experiments were performed at the Food Technology of Latvia University of Agriculture in May 2011-February 2012. The particle size distribution of the bran samples was determined by sieving. The content of titratable acidity (TA) was detected by titration with 0.1 M NaOH till pH 8.5 was stable for 1 minute. Wheat bran colour was analysed by Hunter Lab colour measurement instrument using ColorTec colorimeter PCM/PSM in CIE L * a * b* system. Moisture content was analyzed using standard ICC 110/1 method by sample drying for 2 h at 150 °C. Results showed that there were significant differences between varieties (p0.05) for titratable acidity and for particle size, but no significant differences (p0.05) were found between the varieties in moisture, pH and colour. TA varied from 6.40±0.71 to 12.05±0.21°, moisture content- from 10.01±0.51% to 11.61±0.47%, pH–from 6.31±0.61 to 6.80±0.05, but colour of bran between the samples did not significantly differ.

The aim of the work is to increase the efficiency of cyclone technology by using a separator plate. Cyclone technology is used not only in the processing of various agricultural products, but also in air purification from dust. Air flow trajectories and the movement of dust particles inside the cyclone unit were simulated and analysed using Computational Fluid Dynamics (CFD) and particle study analyses. The separator plate was designed in certain sizes and placed inside the cyclone, thus increasing the efficiency of the cyclone. The angle of position of the separator plate significantly affected the obtained results. The experimental equipment was assembled together to test the simulation results. Wood ash was used to determine the efficiency of the cyclone. Studies have shown that the effect of the separator plate on increasing the efficiency of the experimental equipment is less than that shown in the simulations. Most of the experiments used ash particles that were greater than 20 μm, thus cyclone efficiency was 98.9 ± 0.05%. This confirms the compliance of CFD simulations with the physical model. More detailed research should be carried out in order to use the separator plate effectively for the filtration of very small dust particles.