STUDY OF THE NUMBER OF SHELLING CYCLES OF INDUSTRIAL HEMP SEEDS IN A CENTRIFUGAL MECHANISM

Abstract

Hemp seed shelling is an essential stage of its processing, as it enhances the bioavailability of nutrients and expands its potential use in the food industry. This study examines the process of multiple passes of industrial hemp seeds through a centrifugal shelling mechanism with a closed impeller and evaluates the shelling efficiency at different stages of the technological process. For the experiment, hemp seeds from four different samples grown under the soil and climatic conditions of Sumy region were used. These samples varied in moisture content (8.9–11.5 %) and 1000-seed mass (18.32–19.49 g). The shelling process was conducted without prior seed calibration, and after each cycle, the amount of unshelled seeds and the yield of shelled kernels were determined. It was established that shelling efficiency largely depends on the physico-mechanical characteristics of the seeds, particularly moisture content, size, and 1000-seed mass. Increased moisture content enhances the plasticity of the seed coat, making it more difficult to break under impact loading. At the same time, a smaller seed size leads to an uneven distribution of mechanical stress, increasing the amount of unshelled seeds and requiring a higher number of shelling cycles to achieve the desired level of kernel separation. The results showed that after the first cycle, the percentage of unshelled seeds remained high (63.73–76.41 %), requiring additional processing. Data analysis revealed that after the third cycle, more than 80 % of the initial seed mass had undergone shelling, while further cycles had minimal impact on the final outcome and were economically inefficient. The optimal number of cycles for effective shelling was determined to be three, as this stage provides the maximum kernel yield with minimal resource consumption. Based on the obtained results, it is recommended to direct further research towards improving the design of the shelling mechanism’s impeller to reduce the required number of cycles and increase process efficiency.