EVALUATION OF THE CHEMICAL COMPOSITION OF FRACTIONS OF INDUSTRIAL HEMP SEED GRITS

Abstract

The paper addresses the challenge of increasing the efficiency and moving towards a near zerowaste technology for processing industrial hemp seeds by ensuring comprehensive utilization of all products formed during dehulling and separation of hemp seed grits. It is emphasized that in most conventional processing schemes the main focus is placed on the yield of cleaned kernel, whereas intermediate fractions are often treated as waste without quantitative assessment of their nutritional potential. The aim of the study is to determine the chemical composition of the main fractions of industrial hemp seed grits obtained using a specially developed dehulling technology based on a low-capacity air-sieve machine, and to substantiate the possibility of their integrated and targeted utilization. The research objects were the fractions formed during separation of hemp seed grits on an SM-0.15 air-sieve machine equipped with a three-deck sieve system that produces six dehulling products. Four fractions representing the main directions of material redistribution were subjected to chemical analysis: dehulled kernel, fines (sichka), middlings (perevii) and hull-rich wastes. For each fraction, the contents of dry matter, crude protein, fat, fibre, ash and nitrogen-free extractives were determined in both natural and absolutely dry matter, followed by a comparative assessment of the fractions and a quantitative characterization of their nutritional profiles. It was shown that the dehulled kernel combines the highest levels of fat and protein with minimal fibre and ash contents and therefore acts as the primary target product for manufacturing food ingredients. Fines and middlings were found to be close to the kernel in terms of fat and protein content, while being enriched in fibre, which allows them to be considered as full-value raw materials for functional foods and high-energy feed rather than secondary waste. The hull-rich wastes exhibit a fibre- and ash-dominated profile with the lowest fat and protein contents among all fractions, which substantiates their use for energy purposes or as a source of structural fibre in compound feeds. By combining the morphological and chemical characterization of the dehulling products, a processing scheme was developed in which each fraction of hemp seed grits has a clearly defined utilization pathway, ensuring an almost zero-waste character of the technology for processing hemp seeds into kernel.