Hydrothermal treatment of hemp seeds (Cannabis sativa L.): impact on its dehulling yield, fatty acid profile and nutritional characteristics

Abstract

BACKGROUND: Hemp seeds are highly nutritious and a sustainable source of protein and omega-fatty acids. The outer shell of the seeds restricts its utilization in the food industry. Dehulling of the seeds leads to a lot of processing losses due to high oil content and hard shell of the seed. Therefore, in the present study, hydrothermal treatment of the hemp seeds (Cannabis sativa L.) before dehulling was proposed to reduce the endosperm breakage and improve dehulling yield of seeds.RESULT: The hemp seeds were subjected to four types of treatments, namely moisture addition (at 14%) with tempering for 10 min and 60 min followed by drying (28-30 °C) and steaming at atmospheric pressure for 5 min and 10 min. Results from the study showed that the hydrothermal treatments impacted the hardness of the endosperm and therefore improved the dehulling yield by 1.3 to 1.5 folds. Also, the dehulling losses significantly reduced from 26.80% to 9.52% after the steaming treatments. Though steaming to some extent affected the colour of the dehulled seeds compared to other treatments, it showed an increment in protein digestibility from 86.53% to 88.73%.CONCLUSION: Among all the hydrothermal treatments, steaming showed significant improvement in the yield of dehulled hemp seeds. It reduced endosperm breakage without affecting the seeds' fatty acid profile and nutritional quality. It can be concluded that steaming as a pretreatment can be used for improved dehulling of hemp seeds, aiding the better valourization of hemp seeds in the food industry.

Proteomic Profiles of Whole Seeds, Hulls, and Dehulled Seeds of Two Industrial Hemp (Cannabis sativa L.) Cultivars

“…Removing the hull eliminates or reduces the contents of antinutrients, improves the sensory properties of the dehulled seeds, and enhances their digestibility [ 42 , 43 ]. Previous work [ 27 , 43 , 44 ], and our presented results, have confirmed that dehulling can also be an important technological step in producing hemp seed protein concentrates and isolates, while this step removes big amounts of ballast substances (especially fibre components). At the same time, the proteomic results indicate the importance of hemp seed hulls as a source of a specific protein.…”