Impact of Processing on Nutritional and Functional Properties of Hemp and Sunflower Oilcakes

Global environmental challenges and expanding dietary demands have driven interest toward upcycling agri-food by-products into sustainable, functional ingredients within circular bioeconomy frameworks. Oilcakes derived from industrial hemp (Cannabis sativa L.) and sunflower (Helianthus annuus L.) processing are rich in storage globulins (edestin and helianthinin), balanced polyunsaturated fatty acids, dietary fibers, minerals, and bioactive phenolics. However, their broad adoption in human foods remains constrained by low protein solubility, rigid insoluble fiber structures, antinutritional compounds (such as phytic acid and condensed tannins), off-flavors, and chlorogenic acid-induced oxidative greening. This review comprehensively examines the nutritional, structural, and techno-functional evolution of hemp and sunflower press cakes across primary oil extraction routes (cold pressing, hot expelling, solvent extraction, supercritical, and enzyme-assisted aqueous extraction) and downstream processing operations (thermal treatments, extrusion cooking, solid state/submerged fermentation, and ultrafine micronization). While cold pressing and supercritical extraction preserve native globular folding, solubility, and interfacial activity, thermal expelling and solvent desolventization induce severe protein denaturation and hydrophobic aggregation. Secondary interventions, particularly high moisture extrusion and microbial bioprocessing, facilitate protein texturization into anisotropic fibrous networks, increase soluble fiber ratios, degrade antinutritional complexes, and mitigate beany/bitter sensory attributes. Furthermore, Life Cycle Assessment (LCA) and techno-economic benchmarks underscore the environmental and economic advantages of upcycled oilseed proteins over conventional soy and dairy isolates. Strategic integration of green extraction, computational modeling, and formulation science offers a viable pathway for valorizing crude oilcakes into clean label, high-value functional ingredients for novel plant-based food and food colloids.